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University of California Publications in

AGRICULTURAL SCIENCES

VOLUME III
1917-1919

EDITORS
CHARLES B. LIPMAN
ERNEST B. BABCOCK
JOHN W. GILMORE

UNIVERSITY OF CALIFORNIA PRESS b .
BERKELEY, CALIFORNIA ¢ :
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CONTENTS

PAGE
New Grasses tor Calrornia, by P. B, Kennedy... 2.scccceccsssssovesenaneses ]
Optimum Moisture Conditions for Young Lemon Trees on a Loam
OE NE SED ey hat ch Mi Oe A OY 000) | ec 25
Some Abnormal Water Relations in Citrus Trees of the Arid South-
west and Their Possible Significance, by Robert W. Hodgson.......... 37
Bei LPomgrouIoner, DY LIODAIG BYiC@ la... nic. 0-snosnsecsnssesinennecasseadenesmeres 55
Toxie and Antagonistic Effects of Salt on Wine Yeast (Sacchar-
GMNUCCS: CIDSOUA CURT, WY ii. MAGE. ino orc. ce cscncnnsesantaccrrecsvosaztnvacnenconesiecn 63
Changes in the Chemical Composition of Grapes during Ripening,
eet eOLEb bl Wee ce hteme, BIN EL; DAV 1. oca ue ciescenincnsrunceiends 103
A New Method of Extracting the Soil Solution (A Preliminary
Coimmunication), by Charles 5. Taapman ... ...<icec01---00c-aleccanrctteurcesinns 131

The Chemical Composition of the Plant as Further Proof of the
Close Relation between Antagonism and Cell Permeability, by
REIGN g Po RRAVYE I a) aud OS © deh a ec a ce rere 135

Variability in Soils and Its Significance to Past and Future Soil
Investigations. I. A Statistical Study of Nitrification in Soils,

Oe SREB Sg UN GSS, Ecsta eae CE ee 243
Does CaCOz or CaSO, Treatment Affect the Solubility of the Soil’s
Constituents?, by C. B. Lipman and W. F. Gericke..........0..00000000000.... 271

An Investigation of the Abnormal Shedding of Young Fruits of the
Washington Navel Orange, by J. Eliot Coit and Robert W. Hodgson. 283
Are Soils Mapped under a Given Type Name by the Bureau of Soils
Method Closely Similar to One Another?, by Robert Larimore
Se EINES rc Ra Ss RRL AS SA aod ie oR ee 369

UNIVERSITY OF CALIFORNIA PUBLICATIONS
IN

AGRICULTURAL SCIENCES
Vol. 3, No. 1, pp. 1-24, plates 1-8 July 13, 1917

NEW GRASSES FOR CALIFORNIA, I

PHALARIS STENOPTERA HACK.

BY
P. B. KENNEDY

A survey of the soil and climatic conditions of California soon
revealed the fact that most of our grasses, the seed of which is now
procurable on the market, could not establish themselves and produce
a strong sod on lands not susceptible of irrigation. Over large areas
of the state. there are good soils receiving moisture only in the form
of rain on which there is no green pasturage for stock soon after the
rains cease. This condition may set in as early in the season as May
1, and may continue during some seasons into November or even
December. Therefore a perennial grass that will withstand the winter
temperatures as well as the long, dry season in the great central
valleys would be of great value to the live-stock industry of California.
Recent investigations and experiments lead me to believe that I have
found such a grass.

Several years ago an illustration of a grass in a trial plot in a
seedsman’s catalogue from South Africa attracted the author’s atten-
tion. The report of its behavior under conditions of heavy frosts and
long droughts made it appear that it might prove valuable under
California conditions. Sufficient seed was purchased to sow one-
twentieth of an acre only, as it was too costly to be considered
in larger quantities. It was called perennial canary grass, or Too-
woomba grass, Phalaris bulbosa. Perhaps the most authentic account
of the introduction of this grass is to be found in the following letter
received from Mr. R. R. Harding, curator of the botanic gardens,
Toowoomba, Queensland.

2 University of California Publications in Agricultural Sciences [ Vol. 3

In 1883 I received twenty-one packets of seeds from Italy, These I put
in the nursery. All germinated, but the frost killed all except this wonderful
grass, Phalaris commutata,. In two years it had taken possession of nearly the
whole plot of ground in the nursery from the seed self-sown.

It is a perennial. We had to remove the grass, so we dumped the root-clumps
in a corner on hard ground, but it still grew to five feet in height. This was
during the drouth and frost, and although it was cut it grew again.

Mr. Harding also concludes with the statement that it was dis-
tributed by him to all the Colonies, Africa, and even Italy. As will
be pointed out later, neither Phalaris bulbosa nor Phalaris commutata
is the correct scientific name for this grass, as those names belong to
other and distinet species.

The seed secured from South Africa under the name of Phalaris
bulbosa proved to be a strong perennial and to be pure, but not true
to name. In the same year we planted a twentieth-acre plot with seed
also called Phalaris bulbosa secured from seedsmen in Australia. It
proved for the most part to be an annual Phalaris and not the same
species as that from South Africa, although received under the same
name. That there were a few seeds in this lot of the perennial species
corresponding exactly to the grass from South Africa was evident, as
some fifteen or twenty plants in the plot sown to the Australian seed
lived throughout the next winter and summer, finally forming strong
clumps.

The following year I noticed a sack of seed exhibited by the New
Zealand Government at the Panama Pacific International Exposition.
This, too, was labeled Phalaris bulbosa. The seed was so similar in
appearance to the South African lot that at the close of the Expo-
sition we arranged for its purchase. When grown, however, it proved
to be an annual and not the desirable perennial grass called Phalaris
bulbosa as received from South Africa.

A large number of packets from this sack were secured with per-
mission from the New Zealand authorities by representatives of many
experiment stations and by the United States Department of Agri-
culture. We desire simply to eall attention to this to avoid further
confusion and to make plain the fact that Phalaris bulbosa as dis-
tributed at the Exposition is not the same as the perennial Phalaris
bulbosa (2?) from South Africa. It is the latter grass that we desire
to introduce into California, as the annual species do not offer any
especial characteristics that would make them any more valuable
either as pasture or hay than the cereal hays now so extensively and

1917 | Kennedy: New Grasses for California, 1 3

satisfactorily utilized. That much, if not all, of the seed of Phalaris
now on the markets of New Zealand and Australia is hopelessly mixed
seems to be certain; and also that a selection of the perennial species
will have to be made before one can recommend the purchase of seed
from those countries. \

A eareful comparison of our perennial plant as grown at the
University Farm with the original descriptions of Phalaris bulbosa
and Phalaris commutata soon proved that it could be neither of those
species. On further search of the literature, including descriptions
of some twenty additional species, the author failed to find a deserip-
tion that would agree with our grass. I was about to describe it as
a new species when a paper entitled ‘‘Gramineae Novae,’’ by Eduard
Hackel, was discovered, in a somewhat obscure publication, which
described the species in question. In order that this original descrip-
tion may be made more readily accessible to agronomists, we are
including it here. We have been distributing seed from our plot
at the University Farm and more or less confusion is likely to occur,
as it has been distributed under the incorrect name of Phalaris
bulbosa. This grass is not described or mentioned in any American
literature on grasses and forage plants.

The following description with the accompanying illustrations
should aid in its identification.

GRAMINEAE NovaE IV. Eduard Hackel in Fedde, Repertorium novarum
Specierum Regni Vegetabilis, 5, 1908, p. 333.

Phalaris stenoptera Hack., nov. spec.

Perennis, caespitosa, sine stolonibus. Innovationes extravaginales, squamis
elongatis herbaceis purpurascentibus fultae. Culmi erecti, robusti, ultra 1.5 m.
alti, teretes, glaberrimi, plurinodes, simplices, internodiis basalibus non incrassatis.
Vaginae teretes, arctae, internodiis breviores, glaberrimae. Ligula rotundata v.
subtruncata, 5-7 mm. lg., denticulata, siccando fissa, glabra. Laminae linearis,
sensim acuminatae, innovationum longissimae (50 em. v. ultra), 1.2-1.5 em. latae,
culmeae superoires abbreviatae, omnes flaccidulae v. rigidulae, glaberrimae vel
margine et in pagina superiore versus apicem scaberulae, virides, tenui-nerves.
Panicula spiciformis linearis vel lineari-oblonga, 6-16 cm. longa, cire., 1.5 em.
lata, densissima, haud interrupta, non vel obselete lobata, rhachi laevi, ramis
appressis ramulosis multispiculatis, pedicellis quam spiculae plures v. multoties
brevioribus scabris. Spiculae elliptico-lanceolatae, 5-6 mm. longa, albido-viridulae,
marginibus viridi-striatae. Glumae steriles 2 inferiores aequales, naviculares,
acutiusculae, carina in % superioribus anguste (in gluma I, angustissime vel sub-
obselete) alatae, ala integra in apicem sensim decurrente, scaberula, trinerves, nervis
(uno in basi alae, duobus ad latera) saturate viridibus. Gluma III nulla, IV vacua
1 mm. longa e squamula callosa ovata 0.3 mm. longa et ex appendice membranaceo
lanceolato 0.7—-0.8 mm. longo infra apicem squamulae inserto apice penicillato-

t University of California Publications in Agricultural Sciences [Vol.3

ciliato constans. Gluma V (fertilis) 3.5 mm. longa ovato-lanceolata, acuta, char-
tacea, appresse pubescens, tenuissime 5 nervis. Palae glumam aequans, angustior,
carina ciliolata. Antherae 3.5 mm. longae. Ovarium glabrum. Caryopseos macula
hilaris fere dimidiam caryopsin aequans.

Patria ignota, culta in Australia sub nomine Phalaridis commutatae. Plantam
et semina misit A. J. Ewart, Melbourne.

Es ist auffallend, dass diese gut unterschiedene Art, welche in Australien als
Futtergrass gebaut und sehr geriihmt wird, bisher meines Wissens nirgends
beschrieben wurde. In Australien wurde sie durch Mr. Harding, Kurator des
Botanischen Gartens in Tuwumba, Queensland (unbekannt woher) under dem
Namen Ph. commutata eingefuhrt und unter diesem Namen von Samenhindlern
in Melbourne verbreitet. Ein mir vorliegendes Reklameblatt zeigt die Darstellung
eines dichten Rasens van angeblich 7 Fuss (2.2 m.) Hohe, der nach dem Schnitt
in 46 Tagen wieder einen 41 Zoll (106 em.) hohen Rasen hervorgetrieben hatte.
Besonders wird sein wert als Wintergras hervorgehoben.

This excellent detailed description agrees with our grass from
South Africa in everything but the sterile florets. As these are used
as the chief distinguishing characters in the genus to separate one
species from another, a disagreement in regard to these particular
structures makes a positive identification difficult. Our specimens
show a variation in the sterile florets, one 1.5 mm. in length and
the other much smaller, .7 mm. The latter may be reduced to a mere
point protruding from the ovate scale (pl. 1, fig. 4).

Hackel’s deseription is as follows:

Gluma IIT nulla, IV vacua 1 mm. longa...infra apicem squamulae inserto
apice penicillato-ciliato constans.

That Hackel seemed convinced that there was constantly only one
sterile floret is emphasized by the fact that in a diseussion of the
relationship of the new species, he writes ‘‘doch ist der Hillspelzen-
fliigel bei Ph. stenoptera noch schmaler als bei Ph. nodosa und es ist
stets nur eine kleine Leerspelze (die glume IV) am Grunde der Vor-
spelze’’; also ‘‘ Kin merkmal aber, das sie von beiden genannten Arten
(Ph. arundinacea and Ph. bulbosa) scharf trennt, ist das Fehlen der
eluma III, das mir ganz Konstant zu sein scheint.’’

Through the kindness of Mr. Harding, who forwarded us some old
seed from the Botanic Gardens at Toowoomba, Queensland, we were
able to examine original material. There were present in the packet
some spikelets with two sterile florets, others with one sterile floret,
and another very minute one and still others with only one present.
This same condition was found in our specimens grown at Davis and
which may be seen under sheets nos. 5000, 5001, 5002, and 5003 of

1917 | Kennedy: New Grasses for California, I 5

the herbarium of the Division of Agronomy, Department of Agricul-
ture, Berkeley. Among the seeds in the packet from Harding was
an outer glume whose narrow wing showed distinctly the scaberulous
margin characteristic of Ph. stenoptera,

Hackel mentions that he received the plants and seeds from which
he drew up the original description of Ph. stenoptera from A. J.
Ewart, of Melbourne. Since the seeds of at least two species are so
hopelessly mixed in Australia, is it not just possible that the seeds
sent to Hackel may have been the annual species which constantly
has only one sterile floret and that the plants were those of Ph.
stenoptera, the perennial species ?

A most interesting fact in connection with this grass is that it
should not have been deseribed from Europe previous to its introdue-
tion to the Toowoomba Botanical Gardens by seed sent from Italy.
Haeckel in his deseription says ‘‘Patria ignota.’’ This from such a
renowned agrostologist who has traversed the whole of southern
Europe many times, is of especial significance. Could it be a hybrid
from other existing species ?

EcoNoMIc CONSIDERATIONS

The giving of a name to this grass which will be suitable for
everyday agricultural usage deserves some consideration. Perennial
canary grass is not desirable, as there are several ‘‘ perennial canary’
grasses. Toowoomba grass is too unwieldy. I propose to eall it
Harding grass, after the man who first grew it in Australia.

Our experiments demonstrate that the seed may be sown at Davis
during the winter season so as to take advantage of the rains. The
young plants, although very slender, almost like threads coming
through the ground, are very hardy and were not harmed by severe
frosts. At the same time cotyledons of such hardy species as Melilotus
alba turned yellow and many seedlings were killed outright by the
drouth and cold. The grass grows rapidly, stooling profusely, and
producing large clumps the first season. A feature of great merit
from a pasture standpoint is the large number of dense leafy shoots
produced from the base. The first year these are much in evidence
and comparatively few flowering culms are sent up. These are only
about two to two and a half feet tall and bear short, somewhat ovate
heads. The leafage is devoid of hairy coverings of any kind, thus
tending towards a clean hay and palatable pasturage.

6 University of California Publications in Agricultural Sciences | Vol, 3

The roots are fibrous, radiating downwards to a depth of one or
two feet. They are covered with a downy coating similar to that
found on many desert grasses. That they are able to make use of
slight amounts of hygroscopic moisture in the soil seems possible, as
when a clump was dug up and placed upon the surface of the ground
the grass continued to grow, although exposed to severe conditions
of drouth with no rainfall for several months.

The plot of Harding grass attracted considerable attention during
the hot summer months, with its long green leaves showing no tend-
ency to wilt. It makes a decided contrast in July and August by
its vivid green among the dry brown stubble of the cereals and other
erasses given the same care and treatment. We also had occasion to
observe its behavior during the winter. On the coldest morning, with
ice everywhere, we visited the grass plot and observed the hoar frost
on the leaves and the ground frozen, yet the foliage remained green.
Even our generally recognized hardy grasses like Kentucky blue-
erass, orchard grass, and red top had turned brown.

The second year from the seed it still maintained a dense leafy
erowth from the base of about three feet, the flowering culms extend-
ing about two feet higher, making a total height of five feet. This
is a growth rarely reached by any of the cultivated perennial species
of grasses known at the present time.

We did not wish to be understood that the Harding grass will
withstand a lower or as low a temperature as our common hardy
erasses and that it is adapted to regions with severe winters as in
parts of the east or middle west. As yet we do not know its cold-
resistant qualities. The fact that it remains green during the com-
paratively mild winters at Davis, Yolo County, California, does not
indicate the minimum temperature the roots may withstand. In-
formation as to its latitudinal and altitudinal! tolerance is not at
hand.

In order that some comparison may be made as to the probable
adaptability of this grass to other states and to different parts of
California, we give the following conditions for Davis.

According to S. H. Beckett, of the United States Department of
Agriculture, ‘‘the mean annual rainfall is 16.54 inches, the greater
part of which comes in December, January, February, and March,
while from May to October very little rain falls.’’ There is con-
siderable variation in the amount of rainfall in different years.
Frequently it amounts to 20 inches, but occasionally only 8.74

1917 | Kennedy: New Grasses for California, I

ba |

inches is precipitated. It is the so-called dry years that cause a short-
age in all farm crops not under irrigation, and interfere seriously
with the pasturage on the ranges. The mean annual temperature is
62.7° F, with a known maximum of 112° F, and a minimum of 16° F.
Intense sunshine prevails throughout the summer.

Technically the soil is known as Yolo silt loam. Professor C. F.
Shaw describes it as follows:

A fine, smooth-textured brown soil at the surface, grading at about three feet
to a light brown subsoil containing slightly more clay loam or clay. It is usually
free from gravel. The soil when wet has a tendency to run together and become
puddled, preventing the free downward percolation of water. On drying it
tends to form a crust on the surface. If plowed when wet it forms hard clods
and lumps. When handled in the proper condition of moisture, however, it be-

comes loose and mellow. It has good moisture-holding capacity, is very pro-
ductive, and adapted to a wide range of crops.

That the soil has exceptionally good moisture-holding capacity,
especially at the lower depths, is shown by the following furnished
us by Professor B. A. Madson. The figures represent an average of
several plots believed to be similar in all essential details to that on
which the Harding grass was grown.

MoIstTuRE CONTENT OF SorL, 1916, Davis

Per cent Per cent Per cent Per cent
Depth, Moisture, Moisture, Moisture, Moisture,
feet April 1 May 25 July 7 August 24
if 17.35 10.34 10.32 7.44
2 21.91 12.31 12.66 11.12
3 27.39 20.75 19.47 17.00
4 27.98 19.84 20.21 16.87
5 28.60 25.44 21.19 22.01
6 34.44 27.64 28.98 27.65

The land on which the experiment with Harding grass was con-
ducted had for many years previous been cropped to grain. No
manure, artificial fertilizer or irrigation were given the plot, nor
could it have been affected by moisture from any adjacent irrigation.

A strip six by eighteen feet was cut from the plot on May 25,
1916, the second year (pl. 7). The estimated green weight of forage
per acre was twenty tons and of cured hay three tons. There still
remained on the ground a dense aftermath which would have fur-
nished good pasturage. The average yield under field conditions
can not be ascertained until the grass has been grown on a larger area.

The remainder of the twentieth-acre plot was allowed to go to
seed. From this we harvested seventeen pounds of seed, 43 per cent

s University of California Publications in Agricultural Sciences [Vol.3

of which germinated. This somewhat low viability was due to the
fact that we had no fanning-mill that was suitable for cleaning grass-
seed, so that much chaff remained.

From this home-grown seed we have sown an acre in rows mainly
for seed increase purposes. In addition we have distributed a large
number of packets to co-operative experimenters in different parts of
the state in order to find out the range of soil and climate in which
it might prove valuable.

In regard to its palatability, | have not yet had sufficient personal
experience to determine this with certainty. Nor do we know its
chemical composition or nutritive value. We fed some of the hay
to work-horses accustomed to alfalfa and they ate it readily. Reports
from other sources would lead us to believe that it is well liked by
stock. The following excerpt from the catalogue of a branch of the
well-known and reliable British seed firm, George Carter and Com-
pany, located at Pietermaritzburg, South Africa, speaks for itself.

A magnificent winter grass for fairly good lands. This is our sixth season
of experience with this grass, and we have had no reason as yet to alter our high
opinion of its value. For farms where the land is of a poor, light, sandy nature,
we do not recommend it. But on good, fairly heavy loams (say wherever a
good crop of Mealies can be grown), or on deep veldt lands, it is magnificent.
The yield of luscious feed is tremendous all the year round, and it is particularly
valuable for the winter and early spring months, growing even during heavy frost
and long droughts. The rooting system is very large and deep. In seed the
plants reach the height of over five feet, while the ordinary growth without seed-
stems is about three feet high, and just like a permanent crop of rich green
barley. It can be cut continually, growing at the rate of an inch per day.
While growing with great success on dry lands, it will well repay both good
manuring and irrigation.

For dairy farms we can not praise it too highly, particularly for producing
milk during the colder months, when other food is so scarce; while it is just
the grass to grow near the homestead for cutting for calves, horses, or indeed

any animal which eats grass. There is no need to say that the cattle relish it—
it is a difficult matter to keep them fenced out at all from a crop of this grass.

I refrain from quoting the praiseworthy accounts of it in the
pubhe press of Australia, as we are unable to determine whether the
comments are attributed to Phalaris commutata or Phalaris stenop-
tera, both of which (as previously explained) are indiscriminately
mixed on the seed market of that country.

Even if the Harding grass should not prove to be adaptable to a
wide range of territory in California and elsewhere, the immense
stretches of land between the foothills on the east and west in the
great central valley, where in many instances only a poor crop of

1917 | Kennedy: New Grasses for California, I i)
grain is secured every other year, would be sufficient to warrant its
thorough investigation.

A system of pasturing cattle and sheep on Harding grass for a
period of years would be most profitable as well as beneficial to the
soil.

Much, however, remains to be investigated, particularly as to its
ability to withstand grazing without injury, its carrying capacity,
nutritive value, longevity, and the quality of beef and mutton that
it will produce.

Transmitted March 80, 1917.

PLATE 1
Phalaris stenoptera, Hack.

Fig. 1. Root system. A. Velvety covering on roots. B. Short stolons.
Fig. 2. Portion of sheath, blade, and culm. A. Ligule. . a ~S
Fig. 3. Spikelet. .4. First empty glume. 4’. Wing of glume. B. Second |
empty glume. B’. Wing of glume. C. The lemma. D. Palea. E. Stamens. ‘

Fig. 4. Lemma and sterile florets. C. Lemma. F. Ovate scales. H.
sterile floret. G. Second sterile floret.

10

UNIV. CALIF. PUBL. AGR. SCI., VOL. 3

[KENNEDY] PLATE 1

BA,

=

PLATE 2 .

Spike-like panicles of Phalaris stenoptera, showing different stages of d svelo
ment.

UNIV, CALIF. PUBL. AGR. SCI., VOL. 3 [ KENNEDY ] PLATE 2

re . — oa v _ Lae he » s 7 Pane "a a

PLATE 3

Young plant of Phalaris stenoptera, showing stooling habit
of roots. z

UNIV. CALIF, PUBL. AGR. SCIl.,

VOL. 3

[ KENNEDY] PLATE 3

wa

fist
By is

Wye. : Pf a y iT rr
aie ayo) re ne ae lcs mh

cy ry “4 its:

ee iy ys Re A ae ae
4 7 <7s : ; ri 7. 7 ;

4

aoe growth of Phalaris stenoptera, dense tender leafage in Januar
1916. | : aa

[KENNEDY] PLATE 4

UNIV. CALIF. PUBL. AGR. SCI., VOL. 3

Pee pile ge

ft

os

we

MOO a GE SBR Ne

abe |

bois ot

7 ages

i
?
i
.
;
Fy

PLATE 5 ane
Phalaris stenoptera in full bloom, second year from seed. Photo -
University Farm, May 25, A916. Height of panes five feet.

|

~~

UNIV. CALIF. PUBL. AGR. SCI., VOL. 3 { KENNEDY ] PLATE 5

|, cna?

PLATE 6 rs

Phalaris stenoptera, showing strip cut across plat and dense aftermath, |
taken May 25, 1916.

UNIV; CALIF, PUBL: AGR., SCI., VOLES {KENNEDY ] PLATE 6

ers

7 AA

-
7 q
. ae |

bs

PLATE 7 ‘ 7

_

Phalaris stenoptera—sheaves from experimental plot, University Farm, May ‘
25, 1916.

PLATE 7

[ KENNEDY ]

UNIV. CALIF. PUBL. AGR. SCI., VOL. 3

ae
By y ; |

a

Ww

PLATE 8
Lodged plants represent the annual species, the so-called Phalaris c tata
with an erect perennial clump of Phalaris stenoptera. Gee wanna $n: wk ESOT
tralia under name of Phalaris bulbosa.

UNIV. CALIF. PUBL. AGR. SCI., VOL. 3 [Ke NNEDY ] PLATE 8

UNIVERSITY OF CALIFORNIA PUBLICATIONS
IN

AGRICULTURAL SCIENCES
Vol. 3, No. 2, pp. 25-36, plates 9-11 September 29, 1917

OPTIMUM MOISTURE CONDITIONS FOR YOUNG
LEMON TREES ON A LOAM SOIL

BY
L. W. FOWLER anp C. B. LIPMAN

Among the numerous problems emanating from the use of irriga-
tion water on land is the important one of maintaining as nearly as
possible an optimum moisture content in the soil. While much
research work has been done in an attempt to determine what consti-
tutes such an optimum moisture content, it seems that our knowledge
is still too indefinite for accurate application to specific cases. For
that reason it has appeared to the junior author that some specific
information should be gathered concerning the moisture needs of soils
which are used for growing crops under field conditions and also the
variations in such moisture needs occurring through changes in soil
type and changes in the kind of crop grown. Obviously the task just
mentioned is too great to be disposed of quickly, and in one series
of experiments, and it has, therefore, seemed wise to start the work
with one crop and one soil type first. Owing to the fact that the
Limoneira Company of Santa Paula, California, expressed its willing-
ness to co-operate in such an experiment and to give to it the time
and attention of the senior author as well as the necessary equipment,
the experiment was started with young lemon trees on a loam soil,
characteristic of much of the large ranch in the possession of the
company. It was further hoped that the results obtained from the
experiment, along with contemporaneous results of careful moisture
determinations at short intervals in the lemon orchards, would give a
basis for planning a scientific system of irrigation in the orchards in
question. A plan for the specific experiment, and one for the field
work were arranged by the junior author and they were executed
under the direction of the senior author. The detailed results of the

26 University of California Publications in Agricultural Sciences {Vol.3

field work cannot be given in this paper but will need discussion
separately elsewhere at some future time. The experiment proper,
however, has now been in operation for more than two years and the
results obtained have been so interesting as to more than justify their
presentation and discussion here.

PLAN OF THE EXPERIMENT
It was decided to grow the young lemon trees in galvanized iron
cylinders, 24 inches in depth and 15 inches in diameter. The cylin-
ders were painted with a heavy coating of asphalt. The soil used in
them is a loam having the following mechanical analysis (Bureau of
Soils method),. which was furnished us through the courtesy of
Professor C. F. Shaw:

First foot Second foot Third foot
Ping: ovaye 1.45 1.14 1 gk
Co a) ae! oe aS 3.2 3.13 4.27
Madi sane. o. .... 3.32 3.25 4.13
Wine Sane ace ee eS 12.77 12.33 12.58
Very fine send 2:.....2<... 42.99 44.93 43.22
OE era rm 18.74 19.31 16.61
Clee Ste eg 17.49 15.91 17.48

On the basis of this mechanical analysis the Bureau of Soils would
classify the soil as a fine sandy loam, but owing to its relatively high
clay and silt content it should, in the junior author’s opinion, be
classified as a light clay loam, but certainly as no less than a loam.
Mr. Chas. A. Jensen of the Bureau of Plant Industry, United States
Department of Agriculture, was good enough to furnish the ‘‘ moisture
equivalents’’ and ‘‘ wilting coefficients’’ of the first three feet in depth
of the soil used, as it occurs under field conditions. Mr. Jensen’s
determinations follow:

Wilting per cent Moisture equivalent
DE ee Ae 9.3 17.0
BOGOR FOOE | wos cneivccsocecenscs 8.7 15.9
pal, So) oe ee eee ae oe 8.1 14.0

The soil used in the cylinders was obtained from a lemon orchard
now twenty-three years of age in which the trees have always shown
good vigor and high productivity. The soil from the first and second
feet in depth was thoroughly mixed in preparation for use in the
cylinders. The same amount of soil was weighed into every cylinder.

The variety of lemons selected for the test was the Lisbon. The
trees were one year old and as nearly uniform as could be obtained.

1917] Fowler—Lipman: Optimum Moisture Conditions for Lemon Trees 27

Before planting, the roots of the trees were entirely freed from soil
and the tops were pruned to a whip. The planting was done on March
17, 1915, after which the cylinders were placed in a row (see plate
9) in a trench 24 inches deep, in order to prevent the undue heating
of the soil from the exposure of the cylinders to the direct sun. From
the time of planting until June 1, 1915, a soil moisture content of 20
per cent based on the dry weight of the soil was maintained in all
the cylinders in order to give all the trees the same start. At the
last date mentioned the growth of all the trees was sufficiently good
and uniform enough to allow of the arrangement for the variation
in moisture content in the different cylinders. In order to allow for
individual variations among the trees, every moisture content was
employed on triplicate trees and the moisture percentages tested were
as follows:

10 per cent based on the water-free soil.
iL ce 6c ce sé sé oe “é sé

14 cé 6é 6é éé sé sé ‘6 sé
16 ce 6é ‘é 6é ‘é sé ce sé
18 “6 ce 66 6c 6é 6eé 6 sé
20 éé ce as 6é “é 6c ‘é sé
92 ec 6c “é éé sé ce ‘é cé
94 ce 6é 6c ec éeé ce 66 6é
26 6 cc 6 cé 6é 6é cé cé
28 ce ce cé ‘é ce 6 ‘é ce

30 6é 6é 6c “6 ‘é cé 6 oe

The cylinders are weighed three times per week and the losses of
moisture due to evaporation are replaced by additions of the necessary
amounts of the ordinary irrigation water employed on the ranch.
The weighing is done on steelyards and a derrick is available for
raising and lowering the cylinders as desired. The water is added in
a depression in the surface soil corresponding in nature to an irri-
gation furrow and is applied by means of a very small stream flowing
from a hole in a can used for the purpose. This method is employed
to obviate puddling. During rainy weather the cylinders kept at less
than 20 per cent moisture are protected by canvas roofs. Between
irrigations the surface of the soil in all the cylinders is kept cultivated.

RESULTS OF THE EXPERIMENT
Seventeen months after the experiment was started or when the
trees were two years and five months old, measurements were made
and a diagram showing their relative heights at the time is given in

25 University of California Publications in Agricultural Sciences [Vol 3

figure 1. While, however, the measurements show clearly enough the
effects of the different soil moisture percentages on the growth of
the young lemon trees, they do not really tell the whole story, since
the general vigor and abundance of foliage are naturally as much and
perhaps more affected than the height by the moisture conditions in
the soil. For that reason photographs taken at about the time the
measurements were made are submitted herewith to show the actual
condition of the trees.

By whatever criterion the results are gauged, it is at once clear
that the effects of the soil moisture content on the development of
the young lemon trees are most striking. For the soil and plant in
question, 20 per cent of moisture based on the dry weight of the soil
seems to be optimum in so far as the total growth and the height of

40

Fig. 1. Showing the relative heights of lemon trees grown with different
quantities of moisture. Trees 29 months old; in experiment 17 months. The
relative heights are shown on the ordinates and the percentages of moisture under
which they were produced are given in the abscissae. The broken line shows the
height of all the trees at the beginning of the experiment.

the trees are concerned. <A fact which is not brought out by either
the measurements or the photographs is that the general tone and
color of the trees growing in the 20 per cent cylinders is somewhat
inferior to that of the trees growing in the 16 per cent and 18 per cent
cylinders. The optimum moisture content of the loam studied for
young Lisbon lemons seems to be therefore between 18 and 20 per
cent, if we may judge from the experiment deseribed and from the
time given it. The trees at or near the optimum moisture content
doubled in height and general size during the period mentioned, while
the trees at 10 per cent or at 30 per cent moisture contents have
scarcely gained more than half of their original height in the period
named.

Other important points deserve mention in connection with the
results obtained. It appears from the data given that the range of

1917] Fowler-Lipman: Optimum Moisture Conditions for Lemon Trees 29

soil moisture percentages within which the young Lisbon trees will
grow satisfactorily in the soil studied is, relatively speaking, a wide
one, since for practical purposes there is probably little difference
between the growth obtained at moisture percentages varying from
16 to 22, both inelusive. This is a fortunate circumstance from the
point of view of orchard practice since it allows of considerable leeway
in the control of irrigation operations. It does not follow, however,
that as regards fruit production the same wide range of moisture per-
centages in the soil would be similarly effective as in the case of
general vegetative growth. On either side of the range of moisture
pereentages just discussed, there can be no question that conditions
are far from proper for good tree growth. This is especially true,
however, for moisture percentages in excess of 22 per cent, at which
the light-colored foliage and general lack of vigor, increasing with
increase of moisture, accompany the slow growth. In the case of the
eylinders receiving less than 16 per cent of moisture while the growth
is also slow owing to lack of moisture, the leaves and branches appear
to be normal in color and the trees appear to be suffering less from
untoward conditions. It seems to be very clear at this stage of the
experiment, therefore, that, in practice, there is very much more
danger to young lemon trees from too much than from too little
moisture in the soil. The harmful effects of the former seem to be
always more sharply defined and more intense; small additions of
water beyond the optimum produce large and sudden changes, whereas
small decreases of moisture below the optimum show their effects only
eradually with the continued reduction in the moisture percentage.

About six months have passed since the measurements and photo-
graphs discussed above were obtained. The effects of the different
moisture percentages continue to stand out as clearly or more so than
ever before, indicating the probability that they may continue so for
a long period of years. It should be mentioned here that small but
uniform applications of sulphate of ammonia have been made to all
the cylinders during the past year to maintain a more nearly normal
growth than is possible without additional nitrogen in such a limited
volume of soil as that at the disposal of the trees in the cylinders.

In the soil under study in this experiment it was found that the
theoretical wilting point was very close to, if not identical with, the
actual wilting point, as both the field moisture determinations and the
10 per cent moisture cylinders have on very dry days attested. It
will be observed, moreover, that the moisture equivalent and the

30 University of California Publications in Agricultural Sciences {[|Vol.3

optimum moisture percentage in the same soil are not far apart.
While the height of the trees is greatest at moisture percentages in
excess of that of the moisture equivalent, the most vigorous appearance
of the trees is obtained with percentages of soil moisture very close
to the moisture equivalent. As above stated, it is not possible now
to discuss the detailed results of the moisture determinations in the
orchard, but in general it was true that the soil moisture percentages
rarely fell to the wilting point in the orchard soil and very infre-
quently rose to the optimum under the system of irrigation practiced.
In the orchard under consideration, therefore, a lack rather than an
oversupply (a common condition elsewhere in California) of water
seems to be the rule.

1917] Fowler-Lipman: Optimum Moisture Conditions for Lemon Trees 31

SUMMARY

In attempting to determine the optimum moisture content of a
rather heavy loam soil for young Lisbon lemon trees grown in cylin-
ders, at the Limoneira Ranch, Santa Paula, California, the following
information was obtained in the course of the first two years of the
experiment :

1. A moisture percentage of 20 per cent based on the dry weight
of the soil has produced the tallest trees.

2. Trees grown with 16 and 18 per cent of moisture, while not as
tall as those grown with 20 per cent of soil moisture, show better color
and more vigor. The differences are not very marked, however.

3. The foregoing facts seem to show that the range of optimum
or nearly optimum moisture percentages for the soil and plant in
question is a relatively wide one.

4. Much more visible damage results to the young lemon trees from
moisture percentages in excess of the optimum than from those below
the optimum.

5. Every successive increment of moisture beyond the optimum
is accompanied by a sharp depression in growth, color, and general
vigor of the trees.

6. Every successive decrement of moisture from the optimum
shows only a relatively slight depression in growth.

7. The theoretical wilting point and the moisture equivalent for
the soil studied are in close accord respectively with the actual wilting
point as determined in the soil of the orchard and the optimum moist-
ure content as determined in the experiment discussed above.

The authors wish to acknowledge their sincerest sense of obligation
to Messrs. C. C. Teague and J. D. Culberson of the Limoneira Com-
pany, who have so kindly codperated with them in the experiment
above described and who have at all times been willing to place at
their disposal all possible facilities for the prosecution of the work.

PLATE 9
Fig. 1. Showing arrangement of cylinder experiment to Pee wana
of young lemon trees.

Fig. 2. From right to left, cylinders 1, 2, and 3 maintained at 10 per
of soil moisture; cylinders 4, 5, and 6 maintained at 12 per cent of soil r

UNIV. CALIF. PUBL. AGR. SCI., VOL. 3 [FOWLER—LIPMAN]| PLATE 9

“NSD

. sap eP a ; ~ ‘
Pa a Aire Lie
We eo Nosy Te. pe de ieee
ae r % %

PLATE 10
Fig. 1. From right to left, cylinders 1, 2, and 3 soatatanaen at 14 per ec =

of soil moisture, and cylinders 4, 5, and 6 maintained at 16 per cent of |
moisture, Tp |
Fig. 2. From right to left again, cylinders 1, 2, and 3 maintained at 18 _ er
cent of soil moisture, and cylinders 4, 5, and 6 maintained at 20 per cent of si
moisture. Part of cylinder 7 showing 22 per cent of soil moisture,

i | « if vi ut

s

UNIV. CALIF,

is

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. nme et = s

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PLATE 11

Fig. 1. From right to left, cylinders 1 and 2 maintained at 22 per an
soil moisture, cylinders 3, 4, and 5 at 24 per cent of soil moisture, cylinders: 6 ar a
7 at 26 per cent of soil moisture. Ki
Fig. 2. From right to left, cylinder 1 at 26 per cent of soil moisture, “fin ers

2, 3, and 4 at 28 per cent of soil moisture, cylinders 5, 6, and 7 at 30 per contig of
soil moisture.

11

PEATE

LIPMAN]

[FOWLER

SCi.,.VOEL.

PUBL. AGR.

CALIF,

UNIV,

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UNIVERSITY OF CALIFORNIA PUBLICATIONS
IN

AGRICULTURAL SCIENCES
Vol. 3, No. 3, pp. 37-54, plate 12 September 29, 1917

SOME ABNORMAL WATER RELATIONS IN
CITRUS TREES OF THE ARID SOUTH-
WEST AND THEIR POSSIBLE
SIGNIFICANCE

BY
ROBERT W. HODGSON

INTRODUCTION

The progress of the development of the citrus industry, in general,
and that of California in particular, has frequently been retarded or
temporarily stopped by serious obstacles in the form of insect pests
or plant diseases. Some of the most baffling of these troubles fall
naturally into a group which for want of a better name has come to
be known as that of ‘‘ physiological diseases,’’ which are thought to be
caused by various obscure derangements of nutrition or other vital
functions. This group includes mottled-leaf, die-back, chlorosis, June
drop, puffing of the fruit, and others of less importance. Knowledge
of the true nature of this class of diseases is extremely meager in spite
of the fact that they have received much earnest attention from scien-
tific investigators; and little can be accomplished in the way of devis-
ing control measures until much more is known in regard to them.
Nor can we hope to progress far beyond the realm of speculation with-
out greatly augmenting our knowledge of the physiology and anatomy
of the normal citrus tree when grown under any one of a series of
very widely varying environmental complexes which obtain in differ-
ent parts of the arid southwest. |

It is, therefore, proposed to attempt by means of a series of sys-
tematic experimental studies to obtain some definite and accurate
information on the physiology of the genus Citrus. It is hoped that
the results may serve as a basis for the elucidation of some, at least,

38 University of California Publications in Agricultural Sciences [Vol,3

of the important problems referred to above. The studies in ques-
tion will attempt to shed light on transpiration problems, nutrition
problems, and others equally important. The paper which is sub-
mitted herewith forms an introductory contribution to the subject
under investigation.

The writer is not unaware of the essential similarity between the
physiological problems presented by citrus and other fruit trees. He
has chosen, however, to study the physiology of the citrus tree as a
separate entity because of the reasons given above, and the further
one that the peculiar climatic conditions under which this tree is
frequently placed in the arid southwest, demand a special treatment.
Doubtless much may be gained from these studies which will apply
to physiological problems connected with other trees.

The data here presented were obtained during an investigation of
one of the so-called physiological diseases above mentioned, namely,
the June drop.'. Ever since the Washington Navel orange has been
grown in the dry interior valleys of Arizona and California, this
variety has been subject to excessive dropping of the young fruits.
This has came to be known popularly as the June drop although the
fall of the fruits is by no means confined to June but may occur at
any time from petal fall, in April, until the fruit reaches several
inches in diameter in August. The prevalence and amount of this
dropping seems to be influenced to a marked degree by certain
environmental factors to which the trees are subject. The regular
annual shedding of the young fruits is most serious in regions where
the annual precipitation is lowest, the mean summer temperature
highest, atmospheric humidity lowest, solar radiation most intense,
and air movement greatest during the growing season. That the
excessive drop of young fruit is in some way intimately connected
with extreme climatic conditions is indicated by the fact that in some
parts of southern California, where the drop is ordinarily not excess-
ive, the hot wave of June 15-17, 1917, during which a temperature
of 118° F was experienced in the Riverside and Redlands districts,
was immediately followed by a drop so severe that practically the
entire young crop of navel oranges was lost.

The experimental work from which the data were obtained was
earried on at Edison, Kern County, California. Edison comprises
1 This investigation, which is now in progress, was carried on in collabora-
tion with Professor J. Eliot Coit who planned the first series of experiments
and began the work in February, 1916. A joint-authorship paper correlating

this and other aspects of the June drop phenomenon is in course of prepara-
tion.

1917 | Hodgson: Abnormal Water Relations in Citrus Trees 39

a small colony of about seven hundred acres of orange orchard
located eight miles southeast of Bakersfield and surrounded on two
sides by typical desert of the southern San Joaquin valley, with its
characteristic semixerophytic flora. Extreme climatic conditions, as
above mentioned, are operative there but the Washington Navel
orange matures early and is of excellent quality, although crops are
small because the drop referred to is excessive.

WatTER RELATIONS AND ABSCISSION

It has long been recognized that abnormalities or irregularities in
the water relations of plants are often associated with the abscission
of various plant parts. Balls* was able to cause complete shedding
of leaves, flower buds, and bolls of the cotton plant Gossypium her-
baceum within four days by pruning the roots and so limiting the
ability of the plant to take up water. Lloyd* in his investigation of
the cause of abscission in the same plant came to the conclusion that
the causative factor lay in a steady decrease in the moisture content
of the soil in contact with the roots of the plant. This reduction
causes a severe tax on the power of the plant to maintain normal
water relations and results in fluctuations in the water content of
the aerial parts which, in turn, leads to abscission.

Although the work of Lloyd was performed in the humid southern
states, he makes the statement that ‘‘there seldom occurs a day on
which there is no minus water fluctuation in the plant.’’ He based
this conclusion not only on data derived from shedding records but
also on a study of transpiration rates, and water deficit in the leaves.
In connection with his observations on the effect of temperature in
causing acceleration of abscission, he came to the conclusion that ‘‘the
water deficit is the cause of the rise of temperature in the tissues and
that this constitutes the stimulus which directly leads to abscission.’’

Other evidence of the occurrence of marked deficits in the water
content of plant organs is not lacking. Livingston and Brown,‘ work-
ing with a number of plants growing near Tuscon, Arizona, found
that (with the exception of the true xerophytes as Covillea and
Prosopis) during the afternoon the leaves suffered a marked decrease
in water content which was made up during the night. This periodic

2 Cairo Sci. Jour., vol. 5, p. 221, 1911.

3 Trans. Royal Soc. Can., ser. 3, vol. 10, p. 55, 1916, see also Bull. Torr. Bot.
Club, vol. 40, p. 1-26, Jan., 1913.

4 Bot. Gaz. vol. 53, p. 319, April, 1912.

40 University of California Publications in Agricultural Sciences [Vol.3

diurnal condition of dessication has been found by Livingston and
Brown to serve as a check on the absolute transpiration and has been
termed ‘‘incipient drying.’’ Lloyd® independently obtained similar
results in his investigations on Mouquieria splendens and Mrs. Shreve®
established the same phenomonon in 1913 with Parkinsoma micro-
phylla,

Inasmuch as the genus Citrus is undoubtedly a mesophyte of
tropical origin and therefore grown in the interior valleys of Cali-
fornia under purely artificial conditions,’ it would naturally be
expected that the abnormal water relations above discussed might
obtain to an unusual degree, especially during the hot growing period,
when the ability of the plant to make up for excessive transpiration
is taxed to the limit. Citrus fruits are borne on wood of the current
season’s growth which ordinarily bears six to eight leaves on the same
fruiting shoot. Therefore, it seemed reasonable that under conditions
of excessive transpiration the leaves might draw on the water supply
of the fruits and thus bring about an abnormal water relation. With
the above considerations in mind it occurred to the writer that this
premature fall of the fruits might be due to irregularities or abnormal-
ities in the water relations between the fruits and foliage, resulting in
abscission in some way analagous to the shedding of cotton bolls under
the stimulus of a water deficit.

The method used in obtaining the data here presented consisted
in the main of simple moisture determinations of leaves and fruits of
various kinds taken at different hours of the day. The material was
gathered and quickly placed in weighing cups fitted with ground
glass covers. After weighing, the material was thoroughly dried
and then reweighed. For convenience in the case of fruits and large
leaves, the material was cut into small pieces. The calculations are
based on the dry weight of the material, except as otherwise stated.
The data obtained are shown in condensed form in table 1. The
figures shown represent averages of at least ten duplicate determina-
tions, and in most instances of more.

The data presented in table 1 show some very interesting condi-
tions. It is quite clear that, with the exception of the new succulent
growth, the young fruits are at all times higher in water content than
the leaves situated near them. These data also seem to leave no doubt

5 Plant World, vol. 15, p. 11, 1912.

6 Ann. Rpt. Dir. Bot. Res. C. I. W., Feb. 12, 1913, p. 81.

7 For a more complete discussion see Livingston, B. E., ‘‘A single index to
represent both moisture and temperature conditions as related to plants.’’
Physiological Researches, vol. I, No. 9, April, 1916.

1917 | Hodgson: Abnormal Water Relations in Citrus Trees 41

TABLE 1

AVERAGE MOISTURE CONTENT

Average water content
in per cent

Kind of material (Dry weight)
New leaves about two weeks old ........ LE ee a a a 242.0
Full grown leaves of current season’s growth ........................ 162.2
Leaves of one season’s growth—about one year old ............ 132.7
Leaves of two season’s growth—about two years old ........ 126.1
Leaves of three or more season’s growth. Over two years
rs Sep e Bap NRR F evaal Roa Mle TOE NS OE Rc 117.6
Leaves of current season’s growth. Gathered between
“ANN Sag plo Rap Se recep, Bee, Oe oe a oe Ce 164.9
Same gathered between 1 P.M. and 4 P.M. ..........-200-202---.20---200-0 157.2
Leaves of current season’s growth gathered from behind
aries DStween 9. A.M. A0d, DZ Wes soe ecseekpwteesnccecstccnctenverrnrenane 166.8
Same gathered between 1 P.M. and 4 P.M. .............----.------0-e00-+- 160.4
Fruits destined to subsequent abscission, one-third to three-
POtuns, Web. in diameter. ..c eet met ence tee ites 191.5
Fruits apparently normal gathered between 9 A.M. and 12 M.8 260.2
_ Same gathered between 1 P.M. and 4 P.M. ............2-2---2-:0-eeo- 247.7
Fruits destined to subsequent abscission gathered between
ee nS TRS a a eee ae lire. peas 9 |e 201.4
Same gathered between 1 P.M. and 4 P.M. ............--.---.0--000-0---- 179.2

of the fact that as the leaves grow older there is a progressive decrease
in water content.

It is also quite evident that a regular diurnal decrease in the water
content of leaves of the current season’s growth is manifest during
the afternoon. Such leaves averaged 164.9% in water content for the
period between 9 a.m. and 12 m. and only 157.2% for the period
between 1 p.m. and 4p.m. This difference does not appear significant
when viewed in the light of the large differences obtained by Living-
ston and Brown with some of their material. However, it should
be borne in mind that those authors were dealing, for the most part,
with much more succulent plants containing a large amount of water
storage tissue. Further, it should be noted that these figures are
averages, since the determinations on which they are based were not
made at the same hours. Individual pairs of determinations fre-
quently showed differences of as much as 25% to 30% in as short a
period as six hours. On June 5 at 2:30 p.m., with the temperature at
95° F and the relative humidity at 19%, the water content of leaves
of the current season’s growth was 144.3%. At 4 a.m. the next morn-

8 The fruits used for these determinations averaged a little larger than

those gathered in the forenoon and therefore would normally be somewhat
higher in water content.

42 University of California Publications in Agricultural Sciences [Vol.3

ing, with the temperature at 62° F. and the humidity 54%, the water
content of similar leaves was found to be 172.6%, showing a differ-
ence of 28.3%. This phenomenon is taken to indicate the presence of
incipient drying in citrus and is in full accord with the results of
the writers above mentioned as well as with those obtained by Lloyd.

Since the young fruits have a higher water content than adjoin-
ing leaves which, in turn, exhibit a diurnal decrease in relative water
content, the conclusion, a prior, that the leaves might possibly draw
on the water supply of the fruit during periods of excessive transpira-
tion seemed entirely plausible. If such is the case it would seem that
leaves so favorably situated should not show this daily variation, at
least to the degree shown in the leaves not so favorably situated. The
data in table 1 show, however, that the average difference in water
content of the two'sorts of leaves gathered in the forenoon and after-
noon 1s quite small. This is taken to indicate that if such leaves do
utilize the water supply of the fruits, the evaporating power of the
atmosphere is so strong that as fast as they receive this surplus water,
it is lost and thus causes no appreciable difference in their relative
water content.

The next step was to ascertain the water content of different kinds
of fruits, those destined to remain and mature, and those showing
indications of subsequent abscission. It is quite easy to distinguish
between the two, from a week to ten days before abscission occurs,
by the difference in their appearance. Exposed fruits destined to
drop exhibit a small yellow spot about the navel end several weeks
before the actual drop oceurs. This spot gradually extends and
spreads until at abscission it usually occupies at least half the area
of the fruit. In the ease of well-shaded fruits, the yellow color is
evenly distributed over the entire surface. A large number of mois-
ture determinations were made which showed that those fruits destined
to subsequent abscission averaged 59% less water than those fruits
destined to remain and mature. (See table 1.) The presence of this
condition in the fruits, especially when considered in connection with
the daily inerease at certain hours in the water deficit of the leaves
immediately behind them, seems to point to the possibility of the leaves
depriving the fruit of a part of their normal water supply. It cer-
tainly indicates an abnormal water relation.

Lemon growers prune their trees at all seasons of the year, even
while the fruit is still on the trees. It is a well established practice to
gather the good fruit from the excised branches immediately, in order
to prevent it from becoming flaccid. Inasmuch as the fruit, as ordi-

1917 | Hodgson: Abnormal Water Relations in Citrus Trees 43

narily picked from the tree, remains turgid for several months, it is
the common belief that the leaves draw the water out of the fruit when
the branch is severed from the tree. That this is exactly what does
occur, When the leaves are deprived of their normal water supply, is
shown by the following experiments :

Experiment 1— Two shoots bearing small terminal oranges of
approximately the same size and having the same number of leaves
and approximately the same leaf area, were taken to the laboratory,
placed on the table and allowed to dry under similar conditions except
that in one case the fruit was severed from the stem. All cut surfaces
were sealed with vaseline.

Within twelve hours a marked difference in appearance was
observed. The leaves on the shoot from which the orange was detached
were considerably shriveled while those on the other shoot remained
turgid and fresh. This difference became more pronounced as time
elapsed and in thirty hours a distinet difference in the appearance of
the fruits as well as leaves was visible. The detached fruit remained
firm and retained its dark green color and lustre while the attached
fruit was soft and flaccid and exhibited a dull green color without
lustre. This experiment was performed repeatedly with both oranges
and lemons with the same results. (See plate 12, fig. 1.)

As all the eut surfaces were sealed, it seems clear that the leaves
on the shoot with fruit attached actually drew on its water content
and that it was this supply of water which enabled them to remain
alive and fresh long after the leaves on the other shoot had withered
and died.

Experiment 2—Quantitative data on water content were desired
to substantiate the visible indications described in Experiment 1.
Therefore the latter was repeated several times and moisture determin-
ations on leaves and fruits were made at various periods. <A repre-
sentative set of such determinations is given in table 2:

TABLE 2

MOISTURE CONTENT DETERMINATIONS, TWENTY-FOUR Hours AFTER BEGINNING
OF EXPERIMENT 2

Weight of Weight of Weight of Water con-
container and same when material in tent per
Kind of material fresh material dry grams cent

in grams
Orange detached from branch...... 23.40 21.670 2.665 185.0
Orange attached to branch............ 23.585 22.367 2.075 142.1
Leaves from branch 21.831 21.805 AST 9 ee
with fruit removed 22.045 22.010 170 21.4 avg.

Leaves from branch 21.345 21.275 PY (: Cn ese
with fruit attached 20.604 20.477 284 73.7 avg.

44 University of California Publications in Agricultural Sciences [Vol.3

These data show that after twenty-four hours the leaves on the
shoot with orange attached contained an average of 52.3% more water
than those on the other shoot. They further show that the detached
fruit contained 42.9% more water than the attached fruit from which
the leaves had been drawing their supply. This is considered to be
conclusive evidence that in the case of excised branches the leaves
can draw water from the fruit.

Experiment 3—Two shoots in every respect similar to those used
in the previous experiments were treated in the same manner as those
of Experiment 1 and 2. These were then weighed at irregular inter-
vals until they had reached a constant weight. During the interim
they were kept on the laboratory table. The data obtained are found
summarized in table 3:

TABLE 3

WATER CONTENT DETERMINATIONS MADE AT IRREGULAR INTERVALS BASED ON
THE WHOLE WEIGHT

Shoot with orange attached Shoot with orange detached
Number Weight Loss in Loss in Difference Weight Loss in Loss in Difference
of hours in grams grams per cent in in grams in grams. per cent in
elapsed per cent per cent

0 ABT B So ge tly (Mies oe Sy fy Ge ee De re)

3 4.436 436 8.9 6 4.380 397 8.3 —
19 3.957 915 18.7 an 3.830 947 19.8 La
21 3.895 977 20.0 Sve 3.742 1.035 21.7 1.7
24 3.803 1.069 21.9 nes 3.607 1.170 24.4 2.5
26 3.683 1.189 24.4 aere 3.442 1.335 27.9 3.5
27 3.610 1.262 25.9 as 3.342 1.435 30.0 4.1
44 3.263 1.609 33.0 _ 2.911 1.866 39.1 6.0
49 3.047 1.825 37.4 as 2.682 2.095 34.8 6.4
51 2.920 1.952 40.0 =“ 2.575 2.202 36.0 6.0
91 2.125 2.747 56.3 en 2.008 2.769 57.9 1.6
96 2.053 2.819 57.8 cm 1.960 2.817 58.9 1.2
99 2.000 2.872 58.9 aah 1.935 2.842 59.5 6

116 1.921 2.951 60.5 aa 1.873 2.904 60.8 oO
119 1.894 2.978 61.1 id 1.852 2.925 61.2 ok
121 1.881 2.991 61.3 sak 1.844 2.933 61.4 :
140 1.825 3.041 62.5 4 1.807 2.970 62.1
146 1.797 3.075 63.1 m3) 1.783 2.994 62.6
162 1.774 3.098 63.5 6 1.770 3.007 62.9
186 1.736 3.136 64.3 8 1.743 3.034 63.5

195 1.717 3.155 64.7 9 1.726 3.051 63.8
211 1.705 3.167 65.0 1.1 1.720 3.057 63.9
218 1.695 3.177 65.2 1.0 1.710 3.067 64.2
260 1.666 3.206 65.8 ast 1.686 3.091 64.7
285 1.652 3.220 66.0 PL 1.675 3.102 64.9
306 1.642 , 3.230 66.2 1.1 1.664 3.113 65.1
330 1.631 3.241 66.5 pa! 1.652 3.125 65.4
525 1.613 3.259 66.8 1.0 1.631 3.146 65.8

1917 | Hodgson: Abnormal Water Relations in Citrus Trees 45

The data in this table indicate that the amount of water in the
fruit available for use by the leaves was sufficient to maintain the
latter alive for approximately 50 hours after the shoot was cut from
the tree. It is further evident that when three hours had passed the
leaves on the shoot with fruit attached had not yet begun to take water
from the fruit to any appreciable extent because the shoot with fruit
detached shows less water loss than the shoot with fruit attached.
However, this condition was soon reversed and the leaves began to

Fruit Detached

20 40 60 80 100 120 140 160 180 200 220

Fig. 1. Showing the difference in per cent of water loss of shoot with
orange attached and shoot with orange detached. The water loss curve of the
shoot with fruit detached is considered as normal. Ordinates represent differ-
ences in per cent of water loss, abscissae, the time elapsed in hours. Water
content calculated on basis of fresh weight.

draw on the water in the fruit while the leaves to which no water was
available from the fruit showed indications of wilting.

That shortly after 50 hours had passed death occurred in the
leaves of the shoot with fruit attached is shown by the rapid increase
in the amount of water loss. This was undoubtedly due to inereased
permeability of the cytoplasmic cell membranes after death. After
50 hours the difference in water content of the two was 18.3% in
favor of the shoot with fruit attached. However, from this time on
until both had reached a constant rate of water loss (after about 200

46 University of California Publications in Agricultural Sciences [Vol.3

hours), this shoot lost water more rapidly than the shoot with fruit
detached. These relations are very clearly shown in figure 1. The
normal water loss curve is illustrated in figure 2.

Experiment 4—A forked twig bearing a small terminal fruit on
each branch was selected and eut. The fruits were immediately im-
mersed in water and the shoot tied to a support in such a fashion
that all the leaves were exposed to the air, the fruits alone being
immersed. One orange was now removed by cutting it under water
and all eut surfaces were sealed. The two fruits remained under

48

40

24

16

50 100 150 200 250 300 350 400 450 500

Fig. 2. Showing the general type of water loss curve of a shoot detached
from the tree, including detached orange. Ordinates represent water loss in
per cent and abscissae, the time elapsed in hours,

water. The container and support were then placed on a bench in
the shade in the open air and left for fifteen hours, at the end of
which time moisture determinations were made on the fruits.

TABLE 4
MOoIsTURE DETERMINATIONS AFTER FIFTEEN HOuRS
Weight of Weight of Weight of Water con-
container and same when material in tent per
Kind of material fresh material dry in grams cent
in grams grams
Detached orange ...............-.--- 24.680 21.435 3.330 206.9

Attached orange ...........-.-.----- 23.210 21.773 2.570 126.8

1917 | Hodgson: Abnormal Water Relations in Citrus Trees 47

The data in table 4 show that at the end of fifteen hours there was
a difference in water content between the two fruits of 80.1%. There
seems to be no way of accounting for this large difference other than
that the leaves had actually drawn the major part of it at least, from
the attached fruit.

Water TRANSPORT StupIES BY MEANS OF DyE Sturr SouuTions

Experiment 5—Bearing the foregoing findings in mind, it seemed
desirable to determine something of the nature of this reversal of
normal water flow by means of dye solutions. Accordingly a shoot
bearing a terminal fruit was cut from the tree and the orange pared
away at the apical end to open the tracheal elements and admit the
dye.® This paring was done under the solution to prevent the entrance
of air bubbles. Water soluble eosin was used. The orange was
immersed in the liquid for a half hour, after which the shoot was
split open. The tracheal tubes throughout all parts of the leaves,
stems and fruits were found to be strongly stained.

Experiment 6—It seemed desirable to simulate the actual situation
on the tree as nearly as possible and the following experiment was
designed to accomplish this. A crooked fruiting branch bearing a
number of small lateral shoots and leaves, and one terminal orange
was cut under water. The cut end was kept under water and the
branch so supported that the fruit was immersed in an eosin solution.
The apex of the orange was then pared as described above. The
branch then rested with its basal end in water and the vascular
bundles of the fruit open to eosin at the other end of the branch.
(See pl. 12, fig. 2.) If we substitute for the water container the con-
ducting system of the tree, and for the watery solution of eosin the
developing fruit high in water content, we have very similar conditions
to those existing in the experiment, save for the fact that the fruit is
not open to the air and the conducting system bears a certain relation
to the rest of the tree.

The experiment was begun late in the afternoon and the branch
left outdoors over night. At 8 o’clock the next morning the leaves
were examined and found to be very fresh and turgid. Indeed they
were noticeably much fresher in appearance than they had been the
evening before. On careful examination absolutely no trace of eosin

9It should be stated here that the Washington Navel orange is in reality
a double fruit, with a small secondary orange within a large primary fruit.
This interior fruit constitutes what is known as the navel and it possesses an
independent vascular system of its own which traverses the central pith of

the primary fruit before ramifying through the secondary orange. This central
pith thus acts as the stem to the small fruit.

45 University of California Publications in Agricultural Sciences [Vol.3

could be found in any part of the shoot. Samples of leaves for mois-
ture content determination were taken at 8:30 a.m. Although remain-
ing in the shade the leaves showed at 12:15 p.m. distinct evidence of
wilting and upon examination, eosin staining was found in the petioles
of every leaf on the shoot, with the exception of a few on the extremi-
ties of the side branches. At 12:30 p.m. samples were taken for
moisture determination.
TABLE 5

MoISsTURE CONTENT OF LEAVES TO WHICH WATER WAS AVAILABLE FROM
Two SOURCES

Weight of container Weightofsame Weight of mate- Average water

and material in when dry in rial in grams content in
Hour picked grams grams per cent
8:30 A.M. 21.967 21.617 SOn 1°) mee
23.455 23.162 480 160.8
12:30 P.M. 21.914 21.659 @00- °Y ) pe
21.552 21.345 .382 121.6

The data obtained in this experiment show that during the night,
when the draught of the atmosphere on the water supply was low, the
leaves were able to maintain themselves in a normal condition by
using water from the base container. This is evidenced by the normal
water content of the leaves in the morning, as well as indicated by the
fact that no eosin whatever was drawn back, although the vascular
bundles were open to its entrance. However, as the atmospheric
evaporating power increased during the forenoon, it became more and
more difficult for the leaves to obtain requisite amounts of water
through the conducting system in the normal way. At a point near
12 m. the leaves became unable to obtain enough water in this fashion
and they began to draw on the aqueous solution of eosin. The shoot
was now drawing water from both ends to satisfy the demands of the
transpiring leaves. But the atmospheric pull for water became so
severe that even this double supply did not suffice to maintain the
water content of the leaves at normal. The water deficit began to
increase and continued until a condition of actual wilting resulted.
Between 8:30 a.m. and 12:30 p.m. the leaves decreased in water con-
tent by 39.2%, although both ends of the shoot were immersed in
water.

From the evidence above presented it seems clear that under con-
ditions favorable to rapid transpiration it is entirely possible for the
leaves of citrus trees, at least, to draw water back from the young
fruits. Moisture determinations of fruits under such conditions
showed a considerable decrease in water content and indicated that

1917] Hodgson: Abnormal Water Relations in Citrus Trees 49

this water is utilized by the leaves. Indeed, almost exact quantitative
results were obtained, the percentage of water loss of the fruit being
approximately equal to that gained by the leaves. (See Experiment
2.) Dye stuff experiments have shown that there exist no physical
difficulties for such procedure. It then remained to determine whether
this phenomenon actually occurred in fruits on the tree. For this pur-
pose the procedure of the previous experiments was used, namely,
moisture determinations and water transport studies by means of dye
stuff solutions. However, the evidence here is not so conclusive, as
all the experimental work was necessarily performed on shoots in
situ, which introduces a number of uncontrollable adventitious vari-
ables, as has been well pointed out by Dixon’? in his criticism of trans-
piration measurements performed on shoots detached from the tree.
The influence of the remainder of the tree is admittedly an unknown
quantity. Nevertheless it is believed that the data obtained are
strongly indicative of conditions as they exist.

From table 1 it will be seen that there exists a considerable differ-
ence in water content between those fruits, destined to remain and
mature when picked before and after noon. Fruits of this sort
gathered in the morning averaged 12.5% more water than those
gathered in the afternoon. As is mentioned in the footnote to table 1
this difference is probably considerably smaller than it should be on
account of the larger size of the fruits used in the afternoon determin-
ations. That this same condition obtains in those fruits destined to
subsequent abscission is also shown in table 1. In this case the difffer-
ence is 22.2%. There are several ways in which a decrease of water
content in the fruit can be explained: (1) the water is actually
drawn back from the fruits by the leaves; (2) the normal supply to
the fruits is considerably reduced by being appropriated by the leaves
before it reaches the fruits; or (3) the transpiration ratio of the fruit
to the leaves is markedly increased. If the fruit possessed no stomata
and did not transpire, the first condition must hold. However, the
fruit does possess stomata in some numbers and is actively transpiring
at the same time as the leaves. Therefore it seemed advisable to make
a cursory comparative study of the number of stomata per unit of
area on the fruits and leaves and also of the ratio of transpiring area
of the fruits and leaves situated immediately behind them. While
the young fruit possesses stomata even before the style is exfoliated,
stomatal counts showed that the number is comparatively small, rang-

10 Transpiration and the ascent of sap in plants (London, MacMillan, 1914),
pp. 120-125

50 University of California Publications in Agricultural Sciences [Vol.3

ing between 50-100 per square millimeter as compared to 300-450 per
square millimeter on the leaves. Measurements of the leaves situated
within six inches of the fruit showed that, in addition the leaf area
immediately behind the young growing fruit is larger than the area of
the fruit until it reaches approximately two inches in diameter, after
which falling of the fruit is comparatively rare. Therefore, it seems
highly probable that the transpiration of the fruit as compared to
that of the leaves situated immediately behind it is an almost negligible
factor and it appears reasonably certain that either water is actually
drawn back or that the normal supply is decreased.

Considering these two possibilities, the first merits more considera-
tion as it is supported by proof which, though not absolute, is at least
presumptive evidence of a strong enough character ; while on the other
hand the second possibility, agreeing though it does with the most
recent theory on sap movements in plants as put forth by Dixon, is
still a theoretical consideration. According to this theory, which pos-
tulates strong tensions existing in the ascending water columns, no
assumption of an actual reversal of the current is necessary in order
to explain a decrease in moisture content. During normal conditions
the relation between the tensions existing in the water columns leading
to the fruits and those leading to the leaves is such that both organs
receive an adequate water supply. The tension existing in any one
of these water columns is a function of the transpiring force existing
in the transpiring plant organ as modified by atmospheric conditions.
Therefore, as these transpiring forces vary, the tensions vary. Trans-
piration from the leaves, for reasons pointed out above, is subject to
much greater variation than that from the fruits. Therefore during
periods when evaporation is greatly accelerated the tensions in those
water columns leading to the leaves are greatly increased and as a
consequence more water is drawn to them. As the source of supply
in the conducting system is practically constant, the amount in the
fruits is thereby reduced and this results in a decrease of relative
water content of a magnitude conditioned by the transpiration of the
fruit.

However, it should be noted that the data in table 1 show a
decrease in absolute water content of the fruit of 15% to 20%, a loss
of considerable magnitude. There are only two ways in which such
a decrease in absolute water content can take place: (1) the water
is lost by transpiration from the fruit, or (2) it is drawn back by
the leaves. But since the fruit possesses a very small stomatal area

1917 | Hodgson: Abnormal Water Relations in Citrus Trees 51

as compared with the leaves and, moreover, it is highly probable that
a large percentage of this area is non-functional, being obstructed
by accumulations of a resinous nature, there is small lkelihood for
absolute loss of water in this manner to the extent noted. Hence
there seems but one way to explain it and that is by movement back
from the fruits.

Evidence of an indirect nature pointing to the same conclusion
lies in the fact that there are some indications that abscission of a
certain proportion of the young fruits is directly due to the influence
of hydrolysing enzymes secreted by certain saprophytic or facultative
parasitic fungi always found present on the shriveled style and fre-
quently in the proliferations of the navel. Such enzymes in order to
act on the abscission layer must be drawn back through the vascular
systems of the fruit into the pedicel where this layer is located.
Investigations on this point are now in progress.

Experiment 7—Three similar fruits were selected on different
parts of a tree; on one of the lower branches in the shade, at a height
of four feet, and in the top of the tree in full sunlight. At noon each
fruit was pared so as to admit entrance of a solution and then plunged
quickly into a small vial containing a watery solution of eosin. These
vials were securely tied to the shoot and left suspended for two hours.
At the end of that time, on cutting leaves from these shoots, eosin
staining was found in the vascular systems of all. On examining back-
ward toward the tree, eosin was found as far back as thirty centi-
meters. This experiment was repeated a number of times both at
Edison and at Riverside and uniformly gave the same results, although
much less marked at the latter place. In every case the backward
movement of the eosin solution was at its maximum during the
afternoon.

Cutting the ends of branches in situ under a watery solution of
eosin was tried at different times of day and gave similar results.
This experiment was performed at Edison, Riverside and Indio. At
the latter place, with the temperature at 116° F and the humidity at
8% the eosin solution traveled backward at the astonishing rate of
30cm. per minute at 6 p.m. Similar results were obtained using
Eucalyptus rudis as material. In fact with long slender poles of
Eucalyptus tereticornis at Edison, such a remarkably rapid backward
flow of eosin was observed (105 em. in one minute) in the afternoon
as to compel the conclusion that after all, the force responsible for
this movement under such conditions must be negative pressure pro-

52 University of California Publications in Agricultural Sciences [Vol.3

duced by rapid transpiration rather than a mere difference in osmotic
concentration of the sotutions involved. Moreover, negative pressure
produced by transpiration would seem a more plausible explanation
of the results obtained by Chandler'! with tomato plants and by him
attributed to osmosis. For as Dixon’? has pointed out ‘‘it is quite pos-
sible for the solvent, water, to be in a state of tension, 1.e., at a negative
pressure, while the dissolved substance may be at a positive pressure
and be active as a distending force in the cell.’’

These experiments, it is believed show that, during the afternoon
at least, strong negative pressures exist in the water columns of citrus
trees under the climatie conditions here considered and that the young
developing fruits are deprived periodically of a part of their water
supply by excessive transpiration from the leaves.

During the June-drop period of 1916 a number of holes were dug
in various parts of the Edison orchard to a depth of six feet and
moisture determinations made at various depths and on all sides of
the tree. The moisture content was found to range between 5%-6%
just before irrigation and between 10%-12% soon after irrigation. A
fruit grower observing this soil and the vigorous growth of the trees
would hardly conclude that the trees were suffering from lack of
water. However, the specific effect of variations in the moisture con-
tent of the soil on the transpiration rate and water content of orange
leaves has not yet been carefully determined. While there is little
room to doubt that the above-ground complex is more important in
influencing transpiration than the below-ground complex, still it is
entirely possible that this abnormal water deficit in the leaves and
fruit may be more easily induced by sudden changes in the climatic
complex under conditions of a deficient moisture supply in the soil or,
what amounts to the same thing, an inhibition of the normal absorption
due to lack of sufficient aeration or excessively high soil temperatures.
Nevertheless evidence is not lacking that marked changes in air tem-
perature and humidity may be sufficient to cause abscission of young
fruits even though the soil moisture conditions be ideal. Such appar-
ently is the explanation of the heavy drop of Washington Navels
already referred to, which occurred over most of the citrus districts
immediately following the excessive temperatures of June 15-17, 1917,
when the mereury reached 110-120° F in many parts of the citrus
district south of the Tehachapi mountains.

11 Mo. Sta. Res. Bull. 14, pl. 13.
12 Loe. cit. p. 140.

on
iP)

1917 | Hodgson: Abnormal Water Relations in Citrus Trees

CONCLUSION

This paper deals with one phase of an investigation of a so-called
physiological disease, June drop of the Washington Navel orange.
An excessive dropping of the young fruits has been experienced for
years in the dry interior valleys of California and Arizona.

An abnormal water relation is found to obtain periodically in
citrus foliage and in the young fruits during the hot growing season
in these regions. A diurnal decrease in water content of the fruits
oceurs during the afternoon and is accompanied by a considerable
increase in the water deficit of the leaves. Negative pressures of con-
siderable magnitude are found in the water columns of citrus trees
under these climatie conditions. These attain their maximum during
the afternoon. The dropping of the fruits appears to be most severe
where the above mentioned water relations are most abnormal.

Inasmuch as in the ease of certain other plants the abscission of
young fruits has been shown to be due to abnormal water relations it
is suggested that such may be the ease here.

In conclusion, the writer wishes to acknowledge his indebtedness
to Professor J. Eliot Coit, under whose supervision and with whose
assistance a large part of the experimental work was done; also his
obligations to Professor Charles B. Lipman for his kindly interest in
the investigation and for his many useful suggestions, and to the
Edison Land and Water Company for their kind and courteous
cooperation.

PLATE 12

Fig. 1. Showing extent to which the leaves can draw on the water in the fruit.
Both shoots were cut at the same time and had approximately the same leaf
area. All cuts were sealed with vaseline. The fresh-appearing leaves on the
shoot at the left have maintained themselves at the expense of water in the
fruit. Note the difference in reflection of light from the two fruits. See
Experiment 1.

Fig. 2. Photograph illustrating an orange shoot so arranged as to be able to
draw water from one end and eosin solution through the pared apex of a small
fruit at the other. In spite of this double supply a large water deficit occurred,
and eosin was drawn back from the container on the right to the leaf next to the
water container on the left. See Experiment 6.

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3

[HODGSON] PLATE 12

UNIVERSITY OF CALIFORNIA PUBLICATIONS
IN

AGRICULTURAL SCIENCES
Vol. 3, No. 4, pp. 55-61 November 27, 1917

A NEW DENDROMETER

BY
DONALD BRUCE

There is a growing demand for a satisfactory dendrometer, or
instrument which will measure the diameter of trees at points out of
reach from the ground. An indication both of the wide demand and
of the requirements which such an instrument must meet may be
gained from a consideration of the following instances.

In certain regions, United States Forest Service timber estimators
have made use of a volume table based on a diameter measurement
at the top of the first sixteen-foot log instead of at the conventional
breast-high point. This was on account of the abnormal form of the
badly burned butts, which made a lower measurement both uncertain
and a poor index of volume. Considerable trouble resulted through
inability to check the ocular estimates of diameters except by uncer-
tain methods of measuring at breast height and subtracting the esti-
mated taper. For such cases there is needed a dendrometer of
moderate precision, large range, considerable rapidity, hghtness, and
portability.

Many volume tables are based on a measurement of height to a
certain fixed cutting limit, such as six, eight, or ten inches top
diameter. From the ground it is often more difficult to identify this
point than it is to estimate its height, and considerable errors result.
Instruments of only a small range of sizes are needed, and in fact for
a given volume table, or a consistent set of tables, an instrument that
can be fixed and adjusted for a single diameter would serve the
purpose.

Other volume tables are based on height to the limit of merchant-
ableness. This limit, however, varies widely in different regions, even
for a single species, and to use such a volume table accurately one
must know the top diameter corresponding with each value of the
table and estimate heights accordingly. Exactly the same type of in-

56 University of California Publications in Agricultural Sciences [Vol.3

strument is required as in the last case, save that a slightly larger
range of diameters is needed and a fixed adjustment for a definite size
is not adequate.

Many Pacific coast volume tables are based on diameter, height,
and taper. While the first two factors are measured, at least occasion-
ally, the last is usually a matter of guesswork entirely. The instru-
ment needed to strengthen this part of the work is a dendrometer
possessing the qualities above mentioned, and in addition one which
works independently of distance, since both horizontal distances and
heights will usually be but roughly approximated.

In many scientific studies of growth on permanent sample plots in
this country periodic measurements of diameters breast-high and

Fiaad rer

<q--—-—--- — Direc thine of Sight

Fig. 1

heights are being secured, and growth in volume is being calculated
from these data by means of a single volume table for each species.
As a result, whatever growth results from a change in tree form is
being neglected. A dendrometer is needed of considerable precision,
but not necessarily so portable or rapid in action as in the previous
eases. Its range in most cases need not be great, since the more
important growth problems are connected with second-growth timber
or, at least, with trees below a certain diameter limit.

Schiffel’s formula for obtaining volume has not been sufficiently
tested for most American species, but it is regarded as probably having
a high value in many eases. It requires a measurement of diameter
at a point half way up the bole, and hence a dendrometer. The
qualifications of a satisfactory instrument will naturally depend on
the character of the work being done.

All these instances indicate that it is not due to the absence of a
real need that dendrometers are practically unknown in America. It
seems obvious, rather, that no existing type satisfies the conditions

1917} Bruce: A New Dendrometer 57

above outlined. The following pages describe an instrument based on
a somewhat different principle from those previously devised, which
will be seen in a large measure to meet these requirements.

It consists essentially of a straight arm upon which are mounted
two small mirrors, both at an angle of 45 degrees with the axis of the
arm, parallel to each other and facing in opposite directions (see
fig. 1). One mirror is fixed at one end of the arm, while the other
is mounted on a slide which travels along the arm. Graduations
permit a direct reading of the distance between the mirrors.

The principle is indicated by figure 1 which shows the relative
position, as seen from above, of tree, observer’s eye, and of the instru-
ment when in use. It will readily be seen that the instrument is
closely akin to the ordinary calipers in principle, except that for the
parallel fixed and movable arms of the calipers are substituted two
parallel lines of sight. The direct line of sight passes just above the
upper edge of the fixed mirror from eye to one edge of the tree, while
the indirect line of sight is reflected in each of the two mirrors to the
other edge of the tree. That the two lines of sight are parallel and
hence that the distance between the mirrors is equal to the diameter
of the tree is too self-evident to demand geometrical demonstration.

‘In use the observer holds the dendrometer arm horizontal (if the
tree is in the normal vertical position) with one of the mirrors in line
between his eye and the left-hand edge of the tree at the point to be
measured. He then catches the reflection of the second mirror in the
first, thus bringing the arm into a line perpendicular to the line from
eye to tree. By sliding the second mirror in or out, the right-hand
edge of the tree will become visible in it. The adjustment is now
continued until the left-hand edge as seen directly and just above the
fixed mirror, and the right-hand edge as seen indirectly through the
two mirrors, are in a straight line, one immediately above the other.
The distance between the mirrors as read from the graduations on the
arm is then the required diameter.

The advantages and disadvantages of the instrument are evident.

a. It is direct reading.

b. The distance from the observer to the point observed does not
have to be determined.

c. As a result, the instrument is rapid in use.

d. It may be set for a given diameter, regardless of distance.

e. It is light in weight and of convenient shape for carrying;
it is more portable than a pair of calipers of the same range.

58 University of California Publications in Agricultural Sciences [Vol.3

f. It will measure only a moderate range of sizes.
g. While very accurate for a hand instrument, it is not capable
of extreme precision.
The reason for the last two statements will be explained in the fol-
lowing pages.

It is evident that it will meet quite well the requirements already
outlined, It fails at two points only—its moderate range might pre-
vent its use in very large timber, and its lack of absolute accuracy
may militate against it for very precise, scientific work.

Most of the errors of such a dendrometer are easily kept negligible.
Of course at any considerable distance, small variations of diameter
are imperceptible and cannot be measured. Since the minimum visual
angle for normal eyes is one minute, two-tenths of an inch is the
smallest variation recognizable at a distance of fifty feet. This con-
sideration applies equally to all dendrometers which do not involve
telescopic observations, and the use of a telescope at once means a
heavy and awkward instrument.

If the arm is not held at right-angles to the direct line of sight,
the graduations on the arm will no longer measure the distance between
mirrors along the indirect sight line, nor will this distance agree with
the desired diameter. However, this error can never be large since,
unless the arm is in approximately the correct position, the second
mirror cannot be seen at all in the first, and to center its image
therein is an instinctive proceeding. For more precise work, however,
an additional aid may be afforded by vertical lines scratched into the
backing of each mirror at its exact center, which are to be brought
into apparent coincidence when the instrument is in use. An alter- -
native method of obtaining the same result is to mask the fixed mirror
with dark paper until, at the most convenient distance from the eye,
the whole of the movable mirror can just be seen in it. The position
of such a mask is shown in figure 2, A.

A rotation of the dendrometer about the axis of the arm will, of
course, raise or lower the indirect sight line running from the instru-
ment to the tree. Here again, however, unless the position is essen-
tially correct, the image of mirror 2 cannot be found in mirror 1. The
error resulting, moreover, is merely the amount of taper that occurs
between the points observed by the direct and indirect sight lines,
which is usually negligible.

Of course, if the two lines of sight are not parallel, serious errors
will result. This depends on having the two mirrors parallel and is

1917] Bruce: A New Dendrometer 59

in part a matter of adjustment. Two opposed adjusting screws must
therefore control the rotation of one of the two mirrors. Adjustment
is simple. Some target of known diameter or breadth (a sheet of
paper against a dark background will serve) is observed with the
instrument set at the corresponding diameter. The mirror is then
rotated by its adjustment screws until the two edges appear in line.
This process is delicate, but neither complicated nor difficult.

of Ari

[CAV eee) Mee vel, Ee, be
Scale for A,B. andC
Scale for DE, andfF
LE - Slide, Elevation F- Slide, fromend
a.—Arm., e.—Fixed mirror and support.
b.—Stationary mirror platform. f.—Adjustable mirror and support.
e.—Sliding mirror platform. gg.—Adjustment screws.
d.—Slide. h, i.—Springs.
Fig. 2

The one error which dominates all others is that due to a failure
of the arm to be absolutely straight. This is unfortunately a matter
of instrumental construction and not of adjustment, and the difficulty
of making this arm straight is surprisingly great. It is obvious that
almost imperceptible deviations will result in slightly diverging or
converging sight lines and in increasingly serious errors in the
diameter readings, as the distance at which the measurement is taken
is lengthened. In the instrument described the maximum error from
this source is .6 inch when used at fifty feet ; it is doubtful if materially
better results are obtainable. This is not excessive. Even with a transit
read to the nearest minute, the diameters fifty feet away can be read

60 University of California Publications in Agricultural Sciences [ Vol. 3

but to the nearest .2 inch. With a hand instrument of the common
type which involves the measurement of the angle between two sight
lines it is difficult to provide for an accurate reading closer than to
the nearest 10 minutes. This means that at the same distance 1.7
inches would be the minimum recognizable difference in diameter.
Figure 2 shows the details of construction.’ a-a, of A, B, and C,
is the straight arm which is made of a casting of aluminum alloy.
The straight edge is the back surface of the slot which is recessed into
the upper surface of the arm, as is best seen in the cross-section. This
cross-section is perhaps unnecessarily heavy, but was so designed to
insure as perfect a straight edge as possible. In this slot travels the
slide d shown in detail in D, EF and F, which are drawn to twice the
scale of A, Band C. This slide is equipped with two springs, h and 2,

which hold it against the back and upper surfaces of the slot. Upon

tierra
pecbbpatan

phangeens Re ay

uw

iets
Fig. 3

it is mounted the mirror platform, and mirror e turned to an angle
of 45 degrees to the axis of the slide. At the end of the arm a second
fixed mirror platform, b, is mounted on which is the second mirror,
f, which can be adjusted by the two opposed adjusting screws, g-g.
This mirror is shown with both center line and mask, though both are
hardly necessary. The scale is readily seen in A. This is read by
means of the small arrow engraved on the side of c, as shown in both
A and E. In A the reading, for example, is 12.2-.

If the weight of the instrument, slightly less than 27 ounces, 1s
found objectionable, it would probably be safe to lighten materially
the cross-section of the arm by reducing both the depth of the down-
ward projecting ribs and the thickness of the lateral walls. The
mirrors also, as shown, are very generous in size, and might be
reduced to about two-thirds the indicated dimensions without intro-
ducing any serious difficulties through restricting the field of vision.

1To Mr. V. Arntzen of the Civil Engineering Laboratory of the University
of California, credit is due for the major part of the detail of design.

1917 | Bruce: A New Dendrometer 61

The instrument shown has an arm eighteen inches long and will
read diameters from three to seventeen inches. A longer arm is, of
course, possible, but at about thirty inches a point is reached at which
the adjustment of the sliding mirror when held in working position
would become awkward. This may then be taken as the practical
limit, unless some modification of the principle be adopted. This
range will be sufficient for a great deal of the work to be done. If
less accuracy is required, measurements of double this size can be
secured by taking the center of the tree as the target for the direct
line of sight, instead of the left-hand edge, and bringing the reflection
of the right-hand edge in line with the center point. This operation
can be performed more accurately than might at first be supposed,
and the method, while rough, is probably quite adequate for work in
connection with the Pacific coast volume tables already mentioned,
in which taper is a factor.

A quick field test of the parallelism of the sight lines consists in
measuring the same diameter at two different distances. The readings
should, of course, be identical, or rather, since a small observational
error is unavoidable, as nearly identical as would be two consecutive
measurements from a single position. If an error is found and it is
not convenient to make the proper adjustment it may be simply and
quite accurately allowed for, by taking consecutive observations at
two known distances. For example, suppose the first reading is 14.8
inches and the second reading taken at one-half the distance is found
to be 14.4 inches. Since the error is proportional to the distance, a
reduction of the distance to one-half must also reduce the error to
one-half. The reduction in error is .4 of an inch, the total original
error must have been .8 of an inch, and the correct reading is therefore
14.8 — .8 —14.0 inches. Where the errors are small, the major por-
tion of them can thus be eliminated, even if the distances are estimated
instead of measured.

A modification of this type of dendrometer is suggested for timber
survey crews which are using volume tables to a fixed top-cutting limit
such as six or eight inches. All that is necessary in such cases is the
pair of parallel mirrors, one of which is adjustable, mounted six or
eight inches apart on any light but rigid base not affected too readily
by changes of temperature or humidity. By thus eliminating the
straight edge and slide of the instrument herein described, the most
serious source of error will be eliminated and the cost largely reduced.

rik ate rie +

l%
* 2 Saeutee O e
Vis rk eaeees Pilea

————

UNIVERSITY OF CALIFORNIA PUBLICATIONS a

ij J
IN
AGRICULTURAL SCIENCES
Vol. 3, No. 5, pp. 63-102 November 30, 1917

TOXIC AND ANTAGONISTIC EFFECTS OF
SALTS ON WINE YEAST (SACCHAROMYCES
ELLIPSOIDEUS)

BY
S. K. MITRA

CONTENTS

PAGE
ns CesT tied ai CRUDE SS eens Deae FIRS ARPRYILI Cot ope p rs 2 soe an et ee en eee 64
Se R MRIS AIAN NIE Fee pc Se he a ate Oa osc vnc naan pepndatin Sa 65
Rae AE, DOE UOT Gel ULC ac ee a ce eo ag ctw and ucn so 65
WoL EL tote cte lh 76a near Ad ete oats en <I, 0 ee ee ee one Teme nS cod a 66
Methed of determining the activity of yeast -....c2.........-.--0--.--seteeceessesseeneees 67
EROS | She i A destinies, Axi FO Reteshoal Vodlte Lic Ce ec eS OY ed SRL MMeetoeh 68
STEELE BE gaa ite a CR cr =) cr: Sea eens i. ol) Sneek RES Sa LAO RN 68
Combinations—Antaponistic’ eMecte, 610 eee c a ate ccc recon 68
SE em getva Louies 100.11: AMEN mee OUR ce Sal Ratt yee ee ore meNp eee a 68
OR OSB YASE AEC CATT YA NE ea GRO MNG 8g se Oa ca toon em 68
Experimentation with single salts—Toxic effects -.........2...2..22..-:-2:000000eeeeeeeees 68
Beariea tat papain eiloride |e ne et eo pie 69
eerie 1 Mawaeaiiine Chloride). 0 oe Be i nent 71
SE TI NESE CY) et Ca ot 00 C: aaa ete Ra) PRUNE NS Sth i eso. ee 72
ae SE OO SSS s angered 00 Tors Cera Neo oc, lot peor see 8 Ly eh eR en 74

Series V. Effect of the toxicity of salts on microscopical appearance of
vy NC. a aed CE RE op 2. see er rn eee 75
Experimentation with combinations of salts—Antagonistie Effects -........... 80
Series VI. Antagonism between Magnesium Chloride and Calcium Chloride 81
CN SAS RLS AEA Foe OOOO IMR RE aE tt 3 8 Sa CNS ee ee ee 83
EC I: Epa eat Seat UR eel Oe COE a Ee pms 83
ey a a) IRA cana Ry eR PAE, eed POE LEES s n= 1 Se a cae ere eee 84
Series VII. Antagonism between Potassium Chloride and Calcium Chloride 84
SSL Rar oe aioe = eee eS ES re eee ae 86
SG ONC 1 ceo ae MeN Ok Sart th asnecsncnsentnsrenenenaneatmncs 87
CRUG SV 2. 0, Sea OR ee Renee SEO eRe ee Les Aono ee ee, ee 87
Series VIII. Antagonism between Magnesium Chloride and Sodium Chloride 87
Ee PIII psc Spt rel wien tipineee ag indo ener nnnenberinannesecnenenine 89
CaP yh LT | ARR SR A so ape me, aes SNS Oe er 89

(i) De eS yt Sac ge oon ek ee SPE Aen sto Oe ee ne Oo eee

64 University of California Publications in Agricultural Sciences | Vol. 4

PAGE
Series LX. Antagonism between Potassium Chloride and Sodium Chloride 90

CY FUER” vcs biccsccicccansndebcdoasetauinst ase cicemcdidaeeiitnariteteddentedae 90

Cp he 0 Ve ences ee are be CM PE 90

Coy Demande doconcn ckaneieue medias ace 92
Series X. Antagonism between Potassium Chloride and Magnesium Chloride 92
GR UN ae ee icant compenioteal denen + tie obicicaghodcaaepatebnaeeaaae 94

(b) Animals ........... ee a ee eee Son Dee Bee sisidealpscalepaniihana tea 94

(c) Bacteria ......... tases uihisae Senha ebaapiced sousoaliices ie ad ausaaen slsietcneipy-alace\euenietoasiniaaniiecle 94
Series XI. Antagonism between Calcium Chloride and Sodium Chloride .... 94
Con) PR aS scree sere dein sss is ow ev ea eee oe 95

4 DRE Ne RRS 2” ES EY sae Te Se ae aoe eae Meer ee Soe eh A ae MS 96

Ca) Te eras esac svev be nnecectdciecteep asin ca ag cnmaceonciebtes waliaatecdaalion comin Map 96
Relative antagonisms of various combinations ................----:::e::seeeeeeeeeeeeeeeeees 97
LUN So ghee eee See ete Bey Bue aS aie armen Oe aig cep ih Oer ec sounin Aan eNrnnmpeb repr reek ames 2.8 E ae) 2 99
Part A. Toxic effects of simgle: salts) qo.ccnsccscpicortenecsssnnccgxispenexcientegg ieee 99
Part B. Antagonistic effects of combinations of salts ~...................-.-.-.--- 99
MP Bet |: ac aie Be Senet MESES EASE ec ete: Maes SPR oR ERE. 101
Part A. ‘Toxie effocte- df einaia patie se ee hee besten 101
Part B. Antagonistic effects of combinations of salts .................-.----------- 101

INTRODUCTION

Most of the published studies of wine yeast deal with its activities
as related to wine making. Its botanical characteristics and still less
its fundamental physiological reactions have apparently received little
attention. Among the most important and interesting investigations
of higher plants, bacteria and animals in recent years have been studies
of the effects of various single salts and various combinations of salts
on the physiology of these organisms. For example, it has been found
by Osterhout® 7 that practically all of the simple salts, such as
sodium chloride, potassium chloride, ecaleium chloride, ete., have a
decided toxie action upon the plant when it is subjected to the action
of a single pure salt. Further, if certain combinations of two or more
salts were used in certain ratios the toxicity was reduced. ‘This
reduction of toxicity is commonly termed antagonism between the
salts used. It was found also that a combination of all the salts in
the ratios in which they occur in the soil solutions or in other solutions
to which the plant is accustomed afford the best conditions for growth.
Such a combination is spoken of as a physiologically balanced solution.

Loeb working with marine animals and C. B. Lipman with soil
and other bacteria obtained results similar to those obtained by Oster-
hout with the higher plants. As was to be expected, the reaction of
animals to the salts was not identical with that of bacteria, nor does
either reaction follow the behavior of the higher plants closely. In

1917 | Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 65

general, however, the results with all three classes were of the same
kind; that is, single salts, hitherto considered non-toxic, were found
to be toxie to organisms, while various combinations of these salts
showed antagonism or reduction of toxicity in the presence of each
other. In accordance with these facets, a physiologically balanced
solution can be made by using proper concentrations and proportions
of the various salts found in the solutions to which the organism is
accustomed.

So far as the writer could ascertain, no one has investigated the
behavior of yeast in this respect. Results of investigations of the
effects of the heavy metallic salts, such as mercuric chloride, silver
nitrate, ete., on yeast have been published (Bokarny’’), but nothing
has appeared upon the toxic and antagonistic effects of such salts as
sodium chloride, potassium chloride, calcium chloride, and magnesium
chloride. This field therefore seemed especially inviting, and it was
with the idea of studying the fundamental relations existing between
yeast and the chlorides that the writer undertook the work summarized
in the following pages.

ACKNOWLEDGMENTS

The experiments-on which this paper is based were carried out
under the general supervision of Professor W. V. Cruess, and I am
indebted to Professor F. T. Bioletti for suggestions and critical read-
ing of the manuscript.

MetruHop oF EXPERIMENTATION

In the selection of a yeast for my investigation I was led to use
the wine yeast, Saccharomyces ellipsoideus, by the fact that it is one
of the most useful of all yeasts and is universally used in wine making.
It is also one of the most vigorous, is easy to grow, and gives definite
results in a few days. :

The particular yeast, no. 66, used in this experiment, was isolated
by William V. Cruess from one of the wineries in northern California.
It has been found by repeated trials that specimens of Saccharomyces
ellipsoideus collected from different sources are not identical as to
their physiological characters in every respect, and so do not respond
in different salt solutions in the same way. An experiment showing
this will be described later.

Although work on this line may not have immediate practical

66 University of California Publications in Agricultural Sciences [ Vol. 3

value to the zymologist, it is of considerable scientific interest. It is
with this thought that these experiments have been carried out in the
Laboratory of Zymology.*

The salts tested in these experiments were the chlorides of potas-
sium, magnesium, calcium and sodium, each being taken up separately.
The reason for choosing these chlorides was that their metallic ions
(cations) are those most abundant in the ash of grape juice. Besides,
Loebt and Lipman"! have shown that the positive ions of these salts
have the most effect, while their negative ions (anions) have the least.
Owing to the fact that the effect of the chlorine ion is uniform in
all cases, the metallic ions show their characteristic effects on the yeast
culture very clearly.

Choice of Solution.—It has been shown by Loeb with marine ani-
mals (Fundulus), by Osterhout with higher plants (wheat), and by
Lipman with soil bacteria (Bacillus subtilis) that, for the growth of
living organisms, a nutrient solution must be physiologically balanced.
In order to grow the yeast in a medium whose constituents were
known both in quality and quantity, it was necessary to prepare
a nutrient solution from pure materials. Such a solution must con-
tain an adequate amount of nitrogen and phosphorus in order that
the yeast may grow rapidly. For this purpose a number of’ sub-
stances were tried, such as Witte’s peptone, asparagin, urea, and
ammonium phosphate, in different concentrations, with pure cane
sugar or pure dextrose. Witte’s peptone proved to be impure, being
very high in ash, and the others did not give satisfactory results.
As dextrose is not easily available in the market at present, pure cane
sugar had to be used as a carbohydrate food and as a source of fer-
mentable material.

Later a synthetic solution was made with hydrolized pure cane
sugar, phosphoric acid, and ammonia, which was suitable for the
crowth of yeast for experimental purposes. Although this synthetic
solution produces a slower rate of growth than grape juice, which is
a perfect physiologically balanced solution for yeast fermentation, it
gives sufficient growth for experimental work. To make it, a 50 per
cent pure cane sugar syrup was made with distilled water and a
measured amount (1 gram per 100 e.e. of syrup) of phosphoric acid
added. This syrup was hydrolized by boiling for one-half hour on
a slow fire, and was then neutralized with dilute ammonium hydroxide.
Litmus solution was used to test the neutrality of the syrup. The

‘ -* These experiments were carried out under the general supervision of William
V. Cruess.

es

1917 | Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 67

ammonium phosphate that eventually formed furnished both the
nitrogen and phosphorus needed by the yeast. As yeast cells grow
easily in moderately acid, but not in alkaline solutions, the syrup
was left slightly acid, being tested by titration with N/10 solution of
sodium hydroxide. To facilitate the work, the syrup was boiled down
to 65° Balling and put into a corked bottle. From this concentrated
synthetic solution a measured quantity was drawn off and diluted with
distilled water to 5° Bal. for use in the cultures.

Method of Determining the Activity of the Yeast.—The experi-
ments were carried on in a series of 200 ¢.c. Erlenmyer flasks. To
each flask the weighed amount of salt was added and 100 ¢.c. of the
diluted synthetic solution placed in the flask by means of a 100 c.c.
pipette.

The salts were weighed according to their respective molecular
concentrations. The flasks as soon as filled were plugged with cotton
and sterilized. After they had cooled down to the room temperature
they were inoculated with the yeast from a new culture. For this
purpose the new culture was prepared in a 200 ¢.c. Erlenmyer flask
containing 100 ¢.e. of the synthetic solution. The yeast thus became
habituated to this solution and therefore grew rapidly and uniformly
in the flasks. The new culture was transferred from a mother culture
in grape juice and put into the incubator for forty-eight hours at
28°C. At the end of this period the flasks containing the salts were
inoculated with one cubic centimeter of the new culture. After
inoculation, the flasks were put into the incubator, which was kept
at an approximately even temperature of 28°C. during the entire
experiment.

As the alcoholic fermentation in the synthetic solution was not
rapid enough to serve as a criterion, the multiplication of the cells
was taken as the measure of the activity of the yeast. Accordingly
a microscopical count was made every forty-eight hours with a eali-
brated microscope. Five counts were made in each experiment, during
a period of about twelve days. In every case two blanks, with no
added salts, were made up, and the tables given represent the average
of two sets of duplicate experiments, except in the cases of potassium
chloride and magnesium chloride, where the results were so close that
only the first set of duplicates was used. It may be added that the
incubator did not keep exactly the same temperature throughout the
experiments, but ranged from 27°C. to 29°C. This difference of 2°C.,
however, did not interfere appreciably with the uniformity of growth

68 University of California Publications in Agricultural Sciences [ Vol. 3

and the check flasks controlled any slight variation it may have
caused.

Salts Used —During February, 1916, a series of experiments in
two parts was planned. The first concerned the toxicity of the single
salts and the second the antagonistic effects of all their binary and
ternary combinations, as follows:

I. Toxiciry OF THE SINGLE SALTS

1. KCl 3. CaCl,
2. MgCl, 4. NaCl

Il. ANTAGONISTIC EFFECTS OF COMBINATIONS

A. Binary Combinations

1. MgCl, + CaCl, 4, KCl + NaCl
2. KCl + CaCl, 5. KCl + MgCl.
3. MgCl, + NaCl 6. CaCl, + NaCl
B. Ternary Combinations
1. NaCl + KCl + CaCl, 3. NaCl + MgCl. + CaCl,
2. NaCl + KCl + MgCl, 4, KCl + CaCl, + MgCl,

A. EXPERIMENTS Wi1TH SINGLE SAutts—Toxic EFrrects

In all cases chemically pure salts (Baker’s analyzed) were used.
Each amount of the single salts was carefully weighed and put into
the flasks, except .001M and .01M, which were added as solutions of
known strength according to molecular weights. The following pro-
portions were taken:

. KC1— .001M to 2.2M* Molecular
. MgCl, — .001M to 1.2M

. CaCl, — .001M to .7M

. NaCl— .001M to .2M

Hm © DO eR

All of these solutions were clear except the caleitum chloride, which
gave an appreciable amount of coagulated precipitate of calcium phos-
phate with the phosphorus of the synthetic solution. This, however,
did not interfere with the experiment, as the precipitate disappeared
with the growth of the yeast and the solution finally became almost
clear. The tables and curves given in each case show the growth of
yeast at every forty-eight hours in the different molecular concen-

*M represents the degree of concentration in a solution which contains one
gram molecule of the substance in one litre of solution.

——

1917 | Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 69

trations of each salt as indicated above. In the microscopical count

one million yeast cells per cubie centimeter was taken as an appreci-
able number; below that it was not considered that any appreciable
growth had taken place.

SERIES I—POTASSIUM CHLORIDE

Thirty 200 ¢.c. Erlenmyer flasks were arranged in duplicate, in-
eluding two blanks. The first pair had no salt added and was used
as a check. The second pair had .001M KCl and the third .01M KCl,
and so on to the last pair, which had 2.2M KCl, as shown in the table
below. Then, with a 100 ¢.c. pipette one hundred cubie centimeters
of the diluted synthetie solution (5°Bal.) were put into each flask.
The flasks were plugged with cotton, sterilized, and inoculated with
yeast, as stated before, and put into the incubator, and counted every
forty-eight hours. The results are shown in table 1 and the curves
in figure 1.

The curves have been plotted from the results of every forty-eight
hours’ growth, taking the various concentrations of potassium chloride
as abscissae and the number of yeast cells, counted in millions, as
ordinates (fig. 1). Following the table and the curves, it is evident
at a glance that potassium chloride up to the concentration of .2M
accelerates the multiplication of the yeast. Beyond this it becomes
gradually more and more toxic until at 2.2M the yeast cells entirely
cease to multiply. Both Magowan’®? and Lipman," especially the
former, found a strong resemblance between potassium chloride and
sodium chloride in their action on wheat and on Bacillus subtilis.
The yeast shows physiological characteristics differing from those of
either the bacteria or the wheat.

Lipman" found sodium chloride the least toxic to Bacillus subtilis
and potassium chloride second. Magowan,'® with wheat, found this
position reversed, the potassium chloride being less toxic. Both ob-
servers found that these salts were very similar in their degree of
toxicity. To yeast sodium chloride is the most toxic of the four salts
and potassium chloride the least. Ostwald* in experimenting with
animals (Grammarus) found potassium chloride the most toxic, and
Loeb’s work® * with Fundulus corroborates this to a certain extent.
The reaction of yeast, therefore, differs from that of bacteria of the
higher plants or of animals.

70 University of California Publications in Agricultural Sciences | Vol. 3
TaBLE 1—Toxic Errect oF KCL ON Saccharomyces ellipsoideus
M.KCI 48 hrs. 96 hrs. 144 hrs. 192 hrs. 240 hrs.
00 1,695,000 ~—- 7,237,000 ~=—:11,636,000 12,892,000 15,835,000
001 3,325,000 10,786,000 15,400,000 16,217,000 19,670,000
1 7,797,000 15,600,000 18,905,000 21,479,000 23,568,000
J 7,262,000 20,558,000 24,208,000 24,608,000 27,915,000
2 5,650,000 18,493,000 29,689,000 28,783,000 30,541,000
A 5,425,000 20,227,000 25,006,000 27,560,000 28,914,000
6 1,130,000 8,535,000 20,928,000 22,802,000 23,802,000
38 809,000 5,298,000 17,670,000 19,508,000 20,982,000
1.0 226,000 6,787,000 15,205,000 17,986,000 18,453,000
Ee) eS ae 1,102,000 8,986,000 16,207,000 16,951,000
Rat) -3e ee 452,000 8,765,000 11,584,000 12,882,000
ee eekeen eaters 3,204,000 5,794,000 8,232,000
ee ee 904,000 1,243,000 6,252,000
pees teentaeebeeees 1 acne 904,000 2,051,000
BB iam shi ee ee as. Sener eee tee 226,000

Millions of yeast cells

2.0 2.2

DP OOE 60) 588 ree: ik) a) Bs Os eR hs
Concentration of salt
Fig. 1—The ordinates represent millions of yeast cells and the abscissae,

the various concentrations of KCl. The ordinates at 0 represent the number
of yeast cells in the check cultures.

1917]

The same method of procedure was used with MgCl, as with KCl.

Mitra: Toxie and Antagonistic Effects of Salts on Wine Yeast

SERIES II—MAGNESIUM CHLORIDE

The results are shown in Table 2.

TABLE 2—ToxIc

SFFECT OF MGCL, ON S. ellipsoideus

M. MgCl 48 hrs. 96 hrs. 144 hrs. 192 hrs. 240 hrs.
00 2,412,000 8,108,000 12,205,000 16,837,000 17,202,000
001 4,972,000 10,753,000 13,673,000 18,871,000 19,775,000
O01 8,751,000 15,798,000 18,703,000 19,588,000 20,374,000
mi | 3,482,000 12,227,000 20,521,000 25,013,000 26,501,000
2 2,356,000 7,204,000 11,342,000 15,530,000 18,617,000
4 1,695,000 5,400,000 ~—- 9,504,000 ~—-:12,837,000 ~—-17,413,000
6 989,000 2,157,000 —-7,332,000 11,253,000 11,905,000
8 226,000 1,130,000 4,294,000 6,943,000 —-8,436,000

if Pea ee 226,000 1,875,000 2,712,000 +~—-.2,904,000
eee ie ere eS 226,000

Millions of yeast cells

71

FARE
FASS wee
ea aks

“Concentration of salt

Fig. 2.—The ordinates represent the number of yeast cells in millions and
the abscissae, the concentration of magnesium chloride. The ordinate at 0
represents the number of yeast cells in the check cultures.

to

University of California Publications in Agricultural Sciences | Vol. 3

From both table 2 and the curves in figure 2, it is evident that
magnesium chloride is more toxic than potassium chloride. Up to
the concentration of .1M, it is favorable to the growth of yeast, but
beyond this it becomes more and more toxic until at 1.2M concen-
tration there is little or no growth at all. In the case of yeast, mag-
nesium chloride and calcium chloride show less similarity than that
found by Lipman with soil bacteria, and the toxic effect of magnesium
chloride is nearer to that of calcium chloride than to that of potassium
chloride. Magnesium chloride is not so toxic to yeast as Lipman
found it with Bacillus subtilis. In the ease of yeast, .7M concen-
tration of caleium chloride altogether inhibits its growth. The same
concentration, however, of magnesium chloride allows an appreciable
number of yeast cells to grow, and the same toxie effect as that of
7M CaCl, is not attained until a concentration of 1.2M MgCl, is
reached. In fact, magnesium chloride stands midway between the
two extremes of toxicity of these four salts, namely, the more toxie
NaCl and CaCl, and the less toxic, KCl.

Loeb,’ * with marine organisms, found that a .5M solution of
magnesium chloride inhibits the development of embryos in the eggs
of Fundulus, and that even .125M Ca(NO,), is toxic. In his experi-
ment with soil bacteria Lipman" has met with about the same result.
He found that 4M MgCl, inhibits the growth of Bacillus subtilis,
while for the same effect on yeast a concentration of 1.0M MgCl, is
needed. But Magowan’® has shown that with wheat magnesium chlor-
ide is the most toxic of all the four salts; in this respect yeast resembles
neither the animals, nor bacteria, nor the higher plants.

It must be noted that the magnesium chloride used in all the
experiments was MgCl,.6H,O, as this is less hygroscopic than the
same salt having two molecules less of water (MgCl,.4H,O), which
is difficult to weigh accurately. However, magnesium chloride was
found more toxic than potassium chloride and more favorable than
ealeium chloride, which is directly opposite to the result obtained
with higher plants.

SERIES IITI—CALCIUM CHLORIDE

The experiment with calcium chloride was earried on in the same
way. From both table 3 and the curves in figure 3, it is evident that
.01M concentration of CaCl, gives the highest growth, while beyond
this favorable concentration CaCl, is more and more toxic. In its

——

1917]

toxicity to yeast, CaCl,
the four salts.
growth of yeast, while even .2M NaCl stops all growth.

Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast

TABLE 3—Toxic Errectr oF CACL, ON S. ellipsoideus

M.CaClp 48 hrs. 96 hrs. 144 hrs, 192 hrs. 240 hrs.
.00 2,599,000 8,136,000 11,752,000 13,108,000 16,336,000
001 3,051,000 —- 9,989,000 12,656,000 ~—-13,965,000 ~—:17,751,000
01 3,503,000 11,050,000 13,926,000 15,885,000 19,251,000
| 226,000 6,034,000 —- 8,468,000 10,904,000 16,674,000
PN Grades 1,695,000 3,256,000 ~—- 3,821,000 ~—-15,778,090
thy Mate tien 904,000 1,130,000 3,090,000 ~—-14,561,000
Diese | | scpubinicch tae 226,000 904,000 1,130,000 9,771,000
5 ARI) RARE SRL E Oo 226,000 987,000 2,935,000
Ak reeks Bel ils, 2oPe bi i Ti oe 226,000 904,000
SE PORN TS, PO eee teat tt ah Ree 226,000

Millions of yeast cells

1 a eS
CREE
NN !

0

stands second, NaCl being the most toxic of
A .5M coneentration of CaCl, allows an appreciable

OS ecules at 4 5 6 ei

Concentration of salt

Fig. 3.—The ordinates represent the number of yeast cells in millions and
the abscissae the concentration of CaCl, The ordinate at 0 represents the
number of yeast cells in the check cultures.

The work of other investigators with regard to the toxicity of
CaCl, shows a general agreement with the results obtained by Loeb
with Fundulus,? Ostwald‘ with fresh water, Grammarus, and Lip-
man!! with soil bacteria, all of which show CaCl, to be extremely toxic.
An exception to this general statement is found in the work of

74 University of California Publications in Agricultural Sciences | Vol. 3

Magowan, who showed in her experiments that, in the case of wheat,
CaCl, is the least toxic of the four salts. Here also we find that
yeast exhibits a peculiar physiological character which does not agree
with either of the above divisions, the animals or the plants. Perhaps
this may throw some light on the relation of yeast to these two groups.

SERIES IV—SODIUM CHLORIDE

As NaCl is the most toxic of all the salts, only a few pairs of flasks
were taken, from .001M to .2M concentration, together with a pair
of blanks. The experiment was carried on in the same way as the
others. From table 4 and the curves in figure 4, it 1s evident that
NaCl is the most toxic to the yeast. Even the concentration of .01M
NaCl did not stimulate the growth of yeast, as it did with the other
salts. The highest growth in this case was in .001M, and beyond that
it was toxie.

TABLE 4—Toxic Errect OF NACL ON S. ellipsoideus

M.NaCl 48 hrs. 96 hrs. 144 hrs. 192 hrs. 240 hrs.
.00 2,424,000 8,059,000 9,267,000 11,978,000 15,142,000
001 3,819,000 9,605,000 12,430,000 12,995,000 17,967,000
Ol 3,164,000 7,458,000 10,283,000 10,504,000 13,060,000
1 226,000 452,000 452,000 452,000 1,130,000
2 226,000

Millions of yeast cells

Concentration of salt

Fig. 4.—The ordinates represent the number of yeast cells in millions and
the abscissae, the concentration of NaCl. The ordinate at 0 represents the
number of yeast cells in blank cultures.

;

‘
>
a
.
é

<—s ==

—_-=

1917 | Mitra: YVowxie and Antagonistic Effects of Salts on Wine Yeast 75

NaCl shows a directly opposite reaction with yeast from that
found by Lipman"! with soil bacteria. Both Loeb and Ostwald found
NaCl to be toxie for animals, but less so than we have found with
yeast. The toxicity of NaCl to animals may be compared with the
toxicity of NaCl, to yeast. Loeb* found it impossible to develop
embryos in the egg of Fundulus at .625M NaCl. Osterhout* *® found
that a .375M solution of sodium chloride is fairly toxie to marine
plants. Young plants of a fresh-water alga, Vaucheria sessilis, could
not live at a .094M concentration of sodium chloride, and even a
concentration of .0001M NaCl was found to be toxic. Magowan has
shown that sodium chloride is very toxic to wheat seedlings and down
to .02M the root hairs did not grow at all. The relation of yeast to
plants is thus to a certain extent shown by similar physiological
behavior.

It may be noted here that the experiments with yeasts have been
conducted on the same general principle followed by previous investi-
gators with animals, plants, and bacteria. The number of yeast cells
was taken as the measure of multiplication or activity and was de-
termined by a microscopical count of each flask every forty-eight
hours. It must be admitted that experimental errors may occur in
counting, but as the numbers were taken from the average results of
two sets of duplicates it does not interfere with the validity of the
final result, as the range of variation between the results of these two
sets of duplicates was only between 0 and 10 per cent calculated from
the mean variation.

SERIES V—EFFECT OF THE TOXICITY OF SALTS ON THE
MICROSCOPICAL APPEARANCE OF YEAST CELLS

It is generally known that all salts at certain concentrations are
more or less toxic to living organisms. Yeast shows its physiological
condition in relation to various salts in characteristic ways. It is
evident from the above experiments that in this respect it occupies
a place between the animal and the plant kingdoms. Although yeast
grows normally in a physiologically balanced solution, for which
grape juice answers in every way, the addition of a small amount of
a favorable salt, as potassium chloride, may stimulate the growth a
great deal. This is of some practical zalue to zymologists.

Yeast is affected very remarkably by the toxicity of salts at dif-
ferent concentrations. In the extreme concentrations it apparently

76 University of California Publications in Agricultural Sciences | Vol. 3

dissolves. This occurs in the cultures having 2.2M KCl, 1.2M, MgCL,
.7™M CaCl, and .2M NaCl respectively. At lower concentrations there
is a degenerated condition, various shapes occurring, as shown in
figure C. Such diseased cells show a heavy black membrane, especially
in the ease of CaCl, and NaCl, with transparent cell-illusions or black
spots within the cells. Moreover, they vary in size. This variation
in size occurs also with KCl and MgCl,, but in these cases the yeast
cells are larger than with CaCl, and NaCl. In all instances, as the
concentration of salt increases beyond the favorable degree of con-
centration the cells become smaller and smaller until finally, in the
extreme concentrations, they dissolve. Table 5 (a, b, c, d) and the
curves in figure 5 (a, b) show the effect on the size of yeast cells in
different salt solutions.

TABLE 5a—EFFECT OF KCL ON S1zE oF YEAST CELLS (S. ellipsoideus)

Av. length Av. volume
Concentration and breadth of yeast cells
of salt yeast cells calculated from
(M.KCl) in Mu. length and breadth

.00 4.7 x 4.6 77
001 5.4 x 5.4 122
OL 6.7 x 6.7 232
1 6.7 x 6.7 232
2 6.7 x 6.7 232
4 6.6 x 6.6 223
6 6.6 x 6.6 223
8 5.8 x 5.8 151
1.0 5.8 x 5.8 151
1.2 5.8 x 5.8 151
1.4 5.8 x 5.8 -151
1.6 4.9x 4.9 91
1.8 4.9 x 4.9 91
2.0 3.83.3 28
2.2 3.3 x 3.3 28

TaBLE 5b—Errect oF MGCL, oN Size or YEAST CELLS (S. ellipsoideus)

Av. length Av. volume
Concentration and breadth of yeast cells
of salt yeast cells calculated from
(M.MgCle) in Mu. length and breadth
.00 4.5 x 4.5 71
.001 5.1.x 5.1 103
O01 6.2 x 6.2 185
1 6.2 x 6.2 185
2 5.0 x 5.0 98
4 5.1x5.1 103
6 5.0 x 5.0 98
8 4.9x 4.9 91
1.0 4.4 x 4.4 66
1.2 3.3 x 3.3 28

1917 | Mitra: Toxie and Antagonistic Effects of Salts on Wine Yeast 77

TABLE 5c—EFFECT OF CACL, ON Size or YEAST CELLS (S. ellipsoideus)

Avy. length Av. volume
Concentration and breadth of of yeast cells
of salt yeast cells calculated from
(M.OaCl.) in Mu. length and breadth
.00 4.7 x 4.4 70
O01 : 4.6 x 4.6 75
O1 4.1 x 4.1 53
wl 3.3 X 3.3 28
2 3.3 X3.3 28
3 2.8 x 2.8 bts j
4 2.8 x 2.8 17
3) 2.8 x 2.8 17
6 2.6 x 2.6 14
- 2.6 x 2.6 14

TABLE 5d—Errect or NACL ON Size or YEAST CELLS (S. ellipsoides)

Av. length Av. volume
ber ei and breadth of of yeast cells
of salt ot yeast cells calculated from
(M.NaCl) in Mu. length and breadth
.00 5.1 x 4.8 91
O01 5.0 x 4.4 75
OL 4.4 x 3.3 37
oil 4:1xX3.3 34
2 2.6 x 2.6 14

Average volume of each cell

Concentration of salt

Fig. 5a.—Curves showing the average relative volumes of yeast cells in
various concentrations of CaCl, and MgCl,. The ordinates represent the average
volume of the yeast cells and the abscissae, the concentrations of KCl and MgCl,
used. The ordinate at 0 represents the volume in blank cultures.

78 University of California Publications in Agricultural Sciences [ Vol. 3

Da
gi
i
5 ide
a
ee
Hf
ms

o
2
2
s
o
~~
°
Z
3
a=
°
>
©
20
x
he
o
>
<

peda
ole Er SAS Se

Concentration of salt

Fig. 5b.—Curves showing the average relative sizes in volumes of yeast cells
in various concentrations of KCl and MgCl,. The ordinates represent the
volume of the yeast cells and the abscissae, the concentrations of the salts used.
The ordinate at 0 represents the volume in blank cultures.

Fig. 5c.—Appearance of yeast cells in extreme concentrations of salts.

Normal yeast cells in 1, 2 and 3, diseased yeast cells from extreme concen-
trations of KCl and MgCl, in 4 and 5; (white) and diseased yeast cells from
extreme concentrations of CaCl, and NaCl in 6, 7 and 8 (black or shadowy)
(X5000).

1917 | Mitra: Toxie and Antagonistic Effects of Salts on Wine Yeast 79

The measurements given are the average of five counts in each
ease. The volumes from which the curves have been drawn in figure 5
(a, b) have been calculated, for purposes of comparison, as though
the cells were cylindrical.

Both from table 5 (a, b, c, d) and the curves in figure 5 (a, b) it
is evident that KCl and MgCl, favor growth in size up to the most
favorable concentration, beyond which the cells decrease in size until
the extreme concentration is reached, where they dissolve. Both NaCl
and CaCl, limit the growth even in minute concentrations, thus show-
ing their extreme toxicity to yeast cells.

Yeast cells seem to have remarkable resistant power. Many of
them with cell wall thickened to a heavy membrane have been found
in extreme concentrations. Perhaps this heavy membrane is formed
to resist the osmotic pressure outside the cell. Besides some of the
cells in these extreme concentrations are in normal condition and are
even budding, thus showing the power of adaptability of yeast cells
to new conditions. After they have become habituated to the presence
of toxic salts, they grow normally and reproduce. It is probably
owing to fhe adaptability of yeast to different conditions that the
same yeast, S. ellipsoideus, collected from various sources, shows dis-
similar physiological characters. Besides in many cases I have
observed that the diseased yeast cells in extreme toxicity of KCl and
MgCl, form a white membrane with normal cell contents, while those
of CaCl, and NaCl form a rather dark cell membrane with shadowy
cell contents. A similar case to that of Loeb*** may be cited here.
In his experiments with sea urchin eggs he found two distinct phases

rie

of cytolysis which he terms ‘‘black cytolysis’’ and ‘‘ white eytolysis.”’

With regard to the effect of the salts on the size of the yeast cells,
NaCl is the most and KCi the least toxic, while CaCl, and MgCl,
stand midway. The effect is parallel with that of the multiplication
of cells.

An experiment was carried on with a second culture of 8. ellip-
soideus collected from another source by Cruess and named no. 60.
This experiment was also made in duplicate. With this yeast potas-
sium chloride and magnesium chloride gave the same results as with
no. 66, but NaCl and CaCl, showed a marked difference and CaCl, was
the most toxic of all. 4M NaCl gave an appreciable number of yeast
cells, while even .3M CaCl, stopped the growth altogether. Further,
the number of yeast cells was much lower than that of yeast no. 66.
Evidently yeast no. 60 was less vigorous than the other, though other-
wise there was no fundamental difference between them.

80 University of California Publications in Agricultural Sciences [ Vol. 3

B. EXPERIMENTS WitH COMBINATIONS OF SALTS—ANTAGONISTIC
EFFECTS

The toxic effects of the single salts KCl, MgCl,, CaCl, and NaCl
upon a wine yeast, NS. ellipsoideus, have been shown in the first part
of this paper. The results of the study indicate that the reactions
of yeast differ from those of plants, animals or bacteria. This second
part of the paper gives the results of an investigation to ascertain the
effects of various binary combinations of the salts named upon the
Same yeast.

From the four salts, six combinations of two salts each are possible.
All of these were tested. Judging from analogous work of other
investigators with animals, plants and bacteria, it was expected that
these salts would exhibit mutually antagonistic action, i.e., that the
toxicity of one salt would be reduced by the presence of another and
that the total effect of two salts together would be less than the sum
of their individual effects: In some eases definite antagonistic effects
were found. In others antagonism was not so well defined. In a
few instances there was no antagonism shown.

In the discussion of results, considerable space has been given to
the findings of other investigators because it was considered important
to point out how the effects on other organisms compare with those
on yeast. A few words on the development of the idea of antagonism
in binary combinations of salts will be of value as an introduction to
the data in this paper.

Considerable work on the antagonistic effects of salts has been
done by Ringer, Locke, Howell, Loeb, Osterhout, Overton, Ostwald,
Loew, Lipman and others. That the poisonous effect of one salt is
reduced by the addition of another salt has been known for a long
time, especially among animal physiologists. In this matter we owe
a great deal of our knowledge to Loeb, whose investigations brought
forth a large number of unexpected results. It was he who first
developed the theory that the valences of metallic ions have consid-
erable influence on their toxie and antagonistic effects, and that mono-
valent cations may be antagonized by bivalent, trivalent or tetravalent
but not by monovalent cations. His results show some parallelism
to the work of Linder and Picton.* This general statement does not
apply in all cases to plants, animals and bacteria, experimented upon
by various other investigators. Neither does it apply always to yeast.

* Hober and Gordon, Beitr. zur chem. physiol., vol. 5, p. 432, 1904, cited by
Osterhout.”

1917] Mitra: Towxie and Antagonistic Effects of Salts on Wine Yeast 81

The experiments with binary salts were made in the same general
way as those with simple salts, but with slight modifications of tech-
nique. The flasks were arranged as before in duplicate, but in com-
bining the salts in different molecular concentrations the method
followed differed from those of previous investigators.

Of the two salts to be tested for antagonism, one was weighed from
the minimum concentration to that of extreme toxicity according to
the molecular concentration, and the other was weighed and added
to the former in the reverse way in the corresponding flasks. The
flasks containing the extreme concentration of each salt did not receive
any addition of the other salt. Aside from this, the methods of in-
oculation, incubation, and microscopical counting were the same as
those described for the single salts. Duplicates were made in all cases
and two blanks were used in each series, as checks on the growth of
the yeast in the treated flasks. The same yeast, S. cllipsoideus, no. 66,
was employed in these experiments as in the ones with simple salts.
The results given are therefore the average of duplicate experi-
ments.

SERIES VI—ANTAGONISM BETWEEN MAGNESIUM CHLORIDE AND
CALCIUM CHLORIDE

In this series MgCl, and CaCl, were combined in various mole-
cular concentrations. A series of 16 Erlenmyer flasks was arranged
in dupheate with two blank cultures. First, amounts of MgCl, cor-
responding to from 0M to 2.2M were weighed and put in the flasks,
as was done with the single salts. The CaCl, also was weighed ac-
cording to its molecular concentration and put in the same flasks in
reverse order, leaving the extreme concentrations of each salt free
from the addition of the other. Thus the first two flasks received
.72M CaCl, without any addition of MgCl,; the second received .66M
CaCl, and .001 MgCl,; the third .60M CaCl, and .01M MgCl,, and so
on to the last couple, which contained only 1.2M MgCl, and no addition
of CaCl,. The remaining flasks were combined in different molecular
concentrations, as shown in table 1. Two blanks were taken to which
no salt was added.

In order to facilitate the plotting of the curves, the different
combinations of salts have been indicated by letters A, B, C, D, ete.
A represents the blank cultures, while the other letters represent the
different molecular combinations shown in the table below:

82 University of California Publications in Agricultural Sciences | Vol. 3
TABLE 6—ANTAGONISTIC ErPFECT BETWEEN MGCL, AND CaCL,
MgCl. vs.
No. CaCls M. Cone, 48 hrs. 96 hrs. 144 hrs. 192 hrs. 240 hrs.
A 00 x .0O 1,954,000 6,290,000 10,556,000 14,108,000 16,944,000
B Rt ch) nese: Sen Sees Oe RnR eN ee CAMNNLOE I ooaioryi SEE one Ml wee REO De oe te
C St ROO Cate «= echoes) Sseanineees 226,000 452,000
dD 1 x .60 452,000 2,034,000 3,842,000 4,520,000 5,650,000
E ll x.48 8,362,000 20,860,000 23,120,000 24,730,000 26,842,000
1) 2 X.36 10,548,000 26,024,000 29,706,000 30,856,000 31,960,000
G 4 x.18 9,718,000 28,996,000 32,284,000 33,974,000 36,120,000
H 6 x .06 8,804,000 25,286,000 30,256,000 31,865,000 32,556,000
8 ~x.01 452,000 4,972,000 8,289,000 10,298,000 12,684,000
P TO. 088. 226,000 1,130,000 2,260,000 3,129,000
Se Oo oe eee. | eecaacunepipuins” | __eaxseutudekpesrin. s Usuceiiedbastedatasnel alleen nanan
36
34
32
30
28
26
24

Millions of yeast cells

—

A
MgCls

a: ie
fan een en
OS SSESE Ee
BEE! Bei ee

i

\i
Loves E
CECT
NCHA
NCA
RoE

Concentration of salts

CaCle

Fig. 6—Curves of yeast growth showing antagonism between MgCl, and

Cael...

abscissae, the concentration of the salts in combination.

represent the number of yeast cells in blank cultures.

The ordinates represent the number of yeast cells in millions and the

The ordinates at A

Me
:
:

(PIs 8)

1917] Mitra: Toxie and Antagonistic Lffects of Salts on Wine Yeast 83

From both table 6 and the curves in figure 6 it is evident that
there is a distinct antagonism between these two salts. For example,
in the experiments with simple salts MgCl, alone at .8M concentration
allowed the growth of yeast cells up to only 814 millions, but in com-
bination with .01M CaCl, the growth was increased up to 1214 millions,
ie., 50 per cent increase. Similarly, .6M CaCl, alone allowed an
increase to about one millions, and, with the addition of .01 MgCl,,
an inerease to 514 millions, showing 514 times more growth. The
highest number in MgCl, alone was 2614 millions at .1M, and in CaCl,
alone 19 millions at .01M concentration. In this binary combination
the highest number was obtained at G, the point where 4M MgCl, and
18M CaCl, were combined with a ratio of about 2:1.

For purposes of comparison let us now consider the results obtained
in similar experiments with these four salts on plants, animals, and
bacteria.

(a) Plants—Kearney and Cameron® found a distinct antagonism
between Mg and Ca ions for higher plants. In their experiments with
leguminous plants Lupinus albus and Medicago sativa they found that,
for a combination of these two salts, the plants show about five times
as much tolerance as for the salts separately. The plants also dis-
played a remarkable degree of tolerance when MgSO, was used in-
stead of MgCl,, thus showing in addition the relative difference be-
tween different anions of fhe same salt.

Loew and his pupils,'® ** in their experiments with lower plants
(Spirogyra), have found a strong antagonism between Mg and Ca
ions.

(b) Animals.—Loeb? with sea urchins (blastulae and gastrulae)
found that a mixture of MgCl, (10/8n) and CaCl, (10/8n) will allow
them to swim for about forty-eight hours, while each of the salts
singly at the same concentration is extremely poisonous and kills the
animals. The same investigator’? working with a jellyfish (Polyor-
chis) has shown that the addition of a small quantity of CaCl, to a
mixture of NaCl and MgCl, favors the normal, rhythmical contrac-
tions, while MgCl, alone stops them altogether. Contrary to the
above results, Loeb’ in his experiments with frogs has found that a
combination of Mg and Ca ions completely inhibits the rhythmical
muscular contractions. This has been corroborated by Anne Moore,‘
in her experiments with the contraction of the lymph hearts of
frogs.

Lillie’ has found that the ciliary movement of the larvae of

84 University of California Publications in Agricultural Sciences | Vol. 3

Arenicola goes on normally for a time in a mixture of MgCl, and
CaCl, with the ratio of 4:1 at 10/8n concentration, though either of
the two salts used alone would stop it entirely. Matthews,'? in his
work with the development of embryos in the eggs of Fundulus, found
a distinct antagonism between Mg and Ca.

Meltzer and Auer*! have shown with rabbits and a monkey that
the poisonous action of MgCl, in subcutaneous injection is similarly
diminished by the injection of CaCl,. They found also a strong
antagonism between the nitrates, acetates and sulfates of these two
salts respectively.

(c) Bacteria—Lipman,** ** with a soil bacterium, Bacillus sub-
tilis, found little or no antagonism between the two salts, but, on the
contrary, the addition of one salt to the other was found to be more
toxic than either of the two salts used alone.

All of the above mentioned experiments, except those of the three
eases of Lipman, Loeb, and Anne Moore, are in agreement with the
antagonistic effects between Mg and Ca ions that occur with yeast.
In addition, it may be noted here that the antagonistic effect between
MgCl, and CaCl, with yeast has been found to be the strongest of all
the combinations. This corroborates the opinion advanced by Loew
that there is a strong antagonism between calcium and magnesium
both with plants and animals.'®

SERIES VII—ANTAGONISM BETWEEN POTASSIUM CHLORIDE AND
CALCIUM CHLORIDE

In this series the experiments were carried on in the same way as
with MgCl, and CaCl,. Table 7 and the curves in figure 7 show
there is a distinct antagonism between the two salts. In this case
marked antagonism was found on the side of CaCl,, but little or none
on the side of KCl. For example, the combination of .001M KCl with
.66M CaCl, allowed the yeast to grow up to 61% millions, while in
CaCl, at .6 alone the yeast was found to increase only up to about one
million. Thus there was 614 times as much growth where the KCl
was present. But, on the other hand, the combination of .001M CaCl,
to 2.0M KCI did not accelerate the growth. This unexpected result
may be accounted for by the fact that the higher concentrations of
KCl being very high in comparison to the small concentrations of
CaCl, the latter was not sufficient to reduce the toxicity of the KCl
at such a high concentration. It is also very probable that a concen-

1917} Mitra: Toxie and Antagonistic Effects of Salts on Wine Yeast 85

tration of 2.0M KCl exerts a strong osmotie effect and that the toxicity
is due to osmotic influences rather than to the usual toxicity of the
ion itself. If this were true we would expect little antagonism from
other salts.

Loeb’? in his experiments with a jellyfish (Gonionemus) met with
a similar difficulty. In this ease the KCl concentration was so high
that a small coneentration of NaCl did not remove the toxicity, and
so the combination inhibited the contraction of the animal, while the
same concentrations used in the ease of another kind of fish, Mundulus,
allowed the development of embryos in the eggs. He has pointed out
the fact that in the embryos of Pundulus the solutions in which cleay-
age proceeds normally interferes seriously with the heartbeat of Coni-
onemus, if the proportion of KCl exceeds a certain limit. In this
instance we find proof of the fact that in the same organism eell-
division and muscular contractility are influenced by entirely different
combinations of ions, and therefore these vital activities must depend
on widely different chemical constitutions. However, the highest
growth in the case of yeast was obtained at H, where .6M KCl and
.36M CaCl, have been combined, a ratio of about 2:1. In the case of
KCl alone the highest growth was obtained at .2M concentration,
allowing growth up to 3014 millions per ¢c.e. CaCl, allowed growth
up to 19 millions at .01M concentration.

TABLE 7—ANTAGONISTIC EFFECTS BETWEEN KCL AND CACr,

KOl_ vs.

48 hrs.

144 hrs.

No. CaClo M. Conc. 96 hrs. 192 hrs. 240 hrs.

A .00 x.00 2,101,000 8,589,000 13,908,000 16,896,000 17,520,000
B gad ay i late OID thi NGI gh Ne ie Re RRA nk ete: Pie Ors SEE ad |
eee Ue esGG |) he Se 226,000 2,034,000 3,985,000 6,722,000
D 4.01 x.60 452,000 4,972,000 13,315,000 18,604,000 22,720,000
E 1 x.54 4,020,000 10,328,000 20,245,000 23,266,000 25,120,000
F 2 x.48 5,558,000 12,840,000 22,190,000 26,880,000 29,380,000
G 4 x.42 3,034,000 12,840,000 26,852,000 19,126,000 32,285,000
H 6 x.36 1,017,000 8,398,000 13,645,000 28,904,000 34,500,000
I 8 xX.30 226,000 4,256,000 10,250,000 14,966,000 18,732,000
AGE 2 Bie 2” ree ai 2.965,000 6,126,000 9,551,000 16,159,000
lage | Te ee | a ee 1,130,000 3,986,000 ~—-5,410,000 ~—7,119,000
L BAe ee 452,000 2,550,000 2,712,000 4,438,000
es Wb RRS a | ae eee as RS ee eer 904,000 1,130,000 3,906,000
N fil SURG 8 RE Ieee, 2 Ros Wee ae pene pea ne 452,000 904,000 2,652,000
Be OR FSCS yc Sh aalaale a wekievccs mp “meet 226,000 1,130,000
i Bee ae | ocean | CO aeeGMRRESRSTCE . aimciannereytndaee ) epee

86 University of California Publications in Agricultural Sciences | Vol. 3

A a
PCY
ca Zoe OE BES
HBP a a FO, ND
ECC Acre
py ye is

| | AN
COPECO

Millions of yeast cells

(ae See
ML | IAT NAL
Te oo

KCl Concentration of salts CaCle

Fig. 7—Curves of yeast growth showing antagonism between KCl and CaCl.
The ordinates represent the number of yeast cells in millions and the abscissae,
the concentration of salts in combination. The ordinate at A represents the
number of yeast cells in blank cultures.

For comparison with these results, a number of cases dealing with
plants, animals and bacteria may be cited below:

(a) Plants——Osterhout”? has shown that for higher plants a com-
bination of 100 ¢.c. KCl and 5 ¢.e. CaCl, at the concentration of .12M
is best suited for the highest development of roots. Benecke’® has
shown that for lower plants (Spirogyra) the harmful effect of the K
ion is very distinctly antagonized by the addition of the Ca ion at a
certain definite concentration.

1917] Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 87

(b) Animals.—In regard to the development of embryos in the
eggs of Fundulus, Loeb’ has met with a marked antagonism between
the two salts, using 75 ¢.c. of KCl (5/8n) and 25 ¢.e. of CaCl, (10/8n).
This combination allowed the development of a number of embryos,
while in the same concentration of KCl alone no development was
shown. He also obtained a similar result with the muscular contrac-
tion of a jellyfish (Polyorchis),’ thus showing an antagonistic effect
between the two salts. The same investigator* in his experiments with
the hydromedusa Gonionemus has shown that the combination of K
ion (5/8n) and Ca ion (10/8n) is poisonous to the animals. Anne
Moore’ obtained a similar result in her experiments on the contraction
of the lymph heart of frogs.

Meltzer and Auer*! have shown that with rabbits and a monkey
in subcutaneous injection there is a limited antagonism between the
two salts. Matthews" with Fundulus met with a similar result. He
found that at the dilution of M/1600 CaCl, to 6/8n KCl the develop-
ment of embryos in the eggs was found to be the best.

Lillie’ found that with the larvae of Arenicola the ciliary activity
went on when he used 97.5 e.e. CaCl, (10/8n) and 2.5 ¢.e. KCl (5/8n),
showing an antagonism between the two salts.

(c) Bacteria.—Lipman*® has shown that for Bacillus subtilis the
highest production of ammonia is found at the point where 100 c.c.
KCl and 5 «.e. CaCl, at the concentration of .35M is used, thus showing
a distinct antagonism between the two salts. His work has a striking
similarity to that of Osterhout on wheat.

Summarizing the antagonism between K and Ca, it may be said
that the toxicity of high concentrations of Ca is greatly reduced by
the presence of K, but that the toxicity of high concentrations of K
is not appreciably reduced by small amounts of Ca. The optimum
ratio of KCl to CaCl, was about 2:1 for yeast.

SERIES VIII—ANTAGONISM BETWEEN MAGNESIUM CHLORIDE AND
SODIUM CHLORIDE

The experiments in this series were carried on in the same way as
the others. Both table 8 and the curves in figure 8 show that there
is a distinct antagonism between these two salts. The highest growth
in this case was found at G, the point where .4M MgCl, and .06M
NaCl were combined, a ratio of about 6:1. As already shown, when
used singly MgCl, allows the highest growth at .1M, 1.e., 2614 millions,

338

University of California Publications in Agricultural Sciences

TABLE 8—ANTAGONISTIC EFFECTS BETWEEN MGCL,

AND NACL

MgCl. vs.
No. NaCl M. Cone 48 hrs. 96 hrs. 144 hrs.
A 00 x .0U 3,100,000 7,644,000 13,686,000
B J.) MR ah Bue ere te: s 2b aay Bova e Peete ance. eke Ste te
C SCS 36 TD eecceeee | Oacccceenaes . gemetaabcuaien
D Ol x .160 226,000 452,000 452,000
E » Pee gk 3,250,000 6,212,000 11,201,000
F 2 x .096 5,424,000 10,396,000 16,368,000
G 4 x .064 2,260,000 12,656,000 20,696,000
H 6 x.032 1,582,000 8,684,000 14,956,000
I SOP 904,000 3,102,000 6,358,000
J OQ “30 DOL. 904,000 1,872,000
|e ys iis Sie sya ee mene a Baie Se een SNe oy
30

2c Se a BP else
HGR
“

CONE

192 hrs.
15,203,000
226,000
678,000
14,258,000
21,690,000
25,882,000
17,009,000
10,605,000
3,896,000

: ‘ bane! (mia
e a
S 18
3S
2 16
: PCN
2 14
=
S 12
10
8
6
; rah SEN
2
van an ae
A G H J K
MgCle Concentration of salts NaCl

Fig. 8.—Curves of yeast growth showing antagonism between MgCl, and
NaCl. The ordinates represent the number of yeast cells in millions and the
The ordinate at A repre-

abscissae, the concentration of salts in combination.
sents the number of yeast cells in blank cultures.

[ Vol. 3

240 hrs.
17,009,000
226,000
1,130,000
17,255,000
25,793,000
28,890,000
21,583,000
15,430,000
4,276,000

1917 | Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 89

and NaCl at .001M, 1.e., 18 millions. But in combination the two salts
permit the highest growth of 29 millions per ¢.c. at .4M and .06M
respectively.

The antagonism between these two salts in the case of yeast is
found very distinctly at both ends of the curves. For example, .1M
NaCl alone shows a growth of seareely more than one million, while
in combination with .1M MgCl, it shows over 17 millions, or 17 times
as much. On the other hand, .8M MgCl, alone allowed a growth
of about 81% millions, while in combination with .01M NaCl the
growth was increased to about 1514 millions, or about twice as
much.

In comparison with these results, a number of cases dealing with
the effects of combinations of MgCl, and NaCl on plants, animals and
bacteria are cited below.

(a) Plants——Osterhout® found a distinct antagonism between the
two salts with the growth of a fungus (Botrytis cinerea). He found
that 15.M NaCl alone was very toxic, but that when this concentration
of NaCl was combined with .4 M MgCl, the toxicity was much re-
duced. He also found with wheat that neither NaCl nor MgCl, at
12M alone allowed root development, but in a combination in the
proportion of 100 ¢.c. NaCl to 75 ¢.c. MgCl, the root developed very
well. The same investigator obtained a negative result with green
algae.?°

Kearney and Cameron® with Lupinus albus and Medicago sativa
have shown that the addition of MgCl, to NaCl raised the tolerance
of these plants to the latter 3-10 times.

(b) Animals.—Loeb” with Fundulus has found that in a mixture
of 98 ec. 5/8n NaCl and 2 «ec. 10/8n MgCl, all the eggs develop
embryos, while the same salts alone at the same concentration are
extremely toxic. Even an equal proportion of the two salts in the
same concentration allowed about 75 per cent of the embryos to de-
velop. He also found a similar antagonism with a sea urchin (Ar-
bacia) and a jellyfish (Polyorchis).

Lillie® found that with the larvae of Arenicola the ciliary move-
ment continued for a time when he added 10 ec. MgCl, (10/8n) to
90 ec. NaCl (5/8n), while the same concentrations of NaCl alone
would stop it immediately. Matthews with Fundulus found an an-
tagonism between the two salts.

Ostwald,!? however, with fresh-water Grammarus obtained con-
trary results. In this case a combination of the two salts was found

90 University of California Publications in Agricultural Sciences [ Vol. 3

to be more toxie than NaCl alone, isotonic with sea water (2.7 per
cent NaCl in sea water or about .4M NaCl).

(c) Bacteria—Lipman** with Bacillus subtilis obtained a result
similar to that of Osterhout. A mixture of the same concentration
of MgCl, and NaCl (.35M) in the ratios of 10:1 gave the maximum
production of ammonia.

‘To summarize the results of these experiments, it may be said
that there is a distinct antagonism between MgCl, and NaCl, which
is evident on both ends of the curves in figure 8. In this case the
yeast agrees with the observations on plants, animals and bacteria
except in the two instances cited above in regard to fresh-water
Grammarus and green algae.

SERIES IX—ANTAGONISM BETWEEN POTASSIUM CHLORIDE AND
SODIUM CHLORIDE

In this series the flasks were arranged as before. It has been
pointed out by Loeb that two salts with ions of like valence, especially
in the case of monovalent ions, do not antagonize the toxicity of each
other, but rather show a moderately increased toxicity when com-
bined. This is evident with yeast, as is shown by table 9 and the
curves in figure 9. The highest growth in this ease was found at F,
where .2M KCl and .12M NaCl have been combined, having a ratio
of about 2:1. KCl alone at .2M concentration allows the growth
about 114 times that found in this combination. Thus the antag-
onism of NaCl for KCl is found to be negative. But, on the other
hand, there is a distinct antagonism of KCl for NaCl. For example,
NaCl alone at .17M concentration hardly allowed any growth, but in
combination with .01M KCl the growth was accelerated up to about
15 millions, thus showing a distinct antagonism. The reason of this
unexpected negative result on the side of KCl is perhaps the same
that I have suggested in the ease of KCl and CaCl, in Series IT.

For comparison with these results, a number of cases dealing with
plants, animals and bacteria are cited below:

(a) Plants—Osterhout?? with wheat (Early Genésee) has found
a sight antagonism between K and Na ions. But in his work" on
a green alga he obtained a negative result using 3/8M concentration
of two salts in combination.

(b) Animals—Loeb* with Fundulus found a shght antagonism
between the K and the Na ion in relation to the development of em-

1917] Mitra:

TABLE 9—ANTAGONISTIC

KCl vs.

No. NaCl M. Cone

A 0 x .00

B .00 x.208
C .00O1 x .192
D Us Kahlo
BE tL «160
F 2 X.144
t 4 x<.128
H 6» |x%..242
I 8 x.096
Po! (Ae “3 080
K 1.2 ~x.064
my - 14-- x.046
M 1.6 x .032
No 2.8% O10
in 0? M001
P) > 2. <200

= = = =
o no rx a oo

Millions of yeast cells

oo

48 hrs.
1,954,000
2,678,000
5,424,000
2,938,000
2,260,000

678,000

226,000

96 hrs.
6,290,000
226,000
7,184,000
10,786,000
12,339,000
7,838,000
6,780,000
5,650,000
4,156,000
2,906,000
1,130,000
452,000

%
Sig a Sees
Jf ON
Hele SAV UNG ace

144 hrs.
10,556,000
1,808,000
9,256,000
14,690,000
15,942,000
11,526,000
8,678,000
7,205,000
5,882,000
4,900,000
3,390,000
1,130,000
226,000

Concentration of salts

Toxic and Antagonistic Effects of Salts on Wine Yeast

EFFECTS BETWEEN KCL AND NACL

192 hrs.
14,108,000
6,780,000
12,176,000
16,922,000
18,206,000
15,830,000
12,687,000
10,256,000
8,120,000
7,750,000
4,968,000
2,260,000
1,130,000
452,000

91

240 hrs.
16,944,000
7,888,000
14,952,000
18,566,000
21,250,000
17,248,000
13,266,000
12,984,000
9,886,000
8,205,000
6,983,000
4,452,000
2,960,000
904,000

Fig. 9—Curves of yeast growth showing antagonism between KCl and

Nacl.

abscissae, the concentration of salts in combination.

sents the number of cells in blank cultures.

The ordinates represent the number of yeast cells in millions and the
The ordinate at A repre-

92 University of California Publications in Agricultural Sciences | Vol. 3

bryos in the eggs. He also found a similar result with sea-urchins,
Hydromedusa gonionemus, and a jellyfish, Polyorchis.

Lillie’ found that with the larvae of Arenicola the cilary move-
ment goes on in a solution containing 20 parts of NaCl (5/8n) and
8 parts of KCl (5/8n), while each salt used alone stops the movement
altogether.

Ostwald"? with fresh-water Gammarus has shown that there is a
distinct antagonism between K and Na ions in regard to the duration
of life of that animal. Matthews": has found that it takes twice as
much KCl to neutralize the toxicity of NaCl in the case of the devel-
opment of embryos in the eggs of Fundulus. This is rather similar
to the case of yeast, where it takes .2M KCl to neutralize the toxicity
of .14M NaCl to allow the highest growth.

(c) Bacteria—Lipman* with Bacillus subtilis has found that none
of the combinations of these two salts gives as favorable conditions
for growth as is found with each salt alone at the same concentration,
thus showing non-antagonism between the two salts.

To summarize the results in this experiment, it may be said that
with yeast, like valences prevent the antagonistic effects, contrary to
what was found by Lipman with soil bacteria, but in accordance with
the results of Osterhout with wheat, Loeb with FPundulus, and other
investigators with other organisms. The yeast agrees in this case with
all the above-mentioned cases except with that of green algae tested
by Osterhout and that of Bacillus subtilis by Lipman.

SERIES X—ANTAGONISM BETWEEN POTASSIUM CHLORIDE AND
MAGNESIUM CHLORIDE

The experiments in this series were conducted like the others. The
highest growth in this case was found at H, the point where .6M KCl
and .5M MgCl, were combined in a ratio of about 1:1. In the case of
simple salts KCl alone at .2M concentration allowed the highest growth
up to about 3014 millions and MgCl, at .1M about 2614 millions. KCl
alone at .6M and MgCl, at .5M permitted the growth of yeast more
than is found in this combination at H. But this indicates a mild
antagonism, because the toxic effect was less than the sum of the
separate toxic effects of the two salts used alone. Distinct antag-
onism to the effects of MgCl, is shown by KCl, but not the converse.
For example, .8M MgCl, alone allows the yeast to grow only to
8 millions, while in the combination with .1M KCl the growth has

1917} Mitra: Toxie and Antagonistic Effects of Salts on Wine Yeast 93

been increased to 1114 millions. On the other hand, the smaller con-
centrations of MgCl, with higher concentrations of KCl did not show
any antagonism. The reason for this unexpected result 1s perhaps
that previously mentioned in the case of KCl vs. CaCl, in Series VII.

TABLE 10—ANTAGONISTIC EFFECTS BETWEEN KCL AND MGCL,

KCl vs.

No. MgCle M. Conc. 48 hrs. 96 hrs. 144 hrs. 192 hrs. 240 hrs.
A 00 x .00 2,356,000 ~—- 9,701,000 += 12,170,000 + 14,890,000 ‘17,526,000
B POEM are, ce tee de en ee Ae ke ee A) ewe niccatananeniiye * | wcemensanenapaibe
Bat amegey i 2a FS 226,000 1,130,000 = 2,260,000 ~—-3,845,000
Bi; 208 x49 226,000 1,356,000 6,780,000 10,070,000 11,560,000
E 1 x .8 1,130,000 6,780,000 —- 7,408,000 += 10,975,000 12,180,000
F 2 x .7 1,356,000 7,458,000 11,578,000 13,449,000 14,328,000
G 4 x 6 2,486,000 4,838,000 7,006,000 14,690,000 15,500,000
BY oe eS 904,000 3,816,000 5,296,000 12,850,000 16,280,000
I a xa 678,000 2,612,000 4,852,000 8,286,000 9,856,000
Bt ele 8 452,000 2,260,000 3,706,000 5,463,000 —-5,902,000
Kk 18° x 2 452,000 2,040,000 3,295,000 4,895,000 —+5,240,000
as cK! 678,000 1,926,000 2,940,000 3,656,000 —-4,864,000
M 16 x 05 226,000 904,000 3,050,000 3,006,000 4,628,000
Ree OOS | eg 226,000 2,260,000 2,990,000 3,862,000
MRO MASE CHIT Why cs ize” Sy Ge ede 2,226,000 1,130,000
ge eee ee a es Emenee oth ee eT eee
ay We ee ae a a Ba eo ae
mn a |

aki
iM ee oro
NCOP
We NE
NOSSO
SERRE
NZ ESN

J K L M N O P

Millions of veast cells ~

KCl Concentration of salts MgCl.

Fig. 10.—Curves of yeast growth showing antagonism between KCl and
MgCl,. The ordinates represent the number of yeast cells in millions and the
abscissae, the concentration of salts in combination. The ordinate at A repre-

sents the number of cells in blank cultures.

v4 University of California Publications in Agricultural Sciences [ Vol. 3

For comparison with these results a few cases may be cited as
follows:

(a) Plants——Osterhout*® with wheat (Early Genésee) has shown
that the root develops better in a solution having 100 ¢.c. KCl and
7.5 ee. MgCl, at .12M concentration than in KCl alone. He also
found with a marine alga,*? Enteromorpha hopkirku, that both salts
are polsonous when used alone, but a combination in the proportion
of 100 ¢.c. MgCl, and 40 ¢.c. KCl allows considerable growth. He
found a similar antagonism with liverworts.”

(b) Animals.—Matthews" found with Fundulus that in order to
permit development of the embryos in the eggs at the concentration
of 33/48n KCl at least about M/160 MgCl, is needed. He also found
that a solution of 6/8n KCl requires M/80 MgCl, to give the best
result.

(c) Bacterta.—Lillie® has shown that a combination of 10/8n
MgCl, and 5/8n KCl allows the ciliary activity of the larvae of
Arenicola, which is stopped when one salt is used alone.

To summarize, it may be said that a distinct antagonism was found
by Osterhout with higher and lower plants and by Matthews and
Lilhe with animals. With yeast a slight antagonism is found, which
is shown on the curves in figure 10 on the side of MgCl..

SERIES XI—ANTAGONISM BETWEEN CALCIUM CHLORIDE AND
SODIUM CHLORIDE

The plan of this series of experiments was the same of that of the
others. In the ease of simple salts both CaCl, and NaCl were found
to be very toxic, and it may be owing to this extreme toxicity that
the combinations of the two salts showed increased toxicity. Both
from table 11 and the curves in figure 11 it is evident that this toxicity
is very marked. The highest growth was found at E, where .1M CaCl,
and .12M NaCl have been combined in the ratio of 1:1. But even
here the number of yeast cells went up only to 8 millions, which is
far below the highest growth obtained when the salts were used alone.
However, CaCl, shows slight antagonism to the toxicity of NaCl, for
example, .1M NaCl, alone allows the growth only to one million,
while in combination with .1M CaCl it reached more than 8 millions.
On the whole, however, both from the table and the curves it is evident
that the combinations of the two salts are more toxic than the single
salts.

1917 | Mitra: Towic and Antagonistic Effects of Salts on Wine Yeast 9
TABLE 11—ANTAGONISTIC EFFECTS BETWEEN CACL, AND NACL
CaCle vs.

No. NaCl M. Cone 48 hrs. 96 hrs. 144 hrs. 192 hrs. 240 hrs.
A 00 x 00 2,356,000 9,381,000 12,172,000 14,890,000 17,108,000
B AS 0 OR a er ee ee ool vanarakh ! erductsascsduvensp ||” cuwsdyweandosoyses
CG .001x.18 226,000 226,000 226,000 904,000 1,130,000
D .01 x.16 226,000 1,582,000 3,390,000 = 4,682,000 ~—-55,842,000
Moet 13 226,000 1,808,000 —- 5,650,000 ~—- 7,910,000 8,290,000
a SSS Rees vo 1,356,000 3,482,000 = 4,520,000 ~—- 7,042,000
re Bee OG) Soca 226,000 1,130,000 5,650,000 6,820,000
PH 3% .08.> > Anneka 226,000 3,390,000 4,526,000
I SPE cco EN Ad ie eee aL GREE (0. bidpiancdaeniein 452,000
J ee INES 9 = Senet it 9 rs ee RE eects | \GSeccaymaninninaedc’| 9 “debpatuninosedaies
cp WO: UG >: SARI a AR cue tll SB PAS sali GEA 8 «y's, SCR ee

Millions of yeast cells

| Zia
cele es eae

ger

A B C D E FE G
CaCle

Fig. 11—Curves of yeast growth showing effects of NaCl on CaCl,. The
ordinates represent the number of yeast cells in millions and the abscissae, the
concentration of salts in combination. The ordinate at A represents the
number of yeast cells in blank cultures.

For comparison with other organisms the following cases are cited:

(a) Plants —Osterhout® with wheat found a distinct antagonism
between the two salts. He obtained a similar result with green algae
in which he used 100 e.c. NaCl and 10 ec. CaCl, at the concentration
of 3/8M. Kearney and Cameron,’ with leguminous plants, found that
a combination of the two salts increased the tolerance of the plants for
CaCl, three times.

96 University of California Publications in Agricultural Sciences | Vol. 3

(b) Animals——Loeb'! with Hydromedusa Gonionemus has shown
that a combination of 10/8n CaCl, and 5/8n NaCl is harmless to
animals. He also found a distinct antagonism with a_ jellyfish,
Polyorchis, using 50 ¢.c. NaCl and 1 ¢.¢. CaCl,, which allowed the
animal to swim, while NaCl alone was poisonous. The same investi-
gator found a distinct antagonism between these two salts working
with the development of embryos in the eggs of the Fundulus. Anne
Moore’ with the contraction of the lymph heart of frogs and Lingle*
with that of the turtle’s heart noted similar phenomena, thus corrob-
orating the work of Loeb.

Lillie’ working with the larvae of Arenicola has found a distinct
antagonism between Ca and Na ions. MacCallum'* found the same
with his experiments on cathartics.

Meltzer and Auer?! found a distinctly antagonistic effect with
animals in subeutaneous injections. Ostwald'* wth fresh-water Gram-
marus found a strong antagonism between NaCl and CaCl, in regard
to the duration of life of that animal. Finally, Matthews"? has shown
that there is a slight antagonism between the two salts in the develop-
ment of embryos in the eggs of Fundulus.

(c) Bacteria—Lipman* with Bacillus subtilis found a marked
lack of antagonism between the two salts. In his case any combi-
nation of the two salts at .35M concentration was found to be more
poisonous than a single salt.

All these experiments except that of Lipman show that there is
antagonism between CaCl, and NaCl. The yeast agrees very mark-
edly with Bacillus subtilis in showing little or no antagonism between
the two salts, CaCl, and NaCl,.

1917 } Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 97
RELATIVE ANTAGONISMS OF VARIOUS COMBINATIONS

the
are

Table 12 is intended to show the relative antagonisms of
various combinations. The data used in constructing the table
the final counts in each flask.

The average of the counts in all the check flasks is taken as the
basis from which to estimate the influence of the various salts and of

their combinations. The caleulation is made as follows:

Yeast growth in check flasks = 17 (millions).
Yeast growth with single salt no. 1—=a.
Yeast growth with single salt no. 2=b.
Yeast growth with combination no, 1 + 2=ce.
Toxicity — expected = (17 — a) + (17— Db).

Toxicity — observed = 17 —c.
Antagonism of combinations* = (17 —a) + (17 — b) —.(17 — ¢).
_, Antagonism = 17 + c—a—bD.

TABLE 12—RANGE OF ANTAGONISM OF THE BINARY COMBINATIONS CALCULATED
From THE LAST MICROSCOPICAL CoUNT*

No. MgCle X CaCle KCl X CaCle MgCle X NaCl KCl X NaCl KCl X MgCle CaCle X NaCl
At 17,000,000 17,000,000 17,000,000 17,000,000 17,000,000 17,000,000
oto Ue Ue Rs ERR URI eee fer 1 > A cD Ac
ae es 2000000, La cele 5,000,000 4,000,000 na...
D 4,000,000 17,000,000 —.....20.... 8,000,000 10,000,000 4,000,000
E 27,000,000 17,000,000 8,000,000 9,000,000 ~— 9,000,000 +~—- 7,000,000
F 24,000,000 + ~—18,000,000 25,000,000 8,000,000 + ~=—- 7,000,000 ~—- 7,000,000
G 20,000,000 30,000,000 27,000,000 + ~—- 7,000,000 +~=—16,000,000 6,000,000
H 21,000,000 31,000,000 + 14,000,000 7,000,000 9,000,000 ...............
I 7,000,000 8,000,000 11,000,000 10,000,000 22. 2.
J 21,000,000 °1,000:000 © “Zion. pod Ft0geoDI0 2. .
het Ethan a Rai nA TN ac Lit 2) em SE a. Oke
Re. eho ae Be, ee Oe Se A
Re. os eee ee a
SE RS PS ae: ware lie Re SE) Ss ae oe
1s ERG Ee any Ad APE ELE 5) oS rn ee ees he
ee ake et ie ee eee a

+ Millions on average.
* These results are shown graphically by the curves in figure 12.

* This defines ‘antagonism’ as the difference between the expected and the
observed toxicity.

The curves have been drawn to show the antagonism of the com-
binations and not the actual growth of the yeast as has been shown
in the previous curves.

98 University of California Publications in Agricultural Sciences Vol. 3
y g

32
30 KCI & CaCl
MgCle, & Cal
28 mame Mell. < NaCl
weeee eee EC) St Maou
26 KCl &* NaCl
CaCl. x NaCl
24

Millions of yeast cells
=

ACR PAE
VAALLLAALEL LLL
VASE TTT

Combinations of Salts

A

Fig. 12.—Curves showing range of antagonism of binary combinations of
salts. The ordinates represent the average number of yeast cells in millions
and the abscissae, the concentration of salts in combinations. The ordinate at
A represents the average number of cells in blank cultures.

— i

1917] Mitra: Toxie and Antagonistic Effects of Salts on Wine Yeast 99

SUMMARY
PART A—TOXIC EFFECTS OF SINGLE SALTS

1. Each of the four single salts—KCl, MgCl,, CaCl,, and NaCl—
is more or less toxie to the yeast, Saccharomyces ellipsoideus, at certain
concentration. KCl is the least toxie and NaCl the most for the yeast
(no. 66) used.

2. The lower concentrations of each salt stimulate the growth of
yeast. The highest number of yeast cells in microscopical count was
found at .2M KCl, .1M MgCl, .01M CaCl,, and .001M NaCl, KCl
being the most favorable and NaCl the least. Beyond the favorable
concentrations the various salts are toxic to yeast.

3. The concentrations of salts that inhibited the growth of yeast
cells were found at 2.2M KCl, 1.2M MgCl, .7M CaCl,, and .2M NaCl.

4. The results of the experiments are quite different from those
found with either bacteria, the higher plants or animals. The yeast
stands in this respect midway between plants and animals and swings
to either direction according to the environment.

5. The salts used had a marked effect on the size and appearance
of the yeast. Taking decrease in size as a criterion, the salts affected
the yeast toxically in the same relative ways as indicated by the rate
of multiplication of the cells.

PART B—ANTAGONISTIC EFFECTS OF COMBINATIONS OF SALTS

1. As shown by growth of yeast, the variation in antagonism be-
tween the four single salts in all possible combinations may be ar-
ranged in order as follows:

. MgCl, vs. CaCl, (most)
. KCl vs. CaCl,

. MgCl, vs. NaCl

. KCl vs. NaCl

. KCl vs. MgCl,

. CaCl, vs. NaCl (least)

aor WD

2. The effect of binary salts with yeast, whether positively or nega-
tively antagonistic in comparison to animals, plants and soil bacteria,
may be tabulated as follows:

100 University of California Publications in Agricultural Sciences [ Vol. 3

Binary salts Yeast Animals Plants Soil bacteria
1. MgCl, vs, CaCl, of + and — -f- ——
2. KCl vs, CaCl + and — + and— + +
3. MgCl, vs. NaCl } + and — + and — +
4. KCl vs. NaCl + and — + + and — + and —
5. KCl vs. MgCl, + and— + ee DM freee ie ok
6. CaCl, vs. NaCl + and — of} + —_
+ = strong antagonism. + = mild antagonism. —- = strong increase of toxicity. — = slight

increase of toxicity.

3. In regard to the effects of valences of ions the following results
have been obtained with yeast :

(a) That divalent ions may antagonize monovalent ions is evident from the
combinations of MgCl, vs. NaCl and CaCl, vs. NaCl. Ngative results were ob-
tained from the combinations of KCl vs. CaCl, and KCl vs. MgC).

(b) That a divalent ion may be antagonized by a divalent ion is evident
from the combination of MgCl, vs. CaCl..

(c) That monovalent ions may antagonize divalent ions is shown in the
combinations of KCl vs. CaCl.; MgCl, vs. NaCl and KCl vs. MgCl..

(d) That a monovalent ion may antagonize a monovalent ion, though not
very markedly, has been found in the combination of KCl vs. NaCl.

1917 | Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 101

LITERATURE CITED
PART A—TOXIC EFFECTS OF SINGLE SALTS

11900. Loeb, J. On the different effects of ions upon myogenic and neuro-
genic rhythmical contractions and upon embryonic and muscular tissues, Am.
Jour. Physiol., vol. 3, pp. 883-396.

21900.—On the ion proteid compounds and their réle in the mechanics of
life phenomena, Am. Jour. Phyiol., vol. 3, pp. 327-338.

8 1902.—Studies on the physiological effects of the valency and possibly the
electrical charges on ions, Am. Jour. Physiol., vol. 6, pp. 411-433.

41905. Ostwald, W. Studies on the toxicity of sea-water for fresh-water
animals: (Grammarus Pulex De Geer), Publ. Univ. Calif. Physiol., vol. 2, pp.
163-191. ;

51905. Loeb, J. On fertilization, artificial parthenogenesis and Cytolysis
of the sea urchin egg, Univ. Calif. Publ. Physiol., vol. 2, no. 8, pp. 73-81.

61906. Osterhout, W. J. V. On the importance of physiologically balanced
solutions for plants, Bot. Gaz., vol. 42, pp. 127-134.

7 1907.—On the importance of physiologically balanced solutions for plants,
Bot. Gaz., vol. 44, pp. 259-272.

8 1909.—On the similarity of behavior of sodium and potassium, Bot. Gaz.,
vol. 48, pp. 98-106.

9 1906.—Extreme toxicity of NaCl and its prevention by other salts, Jour.
Biol. Chem., vol. 1, pp. 363-369.

101908. Magowan, F. W. The Toxic Effects of certain common salts of the
soil on plants, Bot. Gaz., vol. 45, pp. 45-49.

111909. Lipman, C. B. Toxic and antagonistic effects of salts as related
to ammonification by Bacillus subtilis, Bot. Gaz., vol. 48, pp. 105-125.

121912. Bokurny, T. The effects produced by metallic salts on yeasts and
other fungi, Centrbl. Bakt., 2. Abt. Bd. 35, no. 6-10, pp. 118-197.

131913. Loeb, J. Artificial Parthenogenesis and Fertilization, pp. 173-190.

PART B—ANTAGONISTIC EFFECTS OF COMBINATIONS OF SALTS

11900. Loeb, J. On the different effects of ions, Am. Jour. Physiol., vol. 3,
p. 383. Complete entry to be found in Part A.

21900. Loeb, J. On the ion proteid compounds, Am. Jour. Physiol., vol. 3, p.
327. Complete title in Part A.

31900. Loeb, J. Ueber die Bedeutung der Ca and K ionen fiir die Herzthat-
igkeit, Pfluger’s Archiv, vol. 80, pp. 229-232.

41900. Lingle, D. J. In action of certain ions, Am. Jour. Physiol., vol. 4,
p. 265-282.

51900. Osterhout, W. J. V. Die Schiitzwirkung des Natriums fiir Pflanzen,
Jahrb. Wiss. Bot., vol. 46, p. 121-136.

61901. Lillie, R. On the differences in the effects of, ete., Am. Jour.
Physiol., vol. 5, pp. 56-85.

71901. Moore, A. Effects of ions on the contraction of, etc., Am. Jour.
Physiol., vol. 5, pp. 86-94.

81902. Kearney & Cameron. Some mutual relations between alkali soils
and vegetation, U. 8. Dept. Agr. Report, no. 71.

91902. Loeb, J. Studies on the physiological effects, Am. Jour. Physiol.,
vol. 6, p. 411. Complete title in Part A.

101903. Loew, O. The physiological réle of mineral- nutrients in plants,
U. S. Dept. Agr. B. P. I., Bull. 45.

111904. Matthews, A. P. Toxie and antagonistic effects of salts, Jour.
Am. Physiol., vol. 12, pp. 419-443.

121905. Loeb, J. Studies in general physiology, vol. 2, pp. 518, 572, 584.

131905. Ostwald, W. Studies on the toxicity of sea-water, Publ. Univ.
Calif. Physiol., vol. 2, pp. 163-191.

102 University of California Publications in Agricultural Sciences [ Vol. 3

141905. MacCallum, J. B. The action of purgatives in a crustacean, Bull.
Univ. Calif. Physiol., vol. 2, no. 6, pp. 65-70,

15 1906. Loeb, J. The stimulating and inhibitory effects of Mg and Ca.,
Jour, Biol. Chem., vol. 1, p. 427-436.

161906. Osterhout, W. J. V. On the importance of physiologically balanced
solutions for plants, Bot. Gaz., vol. 42, pp. 127-134.

17 1906. Extreme toxicity of NaCl and its prevention by other salts,
Jour. Biol. Chem., vol. 1, pp. 363-369.

181907. Loew & Azo. On the physiologically balanced solutions, Bull.
Agric. Univ. Tokyo, vol. 7, no. 3.

191907, Benecke, W. Uber die Giftwirkung verscheidener Salze auf Spy-
rogyra und ihre Entgiftung durch Calciumsalze, Ber. deutsch. botanisch. Ges.,
vol. 25, pp. 322-337.

201908. Osterhout, W. J. V. Antagonism of Mg and K on plants, Bot.
Gaz., vol. 45, pp. 117-129.

21 Meltzer & Auer. The antagonistic action of calcium, Am. Jour. Physiol.,
vol. 21, pp. 400-419.

221909. Osterhout, W. J. V. On the similarity of behavior of Na and K,
Bot. Gaz., vol. 48, pp. 98-104.

231909. Lipman, C. B. Toxie and antagonistic effects of salts, Bot. Gaz.,
vol. 48, p. 105. Complete title in Part A.

241910. Lipman, C. B. On the lack of antagonism, Bot. Gaz., vol. 49, pp.
41-50.

251910. Lipman, C. B. On physiologically balanced solutions for bacteria,

Bot. Gaz., vol. 49, pp. 207-215.

UNIVERSITY OF CALIFORNIA PUBLICATIONS /[
IN

AGRICULTURAL SCIENCES
Vol. 3, No. 6, pp. 103-130 . March 9, 1918

CHANGES IN THE CHEMICAL COMPOSITION
OF GRAPES DURING RIPENING

BY
F. T. BIOLETTI, W. V. CRUESS, anp H. DAVI

The investigations reported in this paper were undertaken to
determine the changes in chemical composition of vinifera varieties
of grapes in California during the growing and ripening stages. A
survey of the literature indicated that, although the subject had been
quite fully investigated in Europe with vinifera varieties and in
America with the native varieties, very little had been published upon
the ripening of vinifera varieties under California Conditions. A
great many analyses of different varieties of grapes have been made
by chemists of the University of California Experiment Station, nota-
bly by G. E. Colby, and are reported in the publications of this station.*
A paper by G. E. Colby? gives data upon the nitrogen content of a
number of varieties of ripe vinifera grapes. Most of the analyses,
however, do not show the changes in composition during ripening.

Of the more recent European investigations* some deal with the
changes in general composition, others are confined to a discussion of a
single component, such as sugar, or coloring matter, or acid principles.

The changes in composition of American varieties of grapes during
ripening have been studied quite thoroughly by W. B. Alwood?* and
his associates. These investigations gave particular attention to the

1 Hilgard, E. W., The composition and classification of grapes, musts, and

wines. Rept. of Viticultural Work, Univ. Calif. Exper. Sta. Rep., 1887-93, pp.
3-360.

2 Colby, G. E., On the quantities of nitrogenous matters contained in Cali-
fornia musts and wines. Ibid., pp. 422-446.

3 Kelhofer, W., The grape in the various stages of maturity; trans. by L.
Zardetti. Gior. Vin. Ital., vol. 34 (1908), no. 30, pp. 475-477.

Barberon, G., and Changeant, F., Investigations on the development and

104 University of California Publications in Agricultural Sciences [ Vol. 3

increase in sugar content and changes in acidity during the period
in which the grapes were under observation. Alwood and other mem-
bers of the Bureau of Chemistry, United States Department of Agri-
culture, have also published a number of reportst on the general
composition of American varieties of grapes as affected by season,
locality, ete.

The most notable changes taking place during ripening were found
by the European and American investigators mentioned above to be:
(1) increase in total sugar ; (2) decrease in ratio of glucose to fructose ;
(3) decrease in total acid; (4) increase in ratio of cream of tartar to
total acid due to decrease in total acid ; (5) decrease in tannin; and (6)
increase in coloring matter. The cream of tartar and protein change
very little in percentage during ripening, although, according to the

composition of varieties of grapes in Abraon-Durso. Ann. Soc. Agr Sci. et Ind.,
Lyon (8), vol. 1 (1903), pp. 97-159.

Laborde, J., The transformation of the coloring matter of grapes during
ripening. C. R. Acad. Sei. (1908), vol. 17, pp. 753-755.

Martinand, V., On the occurrence of sucrose and saccharose in different parts
of the grape. C. R. Acad. Sei. (1907), vol. 24, pp. 1376-79.

Roos, L., and Hughes, E., The sugar of the grape during ripening. Ann,
Falsif. (1910), vol. III, p. 395.

Bouffard, A., Observations in regard to the proportion of sugar during ripen-
ing. Ann. Falsif. (1910), vol. III, pp. 394-5.

Zeissig, Investigations on the process of ripening on one-year-old grape wood.
Ber. k. Lehranst. Wien, Obst-u. Garten-bau (1902), pp. 59-64.

Koressi, F., Biological investigations of the ripening of the wood of the
grape. Rev. Gen. Bot., vol. 13 (1901), no. 149, pp. 193-211; no. 150, pp. 251-264;
no. 151, pp. 307-325.

Brunet, R., Analysis and composition of the grape during ripening. Rev.
de Viticulture, vol. 37, pp. 15-20.

Garina, C., Variations in the principal acids of grape juice during the process
of maturing. Canina. Ann. R. acad. d’agricultura di Torino, vol. 57 (1914),
p- 233. Cf. Ann. Chim. applicata, vol. 5 (1914), pp. 65-6. See also Ann. r. acad.
d’agr. di Torino, vol. 57, pp. 233-90.

Baragolia, W. I., and Godet, C., Analytical chemical investigations on the
ripening of grapes and the formation of wine from them. Landw. Jahrb., vol.
47 (1914), pp. 249-302.

Riviére, G., and Bailhache, G., Accumulation of sugar and decrease of acid
in grapes. Chem. Abs. Jour. (1912), p. 1022; Jour. Soe. Nat. Hort. France (4),
pp. 125-7; Bot. Cent., 1912, pp. 117, 431.

Pantanelli, Enzyme in must of overripe grapes. Chem. Abs. Jour., vol. VI
(1912), p. 2447.

+ Alwood, W. B., Hartmann, J. B., Eoff, J. R., and Sherwood, 8. F., Develop-
ment of sugar and acid in grapes during ripening. U.S. Dept. Agric. Bull. 335,
April 11, 1916.

—— The occurrence of sucrose in grapes. Jour. Indust., vol. IT, Eng. Chem.
(1910), pp. 481-82.

—— Sugar and acid content of American native grapes. 8th Inter. Cong.
Appl. Chem. (1912), Sect. VIa—XIv, pp. 33, 34.

—— Enological Studies: the chemical composition of American grapes grown
in Ohio, New York, and Virginia. U.S. Dept. Agric. Bur. Chem. Bull. 145, 1911.
Crystallization of cream of tartar in the fruit of grapes. U.S. Dept.
Agric. Jour. Agric. Research (1914), pp. 513, 514.

Alwood, W. B., Hartmann, B. G., Eoff, J. R., Sherwood, 8S. F., Carrero, J. O.,
and Harding, T. J., The chemical composition of American grapes grown in the
central and eastern states. U.S. Dept. Agric.( 1916) Bull. 452.

a

1918 | Bioletti-Cruess -Davi: Chemical Composition of Grapes 105

investigations referred to, there is a slight increase in both of these
constituents.

In the investigations reported in the present paper, particular
attention was given to increase in total solids and sugar, decrease in
total acid, and changes in protein and cream of tartar in the must or
juice of the grapes. The ripening of the leaves was traced by noting
the changes in starch, sugar, acid, and protein content.

Sampling —During 1914 and 1915 samples of fruit were taken
from the time the grapes had reached full size but were still hard and
green until they had become overripe. During 1916 the first samples
were taken shortly after the berries had set and before the seeds had
formed. The last samples were taken when the grapes had become
overripe. Samples of leaves were also taken in 1916 on the same
dates that samplings of the grapes were made. The samples were
taken at intervals of approximately one week. They were in all cases
taken from the experimental vineyard at Davis.°

Five-pound samples of grapes were used. The grapes were picked
from the first crop, except in 1914, when a comparison of the ripening
of first and second crops was made. An ordinary five-pound grape
basket was filled with leaves at each sampling. The samples of grapes
and leaves were shipped from the vineyard to the laboratory at
Berkeley, where the grapes were placed in an Enterprise fruit crusher
and pressed. The juice was sterilized in bottles at 212° F. The leaves
were ground in an Enterprise food chopper and sterilized at 212° F
in wide mouth, air tight bottles. The samples were then reserved for
chemical examination.

In 1914 it was found that there was considerable irregularity in
the variation of samples from week to week. For example, instead
of an increase of total solids during the periods between samplings, a
slight decrease was found in a few samples. During the 1915 season
it was therefore considered of interest to note what effect certain
factors might have upon the composition of samples taken on the
same date.

1. Effect of Age of Vine. The entire first crop from three large
old vines and from three small young vines, all of the Muscat variety,
was picked, crushed, and pressed.- Analyses of the juices were made
with the following results:

_ 8 The authors wish to express their appreciation of the assistance of F. C.

Flossfeder, of the University Farm at Davis, who gathered most of the samples
reported upon in this paper.

LOG University of California Publications in Agricultural Sciences | Vol. 3

TABLE 1—EFPFECT OF AGE OF VINE ON BALLING AND ACID OF Must oF Muscat

GRAPES

Vine Balling Acid
po | ST, ee a ae ie 24.7 .67
EE RRR 8 oo Tae he SAT 27.7 49
Ria WOO seco oes 27.6 .67
ERGO, MONE irc ce tae yecee ete 22.0 88
ENOTES By Ok cantons 23.5 .75
NO AE ot 23.6 76
PVerere. OTA) fin cccccccteone 26.7 61
Average, large .............----.-.-. 23.0 381
TOI os So. a cteacoies 3.7 —.20

The results show rather strikingly that young vines ripen their
fruit earlier than do mature vines. This fact makes it essential that
samples, to be comparative, must be taken from vines of the same age.

2. Comparison of Grapes from North and South Sides of Vines.
The whole first crop from three large Museat vines was picked. The
bunches from the north and south sides of each vine were kept sep-
arate. They were crushed, pressed, and analyzed for Balling and acid
content.

TABLE 2—COMPARISON OF BALLING AND ACID OF JUICE FROM GRAPES PICKED FROM
NorRTH AND SoutTH SIDES OF VINES

Vine and side of vine Balling Acid
ie er Se ne ee er 21.3 92
1 A) eer Rated Cer ee eke 22.7 84
, 2) | SSeS Sas Se ee es ieee. 7 DOS 23.5 81
es ee ER Pe ae eae eee 23.5 80
ol [eae ae Ee OEP ERR SON 23.1 81
SRR rs Ses ot ere a ee 24.1 Ay fe
Avyerare, N side ..-...-<...5 22.63 85
Avyorage, 8: side 2053.55.63 23.43 .78
UMOTBONG 3. 6 80 —.07

The tests indicate that grapes located on the south side of the vine
ripen more rapidly than those on the north side. This difference is
apparently due to the fact that the south side of the vine receives
more heat than the north side.

3. Effect of Location of Bunch on Cane. Grapes of first crop, from
canes showing two bunches each, were picked and the bunches from
near the bases of the canes kept separate from those near the tip of
the cane. They were crushed, pressed, and analyzed for Balling and
acid.

1918 | Bioletti—Cruess—Davi: Chemical Composition of Grapes 107

TABLE 3—Errecr OF LOCATION OF BUNCH ON CANE

Nearest base of cane Nearest tip of cane

Vine ‘Balling Acid Dalling Acid
MEUBGNG, TIO, 15 COMO Zo beccrsacieesnmn 25.1 73 23.7 83
Muscat, no. 1, cane 2 .................. 25.6 19 24.8 80
Muscat, mo. 2, Cane: Te .ucncsasihsens 25. 85 24.6 87
Muscat, no. 2, Cane B. ..ccsccascs->-s- 25.2 .78 24.7 85
Muscat, MO. BS, GARO 1. coiccscis.ccss. 23.0 79 22.6 82
Muscat, no. 3, cane 2 .................. 24.5 13 23. By i
Museat, no. 4, cane 1 ..................- 24.2 90 25.2 90
Muscat, no. 4, cane 2 ................... 24.5 68 23.8 83
CL OELY 5 CGING Lc. ckain tis. ceniaatetenae 21.2 67 21.2 80
TOMSEY, OTIS 2. soso secthtencineseactocenatie 23.0 63 22.4 .76
PUENTE CONG Le cticiienscncteciese 23.3 61 22.3 62
SUILARINA, CONG (2) access ec ieicseeten 22.5 61 23.0 63
OTL UPON Ris GILG: Bio cc an obi aceanoneae 23.2 Rif. 21.6 70
SOU AA I ORTUG etewvtansn te Roose 21.1 90 20.0 1.20
POlOMING, | COIS si. ee BO Aa teak Ou ine
PF BLOMING) COME! B02. epic nf nese ASE a Saale EOE) wn, . acasun
NCUA TN eet cat hie pha ons 24.9 75 23.1 81

The data indicate that bunches at the base of the cane ripen in most
cases more rapidly than those near the tip, although this relation does
not always hold and may be reversed in some instances.

4. Variation in Balling Degree of Must from Bunches of Similar
Appearance and Size from Same Vineyard and Gathered on Same
Date. A five-pound basket of grapes of first crop and selected for
similarity of color, size of bunch, and general appearance was picked
from each of a number of vines in the same vineyard. Vines of
similar size and appearance were chosen. Several varieties were rep-
resented in the experiment. Tests of Balling degree only were made.

TABLE 4—VARIATION IN BALLING IN Must FroM GRAPES OF SAME VARIETY PICKED
H'ROM DIFFERENT VINES OF SIMILAR APPEARANCE

Vine Mean Maximum

Variety number Balling Balling variation
Cornichon 3 eds | ee een
Cornichon 6 Pye eee eee
Cornichon 9 if Sep 9) SE eee
Cornichon 11 Wepre were ass,
Cornichon____....... 16.1 14.9 1.9
Emperor 10 (Uo) gS «Se ia ose
Emperor 1 eR aor
Emperor 13 PELE gl | acs See ee ners
Emperor 14 Lg |. as
Emperor 17 15.0 14.4 ° 3.5
Malaga 5 Ua Ss

Malaga 6 id hl <3 es

108

Variety
Malaga
Malaga
Malaga
Museat
iuuscat
Muscat
Muscat
Museat
Palomino
Palomino
Palomino
Palomino
Palomino
Sultanina
Sultanina
Sultanina
Sultanina
Sultanina
Tokay
Tokay
Tokay
Tokay
Tokay

TABLE 4—(Continued)

Vine
number
7
i]

11

Pedro Zumbon
Pedro Zumbon

Pedro Zumbon
Pedro Zumbon

Emperor
Emperor
Emperor
Emperor
Emperor
Cornichon
Cornichon
Cornichon
Cornichon
Cornichon
Malaga
Malaga
Malaga
Malaga

Mean variation, six ripest varieties
Mean variation, six least ripe varieties

*
7
4
Pedro Zumbon 6
3
5

Balling
19.7
18.5
19.2
21.7
21.1
20.9
21.5
21.7
19.5
21.0
21.2
20.7
18.8
22.5
21.5
18.7
22.0
22.6
19.8
19.3
18.7
20.7
19.5
21.5
21.2
20.6
18.5
19.8
18.1
15.8
16.2
16.8
16.3
17.3
16.3
17.9
17.8
18.0
18.3
20.4
20.0
20.1

Average variation, whole series

* Adjacent vines.

Mean
Balling

University of California Publications in Agricultural Sciences

Maximum
Variation

waeeee

[ Vol. 3

1918 | Bioletti-Cruess-Davi: Chemical Composition of Grapes 109

The data illustrate the difficulty of selecting five-pound lots of the
same variety that will represent average samples.

5. Effect of Location of Berries on the Bunch. All of the bunches
of the first crop were taken from two Muscat vines. The bunches
were cut into top and bottom halves. These lots were crushed sep-
arately, pressed, and the juices analyzed.

TABLE 5—Errect or LOCATION OF BERRIES ON BUNCH

Sample Balling Acid
Vine no. 1, stem: 6nd of. Sunel i027 k i ..s..:. 23.6 .76
Vine no. 1, apical-end of ‘bunen: ....2....2....4...... 22.7 87
Vine no. 2,:stem end of bunch <.:-..i ern. 21.3 92
Vine no. 2, apical end of biumeli ........2-............... 21.3 93

The results show that considerable variation in composition of the
berries may exist within the same bunch.

6. Effect of Thoroughness of Pressing. About ten pounds of Mus-
eat grapes were crushed and lightly pressed. The pulp and skins left
from this pressing were then thoroughly crushed and pressed a second
time. The juices from the two lots were analyzed separately.

TABLE 6—EFFECT OF THOROUGHNESS OF PRESSING

Sample Balling Acid
PIESE: PTOGRIND -..c sd cee ee 22.8 .78
Second pressing .................... 22.8 .79

There was practically no difference between the juices from lightly
and thoroughly pressed grapes of the same lot.

The data from the above six tests indicate that it is a very difficult
matter to select grapes that will represent a fair average sample of
the grapes to be studied. The size and age of the vine, the side of
the vines, the location of the bunch on the cane, and individual vines,
all affect the composition of the juice from the grapes very materially,
and these factors should be taken into account when samples are
taken.

Preservation of Samples and Preparation for Analysis —In 1914
the samples of juice were preserved with HgCl,, 1:1000. In 1915 and
1916 the samples were sterilized at 100° C. Before analysis the bottles
were heated to 100° C for an hour to dissolve any cream of tartar which
might have separated. The juices were filtered before analysis. Con-
siderable coagulation of dissolved solids took place during sterilization.

L110 University of California Publications in Agricultural Sciences | Vol. 3

Methods of Analysis —The samples were analyzed by the methods
in use in the Agricultural Chemistry Laboratory and the Nutrition
Laboratory of this station. A brief description of the methods follows:

1. Total Solids. The juice was filtered clear and cooled below
15° C, The specific gravity was determined by a pycnometer at
15°5 C. The corresponding total solids, or extract, was found from
Windisch’s tables in Leach’s Food Analysis, page 697. This table
gives the extract as ‘‘grams per 100 grams’’; that is, per cent by
weight. To caleulate the corresponding grams per 100 e.c., the per
cent by weight was multiplied by the specific gravity. This gives a
figure not very much greater than grams per 100 grams in juices of
low specific gravity, but gives a figure as much as 2 per cent greater
where the total solids are much above 20 per cent. The two methods
of reporting total solids has in the past led to much unnecessary
confusion. It is therefore urged that the reader bear in mind the
distinction between the two methods when reading the discussions in
this paper or examining the curves.

2. Sugar. The sample was filtered; an aliquot was treated with
lead acetate; diluted to mark; filtered; lead removed with anhydrous
Na,CO,, and the sugar determined in an aliquot by the gravimetrie
method, using Soxhlet’s modification of Fehling’s solution. The Cu,O
was weighed directly after drying at 100° C. The corresponding
sugar as invert sugar was obtained from Munson and Walker’s table
in Leach’s Food Analysis. The grams of invert sugar per 100 ee.
found in this way was divided by the specific gravity of the must to
obtain the corresponding grams per 100 grams of juice.

3. Total acid was determined by titration of a 10 ¢.c. sample with
N/10 NaOH, using phenolphthalein as an indicator, and is reported
as tartarie acid, grams per 100 e.e.

4. Cream of tartar was estimated by a method suggested by Pro-
fessor D. R. Hoagland of the Division of Agricultural Chemistry.
Ten e.c. of the juice was incinerated at a low heat in a muffle furnace
until well carbonized, but not to a white ash. (Excessive heating
results in loss of K by volatilization.) The K,CO, formed by inein-
eration was leached out with hot water and a known excess of N/10
HCl added. This was titrated back with N/10 NaOH, using methyl
orange as an indicator. The K,CO, is obtained by difference and
ealeulated back to cream of tartar, assuming that all of the K,CO, is
formed by the oxidation of cream of tartar, KH(C,H,O,). It is

1918 | Bioletti-Cruess-Davi: Chemical Composition of Grapes 111

reported as grams KH(C,H,O,) per 100 ¢.¢., and also as tartaric
acid,

5. Free Tartarie Acid was obtained by difference between total acid
and eream of tartar calculated as tartaric acid. It is reported as
grams per 100 e@.e.

6. Protein in the juice was determined by the usual KJeldahl-
Gunning method upon a 10 ¢.e. sample. It is reported as grams per
100 @.e.

7. Moisture in the leaves was determined by drying the sample at
100° C.

8. Sugar in the leaves was estimated by leaching the dried sample
with cold water and determining sugar by the gravimetric Fehling
method in the filtrate.

9. Stareh in the leaves was determined by hydrolysis of the dried
ground sample with dilute HCl at 100° C., followed by filtration and
the usual gravimetric Fehling method for juice described above.

10. Protein in the leaves was determined by the Kjeldahl-Gunning
method on .5 gram samples.

11. Acid in the leaves was estimated by leaching in hot water and
titrating in the presence of the leaves, using litmus paper as indicator.

Analyses of Musts from Grape-Ripening Samples, 1914, 1915, 1916.
The data from the analyses have been assembled in the following
tables. Owing to the size of the tables, abbreviations have been
necessary for the headings of the columns.

EXPLANATIONS OF HEADINGS OF TABLES

. Sp. gr.= Specific gravity at 15°5 C.
. T.S.G.= Total solids in grams per 100 grams.
. T.S.C.= Total solids in grams per 100 e.e.
. S.G.=Sugar in grams per 100 c¢.c.
. S.I.=Sugar in grams per 100 grams.
. Tl. A.= Total acid in grams per 100 e.c.
. C.T.—=Cream of tartar in grams per 100 ce.
8. C.T. T.—=Cream of tartar as tartaric acid, grams per 100 c.e.
9. T. A.= Total free acid as tartaric obtained by subtracting cream of tartar
as tartaric from total acid as tartaric.
10. P.= Protein, grams per 100 e.¢.
11. 8S. =Sum of sugar, cream of tartar, tartaric acid, and protein in grams
per 100 e.e.
12. T.S.—S.= Total solids (T.S. C.) —S (preceding column).

aon fP WD He

~]

112

Malaga

First crop:

Variety
and date

Aug.
Aug

Aug.
Aug.
Aug.
Aug.
Sept.
Oct.

19
26
26
26
26
31
23

5

University of California Publications in Agricultural Sciences

:
Sp. gr.
1.0396
1.0413
1.0595
1.0613
1.0694
1.0732
1.0736
1.0965

Second crop:

Aug.
Aug.
Sept.
Sept.
Sept.
Oct.

Tokay

First crop:

Aug.
Aug.
Aug.
Aug.
Sept.
Sept.
Sept.
Oct.

Oct.

10
31
14
23

9

—

14

1.0213
1.0495
1.0532
1.0670
1.0869
1.0930

1.0454
1.0624
1.0682
1.0849
1.0865
1.0912
1.0937
1.0991
1.1000

Second crop:

Aug.
Sept.
Sept.
Oct.

19
14
23
14

Cornichon

Variety
and date

Aug.
Sept.
Sept.
Sept.
Sept.
Oct.
Oct.
Oct.

1.0657
1.0701
1.0769
1.0911

‘ABLE 7—GRAPE RIPENING TeEstTs, 1914

T.8.G. 8.0.
10.25 10.65
10.69 11.13
15.42 16.33
15.87 16.84
18.01 19.25
19.00 20.39
19.10 20.50
25.12 27.54

5.51 5.62
12.82 13.45
13.78 14.51
17.43 18.60
22.59 24.55
24.20 26.45

11.75 12.28
16.08 17.08
17.69 18.90
22.09 23.97
22.49 24.44
23.72 25.88
24.38 26.66
25.80 28.36
26.04 28.64

17.04 18.16
18.19 19.47
19.95 21.48
23.70 25.86

TABLE 8—GRAPE RIPENING TESTS, 1915

2 3
7.6.6, 72. 8. C.
8.38 8.65
13.31 13.99
17.85 19.08
18.76 20.12
19.13 20.54
20.28 21.86
21.91 23.76
22.70 24.68

(Grapes from Davis)

4 5

&¢. B.r. Ti

7.32 7.04 2.78 .35
7.84 7.53 2.65 .36

13.37 12.62 .77 .48
14.31 13.50 1.46 .31
16.59 15.52 1.00 .36
17.65 16.45 .87 .55
17.83 16.60 .74 .38
24.89 22.70 .72 .50

2.07 2.03 3.22 .23
958 9.13 2.51 .40
11.89 11.30 2.07 .37
15.29 14.33 1.54 .50
22.04 20.19 1.07 .45
23.90 21.87 .94 .48

8.73 8.35 2.63 .46
14.28 13.44 1.56 .45
15.94 14.92 1.32 .45
21.87 20.16 .63 .59
22.21 20.44 .77 «43
23.44 2148 .59 .64
24.15 22.08 .58 .49
25.55 23.25 .45 .54
25.78 23.44 .52 .58

15.03 14.10. 1.91 .50
16.68 15.59 1.29 .52
19.22 17.85 1.01 .48
23.43 21.47 .69 .60

(Grapes from Davis)

4 5 6 7 8
AG yo ka a OU es ee
23
25
.28
28
30
29
27
ol

3.99 3.86 3.05 .58
10.70 10.18 1.62 .61
15.94 1491 97 .70
16.97 15.83 .94 .71
18.31 17.05 .87 .75
19.41 18.02 .71 -.73
20.40 18.81 .78 .68
21.06 19.87 .75.. .78

6 7 8

wo Ce Cts
13
14
19
12
14
22
15
.20

09
16
15
20
18
19

9
yap

2.65
2.51

2.45
1.38
1.14
40
.60
44
30
24
29

1.70
21
82
45

9
Te
2.82
1.37
69
66
61
42
.62
44

[ Vol. 3

10.53
10.96
14.98
16.29
18.19
19.30
19.32
26.48

5.60
12.61
14.49
17.43
23.79

25.54

11.96
16.38
17.80
23.26
23.56
24.93
25.33
26.78
27.23

16.55
18.64
20.92
24.88

1.10

1.33
1.58
1.41

61
83
56
98

12
T.S. 8.
88
89
1.32
1.32
21
82
1.40
1.94

1918]

Emperor

Variety
and date

Aug. 19
Sept. 1
Sept. 7
Sept. 15
Sept 22
Sept. 29
i a |
Oct.
Oct.

Malaga

Aug.
Aug. Zu
Sept. 1
Sept. 7
Sept. 15
Sept. 22
Sept. §
Oct. 7
Oct.

Muscat

—

Aug.
Aug.
Sept.
Sept.
Sept.
Sept.
Sept.
st. . 7

bo
ane oo

wo Ww e&
© bo

Aug. 19
Aug. 25
Sept. 1
Sept. 7
Sept. 15
Sept. 22

Sultana

Aug.
Aug. 25
Sept.
Sept.
Sept. 2
Sept.

won

1
Sp. gr.

1.0420
1.0479
1.0560
1.0632
1.0652
1.0672
1.0744
1.0765
1.0792

1.0546
1.0651
1.0678
1.0719
1.0758
1.0760
1.0812
1.0838
1.0970

1.0615
1.0744
1.0805
1.0827
1.0917
1.0954
1.1048
1.1079

Pedro Zumbon

1.0555
1.0588
1.0642
1.0693
1.0708
1.0912

1.0673
1.0746
1.0815
1.0893
1.0902
1.0922

Bioletti-Cruess—Davi: Chemical Composition of Grapes

2
of CO = IC

10.87
12.40
14.51
16.37
16.9]
17.43
19.31
19.86
20.57

14.14
16.86
17.59
18.66
19.68
19.81
21.20
21.78
25.25

15.94
19.31
20.91
21.47
23.85
24.14
27.30
28.12

14.38
15.24
16.64
17.98
18.37
23.72

17.80
19.37
21.17
23.22
23.39
23.99

TABLE 8—(Continued)

5
5. I.
6.68
9.37
10.87
14.00
14.51
15.34
16.59
17.06
18.36

11.82
13.64
15.69
15.86
16.89
17.09
17.09
19.40
22.41

13.12
16.72
18.05
18.83
21.52
22.40
24.45
25.53

11.33
13.01
14.67
15.48
16.97
21.10

16.64
16.71
18.73
21.13
21.19
22.01

6 7
Gules. iet > Os

2.00
1.89
1.70
1.40
93
91
79
.79
15

2.05
1.66
1.38
1.29
1.21
1.18
Loy
1.07

9

1.70
1.21

76

38
40
A7
Oo
48
A8
58
9
.63

8
i ie
15

wa & CI

9

T.A.

2.18
1.73
1.57
1.18
14
12
56
6
Ad

1.90
1.48
1.20
AEF

1.56
1.30
92
.60
1.04
63

113

11 12

5. . 2. A.8;

9.90 1.43
12.57 42
14.00 1.32
17.48; .0t
17.23 78
18.23 3
19.47 1.28
20.15 1.23
21.59 + «61
15.48 57
17.3 9
19.28 .50
19.25 .25
20.45 .72
20.67 «65
20.65 2.27
23.22 .39
26.55 1.15
16.54 .38
20.16 .59
21.30 1.29
22.20 1.05
25.38 .66
26.53 .09
28.89 1.27
29.96 1.19
14.51 .67
15.73.41
16.93 .78
18.41 .82
19.72 .05
24.72 1.16
17.84 1.16
20.01 81
22.22 .68
24.40 .89
25.02 .48
25.50 .70

Ll4

Sultanina

Variety
and date

Aug.
Aug.

Sept.
Sept.

Sept.

Sept.
Sept.

Tokay

Aug.

Aug. 2!
Sept.
Sept.

Sept.
Sept.

Sept. 2

Oct.
Oct.
Oct.

Burger

19

Variety
and date

June
June

June §

July

July -

July

July 2

Aug.
Aug.
Aug.
Aug.
Aug.

Sept.

Sept.
Sept.

Sept.

12

12
20
26

Cornichon

June
June
June
July
July
July
July
Aug.

12
19
27

University of California Publications in Agricultural Sciences

1
Sp. gr.

1.0673
1.0743
1.0771
1.0892
1.0927
1.0984
1.1049

1.0598
1.0676
1.0757
1.0781
1.0785
1.0798
1.0823
1.0830
1.0851
1.0895

1
Sp. gr.

1.0212
1.0195
1.0220
1.0220
1.0200
1.0205
1.0225
1.0258
1.0330
1.0391
1.0422

1.0529 °

1.0645
1.0717
1.0765
1.0808

1.0202
1.0200
1.0193
1.0201
1.0206
1.0225
1.0242
1.0373

v.84. 7.8.0.
17.46 18.64
19.26 20.69
20.02 21.56
$3.20 235.97
24.12 26.36
25.62 28.14
$7.33 30.20
15.50 16.43
17.54 18.73
19.65 21.14
20.28 21.86
20.39 21.99
20.73 23.38
21.38 23.14
21.57 23.36
22.12 24.00
23.28 25.36
2 3
T.S.G. T. S.C.
5.48 5.59
5.04 5.88
5.69 5.82
5.69 5.82
5.17 5.27
5.30 5.41
5.82 5.95
6.67 6.84
8.53 8.83
10:13. 30:5
10.92 11.38
13.70 14.42
16.73 17.81
18.61 19.94
19.86 21.37
20.99 22.68
5.22 5.32
RUT 5.27
4.99 5.08
5.19 5.29
5.32 5.43
5.82 5.95
6.25 6.40
9.65 10.00

TABLE 8—( Continued)

4
8. G.
15.87
18.30
18.98
22.42
23.62
25.71

27.41

14.41
15.63
18.17
19.11
19.26
20.17
20.76
20.87
21.53
22.91

5

8. I.

14.87
17.03
17.62
20.58
21.62
23.41
24.81

13,60
14.64
16.89
17.73
17.86
18.68
19.18
19.27
19.84
21.03

6 7
iy A Sa » A.
127 .44
119 .47
85 .49
72 .80
79 .76
60.58
o4 «51
1.74 .41
1.24 .39
384 47
19 = 45
74 48
o9 .51
85 .58
69 .63
65 .69
66 .72

3

Oo F.t.

AS
19
20
oo
B0
23

20

23
25
28
29

TABLE 9—GRAPE RIPENING TESTS, 1916

1.28
1.63
5.00

1.55

1.28
1.28

1.05
1.15
2.19
3.46
6.13
6.27
10.42
15.43
17.36
18.73
19.99

93
88
86
89
87
1.30
1.66
5.19

6 (i 8
Th. 2. 0. 2. 6. YF.
2.95 .55 .22
2.88 51 .21
2.94 .33 .13
2.98 .49 .20
3.32 57 .23
3.13 55 .22
2.93 .48 .19
2.71 83° 425
2.67 8&7 .35
2.41 95 .38
2.10 98 .39
115 1.03 .41
1.01 1.07 .43
95 . .98 .39
87 1.06 .42
81 1.01 .40
S15 64 26
2.96 .62 .25
2.89. .39 .16
2.88 .44 .18
3.27 54 .22
acy 00 \~ eee
2.94 .54 .22
2.87 .59 .24

9

¥. A.

1.09
1.00
65

40

bo po bo
“I a
—

10

| Vol, 3
11 12
6, 2232.8
17.82 82
20.14 ~=.55
20.54 1.02
24.24 1.03
25.22 1.14
27.11 1.03
28.68 1.52
16.69 = 26
17.80 .93
19.74 1.40
20.54 1.32
20.69 1.30
21.43 95
22.24 .90
22.36 1.00
22.96 1.04
24.37 .99
11 12
Ss. Tass
D.27 836d
4.51 1.37
4.87 .95
4.86 96
4.97 .30
4.86 55
4.71 1.24
5.68 1.16
7.12 1.21
9.57 .94
9.59 1.89
12.70 1.72
17.79 .02
19.72 22
20.86 .51
22.24 44
4.78 54
4.63 .64
4.54 44
4.55 .74
4.99 44
5.30 — .65
5.26 .14
8.97 1.03

1918 |

Variety

Bioletti—Cruess—Davi

’
“

as tas ee

9.70
11,28
16.47
17.77
18.01
19.65
20.41

21.52

65
1.06
06
10
90
1.14

.94

83

TABLE 9—( Continued)
3 A 5 6 7
1s Oper eee: (ee Hoe Olt.
10.06 5.28 5.48 2.79
11.71 630 6.57 . 2.75
17.51 12.19 12.96 1.85
18.97 14.75 15.61 1.16
19.25 15.03 16.07 .93
21.09 16.37 17.60 .87
22.00 17.52 18.88 .84
23.30 18.52 20.03 .72
5.39 91 93 2.93
5.24 .70 12_-3t
5.54. 1.383 --1.36 3.33
5.54 1.63 1.66 3.32
‘5.14 1.33 1.36 3.60
6.65 2.55 2.61 3.40
8.22 3.56 3.67 2.67
13,20) S78) * LOITO4 Pe
16.58 12.72 13.53 1.60
2200 16.81 18:15. 1.16
25.82 20.20 22.04 .82
27.75 21.87 22.99 .65
29.36 23.28 24.74 .60
31.85 25.95 27.83 .56
32.72 26.43 29.39 .68
32.89 26.68 29.70 .56

8

Led ey
26
43
43
44
36
46
37

2
)
4
)

2.6
-~

27

9
d itay
9.53
2.32
1.42
vB
mY
4)

TABLE 10—CATAWBA GRAPE RIPENING TESTS

: Chemical Composition of Grapes

58

115
11 12
8 Tr, A. 8

10.48 1.23
16.02 1.49
18.06 .91
18.12 1.13
19.97 1.12
20.85 1.15
22.10 1.20

16.12 46
20.38 1.70
24.04 1.78
25.94 1.81

(Table from U.S. Dept. Agric. Bulletin 335, by W. B. Alwood)

and date Sp. gr.
Aug. 7 1.0875
Aug. 16 1.0434
Aug. 23 1.0635
Aug. 30 1.0685
Sept. 5 1.0694
Sept. 12 1.0757
Sept. 20 1.0786
Sept. 26 1.0828
Muscat
June 12 1.0203
_ June 19 1.0199
June 27 1.0210
July 7 1.0210
July 10 1.0195
July 19 1.0251
July 27 1.0308
Aug. 3 1.0488
Aug. 7 1.0582
Aug. 16 1.0803
Aug. 23 1.0910
Aug. 30 1.0972
Sept. 5 1.1023
Sept. 12 1.1101
Sept. 20 1.1122
Sept. 26 1.1133
Catawba
1912:

Variety

and date

Sept. 4

Sept. 9

Sept. 12

Sept. 17

Sept. 24

Oct. 1

Oct. 7

Oct. 16

Oct. 23

Oct. 29

Nov. 4

Nov. 8

il

Sp. gr.

1.0329
1.0419
1.0515
1.0537
1.0569
1.0614
1.0663
1.0725
1.0716
1.0769
1.0790
1.0755

2
1. 8. G.
8.51
10.84
13.34
13.91
14.74
15.92
17.20
18.82
18.58
19.97
20.52
19.60

3
J hig — RN

8.84
11.29
14.03
14.66
15.58
16.89
18.54
20.18
19.90
21.50
22.14
21.07

5

BerG:

3.72

6.96

9.78
10.95
11.96
13.48
14.71
16.46
16.09
17.75
18.08
17.61

6
db ae:
3.68
3.02
2.48
2.12
1.74
1.63
1.53
1.34
1.28
1.22
1.28
1.09

ff 8 9
O72 OT es Daye
oo 6 0
41 16 5
46 18 8
45 18 13
53 5 | 20
04 22 27
61 24 33
61 24 42
59 24 47
7 23 53
71 28 59
Je ' wb , Oe

116 University of California Publications in Agricultural Sciences | Vol, 3

Curves of Total Solids, Sugar, Total Acid, Free Acid, and Cream
of Tartar.—In order to present the data in a form in which they may
be readily studied, graphs have been constructed using time in days
as abseissae and the above constituents expressed in grams per 100 ¢.¢.
as ordinates. The curves represent the data for 1914, 1915, and 1916.
For comparison, curves of the changes in composition of Catawba
grapes reported by W. B. Alwood in the United States Department
of Agriculture Bulletin 335 have been included. The acid principles
have been plotted to a scale five times as great as that used for total
solids and sugar in order that the variations in acidity might be more
apparent.

Discussion of Graphs of Total Solids, Sugar, Total Acid, Cream of
Tartar, and Free Acid.—(1) Total Solids and Sugar. The data are
more complete for 1916 than for 1914 or 1915, and include the period
during which the berries are growing to full size as well as the ripen-
ing period itself, during which the rapid increase in sugar occurs.
The curves for 1916, therefore, are of more interest than those for
1914 and 1915. In the case of the Burger variety, total solids and
sugar remained constant for approximately forty days after the tests
were started. There was then a slight rise in these components for
a period of about ten days. From that point on the rise in total solids
and sugar was very rapid and fairly uniform. The behavior of the
Corniehon was very similar.

The Museat began ripening about ten days earler than the Burger
and Cornichon, and proceeded much more rapidly up to about the
ninetieth day after the experiment was started. There was then a
slowing up in the increase in total solids and sugar corresponding to
the period of over-ripeness. This slower increase in total solids is
also evident in the curves for Emperor, Muscat, Sultana, and Tokay
for the 1915 season, and would undoubtedly show in all eases if the
observations were continued sufficiently.

The effect of the season upon the rate of ripening is shown by a
comparison of the Cornichon and Museat varieties for 1915 and 1916.
All varieties ripened more slowly in 1915 than in 1916, resulting in
steeper curves for 1916. However, owing to the fact that sampling
was started later in 1914 and 1915 than in 1916, the curves for the
former two years show only the changes taking place during the latter
half of the ripening period. No very close comparisons therefore can
be made of the three years.

The Catawba reported by Alwood, and for which curves appear

117

SICH
. SEN ECCT

NG
TEA NCI
CCIE

Bioletti-Cruess—Davi: Chemical Composition of Grapes

Y aw

1918]

de
I
ri
fe
ALN
EREINSRO GOAN
PSEC
SCCM
PCT CCN TI
He
aa AN
CULE CULLENINT

ES

TIVE (N DIFYS

TIME /N as

Fig. 1—Malaga first and second crops, 1914.

[Vol. 3

Agricultural Sciences

University of California Publications in

118

MELT TT |
SAN ETAT
He AAT LTE TT
aN UL
yt EW

|
HOPnE IRIOE Hn
Seca Vd il

TIME /N DAYS

1914.

Fig. 2—Tokay first and second crops,

1918 | Bioletti-Cruess—Davi: Chemical Composition of Grapes 119

=
TIME IN DAYS

Bile
i
lf

|
Lt

| MF Bb, 5

Fig. 3—Cornichon and Emperor, 1915.

TIME IN DAYS

[| Vol. 3

University of California Publications in Agricultural Sciences

L20

SUT BERBER
ARSC HARE EEE IE-HIE
al Aga TUTTI

ENCURRR ERG
Baan ELLA

RAAT
EEF G DOE ai
See MTU TLE
SAT
AMT GT

BCCHMMENVRRE HIE
GRGRNK N/A TELIA

BuaAN UIT IATn
aa :

TIME IN ORY: S

TIME iN DAYS

Fig. 4—Malaga and Muscat, 1915.

121

Bioletti—Cruess—Davi: Chemical Composition of Grapes

1918]

“Las

UNE

4

7/ME /N nae

5.

Fig. 5—Pedro Zumbon and Sultana, 191

| Vol. 3

University of California Publications in Agricultural Sciences

i |

ani

dee atiint ani

aa

TIME IN DAFYS

Tefal Sol

Fig. 6—Sultanina and Tokay, 1915.

Bioletti-Cruess-Davi: Chemical Composition of Grapes

1918]

4M IN OATS

' TIAL
INI
a

al |
a We
PEUMMNEL-ABARIG

Hr |
ee

y

aaa
ChhtAAAAY APERIRK

A aid

Ho

Fig. 7—Burger and Cornichon, 1916.

124 University of California Publications in Agricultural Sciences [ Vol. 3

lo

4, 0 a
TIME IN DAYS
Fig. 8—Muscat, 1916.

a ee eC ee
to eee a

TIME /N DFFYS
Fig. 9—Catawba (U.S. Dept. Agric. Bull. 335).

1918 | Bioletti-Cruess—Davi: Chemical Composition of Grapes 125

in figure 9, ripened more slowly than the Vinifera varieties. For
example, during a period of fifty days, the total solids increased only
4 per cent. It can not be said from the data at hand whether this
slow ripening is due to the conditions under which the grapes were
grown or to the variety.

By reference to figures 1 and 2 it may be seen that the general
form of the ripening curves is the same for the first and for second
crop. In one ease, the Malaga, the curves are almost identical for
the period common to both, 1.e., from 10.6 Bal. to 26.3 Bal., showing
an equal rate of ripening. In the other, the Tokay, the curve of the
second crop, from 18.2 Bal. to 24.6 Bal., is much flatter than that of
the first, indicating a rate of ripening with the latter of about two
and a half times that of the former. This difference can be accounted
for by the cooler weather during the time the second crop Tokay was
ripening, which was about ten days later than in the case of the second
crop Malaga. The slower ripening is probably due both to the direct
effect of the cool weather and to the decreased activity of the leaves
at lower temperatures.

(2) Changes in Total Acid, Cream of Tartar, and Free Acid.
Owing to the fact that the analyses were started in 1914 and 1915
after ripening had commenced, the curves for these years show a
decrease in acid throughout the period of the tests. In 1916, however,
a rise in total acid occurred during the growing stage, as shown by
a rise in the curve during the first thirty days of the experiment.
Although this rise is not very large, it is quite definite, and occurs
in all three varieties tested. The rise was most positive in the case
of the Muscat grape, and amounted to .67 per cent acid as tartaric.
From the point of maximum acidity, the total decreases slowly until the
period of rapid ripening sets in. The total acid then decreases very
rapidly for a time and more or less in proportion to the increase in
total solids and sugar. As the grapes near maturity, the rate of de-
erease of total acid becomes less and the total remains practically
constant after the grapes have reached maturity.

The cream of tartar in general increases very slightly during the
periods of growth and ripening.

The inerease in total acid during the first stages of growth is due
to increase in the free acid. Since the cream of tartar remains almost
constant throughout the ripening period, the curve of the free acid
is practically parallel with that of the total acid.

As the grapes approach maturity, the cream of tartar calculated as

126 University of California Publications in Agricultural Sciences [ Vol. 3

tartaric acid approaches the total acid, and in one case, (Musct, 1916),
actually became equal to the total acid, indicating that in this instance
no free acid remained.

Second crop grapes were found to be higher, in free acid than
first crop grapes of the same total solids and sugar content. The
Catawba grape grown under eastern conditions (fig. 9) exhibits rela-
tively high free acid. Alwood® has found this free acidity in eastern
grapes to be due largely to malic acid. No attempt was made in the
analyses of the California samples to identify the various acids making
up the free acidity which was calculated as tartaric acid.

Mean Differences Between Total Solids and Sugar.—The following
table contains figures representing the differences between total solids
and sugar at the various percentages of total solids indicated at the
tops of the columns. The data represent a range of total solids from
5 per cent to 30 per cent. The figures were taken from the data
reported in tables 7 to 9, and represent several varieties of grapes.
Only a few determinations of total solids and sugar were available
for the lower concentrations (5 per cent to 15 per cent), and therefore
the figures for this range may not represent averages so accurately
as the figures above 15 per cent total solids.

Between 5 per cent and 11 per cent solids, the average difference
between total solids and sugar remains practically constant. From
11 per cent to 17 per cent total solids, the mean difference decreases
quite rapidly. From 17 per cent to 30 per cent, the difference remains
fairly constant. The variations noted after 17 per cent total solids

Lit

ia BS Pee, Sey

Fig. 10—Mean differences between total solids and sugar between 5 per cent
and 30 per cent total solids.

6U. 8S. Dept. Agric. Bull. 335.

127

Bioletti-Crucss- Davi: Chemical Composition of Grapes

1918}

(Figures in columns re

5 6 7
42 4.7 49
42 45 ..
£4; 30) ~ an

Samples:

3 3 1

Average:

4,26 4.33 4.5

4.3

9 10
4.6 4.4
4.6 4.2
vaen | Si4

2 5)

4.6 4.3

11
4.1
4.9
4.9

4.66

present difference be

12

9Q
oO.

4.0

3.9

9
oO.

13

o

3.2
2.9

Go

14
3.2
3.0
3.8

3.0

15
2.3
3.2

3.8

i)

3.1

16
2.4
2.8

2.88

17

2.6

3.0
3.3
2.7
2.3
2.7
3.0

2.2

9.69 2.84 2.85 2.69 2.73

tween total solids and sugar for

18

2.2
3.3
3.3
2.7

19

2.6
2.3
3.3
2.3
3.1
2.7
2.6
2.9
3.2

TABLE 11—MEAN DIFFERENCES BETWEEN TOTAL

20

1.5
2.7
3.2
2.7
3.1
2.4
2.4
2.8
3.0

II

21

lid
3.1
2.3
2.0
2.9
2.4
2.3
29
2.9
2.5
2.9
4.0

12

various juices of total soli

22

2.0
3.6
2.5
2.6
2.8
2.6
2.8

10

2.76 2.62 2.43

ds content indic

Le)

SoLIDS AND SUGAR

10

25 26
2.5 2.9
2.6 2.8
2:5. 2.7
2.9 2.5
2.4 2.2
Mle
2.4
3.4

9 5
2.37 2.62

ated at tops of columns)

27 28 29

29 29 2.8
25 2.6 2.8
2.55 2.4 2.8
Babs | Sar Stare

5 3 3

2.68 2.50 2.8

30
» 9

3.1

2.96

128 University of California Publications in Agricultural Sciences [Vol. 3

was reached are probably within the experimental error. The large
difference between the total solids and sugar noted during the first
stages of ripening is no doubt due to the high acid content of the
unripe grapes. ‘The fact that the difference remains fairly constant
after the grapes have become mature is to be expected, because the
cream of tartar, total acid, and protein remain fairly constant as
maturity is approached and during the periods of maturity and over-

ripeness.

Stil

CNET
UENCEEENEL EL

Q d
9
9

Fig. 11—Variation in non-coagulable protein content for three varieties, 1916.

Protein.—The total nitrogen content of the various samples was
multiplied by 6.25 to convert it into its protein equivalent. Owing
to the fact that the samples were sterilized by heat and filtered before
analysis, the figures represent only the protein not coagulated by heat.

The curves show that there is a slow increase in protein content
during growth and ripening and the greatest increase occurs during
the period of most rapid increase of sugar and most rapid decrease
of acid. The increase amounted to about .2 per cent in the case of the
Museat and .6 per cent in the ease of the Cornichon. The increase
seems to be quite definite, although the protein curves are not so
regular as those of total solids, sugar, and total acid.

1918 | Bioletti-Cruess—Davi:; Chemical Composition of Grapes 129

SUMMARY OF CHANGES IN Must oF GRAPES DuRING GROWTH AND

RIPENING OF BERRIES

1. Votal Solids.—The total solids remain fairly constant during
the period of growth, corresponding to the period between setting of
the berries and the time at which the berries have reached almost
full size but are still hard and green. From this point on, there is a
rapid increase in total solids due to increase in sugar.

After the period usually considered as full maturity is reached,
the increase in total solids is slow. The question may be raised as to
whether this last increase is due to an actual synthesis and secretion
of sugar or other solids, or simply to evaporation of water. The fact
that there is no change in the curve of the acid decrease at this time
indicates that the same processes are continuing and that the increased
Balling degree represents an actual increase of solids. This view is
fortified by observations regarding the increase of weight of solids
during the ripening of raisin grapes. It has been shown that the
weight of dried grapes shows a continuous increase up to the highest
degree observed, 28.75 Balling.’

2. Sugar.—The total sugar during the growth period comprises
only a small amount of the total solids. During ripening, the sugar
rapidly inereases and then constitutes a much greater proportion.
During ripening, the sugar curve follows the total solids curve closely.
It is more or less the mirror image of the total acid curve multiplied
by five, i.e., Increases as the acid decreases.

3. Total Acid and Free Acid.—During the early stages of the
crowth of the berries, the acidity increases owing to an increase of
free acid. This is a fact that the authors have not found mentioned
in the literature. During ripening, the total and free acid rapidly
decrease. After maturity is reached, the decrease is very slow.

4. Cream of Tartar—tThere is a very slow, but usually fairly defi-
nite, increase in cream of tartar during ripening. This increase is
very much less than the decrease in free acid, and therefore can not
account for any great part of this decrease.

7 Bioletti, Frederic T., Relation of the maturity of the grapes to the quantity and

quality of the raisins. Proc. Inter. Cong. of Viticulture, San Francisco, 1915,
pp. 307-314.

130 University of California Publications in Agricultural Sciences [ Vol. 3

5. Protein—The protein not coagulated by heat increased defi-
nitely during growth and ripening, although the increase was not so
regular nor so marked as the increase in sugar or the decrease in total
acid.

6. Difference Between Total Solids and Sugar.—This factor re-
mained constant for the lower percentages of total solids, decreased
during the rapid ripening stage, and remained constant through
maturity and over-ripeness.

UNIVERSITY OF CALIFORNIA PUBLICATIONS (>|

IN

AGRICULTURAL SCIENCES
Vol. 3, No. 7, pp. 131-134 March 15, 1918

A NEW METHOD OF EXTRACTING THE
SOIL SOLUTION
(A Prelininary Commumeation)

BY
CHAS. B. LIPMAN

While studying, in 1914, some of the data obtained by Quincke
in measuring the forces by which thin water films are held by tiny
particles of solid matter, there occurred to the writer a new possibility
for a method of extracting the soil solution from soils with optimum
moisture contents. By making a simple calculation, I found that if
Quincke’s figures were correct, particles of .005 mm. in diameter had
the power of holding very thin films of water with a force equivalent
to about 300,000 lbs. to the square inch. I argued, therefore, that
since particles of .005 mm. diameter constitute the ‘‘clay’’ fraction in
some mechanical analysis systems and since a large part of soil
material may consist of much larger particles, that it should be
possible to bring to bear on soils by pressure apparatus already in
existence enough force to separate soil particles from some water,
even when soils contained relatively small quantities of moisture. It
appeared to me, moreover, that the large machines used in engineering
laboratories for testing the strength of materials should be admirably
adapted to the task of expressing water from soil if suitable containers
for the soil are employed. With this idea as a basis, I started, in the
year above mentioned, to experiment first on peat soils with a letter
press of the old fashioned sort and found that water could be obtained
with it from peat containing 40% of moisture. I then proceeded to
have made a special perforated brass plate for the bottom of an iron
casing about 12 inches long and about 6 inches in diameter. A quan-
tity of clay adobe soil with optimum moisture content was placed in

132 University of California Publications in Agricultural Sciences [Vol.3

the tube, a plate placed over it and pressure applied in a machine of
a capacity of 200,000 lbs. to the square inch. About 25 ¢.¢. of liquid
were thus obtained from eight pounds of soil. The result of this ex-
periment was unsatisfactory, owing to the small amount of lquid
obtained from a soil with an optimum moisture content. I determined,
therefore, to use a tube with a much smaller diameter (1 to 2 inches),
so that the pressure exerted by the machine could be concentrated
on as small a surface as possible and thus rendered more efficient.
When such a tube was made, other difficulties were encountered. A
few months later, these were surmounted and revised forms of appa-
ratus were thus prepared from time to time as other duties permitted.
No form of these was satisfactory even though I had demonstrated
that small amounts of the soil solution could be obtained with some
of them. During the last few months, however, I have had the privi-
lege of the counsel of Mr. C. T. Wiskocil of the Department of Civil
Engineering of this university, who has designed a new form of
pressure tube for my purposes. Such a tube was made up and we
have tried it out, recently, on several occasions with gratifying results.
In the ease of a very fine sandy soil containing an optimum moisture
percentage (about 15% by weight), nearly two-thirds of the moisture
was expressed from samples of 300 to 400 grams of moist soil. In
the ease of a clay loam soil, we were not so successful, but from two
or three samples of about 300 grams each of such a soil containing
about 20% of moisture (by weight), we obtained enough of the soil
solution to make conductivity measurements and, if needed, quanti-
tative analyses. Certain difficulties were encountered in pressing the
clay loam soil, which did not obtain in the ease of the fine sand, but
these were also surmounted by another suggestion originating with
Mr. Wiskocil. Even now we find that our apparatus needs to be
changed, or a new one must be made to stand pressure in excess of
50,000 Ibs. to the square inch, so that greater efficiency in pressing
clay loams and clays may be attained. The detailed description of
our apparatus, and of the results of conductivity measurements and
analyses of the solutions obtained are reserved for description in
another paper in which due eredit will be given Mr. Wiskocil and
Dr. D. D. Waynick for invaluable assistance rendered in connection
with these matters.

My principal object now is to direct the attention of my colleagues
in soil investigations to the fact that, after nearly four years of desul-
tory effort, I have succeeded in demonstrating that direct pressure

———

1918 | Lipman: A New Method of Extracting the Soil Solution 133

can be used successfully for purposes of obtaining the soil solution
as it exists in relatively thin films around the soil particles. The pro-
y. With further improve-
ments in apparatus which we are now planning, the method should
supplant all other methods known today, including even the Morgan
procedure.'| None of the other methods are really satisfactory and
even that of Morgan is laborious and slow, and introduces the factor
of oil, which complicates and renders it extremely time-consuming
and untidy. Within recent months, I have noted in the lterature
that attempts have been made by Ramann, Marz, and Bauer? and by
Van Zyl® to use direct pressure as I have done. The original papers
detailing the work of these investigations are not available to me,
however, and I am almost entirely in the dark as to the details of
the method and, in one ease, of the magnitude of the pressures em-
ployed. The maximum pressure thus far exerted in my method has
been approximately 53,000 Ibs. to the square inch, whereas Ramann
and his associates with a hydraulic press seem to have used only about
1500 lbs. per square inch. Moreover, if the abstract of their paper
which is available to me has interpreted the authors correctly, their
method is only applicable to soils made up of very fine particles or
containing much organic matter. My experience has always been
that the coarsest soils are always the easiest to manage in expressing
water from them. Indeed, until recently, the fine grained soils, as
above intimated, gave me considerable trouble, because they would
ereep out of the container in fine ribbons, while the pressure was
being applied. Mr. Wiskocil’s suggestion of a thin casing of sand for
the fine grained loam or clay loam has obviated that difficulty, how-
ever. I judge from my experience, moreover, that Ramann and his
coworkers must have used very wet soil or they could not possibly
have secured solutions from them at the low pressure mentioned. The
abstract of Van Zyl’s paper says nothing about the pressure used by
him and: the manner in which it was applied. The statement is that
the soil can be ‘‘squeezed.’’ Other comparisons of my method with
the comparable ones just discussed will be given in a later paper.
Finally, it may not be superfluous to emphasize the importance to
all soil studies of the proper use of the method which I have described
above. It allows of the direct determination of the concentration of

cedure is rapid, clean, and of high efficiency

c¢

1 Soil Science, vol. 3, p. 531 (1917).

2 Int. Mitteil. Bodenkunde, vol. 6, p. 27 (1916), cited from Chem. Abst., vol. 11,
no. 22, p. 3078 (1917).

8 Jour. Landw., vol. 64, p. 201 (1916), cited from E. 8. R., vol. 36, p. 720.

134 University of California Publications in Agricultural Sciences | Vol. 3

the soil solution, and of the amounts of each of the solutes contained
therein. It renders possible, further, such studies as will clarify our
vision with regard to the relations, if any, which obtain between the
soil solution and soil extracts as ordinarily made. It permits us for
the first time, so far as | am aware, to obtain quickly and directly
large portions of the soil solution as it exists naturally under field
conditions when crops are growing, and thus to correlate these solu-
tions in all their qualities with the conditions of the growing crop.
it may doubtless be the means of throwing much light on the methods
for making nutrient solutions for growing plants, and probably also
on many obseure problems in plant physiological pathology. Indeed,
the possibilities are many in which the method which I have described
for obtaining the soil solution can be used to the very great advantage
of soil and plant studies.

Transmitted March 8, 1918.

Pa
UNIVERSITY OF CALIFORNIA PUBLICATIONS
IN
AGRICULTURAL SCIENCES

Vol. 3, No. 8, pp. 135-242, plates 13-24 July 12, 1918

THE CHEMICAL COMPOSITION OF THE PLANT
AS FURTHER PROOF OF THE CLOSE RELA-
TION BETWEEN ANTAGONISM AND
CELL PERMEABILITY

BY
DEAN DAVID WAYNICK

CONTENTS
PAGE
LES CU TFC) bel See ee aie ae ae Fc, eS SES Ve Ao. es ONCE ee ae tert SRR Te en Be 135
MIORUEOR. UNG TNVeSul AOI 80) 2 OA) FN LoTR ee ids Sled) ota ok a ch easteleseaien 137
eric (00 DEC VPOUS I VERUI SA CROUS 5. 5c ce beget Sai eh se snc oo etd agers 137
ET Gat BOS EN Datta e PAO MOUs ener. 22. 320nt 250.) Se eS ne Ce ew 140
EE 0 i Seacrest PNR alien so ESE” 5 5 sad eat ae mene am 144
See CreI ME LIPOUPMMCEN OL CG PU RIe GS 6 Oia 0 a me eel eee pa ao oat cewnda unde evatioaanaite 154
Beuereal Sovicow OF Oxpérimental regults 2.7 iss el 155
Seamitno wien Salts OF tle: Wen y Teele cee rs acs nenenn iene ae 156

Possible effects of variations in the concentrations of the solutions on the

EDT aC ea ale BT dy Rh Pik ae tai A oO 160
Consideration of a possible Calcium-Magnesium ratio ................2--.22.--2-------------- 160
EE UOC ME CE ET eae Ore eC. ToS 2 none eee oe 162
SN alee a a dg hat re a dana Soin 164

INTRODUCTION

A solution of a single salt at certain concentrations is toxic to
plants grown in it. The addition of a second salt usually permits of
growth superior to that in a solution of a single salt alone even though
the added salt is toxic when used by itself. A third salt added may
permit of a still further increase over the growth in the two salt solu-
tion. Other salts added will increase or decrease growth, depending
upon the salt used. Qualitative relationships only have been consid-
ered. When we adjust the quantitative relationships of the various
salts present, having at the same time due regard for their qualitative

136 University of California Publications in Agricultural Sciences | Vol. 3

nature, we get as a result a solution in which the plant grows and
functions normally. Such a solution has been termed by Loeb, ‘‘ phy-
siologically balanced.’’

It is evident that if growth is better in a two salt solution the toxic
effects of the solution due to a single salt must be lessened by the
presence of the second salt. We may refer to either as the second salt
since either may be toxie alone. On the addition of a third salt the
increase in growth over that obtained in the two salt solution points
to a still further lessening of the toxie properties of the various salts
present taken singly. This action of one or more salts in limiting or
preventing entirely the toxic effects of one or more other salts, is
termed antagonism. Sea water may be taken as an example of a
physiologically balanced solution or a solution in which the mutual
antagonism between the constituents of the solution is such as to
allow of normal growth of numerous organisms.

The fact of the existence of antagonism has been proven by a
number of investigators working in plant and animal physiology, but
the mechanism of antagonistic action is by no means clear. Since
salts are very largely ionized in the nutrient solutions usually em-
ployed, it is probable that antagonism has to do with ions. Further,
antagonism will probably take place between the ions present in, or
between, the ionic constituents of the solution, and the hving mem-
branes in contact with the solution. Loeb!' first advanced the theory
that one ion may prevent the entrance of another ion into living cells
and that in this property lies the reason for antagonistic action. On
the basis of this hypothesis, penetration precedes the manifestations of
toxic effects and where penetration does not occur, due to antagonistic
action, there are no toxie effects evident. Used in this way, the term
penetration means simply the entrance of ions in greater number than
would normally oeeur were the plant cells in their natural environ-
ment. Experimental evidence as to the correctness of this hypothesis
has been furnished by Loeb? in a very interesting series of experi-
ments. Osterhout® has applied the electrical conductivity method
to the measurement of the penetration of ions into plant tissue,
while recently Brooks has confirmed Osterhout’s results (1) by deter-
mining: the diffusion of ions through tissue,t (2) by exosmosis,® and
(3) by the change in the curvature of tissue.®

1 Amer. Jour. Physiol., vol. 6 (1902), p. 411.

2 Science, n.s., vol. 36, no. 932, p. 637.

8 Ibid., vol. 35, no. 890, p. 112.

4Proec. Nat. Acad., Sci., vol. 2 (1916), p. 569.
5 Amer. Jour. Bot., vol. 3 (1916),. p. 483.

1918 | Waynick: Antagonism and Cell Permeability 137

It is evident that these methods are limited in their application
and give no idea of the quantitative relationships existing between
the ions actually entering the cells. They do show, however, that the
permeability of the plant tissue may be greatly altered by salt action
and that solutions which permit of normal growth also preserve normal
permeability as regards the ions present in the solution.

OBJECT OF THE INVESTIGATION

In a preliminary paper’ the results obtained from chemical analy-
ses of plants grown in toxie and antagonistic solutions have been
reported. These results were of interest and the general method em-
ployed seemed to be worthy of a more extended application in the
determination of ions absorbed by plants from solutions, of known
composition and coneentration. From a consideration of the data
in the paper referred to above, it was felt that the results obtained in
a more extensive investigation would be of importance: (1) from
the standpoint of the effect of various salts upon the permeability of
the cell tissue of growing plants; (2) from that of the effects of vari-
ous salts upon the nutrition of plants as evidenced by growth; (3)
from that of a possible correlation of growth with the absorption of
ions; and (4) from the standpoint of the quantitative relationships
existing between certain ions of the solution and the same ionic rela-
tionships in the plant.

The various phases of the problem as outlined above will be con-
sidered in the discussion of the experimental results following.

REVIEW OF PREvious INVESTIGATIONS

It is not intended that the following review of the previous work
done in this field of plant physiology be exhaustive. Robertson® has
reviewed the lterature dealing with antagonistic salt action very
completely up to a recent date. Brenchley® and Lipman and Gericke’®
have referred to all the important work done with regard to the
effects of the salts of the heavy metals upon plants. The present
review therefore touches only the work bearing directly upon the

6 Ibid., p. 562. |

7 Contribution to the causes of antagonism between ions. (Univ. Calif.,
Master’s thesis, 1915.)

8 Ergeb. Physiol. Jahrb., vol. 10 (1910), p. 216.

’ 9Tnorganie plant poisons and stimulants. New York, Putnam, 1915 (Cam-

bridge agricultural monographs).
10 Univ. Calif. Publ. Agr. Sei., vol. 1 (1917), p. 495.

138 University of California Publications in Agricultural Sciences [ Vol. 3

present problem or work so recent as not to be included in the papers
cited above.

A large share of the contribution to the experimental evidence in
regard to antagonism between salts as regards plants we owe to Oster-
hout. In a series of papers he has shown that any salt may be toxic
to plants when used alone in solution at certain concentrations and
further that the addition of a second salt may, in proper concentra-
tion, modify or eliminate entirely the toxic effect of the first salt. He
has shown further that acids, alkalies, and various organic compounds
may likewise be toxic to plants and that their toxic effects may be
modified by the presence of a variety of compounds, depending upon
the toxic substance employed. By measuring the resistance of cylin-
ders of Laminaria in solutions of one salt and in solutions containing
two or more salts, he has brought forward much evidence as to the
penetration of ions into plant cells. While this method has yielded
very valuable results both as to the rate of entrance of ions and also
the total number of ions penetrating, it does net yield results which
give us a knowledge of the relative amounts of the various ions which
penetrate the tissue when the qualitative as well as the quantitative
relationships of the nutrient solution are varied. Osterhout has
shown, however, that penetration is more rapid, and the degree of
permeability is greatly increased, in unbalanced solutions and further
that as the permeability of the plant tissue more nearly approaches
normal the growth of the plant is also more nearly normal.

Szues'! has used Cucurbita pepo as an indicator by immersing the
young seedlings in various solutions for varying periods of time and
counting those still able to show geotropic movement when placed in a
horizontal position in a moist chamber. He found a marked antagon-
ism between copper sulphate and aluminum chloride and concludes
from his experiments that antagonism consists in the mutual hin-
drance of similarly charged ions in entering the cell. He states
further that the rate of absorption of equally charged ions is of great
importance. His chemical methods are open to question, for in the
experiments reported the test for copper used was that of boiling the
roots and testing the resulting solution for copper with hydrogen
sulphide.

By analyzing the solution in which pea seedlings had grown, Pan-
telli?? has determined ion absorption. The growing period was short.

11 Jahrb. Wiss. Bot. (Pringheim), vol. 52, no. 1 (1912), p. 85.
12 Ibid., p. 211.

1918 } Waynick: Antagonism and Cell Permeability 139

He found a rapid absorption of zinc, manganese, iron, and aluminum,
but the total amounts taken up were small. He gives other evidence
of the selective absorption of various other ions from solutions, but
these results are of not direct application here. It is of interest to
note, however, that he found a direct relation between time and ion
absorption. His most important conclusion, which bears directly upon
the problem in hand, is that strong narcosis was associated with the
penetration of ions in large numbers.

Schreiner and Skinner,'® using a similar method, have determined
the amounts of phosphoric acid, nitrates, and potassium remaining in
a solution in which plants had been grown. Various ratios of these
three ions were employed, the total concentration being 80 parts per
million. They found widely varying amounts of these three ions
removed from the solution, and further there seemed to be a possible
difference of 20 to 30 per cent in the removal of any one without
an apparent effect upon the growth of the plants. Under the condi-
tions reported by them increased growth was correlated with increased
absorption.

By means of conductivity measurements of solutions in which pea
seedlings were growing, True and Bartlett** ' *° have determined
the rate of absorption and of excretion of electrolytes. Their work
was done with one, two and three salt solutions. In general they
found a greater absorption when a mixture of salts was present than
when single salts were used. Further, the absorption relationships
of salts with a common kation seem to be similar. For example, from
solutions of low concentrations, potassium chloride, potassium sul-
phate, and potassium nitrate are not removed, but on the other hand
there is an excretion of electrolytes by the plant. In direct contrast,
calcium nitrate and calcium sulphate are removed from their solu-
tions in every concentration employed and no exeretion of electro-
lytes from the plants could be detected. It seems probable that the
low concentration employed by them acted as a limiting factor in
some cases.

In a recent paper Breazeale’*’ has shown that the presence of
sodium carbonate, and sodium sulphate, when used in concentrations
of 1000 parts per million in nutrient solutions, decreased the absorp-

13 Bot. Gaz., vol. 50 (1910), p. 1.

14 Amer. Jour. Bot., vol. 2 (1915), p. 255.

15 [bid., p. 311.

16 Tbid., vol. 3 (1915), p. 47.
17 Jour. Agr. Research, vol. 7 (1916), p. 407.

140 University of California Publications in Agricultural Sciences | Vol. 3

tion of potassium and phosphoric acid as much as 70 per cent below
that of the control cultures.

The work of Gile*® is of interest in this connection. From ash
analyses obtained in investigating the cause of chlorosis in pineapples,
he found a direct relationship between the absorption of lime and
that of iron; that is, when the absorption of lime was high but little
iron was taken up. In soil studies Gile and Ageton’® found no direct
relation between the lime content of plants and varying amounts of
lime and magnesia in the soil.

A few investigations have been made on the absorption of specific
elements from solution, but these need only be mentioned in the
present connection. Maquenne*® found that mercuric chloride causes
marked increase in permeability of the protoplasm, although it is not
necessarily absorbed itself in any considerable quantities. Marsh*?
correlates the amount of barium chloride present in the soil with
that found in the plant. Colin and De Rufz*? always found absorbed
barium localized in the roots.

A large number of analyses of plants grown under various condi-
tions have been reported, but the environmental factors have varied
so greatly as to render the results obtained of little value in the
present study.

From this review it is evident that no quantitative study of the
elements actually absorbed from the nutrient solutions, balanced and
unbalanced, has been made with the idea in mind of a correlation
between the absorption of the various ions with their antagonistic
or toxic effects in solution cultures.

MertTHODS

Barley was used as the plant indicator. The seeds were obtained
from the University Farm at Davis and were of a pure strain of the
Beldi variety. The method of sprouting the seeds, while simple, has
not been noted elsewhere and has given such excellent results, both to
the writer and to others, that it seems worthy of mention here in
detail. A piece of oilcloth about 12x18 inches was covered with sev-
eral thicknesses of paper toweling and the whole thoroughly wetted.

18 Porto Rico Exp. Sta. Bull., 11 (1911).

19 Tbid., Bull. 16 (1914).

20 O.-R. Acad. Sci. (Paris), vol. 123 (1896), p. 898.

21 Bot. Gaz., vol. 54 (1912), p. 250.
22 C.-R. Acad. Sci. (Paris), vol. 150 (1910), p. 1074.

1918 } Waynick: Antagonism and Cell Permeability 14]

Selected seeds were distributed over the toweling so that about two
hundred were placed on an area of the size indicated above. Another
layer, made up of several sheets of toweling, was then laid on the
seeds and the whole thoroughly soaked with water. The water was
allowed to evaporate gradually until the paper was but slightly moist
to the touch and the water relation then maintained constant until
the seedlings were transferred to the solutions. If the paper is kept
too moist the growth of molds is often very abundant, but with a low
moisture content no trouble was experienced from this source. By the
time the roots were a quarter of an inch long, the upper layer of
paper was supported two or three inches above the seedlings. This
procedure permits of a straight growth of the shoots, which is of con-
siderable importance in placing the seedlings in the corks. The seed-
lings were transferred when the shoots were about an inch and a half
in length. The paper in which the roots are grown, tears apart readily
without injuring them in any way, the oilcloth not permitting their
downward penetration. There is no contact with metal containers
at any time, the apparatus required is practically nothing, the time
period is short—about six days under greenhouse conditions—and
strong seedlings are obtained which can be transferred to any contain-
ers without injury.

The containers used were quart jars of the Mason type, each
holding approximately 950 ¢.c. of solution. The inside of each jar,
as well as that of the bottles for the stock solutions, was coated with
a layer of paraffin so that the solutions were never in contact with the
glass. The outside of the jar was covered with black paper to exclude
light, the black surface facing the glass. Flat corks, having a diam-
eter of three and a half inches, were used to support the seedlings.
Each cork had seven holes, one in tlie center through which distilled
water was added to maintain the volume of the solution as nearly
constant as possible, and six equally spaced, one and a quarter
inches from the center, for holding the seedlings. After the holes
were made the corks were soaked in boiling paraffin.

To introduce the seedlings the corks were turned upside down,
supported by the rim of the jar, and the shoots stuck through the
holes prepared for them and held in place by a small piece of cotton.
On turning the corks over the seedlings were in their proper position
without being in the least injured, for there was no necessity for
touching the roots at any stage since the plant was always picked up
by the seed coat. The method suggested by Tottingham** was tried,

142 University of California Publications in Agricultural Sciences | Vol. 3

but the one outlined above proved very satisfactory and much
simpler.

The basic nutrient solution used throughout was Shive’s three
salt nutrient** containing the following salts in the given partial

molecular concentrations:

or yt oe eee 0180 M.
Ce (RO re Sa i ae 0052 M.
Mano, Co ek ae ne 0150 M.

The stock solution was made up to twice the strength indicated
above and diluted as necessary by the addition of added salt solution,
or distilled water, or both.

In the case of the chlorides used, viz., calcium, magnesium and
potassium, normal or twice normal solutions were prepared and
standardized by titrating against a standard silver nitrate solution.
Normal solutions of magnesium and potassium sulphate were stand-
ardized by weighing the barium sulphate precipitate. Solutions of
copper, zine, iron, and mercury salts were prepared in concentrations
of 1000 parts per million by weighing out the carefully dried salts.

The final volume of solution required for the duplicate jars was
approximately two thousand ecubie centimenters. Starting with a
thousand of the nutrient solution, various volumes of the standard
solutions were added so that when the total volume was made up to
two liters with distilled water, the concentrations of the various salts
would be those reported in the accompanying tables.

The growing period was six weeks. The duplicate cultures were
grown in specially constructed mouse-proof cages each holding ninety
jars. The tops of the cages were open and the sides made of coarse
wire screening. The different parts of the cages were equally well
lighted, as shown by the nearly equal growth of the controls in dif-
ferent parts of the cages. When necessary the plants were supported
by cords strung across from side to side of the cages.

The solutions were not changed during the growing period, but
the volumes were kept as nearly constant as possible by adding dis-
tilled water. There are objections to this method, as there are objec-
tions to the method of using water cultures at all. The growth was
found to be very satisfactory and compares favorably with the growth

23 Physiol. Researches, no. 4 (1915), p. 174.
24 Amer. Jour. Bot., vol. 2 (1915), p. 157.

1918 } Waynick: Antagonism and Cell Permeability 143

obtained by other investigators in comparable periods of time. A
further discussion of this point will be taken up below.

At the expiration of the six weeks growing period the plants
were removed from the corks, the roots rinsed thoroughly with dis-
tilled water, placed between layers of paper toweling, dried in the
oven at 100°-105°C, roots and tops separated, weighed, and placed
in envelopes ready for analysis. For analysis the roots from dupli-
eate cultures were combined unless the dry weight was sufficient to
allow of separate analysis.

Total ash was determined after direct ignition of the dry material
in a muffle at a low red heat until no trace of carbon remained. The
ash was then taken up in dilute hydrochloric acid and evaporated
to dryness to remove possible contamination with silica. Iron was

precipitated as the hydroxide with ammonia and titrated with =

potassium permanganate after reduction with zine and sulphurie acid.
This determination was made because of the relation Gile has shown
to exist between calcium and iron absorption by plants. Calcium

was precipitated as oxalate and titrated with = potassium perman-

ganate. The double precipitation of the oxalate assured freedom
from magnesium contamination. Magnesium was precipitated by
ammonium phosphate and weighed as the pyrophosphate. Potassium,
where determined, was precipitated and weighed as the chloroplati-
nate. Copper was determined colorometrically by using the ferro-
eyanide method. The amount of material available precluded the
possibility of a more complete analysis than was made if any degree
of accuracy was desired. For example, in Series vu, the weight of
the ash varied from 12 to 233 milligrams in the ease of the roots and
from 32 to 183 milligrams in the case of the tops. While these varia-
tions are not extreme, they are fairly representative. The values of
these elements actually determined cannot be taken as absolute in
every case because of the limited amounts of material available, but
the significant differences are so great as to make a small variation
in this regard of minor importance.

The strength of all solutions is uniformly expressed in terms of
molecular concentrations since this mode of expression has been
quite generally used in experimental work reported by different
investigators.

Under experimental results twenty-six series are reported. A
series, as used in the present work, may be defined as a number of

144 University of California Publications in Agricultural Sciences | Vol. 3

duplicate cultures containing one salt in varying concentrations in
each, or one salt constant and varying concentrations of a second salt.
In some instances both salts varied but only in concentration, the
same ratios being maintained. These are few. The number of con-
centrations reported vary from three to fourteen in a series, depend-
ing upon the salt used. Before two salts were taken together, the
effects of each separately upon the plants were determined. Usually
this meant only the establishment of the toxic limits of the salts em-
ployed when used in the nutrient solution. Several series of this kind
are not reported here, as no analytical work was done upon them.

Calcium and magnesium salts were used to a large extent because
of the fact that their kations can be determined with less experi-
mental error than most other nutrient salts where the small amounts
of material dealt with here are considered; also it was of interest
to determine whether or not there is a lime-magnesia ratio for plants
grown under carefully controlled conditions. Copper, zinc, iron, and
mercury salts were used because of the fact that their toxic and antag-
onistie effects have not been previously determined as regards absorp-
tion. Potassium chloride was the only monovalent salt used.

A longer growing period than has usually been employed was con-
sidered important. McGowan,”° in conducting experiments in pure
solutions of sodium, potassium and ealecium chlorides, found growth
better in the first two at the end of six days, but far superior in a
solution of calcium chloride in twenty-five days. In a qualitative way
the same relationships were observed in the present investigation. It
seems reasonable to assume that the results obtained in six weeks with
plants are more nearly representative of the true effect of various
solutions than those obtained in two or three day periods or even in
three week periods. But it is not assumed that the results herein
reported are the same as those which might be obtained were the
plants grown to maturity. It is hoped that more data may be pre-
sented shortly on this point.

In the following section, in which the experimental results are
given, the time factor and the basic nutrient solutions are constants.

EXPERIMENTAL DATA

All analyses are reported as percentages of the dry weights of the
plants. To make the results obtained as clear as possible, graphs and
photographs have been used throughout as well as the tables giving
the actual percentage composition of the plants.

25 Bot. Gaz., vol. 45 (1908), p. 45.

1918] Waynick: Antagonism and Cell Permeability 145

The relationships of calcium to magnesium salts are reported in
the first seven tables. For a review of the more important literature
bearing directly upon the relationships of the salts to these two ele-
ments reference is made to MeCool,*° who has considered these in
some detail, and to a recent critical survey of the lime-magnesia ratio
hypothesis by Lipman.**

As is evident from table 1, calcium chloride does not become toxic
until present in concentration of over .24 M. Up to and including
this concentration the growth seems to be but little affected by the
increasing concentrations of the salt added. The percentage of cal-
cium in the plants shows no direct increase with increasing concen-
tration of calcium chloride in the solution. The lowest percentage of
calcium given occurs in a concentration of .20 M. calcium chloride.

In table 2 there is a close parallelism between the growth of roots
and tops. Two low points on the dry weight graph are evident, the
first occurring at cultures 4 and 5 and the second from 7 to 11. At
these low points we have a high percentage of magnesium in both
roots and tops, but of calcium only in the second low point. Calcium
is low where growth is good in cultures 2 and 3. But the most inter-
esting feature is the decreased absorption of both elements at cul-
ture 6, where there is a distinct increase in dry weight. [ron was
not present in sufficient concentration to allow of titration until cul-
ture 11 is reached. It may be stated here that the iron determined is
limited to that in the seed as a maximum, for it was purposely ex-
eluded from the solutions except where its toxic or antagonistic action
was under observation. In many instances the titration of this residual
iron is of interest.

Table 3 is a record of one of the most interesting and significant
series reported. The root growth was so limited in nearly every cul-
ture that no attempt was made to segregate roots from tops for sep-
arate determinations except where the total dry weight was so greatly
increased as in cultures 6 and 11. In the first place we have double
maxima of growth, the first in culture 6 and the second in 11. The
total dry weight at culture 11 is twice that at 6, but the dry weight
in culture 6 amounts to a 35 per cent increase over that in culture 7.
A direct inverse relationship is shown between -total growth and ab-
sorption at these two high points; the maximum growth in culture 11 is
accompanied by the lowest absorption of calcium and magnesium.
The percentage of magnesium is low in culture 6, but that of calcium

26 Cornell Univ. Agr. Exp. Sta. Mem. 2 (1913), p. 127.
27 Plant world, vol. 19 (1916), p. 83.

146 University of California Publications in Agricultural Sciences | Vol. 3

is higher than in the cultures of slightly higher or lower concentra-
tions. No explanation of the narrow ratio between these two ele-
ments at this point can be offered. It is of interest to note the very
ereat increase in the amounts of calcium and magnesium found in
the plants grown in concentrations of .20 M. calcium chloride alone.
While magnesium chloride is constant throughout the series, the
amount of magnesium does not increase proportionately to that of
calcium.

A still higher concentration of magnesium chloride was used in
the series reported in table 4. The percentage of magnesium found
in the roots is very high and would indicate that it was not entirely
removed from the roots by washing. In general the percentages of
calcium and magnesium found are high, the calcium content increas-
ing as the concentration of calcium chloride present in the culture,
but not proportionately. Magnesium is lower at the greater dry
weights for the tops, the decrease amounting to 50 per cent in the case
of culture 6.

Magnesium sulphate was used alone in the series reported in
table 5. The decrease in growth is nearly proportional to the increase
in concentration of the added salt. In this series we have a very
marked decrease in the percentages of calcium and magnesium present
in the roots without any evident effect upon the growth of the plants,
especially that of the tops. Here again, however, we have increased
absorption of calcium as the percentage of magnesium increases,
even though the concentration of the former in the nutrient solution
is constant. It is of interest to note that the percentages of both ele-
ments in the tops throughout this series are low and vary but little,
regardless of the increasing concentration of the nutrient solution.

Very marked antagonism between calcium chloride and magnesium
sulphate is shown in table 6. The dry weight of the plants grown in a
solution of magnesium sulphate .18 M. concentration was .29 gram,
but when .04 M. concentration of calcium chloride was added the aver-
age dry weight was 1.20 grams and in a concentration of .18 M.
magnesium sulphate and .24 M. ealecium chloride the average dry
weight was .98 gram. Between these two concentrations of calcium
chloride the dry weights recorded are uniformly high. Correlated
with the rapid decrease in growth, in concentrations of .24 M. of cal-
cium chloride, is the marked increase in the percentage of both calcium
and magnesium found in the plants. The graphs representing the
amounts of these elements found crosses the growth graph coincident

1918 | Waynick: Antagonism and Cell Permeability 147

with its sharp decline. The low percentage of magnesium is of interest
since the concentration of the culture solution was uniformly high
with respect to this ion.

It is striking that there is a marked decrease in the growth of roots
at the concentration which gave the best growth of tops, and further
that the percentage of calcium in the tops and magnesium in the
roots parallel this decrease in the growth of the roots. A comparison
of the results obtained with magnesium sulphate as against those with
magnesium chloride is reserved for later discussion.

In table 7 we have an opportunity to compare indirectly anion
effects, or possibly the effects of combinations of the same kation with
different anions. From preliminary results it seemed advisable to use
.15 M. magnesium sulphate in this series instead of .18 M. as used in
the preceding series, so that the concentration of magnesium ion is
not equivalent in the two series. A solution containing magnesium
sulphate .15 M. plus calcium nitrate .08 M. proved highly toxic, while
a solution containing calcium chloride of the same concentration as
the nitrate in the above solution supported normal growth. It is
possible that the difference is due to the toxic action of the nitrate ion
on the plant directly. Tottingham has shown that the total ionization
of a nutrient solution was decreased 10 per cent below the theoretical
by the addition of calcium nitrate in low concentrations. It is pos-
sible that the ionization of some other salt is repressed so that there
is an actual lack of some ion necessary for growth. The percentage
of calcium found was not high enough in any case to account for the
toxic effects shown. Magnesium was found in extremely large
amounts, 9.20 per cent in the case of culture 6, the largest percentage
recorded in any culture studied. Unfortunately the series in which
the toxic effects of calcium nitrate alone were studied was lost, so it
cannot be reported here.

Potassium chloride was the only monovalent salt studied, and the
results are given in tables 8 and 9. The growth shown in the various
concentrations of potassium chloride used was approximately the
same as that found when magnesium sulphate was used alone. The
increase in the percentage of ash, as far as the tops are concerned in
table 8 is very striking. The percentage of calcium found in the tops
and of magnesium found in the roots remains practically constant
throughout. The amount of potassium absorbed increases as the con-
centration of potassium chloride in the solution increases and in-
versely as the growth of the plants. The toxic effects due to the

148 University of California Publications in Agricultural Sciences | Vol. 3

addition of potassium chloride to the solution are much more evident
in the tops than in the roots with respect to the increasing concen-
trations of potassium chloride.

Using a constant concentration of potassium chloride of .18 M.,
which is an increase of .02 M. over the highest concentration of that
salt reported in table 8, against varying concentrations of magnesium
sulphate, the results reported in table 9 were obtained. There is a
marked increase in total ash as the concentration of the nutrient solu-
tion with respect to magnesium sulphate increases. Parallel with this
increase is the higher percentage of potassium. The growth decreases
inversely. Antagonism between the two salts is evident where the
lower concentrations of magnesium sulphate were used. In cultures 2
and 4 of this series, we have a marked increase in growth over that of
culture 3. Absorption is markedly lower at the two high points than
at the intermediate concentration, where the solution is evidently
more toxic. The least growth obtained in the series was recorded in
culture 7, which shows the highest absorption of all the elements
determined. In the two higher concentrations of magnesium sulphate
used the growth was increased somewhat while the percentage of cal-
clum, magnesium, and potassium in the plants decreased markedly.
It seems worthy of note that the amount of iron in the ash was not
sufficient to allow of titration at any concentration employed in the
series. This series very well illustrates the point which has been
brought out a number of times before of the relationship between
absorption and growth. Here we have five cultures in the one series
of which this relationship is evident. The relations are not absolute
in every instance, but there can be no doubt whatever of the tendeney
toward decreased absorption as growth increases, or that antagonism
between ions results in decreased absorption of at least some of the
ions present in the nutrient solution.

We turn now to a consideration of the effects of a few of the salts
of the heavy metals upon growth and absorption. In table 10 the
effects of adding various concentrations of aluminum chloride are
shown. Growth is decreased in every concentration of the salt used.
The high percentage of magnesium is marked in both roots and tops.
On the other hand, the percentage of calcium is increased relatively
little. The percentage of iron found was practically constant and in
total quantity is in marked contrast to the last series considered in
which the amount was so small that it could not be determined.

In a solution of .20 M. ealeium chloride, the results with the vary-

1918 | Waynick: Antagonism and Cell Permeability 149

ing concentrations of aluminum chloride are shown in table 11. In
general the toxie effects of the two salts seem to be additive, that is,
the growth in this series in which two salts are present together is
less than in the preceding series where aluminum chloride was used
alone. The decrease is not great from the standpoint of total weight,
but proportionately is very considerable, amounting to from 33 per
eent to 100 per cent in the various concentrations employed. The
percentage of magnesium in the two series is about the same. The
amount of ealeium absorbed, on the other hand, is increased over 300
per cent and remains constant throughout. The total absorption with
respect to calcium and magnesium, at least, is uniformly high. This
fact is reflected in the increase in the percentage of ash over that of
the control. In the next series all factors are the same except that
magnesium chloride was used instead of calcium chloride, there being
no difference whatever in partial or total concentration. The antag-
onism shown between magnesium chloride and aluminum chloride in
culture 4 is very marked, and correlated with the increased growth is
the marked decrease in the percentage of both magnesium and cal-
cium found in tops and roots. The percentage of magnesium found
in the plants is not proportional to the concentration in the solution
as was true with calcium chloride. An interesting case of the in-
creased absorption of one element with a decrease in the other is well
illustrated in the case of culture 6 of this series. Such a relationship
has been noted previously, but is apparently of no direct importance
from the standpoint of growth.

Ferric chloride, a second trivalent salt, was used in the nutrient
solution in the concentration shown in table 13. In the concentration
employed, growth is nearly normal and absorption is very nearly the
same as with plants in the control cultures, except in the case of cal-
cium. The decrease in some instances in the percentage of calcium
found, as iron increases in the nutrient solution, is notable, and will
be referred to later in connection with the action of ferric and zine
sulphates.

The effects of adding .20 M. calcium chloride, together with vari-
ous concentrations of ferric chloride, are given in table 14. The
growth of roots and top parallel each other closely. Marked toxic
effects are evident in certain combinations as in cultures 3 and 7.
The percentage of calcium found in both roots and tops is high in
plants grown in the same cultures. The magnesium present in
the tops shows the same relationships as the calcium, although the

150 University of California Publications in Agricultural Sciences Vol. 3
y

amount absorbed varies but little from that of the control. In the
roots magnesium is present in large amount when growth is low in
culture 2, but in succeeding cultures the percentage found falls off
sharply and remains abnormally low without any relation to growth
or concentration of the solution. The percentage of iron is high in
cultures 6 and 7, in which the weight of the plants was small.

Substituting magnesium chloride in equivalent concentration for
the calcium chloride used in the preceding series, the results are of a
very different order from those in table 15. The absolute growth of
the tops is greater than in series 14. Root growth does not parallel
the growth of the tops. The toxicity of the solution is searcely evident
at some concentrations while markedly increased at others. Absorp-
tion, with the exception of the magnesium in the roots, is usually low,
amounting to about that of the control, but the percentages of calcium
and magnesium found bear no apparent relation to the differences in
erowth. Iron, however, shows the inverse relation already noted in
many other series with calcium and magnesium, that is, high percent-
age present when growth is low, and vice versa. The toxic and antag-
onistie effects as well may be due in this instance to the ferric ion, but
this statement is by no means indisputable.

In several tables following, the effects of copper salts are given.
Previously copper salts have been shown to be highly toxie to plants
as well as to a wide variety of vegetative forms. That they may also
be stimulating has been shown recently by Forbes** using solution
cultures, and by Lipman and Gericke” in soil cultures. The reader is
referred to the latter paper for an extensive review of the subject.

The results with copper chloride are reported in table 16. Growth,
especially that of the roots, was limited in every concentration re-
ported. In fact, the growth of the roots was so limited that their
weights are not given. There is a suggestion of antagonistic action
between the nutrient solution and copper chloride in cultures 3 and 5.
The percentage of magnesium found is high where growth is low.
The same is not true of calcium, the percentage of which is low and
decreases as growth decreases to a certain extent. A trace of copper
was found in every case and appreciable amounts had penetrated
the plant tissue at the two higher concentrations. When ferric
chloride is added together with copper chloride marked antagonism is
shown. Table 17 will make this effect evident. In this series, as in

28 Univ. Calif. Publ. Agr. Sei., vol. 1 (1917), p. 395.
29 Tbid., p. 495.

1918 | Waynick: Antagonism and Cell Permeability 151

several following, the concentrations of both salts added increase, that
is, both increasing but bearing the same ratio between the two.
There is an increase of approximately 100 per cent in the dry weight
of culture 2 over cultures 1 and 3. The low absorption of culture 2
as related to 1 and 38 is evident. There is a marked decrease in the
percentages of calcium and magnesium found in the plants grown in
culture 5, in which the dry weight of the plants was also low. At this
second point, however, iron and copper were found in larger amounts
than at any other concentration used. As in the previous series the
percentage of calcium in the tops does not seem to parallel that in the
roots or of magnesium in either roots or tops. <A similar relationship
was brought out in the previous series in which copper chloride alone
was used. No apparent precipitation took place upon the addition of
iron in the concentrations given, but a precipitate composed of ferric
phosphate was present at the time of harvesting. It is possible that
double salts of copper or iron with calcium or magnesium and, for
instance, the phosphate ion were formed at the higher concentrations.
Their complexes may not be taken up by the plants and hence actual
starvation as far as these elements are concerned, may be responsible
for the low amounts found in the plants. Such a condition contrasts
directly with one in which there is low permeability due to antagonistic
effects between the ions in the solution.

In table 18 mercuric chloride was used with copper chloride, since
it was desired to determine the effects produced by the addition of
two highly toxie salts to the nutrient solution. The results with mer-
curic chloride alone are given in table 26. They are somewhat irregu-
lar, but there can be no doubt of the correlation between the quanti-
tative presence of calcium and magnesium in the tops, of magnesium
in the roots, and growth. There is evidence of a distinct antagonistic
action between copper and mercuric chlorides both from the stand-
point of growth and that of absorption. The root growth was very
limited. The percentage of calcium and magnesium in the roots was
very high; high enough to account for the decreased growth by itself
if we use the results of other series in interpreting this one. Not
enough iron was present in any culture to permit of its determination.

Considering the most common salt of copper used in solution cul-
tures and soil work, the results as given in table 19 are especially
noteworthy. The concentrations of the sulphate used are low. Dis-
tinct evidence of the toxic effects of the salt, together with only shght
decrease in growth in culture 4 of the series is shown. High percent-

152 University of California Publications in Agricultural Sciences | Vol. 3

ages of calcium and magnesium accompany low growth; low percent-
ages of calcium and magnesium go with much increased growth. No
iron could be quantitatively determined in cultures 8 and 9. The
copper content shows no variations which may be regarded as impor-
tant, in fact the amount taken up by the plants is somewhat lower
where decreased growth is shown.

Zine sulphate was used with copper sulphate as shown in table 20.
There is little evidence of antagonism between the two salts. At the
same time there is evidently no direct relationship between concen-
tration and toxic effect, since growth does not decrease regularly with
increasing concentration. While the percentages of calcium and mag-
nesium found are somewhat irregular, they increase rapidly as growth
becomes less. The percentage of magnesium found in the tops in
culture 8 was 1.10 per cent, and in the roots 1.91 per cent. This
occurred with the same concentration of the magnesium ion in the
nutrient as in culture 1. The percentage of copper found in the dry
matter is distinctly larger than that found in the preceding series, in
which copper sulphate alone was used.

Copper sulphate used with ferric sulphate shows no evidence of
antagonism between the two if the growth of the tops alone is con-
sidered, but with the roots there is a marked increase in growth in
cultures 3 and 4 of the series. The percentages of magnesium found
in the roots is low and constant, which contrasts markedly with the
amounts determined in the previous series. The calcium likewise
varies but little in the tops and its percentage remains low. On the
other hand, the percentages of calcium in the tops and magnesium in
the roots show marked increases as growth decreases. The amount
of iron remains very uniform until the last culture of the series is -
reached, when a marked increase is recorded. It will be noted that the
percentage of calcium decreases to nearly one-third of the original in
the same culture. This relation has been noted previously in other
series.

The stimulation resulting from the addition of ferrie sulphate to
the nutrient solution in the concentrations given in table 22 is remark-
able, a total dry weight of 3.9016 grams for the tops of six plants
being recorded. The growth of the roots does not parallel that of
the tops. In the highest concentration of ferric sulphate employed,
the root growth decreased while the growth of the tops was increased.
Attention has already been ealled to cases of this kind in which
there may be an increase in the growth of tops with a decrease in

1918 | Waynick: Antagonism and Cell Permeability 153

the root growth, or vice versa. As will be noted, the percentages
of calcium and magnesium found are low, in fact below the control
in every case. Whether or not ferric sulphate would be stimulating
in still higher concentrations is not known, but it is probable that the
limit of stimulation was reached, since the roots show a marked de-
crease in growth in the highest concentration used. The percentage
of iron found is comparatively high. The reason for this increased
growth is evidently bound up with the presence of the ferric salt,
but no idea of the nature of its action can be given. It is very evi-
dent from the present data, however, that the amounts of the elements
present in the plants were low.

In table 23 the results with zine sulphate alone are reported.
There is no stimulation or no antagonism between zinc sulphate and
the other constituents of the solution evident in any concentration.
As growth decreases magnesium was found present in larger amounts
than in the cultures in which growth was more nearly normal. The
percentage of calcium remains very much the same in the tops and
decreases rapidly in the roots with decreasing growth. Here we have
a suggestion of a relationship between zine and calcium as has already
been referred to in the case of iron. It can only be stated, however,
that the results as regards calcium penetration are exceptional in the
hght of the results in other series previously referred to.

Turning to table 24, in which the results with zine sulphate and
ferric sulphate are given, there is a marked contrast on the one hand
with series 20 in which zine sulphate and copper sulphate were used,
and on the other hand with the preceding series in which zine sulphate
alone was used. In this series there is marked antagonism shown be-
tween the salts employed. This is true for both tops and roots, but
the most marked increase in both does not occur in the same culture.
The marked increase in growth of the tops evident in culture 4 is
accompanied by a decrease in the percentages of calcium and mag-
nesium present in the tops but not in the roots. The percentage of
magnesium in the roots increases with decreased growth throughout
the series. The calcium in the tops is low and abnormally so in the
roots. Growth is good throughout the series and in culture 4 is in-
creased about 50 per cent above the control. This.result would hardly
be expected from the decreases recorded where zine sulphate was used
alone in the preceding series. The percentage of iron varies some-
what, but does not increase or decrease with any regularity in any
one direction. Attention is again called to the low calcium content,
especially of the roots.

154 University of California Publications in Agricultural Sciences | Vol. 3

Little can be said of the mercuric chloride ferric sulphate series
given in table 25. Growth is uniformly low throughout, with con-
siderable variation between duplicate cultures. The percentage of
magnesium is very high in the roots and while less in the tops, is
much above that of the control. The percentage of calcium is uni-
formly low in both tops and roots. Attention is called to the fact
that no iron could be determined quantitatively, except in the highest
concentration of salts used. This condition is striking when the
rather large amounts of ferric sulphate in the solution are considered.

A short series is reported in table 26 in which the toxic effects
of mereurie chloride when used alone, are evident. There is a de-
crease in growth with increasing concentration of the added salt and
also an increasing percentage of both calcium and magnesium found.
The very low ash content given by the plants in this series is of
interest and will be discussed below.

EXTERNAL APPEARANCES OF THE PLANTS

It seems worth while to note here a few of the more striking
appearances of the plants. Since iron salts were purposely excluded
from all solutions except those in which it was planned to study their
effects, the control plants were of a more or less yellowish green color.
Aside from this no differences were noted between control plants
grown with or without the addition of a little ferric phosphate to
the nutrient.

In every series in which growth was limited by the presence of
magnesium salts the roots were short and much thickened. With a
high concentration of magnesium in a balanced solution, this effect
was not noted however. High concentrations of magnesium were also
apparent from the decided yellowing of the older leaves. Excessive
amounts of calcium were characterized by the appearance of brown
spots or streaks on the leaves.*°

When any considerable growth was permitted the plants grown in
solutions of copper salts were dark green in color.*' Where growth
was good the roots were apparently normal. In several of the higher
concentrations used, copper hydroxide was deposited upon the roots,
especially about the tips. A suggestion is made that possibly copper
may replace iron as a catalyzer in connection with the building or
activation of chlorophyll.

30 Jost, Plant physiology (Oxford, Clarendon Press, 1907), p. 85.
31 Univ. Calif. Agr. Sei., vol. 1 (1917), pp. 495-588.

1918 } Waynick: Antagonism and Cell Permeability 155

Several cultures in which mereurie chloride was used and in which
growth was good, displayed the same dark green color as noted for
copper salts and the same suggestion as made for the functioning of
copper in this color relationship may hold for mercuric salts as well
in very dilute solutions.

The color was light green when iron salts were present; with the
other salts used no marked external effects were noted.

GENERAL REVIEW OF EXPERIMENTAL RESULTS

It seems advisable to consider the results reported in the previous
tables together, so that the data presented in one table may be more
closely correlated with those given in another. It is proposed to do
this in the present section and further to discuss briefly the more
important relationships shown.

It will be noted in the accompanying tables that there is consid-
erable variation between the controls grown at different seasons of
the year. This was to be expected, since conditions in the green-
house varied between the different growing periods. For this reason
it is not possible to compare one series of cultures with another so
far as absolute weights of the dry matter are concerned. Within any
one series or between series grown at the same time the absolute
weights are comparable. This point must be borne in mind in con-
sidering the results as a whole. In some cultures, however, growth
was stimulated to such an extent as to far surpass any variation
between series due to differing external conditions. Such a ease is
that of series 22, in which ferric sulphate was added to the nutrient
solution in varying amounts. In culture 5 of this series, the dry
weight was over twice that of any control plants grown during the
entire time.

The experimental work with the salts of calcium plus magnesium
was rather extensive. McCool*? has reviewed the previous work with
calcium and magnesium salts as related to plants, so a discussion of
that phase of the relationships between the two need not be entered
into here. In his own work McCool found that calcium chloride was
effective in antagonizing the poisonous effects of magnesium chloride
and magnesium sulphate. He found a slight increase in the growth
of pea seedlings over the controls based upon the green weight of the
plants. This was the case in distilled water and in nutrient solution.
It seems probable that the nutrient solution used by MeCool was not

82 Cornell Univ. Agr. Exp. Sta. Mem. 2 (1913), p. 129.

156 University of California Publications in Agricultural Sciences [ Vol. 3

a balanced solution, since the addition of either magnesium or cal-
cium chloride resulted in an increased growth of the pea seedlings.

In the present investigation there are only two cases in which the
growth of the plants was greater with both calctum and magnesium
chlorides present than when calcium chloride was used alone in vari-
ous concentrations, one in culture 6, series 2, the other in culture 11,
series 3. In the latter culture the dry weight of the plants was twice
that in the same concentration of calcium chloride alone. There are
marked differences in growth recorded between different combinations
and concentrations of the two salts, and as can be easily seen from
the graphs, the percentages of the two ions found in the plants show
an inverse relation to growth in nearly every instance. Proceeding
from series to series, the amount of magnesium found in the plants
increases with the concentration of the magnesium chloride in the
nutrient solution.

Magnesium sulphate is not as toxic as magnesium chloride in
equivalent concentrations of the kation. Growth in solutions of mag-
nesium sulphate plus calcium chloride was superior in every case to
that found when the salts were used separately. There is a marked
contrast between calcium chloride and calcium nitrate in antagoniz-
ing the toxic effects of magnesium sulphate, the nitrate proving less
effective than the chloride in concentrations of .12 M. and over. This
is of especial interest, since the qualitative ionic relations of the nutri-
ent are not altered. It is possible that we are dealing with the effects
of undissociated molecules in the higher concentrations, which may
be very different from ionic effects.

RESULTS WITH SALTS OF THE HEAvY METALS

Since salts of aluminum, copper, zine, iron and mercury were
used, it will be necessary for the sake of clearness to treat each more
or less separately.

Miyake** has shown aluminum chloride to be highly toxic, in con-

centrations above to rice seedlings grown in water cultures.

N
7500’
Similar results have been reported by House*t and Gies, Micheels and
De Heen,** Duggar,** and Ruprecht,** working with several aluminum

33 Jour. Biol. Chem., vol. 25 (1916), p. 23.

34 Amer. Jour. Physiol., vol. 15 (1905), p. 19.

35 Bull. Acad. Roy. Belg. (1905), p. 520.

36 Plant Physiology, New York, Macmillan, 1911.
37 Mass. Exp. Sta. Bull. 161 (1915), p. 125.

1918 | Waynick: Antagonism and Cell Permeability 157
salts. Probably the work of Abbott, Conner and Smalley** is of more
direct interest here. These investigators found aluminum nitrate to
be toxie to corn seedlings in the presence of nutrient solutions.
KE. Kratzmann* has reported stimulation due to the presence of small
amounts of aluminum salts. Miyake*® concludes further that the
effects observed with aluminum chloride cannot be attributed to the
hydrogen ion resulting from the dissociation of the salt.

Aluminum chloride was found to be toxie in every concentration
used in the present work. The effect of the presence of calcium
chloride in a concentration of .20 M. was to decrease growth still fur-
ther, indicating that its toxic effect, as reflected in growth, was but
additive to that of aluminum ehloride. With magnesium chloride
present in equivalent concentration as the calcium chloride, there is a
marked antagonism at a concentration of .000066 M. of aluminum
chloride with .20 M. magnesium chloride. The increase in dry weight
was 100 per cent greater than in an equivalent concentration of
aluminum chloride alone and 300 per cent greater than with mag-
nesium chloride in the concentration given. This culture has been
referred to especially since it furnishes a striking example of antag-
onism between bivalent and trivalent salts, both of which are highly
toxic when used alone. The chloride ion was a constant as far as this
and the preceding series are concerned, the only difference between
the two cases being the use of calcium chloride in one and magnesium
chloride in the other. It seems logical to conclude that the action is
specific as regards the magnesium and aluminum ions. Whatever
the nature of this action may be, it is certainly not shown between
calcium and aluminum ions.

The same general relationships are brought out between ferric
chloride and calcium and aluminum chlorides. Ferric chloride did
not prove toxic in the concentrations used, growth differing but little
from that of the control. When calcium chloride was present in a
concentration of .20 M. throughout the series, growth was half or less
than half that recorded when ferric chloride alone was _ present.
Magnesium chloride in equivalent concentrations, as the calcium
chloride above, affected growth but little. In other words, magnesium
chloride did not prove toxic in the presence of certain concentrations
of ferric chloride. The relations between the four salts may be briefly
summarized as follows: There is no antagonism shown between alumi-
"38 Ind. Exp Sta. Bull. 170 (1913), p. 329.

39 Chem. Ztg., vol. 38 (1914), p. 1040.
40 Jour. Biol. Chem., vol. 25 (1916), p. 23.

158 University of California Publications in Agricultural Sciences [ Vol. 3

num chloride and calcium chloride. There is very little, if any, be-
tween ferric chloride and calcium chloride. Magnesium chloride and
ferrie chloride show marked antagonism in all concentrations used
as do magnesium chloride and aluminum chloride in certain concen-
trations of the two salts. Magnesium chloride and ferric chloride
show marked antagonism in all concentrations as do magnesium
chloride and aluminum chloride in one concentration of the latter salt.

Reference has already been made to Miss Brenchley’s monograph**
and to the paper by Lipman and Gericke,*? in which the literature
relating to the effects of copper, zine, and iron salts on plants is
reviewed. Suffice it to say that the results reported by different
investigators are very conflicting, due largely to the widely different
methods used and the varying conditions under which the various
data were obtained.

In the present work, copper chloride was toxie in every concen-
tration used. There was marked antagonism between copper and
ferric chlorides both from the standpoint of growth and of absorption.

Copper sulphate did not prove to be uniformly toxic. Growth was
nearly normal in one concentration used while very much diminished
in a lower concentration. The term stimulation might be applied
here, but in the present discussion it is applied only when growth due
to the presence of an added salt or salts is undoubtedly greater than
that in the control.

Toxie effects are correlated with inereased absorption and antag-
onistic effects with decreased absorption as in other series reported.

Growth was always less with zine sulphate present in the nutrient
solution than in the latter alone. Copper and zine sulphate together
were no more toxic than a solution of zine sulphate alone.

The case with ferric sulphate is clearly one of stimulation. The
dry weight was over twice that of the controls in one concentration
of the salt used and far superior in several concentrations to that
of the plants grown in the controls. Wolff** has reported similar
results when iron was used in the form of the citrate, an increase
in growth comparable to that noted above having been obtained. He
found further that nickel or chromium could not be used to replace
iron.

The toxie effects of copper sulphate were markedly reduced by
the presence of ferric sulphate when we consider the results as a

41 Inorganic plant poisons and stimulants. 1915.

42 Univ. Cal. Pub. Agr. Sci., vol. 1 (1917), p. 395.
43 C,-R. Acad. Sei. (Paris), vol. 157 (1913), p. 1022.

1918 } Waynick: Antagonism and Cell Permeability 159

whole, although in one instance growth was greater with copper sul-
phate alone than when both salts were added together.

The second case of stimulation was noted with zine sulphate and
ferric sulphate in certain concentrations. In series 26 four cultures
gave growth superior to that obtained in the control for the series,
and throughout growth was good when the two salts referred to above
were present together, over the range of concentrations employed.
Low absorption was noted. In summarizing the relations of ferric,
cupric and zine sulphates, it is evident, from the discussion above,
that zine sulphate was toxic in every concentration used. Copper sul-
phate was toxic, but marked variation in degree was shown between
various concentrations. Ferric sulphate was stimulating. Copper
sulphate and zine sulphate were no more toxic together than when
each was used alone. Ferrie sulphate modified somewhat the toxic
effects of copper sulphate. Zine sulphate and ferric sulphate together
proved stimulating to the growth of plants. As contrasted with the
chlorides, the sulphates of copper and iron were less toxic to barley
over the range of concentrations used in this investigation.

Taking the results as a whole, twelve instances of a marked in-
erease in growth at certain definite concentrations of one or more
added salts have been noted. With every such increase there is a very
notable decrease in the amount of calcium and magnesium absorbed.
The increase in growth is attributed to antagonistic salt action; de-
ereased absorption is undoubtedly due to the same action, which
tends to preserve the normal permeability of the plasma membrane.

In addition to the twelve instances referred to above, we find
in series after series, the toxic effects of the solution in which the
plants were growing, noticeable not alone by decreased growth but
also by increased absorption. The roots and tops may not show the
same relations as regards the amounts of calcium and magnesium
taken up. For example, in series 25, in which ferric sulphate and
mercuric chloride were used together, the toxicity of the solutions was
evident by the very limited growth, yet the composition of the tops
was about normal. In the roots, however, the percentage of mag-
nesium was found to be tremendously increased.

It is of interest to refer again to the very low ash content and
relatively low absorption, considering the very limited growth, in the
few cultures in which mercuric chloride was used alone. It is pos-
sible that relatively large amounts of mercuric salts were taken up
by the plants which were volatilized on ashing the residue; thus the
low percentage of ash may be less surprising.

160 University of California Publications in Agricultural Sciences | Vol. 3

POSSIBLE EFFECTS OF VARIATIONS IN THE CONCENTRATIONS OF
THE SOLUTIONS ON THE PLANTS

No attempt was made to maintain the total concentration of the
nutrient solution constant. This would be exceedingly difficult to do
in work of this character, since it would be necessary to vary the
concentration of the nutrient solution to maintain the balance of the
solution as regards total concentration. The conclusion seems justi-
fied that within the range employed the concentration of the nutrient
solution is of minor importance as far as growth is concerned. For
instance, in table 1, the variation in the concentration of the solution
was .279 M. in terms of calcium chloride, yet the total growth varied
but little from .001 M. to .28 M. Again in table 2 the growth is very
nearly the same at a concentration of .25 M., with calcium and mag-
nesium chlorides, and a total concentration of .54 M. of the same salts.
In table 3 the greatest growth occurred in a concentration of .46 M.
in terms of the salts above mentioned, while at the lower concentra-
tions of .304 M., growth was but a third that obtained in the higher
concentrations. These examples make clear the point above men-
tioned, namely, that the concentration over the range used was of
but minor importance. It is obvious that the above discussion does
not apply to the series in which salts of the heavy metals were used,
since the variations in concentration in those series were but slight.

CONSIDERATION OF A PossIBLE CALCIUM-MAGNESIUM Ratio

Since Loew** first advanced the hypothesis of the lime-magnesia
ratio, much experimental evidence has been collected by various inves-
tigators both for and against the existence of an optimum ratio be-
tween these two elements as regards the growth of plants. The
literature bearing upon the subject has been very fully reviewed by
Lipman,** so that detailed references are not necessary here.

Since the ratios of calcium to magnesium in the solution used by
the writer were known and also because of the fact that the analytical
data allowed of the calculation of such a ratio for the plants, it
seemed of interest to present some of these data here.

The following two tables give the results obtained from two series
in which widely varying proportions of caletum and magnesium were
used.

44 Flora, vol. 75 (1892), p. 368.
45 Plant world, vol. 19 (1916), p. 83.

1918} Waynick: Antagonism and Cell Permeability 16]

TABLE 27

Ratio Ratio Ratio
Mg to Ca Dry weight Mg to Ca Dry weight, Mg to Ca
in solution tops in tops roots in roots
41 3 3536 20 $2 1218 1 a ee
16 ] 484 a0 3 1519 Aare ae
8 1 885 6.0 : 1 .1266 ] ¢
as ee | A774 2.6: ] 1509 ee
EY I | 3433 A Oe A | 1497 bea 22
SS | 6775 Refi Fo .2119 oe oe
1 a | 4136 ae 1500 be fa
Lot 4431 ] . 12 .142] 1s
] Sos 38745 pp Se a 1138 1 1.3
eee 3268 Pie a a .1254 ] 1.5
ue .2815 hour! 10538 - . % doe
Lact 28 5030 ae ae 1044 cE i ae |

Table 27 was computed from the results given in table 2. Mag-
nesium chloride was present in uniform concentration of .24 M. with
varying concentrations of calcium chloride.

It will be noted that the dry weights with a ratio of magnesium to
ealecium of 16:1, 8:1, and 1:18 are nearly the same. The ratios of
these two elements found in the plants grown in these solutions were
wed, 1:1, 1:12 for the roots, and 1:4.6, 1:.1.6, 1:1.2.for the tops.
Further, the dry weight of plants grown in a solution in which the
ratio was 41:1 and with a ratio of 1:1 are nearly the same. It is
evident that the same ratio for the roots may not hold for the tops.

TABLE 28

Ratio Ratio Ratio
Mg to Ca Dry weight, Mg to Ca Dry weight, Mg to Ca
in solution tops in tops roots in roots
20.2 : 1 .3033 eae ae | .0822 Ce eae |
Bis 32d A716 OA ect 1572 SY ae is |
eae | 2799 455 5 .0780 Go 24
es aera 1999 RG .0342 6.021
4.023 1999 48 2d .0636 ewe
ot 1 .4363 Laoveed 1122 A aay |
ae | .4013 oI a i | .1143 rR ua ve |
Pe | .2734 ye ee | 0677 age tk
1 A ae ga .2603 iw £4 .O867 6.8. <1

Table 28 gives the ratios in the solutions used in series 4, in which
the ratios of magnesium to calcium varied from 20.2:1 to 1.7:1.
Growth is nearly the same in solutions in which the ratio was 10.5: 1
as in those in which the ratio is 3.4:1 or 2.5:1. The plants grown
in these cultures gave the following values for the tops: 5.4: 1, 3.4: 1,
2.5: 1, and for the roots, 4.7: 1, 4.1: 1, and 2.8:1. There is a tendency
for the ratio of calcium to magnesium in the plants to become narrower

162 University of California Publications in Agricultural Sciences Vol. 3
y

as the ratio of these two ions in the solution becomes narrower.
Where a wide ratio exists in the solution, there is always a much nar-
rower ratio in the plants.

From the brief discussion above it is evident that the barley plants
erew equally well in solutions having widely different ratios of cal-
cium and magnesium ions. There is no ‘‘optimum lime-magnesia
ratio,’’ as Gile*® and Wyatt*’ as well as others have shown, and their
results are confirmed in the present investigation.

The balance between all the ions present in the solution appears
to be of far greater importance than any single ratio. A considera-
tion of the ratios existing between the various ions of the nutrient
solution, aside from calcium and magnesium used, is reserved for
further study.

PERMEABILITY AND ANTAGONISM

It is not proposed to enter into a discussion of the structure and
composition of the plasma membrane. Davidson** has recently sum-
marized our present knowledge concerning it with special reference
to selective permeability. A discussion of the various theories which
have been advanced to explain antagonistic salt action need not be
taken up in detail here. The reader is referred to papers by Clark,*®
Loeb,®° Osterhout,®! Loew,®*? Koenig and Paul,°* True and Gies**, True
and Bartlett,°> Kearney and Cameron,® and Ostwald*’, for a discus-
sion of the various factors which may be of importance in this con-
nection.

The recent work of Clowes** and Fenn*® is important and some
very striking similarities between the action of toxic and antagonistic
solutions on oil emulsions and on gelatine on the one hand, and plant
cells on the other, have been reported by these investigators.

46 Porto Rico Exp. Sta., Bull. 12 (1912).

47 Jour. Agr. Research, vol. 6 (1916), p. 589.

48 Plant World, vol. 19 (1916), p. 331.

49 Bot. Gaz., vol. 33 (1902), p. 26.

50 Archiv. ges. Physiol., vol. 88 (1902), p. 68.

51 Science, n.s., vol. 35 (1912), p. 112.

52 Flora, vol. 75 (1892), p. 368.

53 Zeitschr. Hygiene u. Infektionskrankheiten, vol. 25 (1897), p. 1.

54 Bull. Torr. Bot. Club, vol. 30 (1903), p. 390.

55 U. S. Dept. Agr., Bull. 231, 1912.

56 U. S. Dept. Agr., Bull. 71, 1902.

57 Archiv. ges. Physiol., vol. 120 (1907), p. 19.

58 Jour. Phys. Chem., vol. 20 (1916), p. 407.
59 Proce. Nat. Acad. Sci., vol. 2 (1916), p. 539.

1918 | Waynick: Antagonism and Cell Permeability 163

To define normal permeability is very difficult. There seems to
be a comparatively wide range of concentration of salts over which
the amount of any element taken up may vary without affecting the
growth of the plant to any considerable extent. There is lkewise a
wide range over which the ratio of any one element to any other may
change without being detrimental to plant growth. The latter point
has been discussed above in connection with a possible optimum
calcium-magnesium ratio for plants. The first point referred to has
been very well treated by Gile and Ageton,®® so that further reference
need not be given here.

For the work in hand the percentage composition of the plants
grown in the control cultures seemed to be the most logical criterion
of normal permeability available. There are variations between the
controls as regards composition, but they are relatively small. On
the other hand, the percentages of magnesium, for instance, range
from .02 per cent to 9.21 per cent, depending upon the solution used.
The percentages of calcium differ over a wide range as well. From
the data presented there can be no doubt whatever that the composi-
tion of the plant, as regards inorganic constituents at least, may be
altered enormously by variations in the surrounding solution.

That portion of the root system in any plant which functions as a
semipermeable membrane is obviously of greatest importance in a
study of the present kind. The actual area of the membrane which
is in contact with the solution must be known in every case before it
ean be said that the permeability of one root system is greater than
that of another. The actual area of the plasma membrane cannot be
measured directly because, in the first place, we have no means of
determining just how much of the root is involved, and secondly, the
area concerned may be changing continually.

Length of the roots and their number and length together as well
as green weight and dry weight have been taken as criteria of the
existence of antagonism. In the present paper the dry weight has
been taken as proportional to the area of the plasma membrane
through which salts may enter the plant. It cannot be stated defi-
nitely that the two are proportional. They have only been so con-
sidered since the dry weight of the plant was the most logical criterion
to employ. The reservation must always be made that the two may
not be directly proportional, even though they are treated as being so.

That the permeability of the plasma membrane of the plant cells

60 Porto Rico Agr. Exp. Sta. Bull. 16, 1914.

164 University of California Publications in Agricultural Sciences | Vol. 3

is changed by the nature and balance of the solution surrounding the
roots there can be no doubt from the data already given. That a
number of ions are capable of acting in a very similar manner to one
another as regards permeability is also evident from the present work.
Further, the same salt may act differently at different concentrations,
preserving nearly normal permeability at some and allowing the pene-
tration of large numbers of ions at others. As previously stated, the
total balance of the solution is of vital importance in the preservation
of normal permeability, which is in turn correlated with normal
crowth.

In connection with the salts of the heavy metals, the amounts of
the kation of cupric and ferric salts which had penetrated the plant
tissue were determined in a number of instances. The percentages
found were low. Further, whenever these salts proved toxic, the
amounts of calcium and magnesium found in the plants were high;
high enough in fact to account for the toxic effect alone. In many
instances the percentages of those two elements found were as high in
toxie solutions of copper, iron, or zine salts as when toxic concentra-
tions of calcium or magnesium chlorides were used. We might,
therefore, in the light of our present knowledge, be justified in attrib-
uting the decreased growth of the plants to the abnormally high ab-
sorption of calcium and magnesium and the consequent reactions
taking place within the plant cells. The permeability of the mem-
brane must be altered to allow of the presence of these ions in large
numbers. The toxic effects due to the presence of large amounts of
calcium or magnesium salts might be evident if we could inject solu-
tions of these salts into the plant without altering the permeability
of the plasma membrane. But from the present data it seems that
the alteration in the permeability of the membrane is the essential
consideration.

It is probable also that the toxicity of any solution is accompanied
by the increased permeability of the plant tissue to all inorganic salts
which are normally found in plants. There may be exceptions as
noted already for iron and calcium, but in general this relation holds
from the data now at hand. |

Ruprecht® has localized the effects of aluminum salts in the few
layers of cells surrounding the root hairs and attributes the death of
the plants grown in solutions of aluminum salts to starvation incident
upon the inability of the plant to obtain nutrient salts for normal

61 Mass. Exp. Sta. Bull. 161 (1915), p. 125.

1918 | Waynick: Antagonism and Cell Permeability 165

metabolism. Forbes** has likewise localized the effects of copper salts,
when present in toxie concentrations, and concludes that the toxic
effect of copper is due to the combination of metal with protein at
the growing tips of the roots.

From the experimental results given in the present paper, it is
evident that the presence of the salts of each element in toxic concen-
tration results in an increased permeability of the plant tissues to
calcium and magnesium at least. Ruprecht’s view that plants starve
for lack of nutrient salts when grown in toxic solutions is untenable,
in the hght of the above discussion.

The results of both investigators are significant in indicating the
localization of the effect of the two metals studied in the extreme
outer portion of the roots, in which the plasma membrane is located.

The results obtained by Loeb with Fundulus eggs, by Osterhout
with Laminaria, using electrical conductivity methods, and by Brooks
employing microscopical methods with various plant tissues, all point
to the preservation of normal permeability as the result of antago-
nistic salt action. The results reported by these investigators using
widely different methods have been confirmed in the present work by
the use of a more direct and more nearly quantitative method than
any hitherto employed.

It must be recognized, however, that a picture of but one stage in
the growth of the plant has been given and that only a portion of the
inorganic constituents have been determined. The results reported
are essentially those of a static system and must be so considered in
comparing them with results obtained by the use of other methods
referred to above.

SUMMARY

In the present paper results are given showing the effect of vari-
ous salt solutions upon the chemical composition of plants, with spe-
cial reference to a correlation between toxic and antagonistic effects
and composition. A uniform nutrient solution was used throughout.
The cultures were arranged in series in which the concentration of
one salt was kept constant while the concentration of a second salt
varied over a wide range. In several series the concentration of both
varied, but the ratio between the two remained constant. The ana-
lytical data cover the percentages of calcium and magnesium found
in the plants grown in every culture, together with determinations

62 Univ. Cal. Publ. Agr. Sci., vol. 1 (1917), p. 395.

166 University of California Publications in Agricultural Sciences | Vol. 3

of potassium, iron and copper in certain series. With these facts in
mind the results of the investigation may be briefly stated as follows:

The composition of the plants grown in different solutions varied
widely.

Normal growth, i.e., approximately that of the controls, was always
accompanied by approximately equal percentages of calcium and
magnesium in the plants.

In nearly all cases in which the growth of the plants was decreased
to a marked extent, the amounts of. the two elements referred to above
were increased greatly.

The degree of absorption of any salt seems to be independent of
the concentration present in the solution over a wide range.

Certain relationships are pointed out between calcium and mag-
nesium absorption and the presence of iron and zine salts in the
solution.

Antagonism as evidenced by growth is correlated with absorption
of the ions, which were determined, in every instance.

Stimulation of growth was recorded when ferric sulphate was
present in the nutrient solution in certain concentrations and with
ferric sulphate and zine sulphate together.

The amounts of the two ions uniformly determined were not neces-
sarily found in the same proportions in roots and tops.

The possible effects of changes in concentrations of the various
solutions are considered, and the conclusion reached that the changes
in concentration were of secondary importance over the range of con-
centrations of the various salts used.

Data are presented showing that growth is the same with widely
varying ratios of calcium to magnesium in the nutrient solution.

The results in general confirm those of Loeb, Osterhout, and
Brooks in finding that antagonistic salt action tends toward the
preservation of normal permeability of the plasma membrane in living
tissue.

This problem was suggested by Dr. C. B. Lipman. The writer
wishes to express his thanks for this and for many other valuable
suggestions offered while the work was in progress. The writer is also
indebted to Prof. L. T. Sharp for helpful advice.

1918] Waynick: Antagonism and Cell Permeability 167

NOTE

The following key applies to ail the graphs. The numbers on the abscissas
represent both the actual weight of tops and roots and percentages of calcium
and magnesium, or of iron, when the latter were plotted. The numbers on the
ordinates correspond to the number of cultures as given in the table on the
opposite page. The heavy lines always refer to the roots, the light lines to
the tops.

The following type lines are used:

— —_ (Solid line) Weight of tops.
— — er (Short dashes) Weight of roots.
—————— ——— —— — — — (Long dashes) Percentage of calcium.
—— — — (One long and two short dashes) Percentage of magnesium.
—— — (One long and one short dash) Percentage of iron.

The numbers given in the ‘‘Explanation of Plates’’ always refer to the
plants arranged in order from left to right, the control being on the extreme
right in every case.

ox

N

oO

10

11

12

Full Nutrient Tops

0.

168

Solution
CaCl.

.002

.004

01

04

.06

.08

10

16

.20

24

Dry weight

Tops

.7633

.7104

Roots.
Tops

3608

.6486

4976

Roots
Tops

.6555
.6419

.6138

Roots
Tops

5628
4814

.6600

Roots
Tops

5750
5950

5442

Roots
Tops

5959
"5692

4998

Roots
Tops

5048
.6706

5015

Roots
Tops

5250
.6114

.4182

Roots
Tops

.3827
4832

4778

Roots
Tops

3918
5668

5218

Roots
Tops

.6123
687

-7637

Roots
Tops

6305
5266

5793

Roots

.6067
.7937

.7418

Roots

.6900

Grown October 24—December 5, 1915.

Mean

.7368
1804

731
3277

.6279
.2814

5707
.2875

5696
.2979

5845
.2524

860
2625

5148
1913

4805
1959

5443
3066

.6662
3154

5529
3033

7677
3450

TABLE 1
Calcium Chloride

Percentage
of Ash

15.38
15.34
26.24

15.34
17.34
29.98

17.29
16.81
28.10

16.80
17.69
31.56

17.52
16.59
33.54

17.67
17.00
29.45

13.92
11.82
29.46

18.46
19.94
30.18

16.80
17.15
29.12

17.45
18.47
29.43

17.03
17.13
31.82

17.62
17.34
27.08

18.80
19.10
20.03

Mean

15.36

16.34

17.05

17.24

17.05

17.33

12.87

19.20

16.97

17.08

17.48

18.95

i» Percentage
of Ca

University of California Publications in Agricultural Sciences

Mean

ATT

435

O15

ATT

.602

715

545

434

434

436

.368

373

391

Percentage
of Mg

| Vol. 3

Mean

.049

.086

.045

.046

.069

057

.064

962

1.32

320

226

218

1918] Waynick : Antagonism and Cell Permeability 169

Fig. 1
Caleium Chloride
(See Table 1)

No.

|

10

11

13

University of California Publications in Agricultural Sciences

Solution
MgCl, CaCl,
24 .004
24 01
24 .02
24 04
24 .06
24 .08
24 10
24 12
24 16
24 20
24 24
24 30
24

TABLE 2

Magnesium Chloride + Caleium Chloride

Dry Weight

Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots
Tops

Roots

3407

.3666

2456

5106
0862

3038

.2758

0885
2533

4450

4828

.3018

3150
3716
2994

6871

.6679

4238

A797
4476
.3000
4583
4279
.2843

.3243
3543
.2276

3404
3132
.2508

.2707

2924
2107
4834
0226
3888
4281
106
.2463

Grown

a
x
v
a

3536
1218

5484
1519

4321
.1266

4619
1509

3433
.1497

6775
.2119

4636
1500

4431
1421

.3393
1138

3268
1254

.2815
1053

5030
1944

4693
1231

Percentage
of Ash

Mean

12.95

16.86

15.58

16.92

18.18

15.97

14.99

16.81

15.29

17.06

18.18

18.06

17.02

Percentage
of Ca

O85
437
387
383
.208

Mean

491

197

339

* 163

457

1.46

O74

385

January 2—-February 13, 1916.

="
i)
for)

ee

—

Percentage

of Mg

bo
—

Mean

1.16

.918

943

.440

.650

1.52

1.83

816

.691

.898

[ Vol. 3

Percentage
of Fe

Mean

012

.012

.015

-1

1918 | Waynick: Antagonism and Cell Permeability 171

\ a ;
ae INV Za
. het a ma
6"
Ca Free a
roa -— 7 cee
a= Pasi ers Sa Cane ay oe oF ata 4

les ae oe or ae oe are a
as Sa, Se,
- | | ! | | | I | | ! |
1 2 3 4 5 6 a 8 9 10 jib 12

Fig. 2
Magnesium Chloride + Calcium Chloride
(See Table 2)

University of California Publications in Agricultural Sciences

172
Solution

No. MgCl. CaCl,
l .30 001
2 .30 002
3 30 004
4 .30 01
5 .30 02
6 .30 .04
7 30 .06
8 30 .O8
9 30 10
10 .30 12
11 .30 16
12 30 .20
13 30 24
14 30 .30
Full Nutrient

TABLE 3

Magnesium Sulphate + Calcium Chloride

Dry Weight

Tops
Roots

Tops
Roots

Tops
Roots

Tops
Roots

Tops
Roots

Tops

Roots
Tops

Roots
Tops

Roots
Tops
Roots
Tops
Roots
Tops

Roots
Tops
Roots

Tops
Roots

Tops
Roots

Tops

Roots

1986
.2650
2700

.2766

2566
2236

3194
1744
2074

.2249

5249
4166

.1309

3036
1836
.0850

.2184
2403
.0648

3978

.3842
2759
1059

8819
9600
6900

.2100
.2700

.2576
.1930

.2600
.2000

.7937
.7418
.6900

Mean

2318

.2300

.7677
3450

Percentage
of Ash

16.60
15.60

16.44
16.39

18.43
17.39

16.49
14.28

14.56
15.73
15.19
15.57
18.10

16.83
17.42
14.70

17.90
15.99
13.05

30.08

17.92
19.57
27.29

17.41
18.11
33.71

18.80
19.10
20.03

16.94

15.40

14.30

18.95

Percentage
of Ca

Grown October 24 to December 5, 1915.

Mean

.209

526

409

025

398

160

[Vol. 3

Percentage
of Mg

ei
g
=
440
413 426
571
O14 42
595
533 564
O15
.088 O15
749
565 .607
405
437 .418
649
.790 719
700
.663 681
.230
1.15
1.15
399
63 481
124
.047
.037 .042
.047
3.660
4,210
3.799
235
202 218
.259

1918] Waynick: Antagonism and Cell Permeability 173

me
|
\
\
\
\

read

vl

Fig. 3
Magnesium Chloride + Calcium Chloride
(See Table 3)

174
Solution
No. MgCl CaCl
1 36 .02
2 36 .04
3 36 .06
+ 36 .08
5 36 10
6 36 12
7 36 16
8 36 .20
9 36 24
Full Nutrient

University of California Publications in Agricultural Sciences

TABLE 4

Magnesium Chloride + Calcium Chloride

Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops

Roots

Dry Weight

.2878
3189
1644

.4128
0210
3144

.2952
.2640
.1560

.1878
2034
.0684

2292
.1698
1272

4788
3938
.2244

3616
.4410
2287

.2963
.2505
.1355

3100
.2106
1734

.7819
.7459
.6209

= Percentage
of Ash
TN

=
So = Ge
me e bo

Or bo

bd

=

—_
oS
cn bo

cor Cr Ol

20.

16.31
17.21
17.90

18.10
.2400
17.80

15.13
16.20
17.90

14.60
13.65
17.60

14,12
15.17
16.00

13.21
12.17
16.99

14.21
13.17
14.20

20.40
19.70
21.70

Mean

17.68

21.05

15.66

14.64

12.69

13.69

20.05

Percentage
of Ca

330
.242

398

461

400

O73

721

787

1.03

339

Grown January 7—February 21, 1916.

ge

of Mg

~]
_

- - Percenta

to mH
oe

— jt
co ©
Oo ©

1.24

2.14
2.37
3.00

2.22
2.48
4.43

2.90
2.61
4.71

890
1.02
3.33

1.23
1.72
2.47

2.01
2.32
4.82

2.31
3.02
4.89

.223
.268
.248

Mean

1.94

2.25

2.35

2.75

1.47

2.16

2.66

295

[Vol.3

Percentage
of Fe

.039
.047

Mean

043

1918]

Waynick: Antagonism and Cell Permeability

Fig. 4
Magnesium Chloride + Calcium Chloride
(See Table 4)

176 University of California Publications in Agricultural Sciences [ Vol. 3

TABLE 5

Magnesium Sulphate

a Es ey
Solution : 3 oe 5 Be 3 Ee E
No. MgSO, Dry Weight = Wi = Ay = Vi =

1 .06 Tops .7326 16.78 358 785
.7838 .7587 16.46 16.62 379 .368 .750 767

Roots .6383 3191 16.84 495 550

2 10 Tops .7150 15.73 .302 .320
.9420 8276 16.21 15.97 313 .307 320 320

Roots .4822 2411 22.91 80 1.270

3 14 Tops .6888 15.09 .201 350
6546 .6717 15.64 15.36 .230 215 .390 370

Roots .4437 2218 20.31 148 740

4 16 Tops .3042 12.65 337 350
.3657 .3349 11.81 12.23 331 334 310 .330

Roots .0762 .0381 21.52 985 me A

5 18 Tops .2875 12.32 496 .280
.2978 .2926 12.72 12.52 371 434 310 295

Roots .0542 .0271 20.49 1.130 1.300

Full Nutrient Tops .7819 20.40 349 , 223
.7459 .7639 19.70 20.05 330 339 .268 295

Roots .6209 21.70 242 .248

Grown December 9—January 20, 1915-16

1918]

Waynick:

Fig. 5
Magnesium Sulphate
(See Table 5)

Antagonism and Cell Permeability

178 University of California Publications in Agricultural Sciences [ Vol. 3

TABLE 6

Magnesium Chloride + Calcium Chloride

ae Be Ete Ec
Solution EES a 2 < “ 50 4 he e oe é

ry Wei = v ‘S oS o's
No. CaCl MgSO, ee s a © = a, ° s 5° © &° a

1 04 18 Tops 1.1626 19.91 261 A407 036
1.2526 1.2076 19.75 19.83 .3832 .296 .722 .564 .023 .080

Roots .9895 .4942 16.52 .030 1312 017

2 .O8 18 Tops 1.1888 20.43 12 O77 .060
1.0948 1.1418 21.15 20.79 .377 .844 .084 .081° .060 .060

Roots .9037 .4518 26.13 151 .180 .020

3 12 18 Tops 1.1287 19.50 275 021 .024
1.2691 1.1989 21.22 2036 .276 .275 .023 .022 .021 .023

Roots .9591 .4795 20.93 560 185 .020

4 .16 18 Tops 1.2293 17.85 .169 .035 .036
31.9134 12218 16.75 17.30 131 250 .049 .042 —— .036

Roots .5444 .2722 16.47 .690 101 .024

5 .20 18 Tops 1.1786 21.67 .333 .039 .033
1.1021 1.1403 21.07 21.387 .256 .294 .044 .041 ...... .033

Roots 1.0500 .5250 25.40 .820 299 .028

6 24 18 Tops .9773 21.47 448 462 . 045
9923 .9848 21.65 21.56 .545 .496 .486 .470 .033 .039

Roots .8600 .4300 26.07 1.290 407 .024

7 28 18 Tops .8459 18.62 A76 437 .032
.7450 .7954 20.05 19.33 .523 .499 .409 .420 .037 .035

Roots .6014 3007 24.87 1.580 565 .023

8 oa 18 Tops .4608 21.43 .640 1.05 .027
wale 4968) 2.22: 21.43 .5568 .604 1.24 114 1.019 .023

Roots .3350 .1675 29.00 3.330 1.07 .026

9 36 18 Tops .1916 18.56 TAT 1.43 .048
2349 .2132 18.80 18.68 .955 .851 1.59 1.50 .049 047

Roots .0976 .0488 18.05 1.000 2.80

2269, .1819 13.60 13.50 .235 370 1.72 1.71 O32 tee

10 18 Tops .1369 13.40 505 2.03 .016

Roots .0614 .0307 16.62 At2 3.68 i

Grown January 24—March 6, 1916.

1918 | Waynick: Antagonism and Cell Permeability 179

Fig. 6
Magnesium Sulphate + Calcium Chloride
(See Table 6)

LSO

Solution

é-
Z Ca(NOz)2 MgSO,

1 .04
2 408
8 22
&: 16
5 .20
6 .24
7 28

8 Full Nutrient

15

15

15

15

15

15

15

Dry Weight
Tops 1.8850
1.1941

Roots .9776

Tops 1.7825
1.5648

Roots .8813

Tops 1.6850

Roots .6284

Tops 1.2078

Roots .5668
pigs). eee aa
Roote <:....:
Tops .5818
Roots .1581
TVons.’ ..-...:.
MOGtE oo 5
Tops 1.5682

1.5775
Roots .9776

Grown April 14—May 27, 1916.

TABLE 7

Potassium Chloride

1 Percentare
of Ash

1.6731
4406

8425
0141

.6030
2834

No growth

18.50
p08
.0740 21.90

No growth

18.33
1.5728 19.40
20.40

Mean

18.95

19.90

16.67

18.50

18.86

Percentage
of Ca

oo
as
4-3

293
312
271

Mean

067

110

90

302

oo to Percentage

08
101

.762
.842
430

2.190

2.390

University of California Publications in Agricultural Sciences

Mean

.887
802
2.190

2.120

9.200

255

[Vol.3

© Percentage
of Fe

oO
= bo
Co

Amounts too small to determine.

Mean

.022

023

OE

1918] Waynick: Antagonism and Cell Permeability 18]

od

Fig. 7
Magnesium Sulphate + Calcium Nitrate
(See Table 7)

182 University of California Publications in Agricultural Sciences [ Vol. 3

TABLE 8

Magnesium Sulphate + Calcium Nitrate

Lv 2, a) Ly oe

&0 i eo bh bp

Se : = : $
Ba Oe. 2S oe) Oa. eee sag
Solution s Es $ he * St $ Ee : bs s
KCl Dry Weight = a, ° a a A a By - & oa

.04 Tops 1.1563 19.65 .078 228 028 1.37
1.1128 1.1345 19.65 19.65 _...... 201 .214 .045 .037 1.80 1.58

Roots .5038 .2519 17.07 .256 175 173 61

.06 Tops 1.0773 24.00 128 .083 .041 3.54
1.0791 1.0782 25.90 24.95 .113 .120 .118 .100 .030 .036 3.54 3.54

Roots .5979 .2989 16.27 .241 10) Fh ee 0 ee
.08 Tops .7638 27.50 302 201 .064 4.81 4.56

Roots .4659 .1829 17.20 238 180 .106 4.80

10 Tops .8417 25.90 .204 302 .268 3.56
7900 .8158 24.40 25.15 .186 .195 .205 .253 .280 .274 3.80 3.68

Roots .3135 .1567 14.20 570 300 072 1.02

12 Tops .5656 31.00 .283 .378 195 4.78
5815 .5734 29.80 30.40 .265 .274 .657 .567 .072 .133 4.30 4.54

Roots .2215 .1107 18.00 .780 101 175 1.67

14 Tops .4825 39.50 217 478 091 9.11
4200 .4531 32.30 35.90 .222 .219 .454 .466 .092 .091 7.10 8.10

Roots .1762 20.83 .617 139 .021 1.53

16 Tops .5375 42.00 .248 .730 071... See
oo OBE cacnsy 42,00 ....... .248 2% 6780 .: O72 eee

Roots .1339 .0669 23.83 505 1.34 250 2.31

Grown January 31—March 13, 1916.

1918]

vism and Cell Permeability

Waynick: Antagoi

9
-

= | | ' '
1 2 3 4 5 6
Fig. 8

Potassium Chloride
(See Table 8)

183

Solution
No. MgSO, KCl
1 ot 8
2 8 418
3 22 18
4.36.38
5 .20 18
6 .24 .18
7 8 . 38
S208: 18
o- 26: 38
Full Nutrient

University of California Publications in Agricultural Sciences

TABLE 9

Magnesium Sulphate + Potassium Chloride

Drv Weight

Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops

Roots

.6579
.6379
.2800

.6800
.7162
.2682

A957
0202
.2200

.6229
6464
3123

3645
4819
.2063

1.0992
1.0750
.8120

~ ~ et ae a?

19.65 141 490

6479 21.20 20.42 .162 .151 500
TA SOT. hee Se, 2.79

22.07 138 430

6981 25.10 23.58 .171 .154 480

1341 23.50 590 1.350

22.60 BOO wae Pe, Ce

5079 26.50 24.55 .310 .3801 923

1100 25.25 745 104

23.50 152 382

.6346 24.70 24.10 .169 .161 wel

1561 333.70 991 561

26.20 440 O77

oS a ees BESO 2 Yi eee

1031 24.00 678 1.060

33.20 407 1.040

2700 37.60 35.40 .423 .415 2.920

0648 22.10 750 1.490

31.10 299 1.030

1786 35.10 33.10 ..265 .289 990

.0456 24.10 tab 2.900

36.10 .263 890

2850 36.20 36.15 211 - 337 S810

0733 239.57 6229 S18

23.90 261 S01

2823 25.00 24.45 .278 .269 895

-0708 21.60 699 .248

20307 310 .268

1.0872 19.12 18.69 .297 .3038 238

20.00 ey gl 233

Grown January 31—March 13, 1916.

Mean

A495

923

381

848

Percentage
of Fe

Amounts too small to determine.

[Vol.3

tage

—-
= © Percen

67

Mean

1.92

3.10

4.16

5.01

7.66

3.64

1918]

Waynich: A ntagonism and Cell Permeability

Fig. 9
Magnesium Sulphate + Potassium Chloride
(See Table 9)

185

186 University of California Publications in Agricultural Sciences [ Vol. 3

TABLE 10

~

Solution
AlCls

.0000033

.0000165

.000033

.000066

.000132

.000331

.00331

Dry Weight

Tops
Roots
Tops
Roots
Tops

Roots

Tops

Tops

Roots .

Tops

Roots .

Tops

Roots .

4438
4688
4315

.2934
2745
1976

2872
3995
2964

3028
.3200
Roots .

Aluminum Chloride

o
LT)

ee

F e<

i a”
22.42
4563 20,40
2157 20,20
23.20
2839 22.70
0988 18.70:
21.09
3233 22.60
1482 19.55
21.09
3114 22.80
1211 19.55
22.60
2599 19,00
1322 26.60
20,20
3597 21,90
1275 27.90
22.30
3116 21.82
1076 = 29.40

Grown August 26—October 7, 1916.

Mean

21.40

22.95

21.84

21.94

20.80

21.05

22.60

Percentage
of Ca

188

318

338

436

246

263

Percentage
of Mg

Mean

970

.610

836

ol

88

Percentage
of Fe

oo
a4
“1 Or

Mean

.O76

145

163

141

L27

130

150

1918] Waynick: Antagonism and Cell Permeability

+ I I \ \
il 2 3 4
Fig. 10

Aluminum Chloride
(See Table 10)

188 University of California Publications in Agricultural Sciences | Vol. 3

TABLE 11

Caleium Chloride + Aluminum Chloride

& & & &
s = & s
<a a 88 Es a, 52
os olution : 2s : hd : ta ¢ a 2
No. AlCl, CaCl, Dry Weight s a? ‘si .° n° . 4 ee
] .0000033 .20 Tops .2962 24.20 1.630 745 ——!
2087 3584 2338.10 23.65 1:820 1.738 880 Wet
Roots .1897 .0948 20.40 .730 B72 0 0lti‘“ St! ee
2 .0000165 .20 Tops .2542 24.23 1.610 890 123
2678 3610 232.18 23.20 1.720 1.66 9.30 .910 313 .21
Roots .2745 .1372 26.17 y 0 et eM
3 0000331 20 Tops .3324 23.00 1.250 187 503
3706 32515 285.20 24.10 1.460 1.35 903 .845 .540 .52
Roots .2942 .1471 26.10 .790 4 But .075
4 0000662 .20 Tops .2139 23.20 1.210 821 237
2337 §6©.32388 21.70 23:45 1.030 1.12 733 .?78 At4 Sa
Roots .1839 .0919 24.20 .621 102 ‘232
5 .000132 .20 Tops .2148 20.58 1.400 .932 248 .18
2085 .2611 2410 323.84 1.060 1.23 897 .913 119.8
Roots .2239 .1119 20.20 518 347 #8“.
6 .000331 .20 Tops .2337 24.10 1.420 .632 105
2137 2887 23.22 29.7) 1.370 1.34 711 . 621 210 8 |
Roots .1682 .0841 20.16 .672 13160. ==
7 00331 .20 Tops .2496 24.10 1.330 490 155
1946 .2221 22.90 23.50 1.550 1.44 516 .503 .385 a
Roots .1296 .0648 26.40 .780 253 021
Full Nutrient Tops .7103 18.17 022 221
fool .telo JO38 "3a-74 377. 349 270 . 245 |
|

Roots .6600 .3300 19.99 300 233

Grown August 26—October 7, 1916

1918 | Waynick: Antagonism and Cell Permeability 189

\
\

0. 5c= |
|
|

0.4 |

Quad t= \

|
aD ae
-_—e—N
Se on
0 1 - a kegeeeaea
+ | 1 ' ! j i '
1 2 3 4 5 6 7
Fig. 11

Calcium Chloride + Aluminum Chloride
(See Table 11)

190 University of California Publications in Agricultural Sciences [ Vol. 3

TABLE 12

Aluminum Chloride + Magnesium Chloride

a Bi a bi

Bic Ba 5 be Eo
Solution F os 3 Eo : oa : zm §
AlCl MgCl Dry Weight & a ° Ss By’ ea si |

.0000033 20 Tops .2819 19.02 426 2.13 121
5457 .4138 18.71 18.86 .371 .398 1.91 2.02 131 186

Roots .2936 .1468 21.31 ool 2.12 «122

.0000165 20 Tops .3539 17.31 one 2.73 141
3000 .3269 19.21 18.16 .421 .374 1.83 1.77 1323 136

Roots .1750 .0875 22.17 .400 f By fl 101

.0000331 20 Tops .2243 21.05 Bs hy” 2.51 .148
2259 .2251 17.70 19.39 .448 .400 2.80 2.65 147 147

Roots .1239 .0614 24.10 .366 1.96 135

.0000662 20 Tops .6327 19.00 147 1.46 .050
7644 .6985 38.10 18.55 130 .1388 2.26 1.42 .047 .049

Roots .5526 .2763 19.95 Be BI wan .040

.000132 20 Tops .2406 19.75 .280 2.78 .069
3156 .2781 19.55 19.65 .288 .281 3.11 2.94 .064 .066

Roots .1250 .0625 24.00 186 5.88 181

.000331 .20 Tops .2279 16.50 407 .940 091
2048 .2163 19.90 18.20 .467 .437 bot .74 081 .086

Roots .1700 .0850 22.76 .302 2.51 .098

.00331 20 Tops .2400 17.40 32 2.14 161
4450 ' 1985. 18:80 28.30 .26) “246. 171 1.92 192 .176

Roots .0990 .0495 32.60 .200 4.53 .439

Grown August 26—October 7, 1916.

1918] Waynick: Antagonism and Cell Permeability 191

|
1 2 3 5 6 7

Fig. 12
Aluminum Chloride + Magnesium Chloride
(See Table 12)

192 University of California Publications in Agricultural Sciences

Solution
No. FeCl; Dry Weight

1 .000089 Tops .7712
8376
Roots .7143

bo

.000168 Tops .7884
1.2762
Roots .6462

3.00168 Tops 1.3519
1.1269

Roots .9034

4 0168 Tops 1.0000
1.2750

Roots .7219

Full Nutrient Tops 1.0992
1.0750

Roots .8120

Mean

8044
2o71

1.0323
3231

1,2394
4517

1.1370
3609

1.0872

TABLE 13

Ferric Chloride

Percentage
of Ash

—

=
co >
So

bo oO
o

17.90
19.30
17.60

15.70
18.10
17.10

16.78
16.51
20.98

20.17
19.12
20.00

Mean

16.85

16.60

16.90

16.64

18.69

bo Percenta

ge

of Ca

Mean

.045

.030

303

Grown January 24—March 6, 1916.

io bo Percenta

we
~]

ge

of Mg

ol
@

.238

.224

[ Vol. 3

Percentage

Mean

198

239

123

1918] Waynick: Antagonism and Cell Permeability 193

Fig. 13
Ferrie Chloride
(See Table 13)

194 University of California Publications in Agricultural Sciences [ Vol. 3

TABLE 14

Ferric chloride + Calcium Chloride

& Se bi bi

ee s g s
Solution I o 4 5 of 5 is E 6 2 cI

a 2 8s B 5% ¢ 535 §& Es
No. FeCl; CaCle Dry Weight si a, ° = a” = a? = a ° S

1 .000089 .20 Tops .4826 18.27 1.02 104 ff

4116 .4471. 18.50 18.88 1:83 148 137 20.2

Roots .4143 .2071 28.35 531 222 100

2 000168 .20 Tops .5238 17.72 1.77 194 080
5847 .5592 16.04 16.88 1.01 1.39 .101 .147 .090 .085

Roots .6115 .3057 22.70 188 229 03,

3 .0003852 20 Tops .2732 20.42 2.78 256 370
3204 .2918 20.61 20.51 3.28 3.03 .255 .255 .400 .38

Roots .1774 .0887 22.40 1.76 692 120

4 000712 .20 Tops .5910 19.01 2.85 212 50
3910 4860... 19.01 2.15 2.00 .262 .237 .40 .45

Roots 5053 .2526 31.30 1.06 .026 .02

5 00142 .20 Tops .5427 16.56 - 1.06 064 36
6353 5890 17.79 17.17 1.33 1.19 .051 .058 .50 .43

Roots .6238 .3119 29.50 350 .010 16

6 .00356 20 Tops .2715 14.76 1.32 097 1.18
2632 .2673 17.09 15.92 1.23 127 .183 .115 1.02 1.10

Roots .2196 .1098 20.03 1.13 018 98

7 0058 .20 Tops .1792 20.03 2.37 256 800
2514 .2153 20.92 20.47 2.08 2.22 .297 .276 .900 .85

Roots .0636 .0318 29.30 1.68 .020 200

8 .0168 20 Tops .3293 17.03 584 246 148
4393 .3843 19.08 18.05 .460 .522 .175 .210 120 .134

Roots .3565 .1783 28.04 505 049 .06

Grown December 9—January 19, 1916.

Tron determined colorimetrically in this series.

1918 | Waynick: Antagonism and Cell Permeability

ig. 14
Ferric Chloride + Calcium Chloride
(See Table 14)

bo

oO

~

196 University of California Publications in Agricultural Sciences

TABLE 15

Ferrie Chloride + Magnesium Chloride

Pr &

3a [=]

E43 Ba

Solution 8 oa | sO
—— ON = os $ Be
FeCl; MgCl Dry Weight Ss a, ° = a”
000089 =.20 Tops .9650 18.48 182
7444 8547 18.70 19.59 .163

Roots’ .6126 3063 25.05 .204
000168 .20 Tops 7875 18.12 181 —
9525 8700 18.67 18.44 .164

Roots .6816 3408 21.40 .229

000352 .20 Tops 8787 1547 172
.7365 BOTE: U7-15 VI6:36 387

Roots .6525 3262 22.95 176

000712 220 Tops 1.0414 16.77 324
TST (IT? +B

1.1515 1.1464
Roots .4837 .2418

no
—_
mn
oO
Do
oC
16 6)

* 00142 20 Tops .6648 17.40 209
7927 6.7287 16.22 16.81 185

Roots .4627 .2313 22.12 .258

.00356 20 Tops 1.1639 16.50 176
9476 1.0557 16.10 16.30 .109

Roots .3298 .1649 20.28 433

0058 .20 Tops .6608 17.08 340
6189 .7398 16.07 16.57 .400

Roots .4846 .2423 20.09 239

.0168 .20 Tops 1.0927 18.96 44
1.0824 1.0875 20.05 19.45 .391

Roots .6358 .3179 21.05 LTT

Grown January 24—March 6, 1916.

154

367

t0 GO Percentage

O47

Mean

853

190

.264

.086

153

1.06

[Vol.3

Percentage
of Fe

=)
=)
—

Mean

.210

070

.093

221

137

.040

130

1918] Waynick: Antagonism and Cell Permeability 197

1 2 3 4 5 6 7 8

Fig. 15
Ferrie Chloride + Magnesium Chloride
(See Table 15)

195

Solution
No. CuCle

1 .000038

2 .000079

.00015

.00031

5 .00047

.00063 *

.00079

~]

.00198

.00392

Full
Nutrient

University of California Publications in Agricultural Sciences [ Vol. 3

TABLE 16

Copper Chloride

ee Se ee ee be

Ba be} be} be] $

aa Se oo Seo es

rR yg 283 2 a ee Poe
Drv Weight Bo f° 2. 8° #8 8° S 6” fe
Tops .4611 25.60 425 194 1900-/ foe
Roots .4692 .4651 23.60 24.60 .420 .412 .191 .192 .201 .160 .......
Tops .2492 20.20 455 .716 155 «Agee
Roots .3242 .2867 24.12 22.16 .563 .509 .723 .719 .221 .188_ ......
Tops .3887 24.50 312 1.10 114 (oe
Roots .4198 .4042 25.30 24.90 .361 .336 .90 1.00 .0261 .070 ......
Tops .2744 18.45 150 1.43 .040 001
Roots 1372 18.45 150 1.48 .040
Tops .2581 22.00 176 1.35 214 .002
Roots .2344 .2462 18.10 20.05 .102 .139 1.02 1.18 .094 .154 .002 .002
Tops .0785 19.10 254 oe 0B eee .003
Roots .0700 .0742 18.21 18.65 .425 .339 5.10 4.43 .248 .248 .005 .004
POG. ese
Roots .....-.- No growth
OR, «oe
Roots .......- No growth
FODe. ccs
Roots: ......:- No growth.
Tops 1.1234 19.20 211 213
1.0268 1.0751 21.00 20.10 .241 .276 .199 .206

Roots .7210 18.99 299 .216

Grown March 9—April 20, 1916.

1918] Waynick: Antagonism and Cell Permeability 199

Fig. 16
Copper Chloride
(See Table 16)

[Vol.3

University of California Publications in Agricultural Sciences

200

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L00°
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1918] Waynick: Antagonism and Cell Permeability 201

Fig. 17
Copper Chloride + Ferrie Chloride
(See Table 17)

No.

or

University of California Publications in Agricultural Sciences

202
Solution

HgCl. CuCl.
.0000047 .0000023
.0000094 .0000047
.0000184 .0000094
.000047 = .000023
.000094 .000047
.000189 .000094
.000378 .000188

TABLE 18
Mereurie Chloride + Copper Chloride

© Percentage
of Ash
Percentage
of Ca
Percentage
of Mg

=| a r=

5 = S

Dry Weight = | a
Tops .1175 20.15 674 1.21
1608 .1392 21.20 20.67 517 .595 935
Roots .0869 .0434 18.65 1.220 .276
Tops .1792 20.00 OoL 873
.2675 .2233 20.32 20.16 612 .572 .942
Roots .0846 .0423 16.71 1.410 .291
Tops .3778 24.70 493 A488

3328 .38503 23.30 2430 .570 531 _......

Roots .0928 .0467 15.45 1.360 211
Tops .3600 21.22 431 834
2334 .2967 23.20 22.21 521 .471 921
Boote .1109° .0554 17.88 © © cum 361
Tops .3643 22.00 399 737
4372 .4007 20.12 21.06 354 .3856 .695
Roots .1109 .0554 17.32 — ...... 361
Tops .2385 22.30 21 921
3105 .2745 24.71 23.50 .503 512 973
Roots .1146 .0573 12.71 1.340 333
Tops .1500 21.60 O73 1.212
2150 .1825 23.40 22.50 .672 .622 1.071
Roots .0609 .0304 12.82 — ...... .412

Grown January 24—March 6, 1916.

[ Vol. 3

907

488

S877

.716

947

1.14

Percentage
of Fe

Too small amounts to determine.

1918 | Waynick: Antagonism and Cell Permeability . 203

Fig. 18
Mercurie Chloride
(See Table 18)

No.

~“

.0000

204

Solution
CuSO,

0000048

.0000094

.Q000188

.0000378

.0000567

Fe
*

“I
{
{

~

.0000945

.000189

.000378

University of California Publications in Agricultural Sciences

Dry Weight

Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots

Tops

Roots

Tops

Roots .

.6148
.7726

4406

5394
.8462
4512

4712

5188" ;

2948

1.5098
1.0836
9436

7544
.8022
5265

.7598
6632
889

3339
.2439
1567

3267

TABLE 19

Copper Sulphate

Percentage
of Ash

a

s

A
22.80
6937 21.71
2203 20.61
21.42
6928 17.50
2256 16.40
24.40
3920 18.90
1474 22.50
22.02
1.2967 18.90
4718 18.85
21.18
7783 20.44
2632 18.10
21.60
7125 20.83
2944 19.71
23.21
2889 23.60
0783 18.00
22.61
3526 24.80
0815 21.40
24.22
.2533 22.00
.0348 23.80

a

20.46

20.81

21.41

23.11

Percentage
of Ca

Mean

110

.061

020

a4

576

469

Grown April 14—May 27, 1916.

tw Percentage
of Mg

446

.688

348

433

1.32

| Vol. 3

Percentage

—
os of he

.082

.025

.042

054

013

Percentage

oeeee

1918 | Waynick: Antagonism and Cell Permeability 205

Copper Sulphate
(See Table 19)

[| Vol. 3

University of California Publications in Agricultural Sciences

Uva;

206

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23 2 23 2 22 ® 22 ® 22 ® —_ ___ — -_ -

23 3 az = 23 = 8 3 > 5 wolznlog

3 os mS a = a

ayeyding surz + a3eydjng saddop
0Z WAV

1918 | Waynick: A ntagonism and Cell Permeability ONT

Fig. 20
Copper Sulphate + Zine Sulphate
(See Table 20)

| Vol. 3

University of California Publications in Agricultural Sciences

208

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1918]

Waynick: Antagonism and Cell Permeability

+
2 3 4 5

Fig. 21
Copper Sulphate + Ferrie Sulphate
(See Table 21)

209

210 University of California Publications in Agricultural Sciences [ Vol. 3

TABLE 22

Ferric Sulphate

a ee Se Ee
So g g g
2 S42 gs iS 5 $3 g oth me
No. Fe(800s Dry Weight s sc os sy @ ¢° S| oe
1 .0000014 Tops 2.2399 17.09 107 098 .246
1.3062 1.7730 17.55 17.382 .099 #.108 113 =.105 281 .263
Roots 1.0626 21.81 122 763 315
peat a. 5313 erie 8 | Berg 122 meee 763 ~ssaes | SU
2 .0000028 Tops 1.9198 20.50 119 O70 264
1.5236 1.7210 30.21 231385 .115 £117 OTS '= O71 201 . .231
Roots .8731 25,50 013 145 220
4850-6769 26.50 25.85 .020 .016 .158 150 286 .253
3 0000070 Tops 1.4150 24.00 05 - ).-* Sia: .393
1.5247 1.4698 22.62 28.31 .080 .087 °&#.102 102 895 304
Roots .6984 31.10 .032 263 223
7624 .7304 30.61 30.85 O41 036 .224 .243 277 .250
4 000014 Tops 2.3544 20.57 .032 O89 258
2.3461 2.3502 18.90 19.73 041 036 .106 8 .097 318 =©.368
Roots 1.0361 27.20 .022 .184 172
1.1861 1.1111 29.20 28.31 O11 016 .250 217 278 ee
5 00007 Tops 4.2000 14.80 018 ° 072 .236
3.6033 3.9016 15.15 14.97 017 017 #£.073 072 268 (252
Roots .9813 25.81 .056 134 103
9168 .9490 26.00 25.90 .077 .067 178" «tae 129 136
Full Nutrient Tops 1.5682 18.33 .293 231
1.5775 1.5728 19.40 18.86 212 302 .279 .200
Roots .9776 20.40 tl 279

Grown April 22-June 3, 1916.

1918]

Waynick:

ror)
|

be
|

Antagonism and Cell Permeability 211

Fig. 22
Ferric Sulphate
(See Table 22

212
Solution
No. ZnSO,
1 00000767
2 = .0000131

3 .0000395

4 .000153

5 .000395

Full Nutrient

University of California Publications in Agricultural Sciences

Dry Weight

Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops
Roots
Tops

Roots

.6718
7541
.6138

.7164
8350
.6009

.6142
.8607
5864

5109
.3800
4628

8208
Lost
4432

1.0992
1.0750
8120

TABLE 23

Zine Sulphate

Percentage
of Ash

:
=

23.00

7129 = 24.04
3069 17.88
25.30

7757 ~=—-24.65
3004 17.20
21.19

7374 22.50
2932 15.90
21.90

4454 19.40
2314 20.50
20.38

CA” Se nee
2216 22.30
20.17

1.0872 19.12
20.00

Grown January

Mean

23.52

25.07

21.84

20.65

20.38

18.69

Percentage
of Ca

Mean

344

404

.200

303

24~March 6, 1916.

tr tw Percentage

for)
Oo

Mean

467

348

22

.710

321

224

| Vol. 3

Percentage

Mean

.089

073

e a ee, r

; Waynick: Autagonism and Cell Permeability 213

_ —
eee peat

Fig. 23
Zine Sulphate
(See Table 23)

No.

1

Grown April 24—June 6, 1916.

Mean

097

.159

140

.090

150

.160

150

ATT

Percentage
of Mg

214 University of California Publications in Agricultural Sciences
TABLE 24

Zine Sulphate + Ferric Sulphate
3 Se
Solution a o<4 8 oO
5) a .) w&
ZnSO, Fes(SQ,)3 Dry Weight Si & ° si a?
.0000019 .0000035 Tops 1.0594 18.50 .096
1.5294 1.2944 18.70 18.60 .098
Roots .10444 .5222 29.80 045
.0000038 .000005 Tops 1.5364 18.60 .149
1.4964 15114 16.16 17:35 270
Roots 1.0716 5258 31.00 .042
.0000057 .000007 Tops 1.2300 18.10 172
1.6150 1.4225 16.90 17.00 .124
Roots 1.1250 5625 32.30 .068
.0000076 .000014 Tops 2.3088 16.40 .083
2.5100 2.4094 17.00 16.70 .098
Roots 1.5623 .7812 28.00 .040
.0000152 .000028 Tops 2.3429 15.70 154
8:0199 23.1774 16.70 15.70 247
Roots 1.5133 .7566 30.30 .050
.0000379 .000070 Tops 2.0533 18.10 .160
1.5544 1.8038 16.20 17.15 .160
Roots 1.4194 7097 25.30 025
.000076 .00014 Tops 1.6164 18.40 57
1.7228 1.6696 19.70 19.05 .144
Roots 1.7611 8801 27.00 .019
000152 .00028 Tops .9850 18.35 179
1.0268 - 1.0029. 20.00 19.17 .17
Roots .6987 .3493 27.30 .006

[ Vol. 3

110

136

.250

Percentage
of Fe

.031

Mean

.030

.033

.070

.063

.049

045

.043

1918]

to

Waynick: Antagonism and Cell Permeability

Fig. 24
Zine Sulphate + Ferric Sulphate
(See Table 24)

21!

No.

|

.0000189

.000047

.000094

.000189

.000378

216

University of California Publications in Agricultural Sciences

Solution

.0000094 .

Fes (SO,)s
.0000047 .0000035 Tops

0000070

.00005

.00014

.0007

.00105

.00210

TABLE 25

Mercurie Chloride + Ferrie Sulphate

Dry Weight

Roots .0!

Tops

Roots .

Tops

Roots .

Tops

Roots .

Tops

Roots .

Tops

Roots .

Tops

Roots .

g,

ao
=4
si a?
2039 22.40
2868 .2553 16.70
0518 .0259 18.70

Mean

19.55

18.05

16.10

16.95

16.50

Percentage
of Ca

Grown March 22—May 3, 1916.

Mean

.206

420

.166

146

Percentage
of Mg

| Vol. 3
PA
s
| oo si
I ee 3
Ss f°: &
618
A421 E
E
vo
®
391-2
niet
are."
|
®
3
463
=
an
=
°
=|
eo
100s
°
Z
.769
101
722 157 .129
1222

—_— —

1918]

~l

Waynick: Antagonism and Cell Permeability

Fig. 25
Mercurie Chloride + Ferrie Sulphate
(See Table 25)

bo

215

Solution
HgCle

.0000135

.000066

.000135

University of California Publications in Agricultural Sciences

Dry Weight
Tops .4904

4967
Roots .1493

Tops .2200
.2236
Roots .0239

Tops .1514

TABLE 26

Mercurie Chloride

fo] oS
Mane eae © See
S Be Es Es 3
= ev = Ay =)
17.20 141
4935 16.71 16.95 098 120
.0746 19.31 478
15.70 .oa2
.2218 14.24 14.97 .380 .396
0119 10.50 4.31
9.12 421

1467 8.95 9.03 .3899 .410

Grown March 14—April 24, 1916.

tp Percentage
of Mg

Lod

Mean

1.28

[Vol.3

to Percentage
of Fe

ns
w

Mean

.248

.013

.012

. Fig. 26
Mercurie Chloride
(See Table 26)

ee i.e eee

EXPLANATION OF PLATES
PLATE 13

Appearance of plants as mounted in corks at
expiration of the six weeks’ growing period.

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 [WAYNICK | PLATE

PLATE 14

No. 1. .24 M. MgCl. .004 M. CaCl,
No. 2. .24 M. MgCl, .01 M. CaCl,
No. 3. .24 M. MgCl, .02 M. CaCl.
No. 4. .24 M. MgCl. 04 M. CaCl,
No. & .24 M. MgCl, .06 M. CaCl,
No. 6. .24 M. MgCl, .08 M. CaCl,
No. 7. .24 M. MgCl, .10 M. CaCl,
No. 8. .24 M. MgCl, .12 M. CaCl,
No. 9. .24 M. MgCl, 16 M. CaCl,
No. 10. .24 M. MgCl, .20 M. CaCl,
No. 11. .24 M. MgCl, .24 M. CaCl,
No. 12. .24 M. MgCl, .30 M. CaCl,
No. 13. .24 M.

Control.

[222]

¥

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 | WAYNICK | PLATE 14 Fe
a

PLATE 15

No. 1. .30 M. MgCl, .004 M. CaCl.
No. 2. .30 M. MgCl, .01 M. CaCl,
No. 3. .30 M. MgCl, .02 M. CaCl,
No. 4. .30 M. MgCl, .04 M. CaCl,
No. 5. .30 M. MgCl, .06 M. CaCl,
No. 6. .30 M. MgCl, .08 M. CaCl,
No. 7. .30 M. MgCl, .10 M. CaCl,
No. 8 .30 M. MgCl, .12 M. CaCl,
No. 9. .30 M. MgCl, .16 M. CaCl,
No.10. .30 M. MgCl, .20 M. CaCl,
No.11. .30 M. MgCl, .24 M. CaCl,
No.12. .30 M. MgCl, .30 M. CaCl,

Control.

[224]

UNIV, CALIF. PUBL. AGR. SCI. VOu, s | WAYNICK | el i de ft

SS

UNIV,

CALIF, PUBL.

AGH SEY, be) Mele

[WAYNICK] PLATE 4

6

ee ve

No. 1.
No. 2.
No. 3.
No. 4.
No. 5.
No. 6.

No. 7.

PLATE 17

00331 - M. AICI,
000331 M. AICls
000132 M. AlCl, 7
000066 M. AICls

900033 M. AICI,

0000165 M. AICI,

0000033 M. AICI,

Control.

NOS 'YDV ‘1ENd ‘4INWS “AINA

“1OA

oO
i)

3ivid LyoINaAvm |

fg

No.
No.
No.
No.
No.
No.
No.
No.

—

2

ie)

PLATE 18

0168 M.
058 M.
00356 M.

00142 M.
.000712 M.
.000352 M.
000168 M.
000089 M.

FeCl,
FeCl,
FeCl,
FeCl,
FeCl,
FeCl,
FeCl,
FeCl,

Control.

[230]

20 M.
20 M.
20 M.
20 M.
20 M.
20 M.
20 M.
20 M.

MgCl,
MgCl,
MgCl,
MgCl,
MgCl,
MgCl,
MgCl,
MgCl,

| WAYNICK | PLATE 18

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3

No.
No.
No.
No.
No.
No.
No.

TD Op Po

PLATE 19

.00331 M. AIC),
.000331 M. AICI,
.000132 M. AICI,
.0000662 M. AICI,
.0000331 M. AIC),
.0000165 M. AICI,
.0000033 M. AICI,

Control.

[232]

20 M.
.20 M.
20 M.
20 M.
20 M.
.20 M.
20 M.

CaCl,
CaCl,
CaCl,
CaCl,
CaCl,
CaCl,
CaCl,

Jivid | MOoINAvM |

6l

No. 1
No. 2.
No. 3
No. 4
No. 5.

PLATE 20

000094 _M. CuCl, .00082 M. FeCl,
.000067 M. CuCl, .000058 M. FeCl, )
.000047 M. CuCl, 000042 M. FeCl,
000028 M. CuCl, .000026 M. FeCl, —
0000094 M. CuCl, .0000089 M. FeCl,
Control.

|

= UNIV. CALIF, PUBL. AGR. SCI. VOL, 3 [WAYNICK] PLATE 20
=~

No.
No.
No.
No.
No.
No.
No.
No.
No.

5.
2
3.
4.
5.
6
7
8
9

PLATE 21

000378 M. CuSO,
000189 M. CuSO,
0000945 M. CuSO,
0000755 M. CuSO,
0000567 M. CuSO,
0000378 M. CuSO,
0000188 M. CuSO,
9000094 M. CuSO,
0000048 M. CuSO,
Control.

[236]

“~

TOA 1SS R13 ame f= | a ‘AITVS ‘AINA

QO
ww

be 3Lwid [YoINAvM]

MD OTR ge po

- oo

PLATE 22

.0000047 M.
.0000094 M.
.0000142 M.
.0000189 M.
.0000378 M.
.000094 M.
.000142
.000189 M.
.00058

M.

M.

CuSo,
CuSo,
CuSo,
CuSo,
CuSo,
CuSo,
CuSo,
CuSo,
CuSo,

.0000035 M.
.0000070 M.
.0000105 M.
.000014
.000028
.000070
.000105
.00014

.00028

M
M
M
M.
M
M

Control.

[238]

Fe, (SO,)s
Fe, (SO,),
Fe, (SO,);

. Fe, (SO,)s
. Fe, (SO,)s
. Fe, (SO,)s

Fe, (SO,)s

. Fe, (SO,)s
. Fe, (SO,)s

“AINA

INd *4INVO

¢
C

‘YOV 7

LOK “Os

oO
GU

22 3Llvid [MOINAvVM]

PLATE 23

0000014 M. Fe, (SO,)s

0000028 M. Fes (SO,)s

0000070 M. Fe: (SO,)s

000014 _M. Fe, (SO,)s

00007. _-M. Fe. (SO4)s
Control.

(mm

os

=

7 e ba
io : mi
> OS &

* eae 4
a

+
=k

i]

.
[<>

aff. ay a e

a.

PLATE 24

No. 1. .000135 M. HgCh
No. 2. .000066 -M. HgCl,
No. 3. .0000185 M. HgCl,
Control.

UNIV, CALIF. PUBL. AGR. SCI. VOL. 3

}

| WAYNICK | PLATE 24

> Ye

UNIVERSITY OF CALIFORNIA PUBLICATIONS
iN

AGRICULTURAL SCIENCES
Vol. 3, No. 9, pp. 243-270, 2 text figures June 22, 1918

VARIABILITY IN SOILS AND ITS SIGNIFI-
CANCE TO PAST AND FUTURE
SOIL INVESTIGATIONS

I. A STATISTICAL STUDY OF NITRIFICATION IN SOIL

BY
DEAN DAVID WAYNICK

It is very generally recognized that different soils vary widely as
regards their physical, chemical, and biological nature. It has also
been recognized among soil investigators, at least, that different samples
of the same soil type taken from a comparatively limited area may
show considerable variation among themselves if we apply quantitative
measurements to the various constituents of the soil mass. In any small
area of the size usually employed in field experiments, these variations
seem to have been regarded as of such limited magnitude as to be
worthy of but secondary consideration. In many instances, a single
sample from such an area has been taken and the assumption made
that it represented the entire soil mass of the depth to which it was
taken. In other words, the soil has been considered as a constant to
which no corrections need be applied. Most workers in the field of
soils have been content with taking relatively few samples and regard-
ing determinations made upon the composite of these samples as accur-
ate within the limits of error of the experiment. That the variations
between different samples taken from a small area may be of such
magnitudes as to bring experimental data obtained with one or a
limited number of samples into very serious question, or even to
invalidate such data entirely, seems not to have been considered. It
is the purpose of this paper to emphasize the importance of this phase
of soil investigation as regards both past and future endeavors.

It is obviously impossible, within the limits of a single paper, to
consider the variations which characterize all the constituents of any

244 University of California Publications in Agricultural Sciences | Vol. 3

given soil, so that the results reported at the present time relate only
to one phase of the biochemistry of soils. But few attempts have been
made by investigators to determine actually the magnitude of varia-
bility in those products of microdrganic activity which are capable of
quantitative measurement and in no instance has a mathematical inter-
pretation been attempted with such measurements. There are but
three references’ * * in the literature, as far as the writer is aware,
dealing with this phase of the biochemistry of soils, and none of them
is extensive enough to be of any value as statistical studies of varia-
bility. A number of papers* have appeared dealing with the variation
in the weight of the crop produced over different parts of an appar-
ently uniform field. Such variations reflect the variability of the soil,
serving simply as a substratum for the growth of plants, but it is
evident that the variations between such measurements as those given
do not depend upon the soil as the only variable factor. Any attempt
to correlate the crop produced on any given soil with the chemical
composition of that soil, for instance, must necessarily take into account
variations in both crop and soil. In fact, it appears to the writer that
any correlation which may exist between the properties of any given
soil and its crop-producing power can only be worked out by the
statistical interpretation of data obtained as recorded below, together
with the data secured in a similar manner for the crops produced on
that soil. The problem of variability in the soil itself is worthy of
careful experimental study, both from the standpoint of soil investiga-
tions in themselves and from that of their possible bearing upon the
problems of variability in field experiments with crops. The results
of such a study, as regards nitrate production, are presented below.

Merruops

The field selected was one on the University Farm at Davis. For
the three years preceding 1917, corn, Sudan grass, and grain sorghum
had been grown in the order named. In 1917, the field was allowed
to lie fallow and at the time the samples were taken (Oct. 20), was
free of vegetation of any kind. No rain had fallen since April so that
the surface soil was practically air-dry, the subsoil, however, being quite
moist. The soil is classified as a silty clay loam. The particular area
chosen was apparently as uniform as one could well find, being level,
of uniform texture and color, and free from small local depressions
of any kind.

1918 } Waynick: A Statistical Study of Nitrification in Soil 245

The samples were taken at the locations as shown in figure 1, the
diameter of the plot being one hundred feet. Each number in the
following table represents two samples, soil and subsoil, the latter term
being used for convenience in expression rather than to represent any
sharp line of demarcation between the two samples taken at any given

Fig. 1

place. All the surface samples were taken with a trowel to a depth of
six inches, an area having a diameter of approximately six inches being
included in each sample. ‘The subsoil samples were taken with a three-
inch auger to a depth of twenty-four inches and, therefore, represent
the section from six to twenty-four inches in depth. All the samples
were placed in sterile soil bags as soon as taken, the total amount of
soil in each sample being about twice that necessary for the laboratory

246 University of California Publications in Agricultural Sciences [ Vol. 3

determinations. Not more than twenty-four hours elapsed between the
time the first sample was taken and the time all the samples were at
the express office ready for shipment to Berkeley, where they arrived
forty-eight hours later.

At the laboratory, the samples were allowed to air-dry for six days
in the original canvas bags, this time for drying being necessary because
of the moisture present in the subsoil samples. At the expiration of
the six-day period all of the samples were sieved through a two-milli-
meter sieve and four one hundred gram portions of each sample
weighed into tumblers. One tumbler from each sample was reserved
for the determination of residual nitrate; to a second no nitrogen com-
pounds were added, and to the others two-tenths of a gram of am-
monium sulfate and one gram of dried blood, respectively, these
amounts having been most frequently used in nitrification experiments
in this laboratory. All the tumblers were brought to an optimum
moisture content by the addition of twenty cubic centimeters of sterile
distilled water and placed in the incubator at 28° C for twenty-eight
days. During the incubation period, the water lost was replaced at
weekly intervals. At the expiration of that period, the soil was dried
at a temperature of 100° C and the nitrates determined colorimetri-
cally by the phenoldisulfonie acid method as modified by Lipman and
Sharp.’ All results are reported as milligrams of nitrate nitrogen in
one hundred grams of soil.

It was not deemed necessary to make duplicate determinations on
all the samples, since from previous results secured in this laboratory,
the variation between duplicates, as regards nitrification studies, is
small and well within the limits of the error made in the readings,
which were never recorded in this study further than to one-tenth of
a milligram of nitrate nitrogen. Aside from this fact, it is doubtful
if duplicate determinations are of value in experiments of this kind in
which the variation between the samples was found to be so large.

The amount of nitrate nitrogen produced was chosen as the criterion
of variability because of the generally accepted idea that nitrate
nitrogen is more directly available to plants than other nitrogen com-
binations and for that reason more significance may rightly be attached
to the amount of nitrate nitrogen found or produced in any given soil.
Then, too, small amounts of nitrate may be determined rapidly, with
a very fair degree of accuracy, and moreover, are less subject to
fluctuations in the duplicate determination as discussed above. The
absolute accuracy of the nitrate determination by the phenoldisulfonie

4
a

ee

pi

I ree ee ee ee

1918 | Waynick: A Statistical Study of Nitrification in Soil 247

acid method is not of moment in this connection, because neither very
low nor very high amounts of nitrate were ever determined and all
of the determinations are directly comparable one with the other, since
exactly the same procedure was followed in every case.

It must be emphasized that no attempt has been made to segregate
the causes of variation and the results as given are the summation of
all the factors which are of importance in causing differences between
samples. All the work was done in a careful manner with due atten-
tion to detail, no new or modified procedure being attempted. The
results of this study, therefore, are intended to serve as a basis for
interpreting the mass of data which has already been obtained by soil
biologists and to emphasize the extreme importance of applying statis-
tical methods to results secured in the future before their value as
contributions to science or practice can be recognized.

CALCULATIONS®

The amounts of nitrate found are reported in tables 1 to 4, follow-
ing, the individual determinations always being given. The mathe-
matical treatment will be discussed briefly from the data given in
table 1, the discussion being applicable to all the tables as well.

The mean as given is obtained by dividing the sum of all the
determinations by the number of determinations. This figure repre-
sents, therefore, a hypothetical composite sample of all the samples
taken. The deviation from the mean of any determination is found
by taking the difference between the mean and the individual result.
The mean deviation of a series of determinations is an expression of
the average amount any single observation taken at random is lkely
to differ from the mean of the series. This figure may be either plus
or minus, but as the sign is of no importance as regards subsequent
calculations, it is not recorded but may easily be found by inspection.
The standard deviation (oc) is found, after the manner usual in statis-
tical investigations, by squaring the deviation of each determination
from the mean, taking the sum of the squares thus found, dividing this
figure by the total number of determinations made and taking the
square root of the quotient. The percentage ratio of the standard
deviation to the mean.expresses the coefficient of variability (C.V.)
for a given series of determinations. It is an expression of the per-
centage deviation on either side of the mean, within which approxi-
mately two-thirds of the determinations may be expected to lie. The

248 University of California Publications in Agricultural Sciences [ Vol. 3

coefficient of variability of the amount of nitrate as found in the field
soil is high, no less than 25.9 + 2.1 per cent in the surface six inches
and 51.4 + 3.3 per cent in the vertical section from six to twenty-four
inches. The range, therefore, within which two-thirds of the deter-
minations may be expected to fall is from 2.0 to 3.4 milligrams in the
surface soil and from 0.3 to 1.1 milligram in the subsoil. The extreme

range is, of course, much greater than this, but the bulk of the deter-

'
:
:
;
¢

minations fall within the limits given.

A single determination, or the mean of a series of determinations
can never be an absolute value and hence before any large degree of
confidence can be placed in any experimental result, its degree of
reliability must be known. The reliability of any determination is
expressed by the probable error (#) of the determination. This
figure is of such a magnitude that the probability of making an error
ereater than it is equal to the probability of making an error less than
it, both probabilities being one-half.

The probable error (E£,) of a single determination is calculated
by the formula

E, = +.6745 X 2 |

where o is the standard deviation, as given above, and » the number of

determinations. Since with a single determination the \/n is equal to 1]
E, = + .6745 X ea.

or in other words, the probable error of a single variant is equal to

approximately two-thirds of the standard deviation of the series in

which it lies. The probable error of the mean (Ey), is given by the

formula
Es .6745 XK o
Ex es ee ae
Vn Vn
Ey, will vary as the square root of the number of determinations and
thus decreases but slowly as we increase the number of determinations.
The probable error (Eo) of the standard deviation is caleulated from

the formula
C

V2n

and for the coefficient of variability :

vj eee ot eee e\el&
Be = 6145 E 4 aon |

when C.V. is greater than ten per cent as is the case with the results
recorded below.

Eo = +.6745

1918 | Waynick: A Statistical Study of Nitrification in Soil 249

TABLE 1
RESIDUAL NITRATE IN SOIL AS SAMPLED
1”—6” 6”—24" 1”-6" 6”—24”
Nitrate Devia- Nitrate Devia- Nitrate Devia- Nitrate Devia-
nitro- tion from nitro- tion from nitro- tion from nitro- tion from
No gen mean + gen mean + No. gen mean + gen mean -
Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs.
1 2.5 0.2 1.0 0.3 42 3.0 0.3 0.6 0.1
2 2.8 0.1 aa 0.4 43 3.4 0.7 0.7 0.0
3 3.0 0.3 1.0 0.3 dd 1.8 0.9 0.5 0.2
4 2.5 0.2 1.2 0.5 45 2.5 0.2 0.6 0.1
5 3.8 bol 1.9 1.2 46 2.1 0.6 0.5 0.2
6 2.7 0.0 1.5 0.8 47 4.0 1.3 0.8 0.1
7 3.3 0.6 1.5 0.8 48 3:1 0.4 0.6 0.1
8 3.2 0.5 1.2 0.5 49 4.4 1 4 0.4 0.3
9 2.5 0.2 1.2 0.5 50 3.5 0.8 0.5 0.2
10 2.9 0.2 1.4 0.7 51 2.3 0.4 0.7 0.0
1] 3.0 0.3 1.5 0.8 52 3.1] 0.4 0.6 0.1
12 2.7 0.0 0.8 0.1 53 2.3 0.4 0.8 0.1
13 1.9 0.8 1.2 0.5 54 2.3 0.4 0.6 0.1
14 3.7 1.0 Ha | 0.4 55 1.4 1.3 0.8 0.1
15 3.8 i 0.8 0.1 56 2.5 0.2 0.5 0.2
16 3.0 0.3 10 0.3 57 1.8 0.9 0.5 0.2
17 2.0 0.7 0.8 0.1 58 Le 1.0 0.4 0.3
18 2.2 0.5 1.0 0.3 ' 59 1.3 0.4 0.5 0.2
19 2.9 0.2 1.0 0.3 60 2.0 0.7 0.4 0.3
20 3.5 0.8 0.8 0.1 61 1.5 1.2 0.4 0.3
21 3.0 0.3 1.0 0.3 62 4.0 1.3 0.4 0.3
22 4.5 1.8 0.8 0.1 63 3.0 0.3 0.3 0.4
23 3.5 0.8 0.9 0.2 64 mt, 0.3 0.5 0.2
24 3.6 0.9 0.5 0.2 65 2.0 0.7 0.4 0.3
25 1.8 0.9 0.6 0.1 66 2.0 O7 0.5 0.2
26 3.4 0.7 0.8 0.1 67 3.0 0.3 0.6 0.1
27 3.0 0.3 2.2 1.5 68 4.3 1.6 1.2 0.5
28 1.5 0.8 0.8 0.1 69 3.2 0.5 0.4 0.3
29 2.3 0.4 0.6 0.1 70 2.6 0.1 0.5 0.2
30 2.6 0.1 0.5 0.2 71 3.5 0.8 0.4 0.3
31 1.3 1.4 0.5 0.2 72 2.7 0.0 0.3 0.4
32 3.1 0.4 0.9 0.2 73 2.4 0.3 0.4 0.3
33 2.6 0.1 0.4 0.3 74 2.0 0.7 0.4 0.3
34 2.8 0.1 0.3 0.4 75 2.1 0.6 0.4 0.3
35 1.8 0.9 0.3 0.4 76 2.6 0.1 0.6 0.1
36 1.3 1.4 0.4 0.3 77 1.5 1.2 0.6 0.1
37 1.0 pth 0.5 0.2 78 2.6 0.1 0.6 0.1
38 4.0 13 0.9 0.2 79 2.4 0.3 0.9 0.2
39 3.0 0.3 0.6 0.1 80 2.2 0.5 - 1.2 0.5
40 3.6 0.9 0.4 0.3 81 2.0 0.7 0.8 0.1
41 3.8 ist 0.6 0.1 a ———=
Mean 2.70+.05 0.5 0.70+.03 0.3
o — EY | ee = I! eo) * 36202
C.V. = 25.9+2.1% = 51.4+3.3%
E =z 1.8% == 43%

250 University of California Publications in Agricultural Sciences | Vol. 3

TABLE 2

NITRATE PRODUCED FROM THE SOIL’S OWN NITROGEN APTER TWENTY-EIGHT
Days’ INCUBATION—INCUBATED BLANKS

7
Iowr wow F

ie 2)

1”-6" 6”"—-24" 1"-6" 6”-24”
Nitrate Devia- Nitrate Devia- Nitrate Devia- Nitrate Devia-
nitro- tion from __initro- tion from nitro- tion from nitro- tion from

gen mean + gen mean+ No. gen mean + gen mean +
Mgs Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs.
4.3 0.9 1.2 0.2 42 4.5 1 | 1.2 0.2
2.4 1.0 1.0 0.4 43 3.8 0.4 1.4 0.0
2.2 1.2 1.0 0.4 +4 3.0 0.4 1.2 0.2
1.6 1.8 0.8 0.6 45 4.0 0.6 1.0 0.4
2.7 0.7 1 0.3 46 3.0 0.4 1.2 0.2
4.0 0.6 1.2 0.2 47 3.8 0.4 1.3 0.1
1.8 1.6 1.8 0.4 48 3.3 0.1 ¥.2 0.2
3.0 1.4 1.0 0.4 49 5.2 1.8 1.2 0.2
4.8 1.4 2.2 0.8 50 4.8 1.4 1.4 0.0
3.0 0.4 3.0 1.6 51 4.0 0.6 2.0 0.6
4.2 0.8 2.1 0.7 52 3.5 | 0.1 1.6 0.2
4.5 a Fe 1.5 0.1 53 3.1 0.3 0.8 0.6
3.1 0.3 1.4 0.0 54 4.7 1.3 1.5 0.1
4.6 1.2 1.5 0.1 55 3.2 0.2 0.7 0.7
4.2 0.8 1B 0.2 56 4.1 0.7 12 0.2
4.2 0.8 1.6 0.2 57 1.2 1.2 2.0 0.6
2.4 1.0 1.5 0.1 58 3.4 0.0 1.0 0.4
2.8 0.6 A Be 0.3 59 2.0 1.4 1.0 0.4
1.8 1.6 3.0 1.6 60 3.0 0.4 2.2 0.8
4.8 1.4 2.2 0.8 61 1.0 2.4 0.5 0.9
4.8 1.4 1.4 0.0 62 1.5 1.9 0.6 0.8
3.5 0.1 1.5 0.1 63 pee | 2.3 0.7 0.7
3.7 0.3 1.4 0.0 64 1.0 2.4 d yy 0.3
3.0 0.4 1.2 0.2 65 3.1 0.3 1.3 0.1
4.2 0.8 i By | 0.3 66 5.0 1.6 1.8 0.4
3.8 0.4 1.8 0.4 67 3.6 0.2 1.5 0.1
3.1 0.3 1.6 0.2 Gs ./ 21 13 _ 2.0 0.6
2.8 0.6 1.4 0.0 69 4.4 1.0 bai | 0.3
4.8 1.4 1.5 0.1 70 3.1 0.3 1.2 0.2
3.5 0.1 1.5 0.1 71 5.0 2.1 Ld 0.3
2.8 0.6 0.4 0.0 72 3.6 0.2 1.4 0.0
3.2 0.2 2.0 0.6 73 3.8 0.4 1.0 0.4
5.2 1.6 1.8 0.2 74 3.8 0.4 0.3 ba |
3.3 0.1 1.2 0.2 75 5.4 2.0 1.2 0.2
4.5 2 i I 0.3 76 3.8 0.4 1.2 0.2
2.8 0.6 1.4 0.0 77 4.6 1.2 1.6 0.2
3.0 0.4 3.7 2.3 78 1.5 1.9 1.5 0.1
4.7 be 6 1 0.3 79 5.0 1.6 1.8 0.4
3.8 0.4 1.2 0.2 80 3.1 0.3 1.9 0.5
4.0 0.6 Lay 0.3 81 3.5 0.1 Ae 0.4
4.1 0.7 1.0 0.4 | -_—_o-

Mean 3.40+.08 0.9 1.40+.03 0.4

c == 1.067.056 om 50202
C.V. = 31.2+1.7% = 35.7+2.1%
E == 2.3% = 2.1%

vA
So

Cre G ho

“1 6

1918 | Waynick: A Statistical Study of Nitrification in Soil 2%

TABLE 3

NITRATE PRODUCED FROM 0.2 GRAM OF AMMONIUM SULPHATE IN
100 GRAMS OF SOIL

1”~6" 6”-24" 1”—6” 6”-24"
Nitrate Devia- Nitrate Devia- Nitrate Devia- Nitrate Devia-
nitro- tion from __nitro- tion from nitro- tion from nitro- tion from

gen mean + gen mean-+ No. gen mean + gen mean +
Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs.
6.6 1.6 1.8 1.0 42 2.1 2.9 6.3 3.5
4.3 0.7 3.7 0.9 43 6.2 1.2 3.0 0.2
8.0 3.0 2.9 0.1 tt 5.2 0.2 1.0 1.8
6.0 1.0 3.3 0.5 45 2.3 2.7 1.2 1.6
4.2 0.8 3.3 0.5 46 1.8 3.2 1.8 1.0
6.0 1.0 2.5 0.3 47 2.5 2.5 1.5 1.3
5.6 0.6 3.2 0.4 48 2.5 2.5 1.2 1.6
5.0 0.0 ' 43 1.5 49 2.0 3.0 1.2 1.6
5.8 0.8 4.0 1.2 50 2.3 2.7 2.2 0.6
5.3 0.3 3.8 1.0 51 4.8 0.2 2.3 0.5
4.0 1.0 1 fl ieg'4 52 5.9 0.5 3 Ely 1.1
5.9 0.5 3.0 0.2 53 5.4 0.4 L7 1.]
5.0 0.0 2.8 0.0 54 6.5 1.5 2.8 0.0
4.6 0.4 2.8 0.0 55 2.3 2.7 3.2 0.4
5.0 0.0 3.1 0.3 56 5.2 0.2 1.2 1.4
6.5 1.5 3.3 0.5 57 2.2 2.6 1.5 1.3
4.6 0.4 5.7 1.9 58 3.6 1.4 3.2 0.4
5.0 0.0 4.0 1.2 59 2.2 2.6 5.0 2.2
6.0 1.0 4.0 1.2 60 3.5 1.5 6.0 3.2
5.0 0.0 2.4 0.4 61 4.2 0.8 3.5 0.7
5.4 0.4 2.8 0.0 62 7.2 2.2 2.0 0.8
6.0 1.0 3.4 0.6 63 7.3 2.3 2.4 0.4
6.5 1.5 3.2 0.4 64 3.7 13 4.1 1.3
4.8 0.2 2.0 0.8 65 5.7 0.7 0.2 0.0
5.3 0.3 2.7 0.1 66 3.8 1.2 2.5 0.3
5.5 0.5 5.4 2.6 67 4.9 0.1 3.0 0.2
4.4 0.6 4.8 2.0 68 4.8 0.2 4.0 1.2
7.5 2.5 4.7 1.9 69 6.8 1.8 1.0 1.8
7.6 2.6 2.8 0.0 70 5.8 0.8 1.3 1.5
6.2 1.2 1.9 0.9 (A 4.0 1.0 1.0 1.8
4.2 0.8 2.6 0.2 72 1.8 3.2 4.0 1.2
5.0 0.0 3.2 0.4 73 5.3 0.3 2.3 0.5
6.0 1.0 3.0 0.2 74 5.8 0.8 3.8 1.0
4.5 0.5 2.2 0.6 75 8.2 3.2 1.5 1.3
4.8 0,2 1.6 1.2 76 5.5 0.5 2.5 0.3
4.8 0.2 1.5 1.8 77 6.2 1.2 3.1 1.5
4.0 1.0 2.6 0.2 78 6.0 1.0 3.0 12
5.4 0.4 2.5 0.3 79 6.3 1.3 2.6 0.2
5.2 0.2 2.8 0.0 80 6.0 1.0 3.9 0.7
6.6 1.6 2.0 0.8 81 6.0 1.0 3.2 0.4
6.4 1.4 2.0 0.8 ———_ —- ——_—_—_—_—_—_——- -—

Mean 5.00.10 1.0 2.80+.08 0.9

o = 1.50+.08 G== LOAF
C.V. = 29.4+1.6% = 40.7+2.4%
E = 2.0% = 3.4%

1
—

University of California Publications in Agricultural Sciences | Vol. 3

7
ur wore ©

1m

6)

bd —- ©

ie)

cosy co OI

bo bo bo bo bo ne bo po bo bo

Oo

TABLE 4
NITRATE PRODUCED FROM 0.2 GRAM OF BLOOD IN 100 GRAMS OF SOIL
1”—6” 6”—24” 1”-6” 6”—24"
Nitrate Devia- Nitrate Devia- Nitrate Devia- Nitrate Devia-
nitro- tion from nitro- tion from nitro- tion from nitro- tion from
gen mean + gen mean + No. gen mean + gen mean + ,
Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs Mgs.
27.0 6.0 11.0 0.3 42 7.0 14.0 20.0 9.5
20.0 1.0 10.0 0.7 43 18.0 3.0 10.0 0.5
13.0 8.0 14.0 3.3 44 18.0 3.0 13.0 2.3
30.0 9.0 15.0 4.3 45 21.0 0.0 12.0 1.3
18.0 3.0 25.0 14.3 46 13.0 8.0 14.0 3.3
40.0 19.0 25.0 14.3 47 18.0 3.0 19.0 8.3
20.0 1.0 18.0 7.3 48 20.0 1.0 12.0 1.3
14.0 7.0 16.0 5.3 49 21.0 0.0 18.0 7.3 |
20.0 1.0 10.0 0.7 50 =. 20.0 1.0 17.0 6.3
22.0 1.0 16.0 5.3 51 24.0 3.0 9.0 1.7 4
18.0 3.0 14.0 3.3 52 21.0 0.0 10.0 0.7
22.0 1.0 12.0 1.3 58 27.0 6.0 12.0 1.3 ;
23.0 2.0 13.0 2.3 54 32.0 11.0 22.0 11.3
22.0 1.0 5.5 5.2 55 = 82.0 11.0 7.0 3.7
16.0 5.0 5.6 5.1 56 =. 20.0 1.0 18.0 | .
21.0 0.0 7.0 a7 57 27.0 6.0 10.0 0.7 }
16.0 5.0 8.0 2:7 58 27.0 6.0 4.3 6.4
20.0 1.0 5.0 5.7 59 14.0 7.0 3.0 1 Bh F
21.0. 0.0 5.5 5.2 60 30.0 9.0 20.0 9.5 .
13.0 8.0 7.7 3.0 61 22.0 1.0 4.3 6.4 }
24.0 3.0 5.0 5.7 62 23.0 2.0 10.0 0.7 7
15.0 6.0 10.0 0.7 63 24.0 3.0 9.0 1.7 ;
22.0 1.0 14.0 3.5 64 14.0 7.0 4.8 5.9
24.0 3.0 8.0 2.7 65 29.0 8.0 10.0 0.7 :
19.0 2.0 8.0 27 66 21.0 0.0 10.0 0.7 4
20.0 1.0 10.0 0.7 67 28.0 7.0 6.5 4.2 4
21.0 0.0 20.0 3.5 68 23.0 2.0 7 0.0 i
21.0 0.0 12.0 1.3 69 19.0 2.0 5.5 5.2
20.0 1.0 4.4 6.3 70 »3=16.0 5.0 3.7 7.0
11.0 10.0 5.9 4.8 Ee - 150 4.0 2.7 8.0
20.0 1.0 7.4 3.3 72 97.0 6.0 4.0 6.7
17.0 4.0 14.0 3.3 73 ~=30.0 9.0 5.3 5.4
10.0 11.0 13.0 2.3 74 28.0 7.0 24.0 13.3
20.0 1.0 5.0 5.7 75 25.0 4.0 10.0 0.7
15.0 6.0 2.4 8.3 76 22.0 1.0 12.0 1.5
12.0 9.0 8.5 2.2 77 2380 7.0 4.2 6.5
19.0 2.0 11.0 0.3 78 24.0 3.0 9.0 17
16.0 5.0 14.0 2.3 79 220 1.0 12.0 1.3
14.0 7.0 8.0 2.7 80. 17.0 4.0 7.2 3.5
13.0 8.0 5.7 5.0 81 30.0 9.0 21.0 10.3
27.0 6.0 11.0 0.3 ————— ee
Mean21.10+0.4 4.0 10.70+0.4 4.5
o = 5.70+0.30 o= 5.30+.30
C.V. =27.141.5% = 49.4+3.1%
E = 2:8% = 40%

1918 | Waynick: A Statistical Study of Nitrification in Soil 253

TABLE 5

SUMMARY OF STATISTICAL DATA

Coefficient Probable
Standard of error of
Mean Ixtremes deviation variability mean +
Milligrams Milligrams Milligrams Per cent Per cent
Residual nitrate,
Surface .......... 2.70.05 1.4—4.5 0.70+.04 25.9 2.1 1.8
PE DBGIE « ccnacgacks 0.70.03 0.38-1.2 0.36.02 51.4+ 3.3 4.3
Incubated blanks.
Surface .......... 3.40.08 1.0-—5.5 1.06.05 o1.2+ 1.7 2.3
SOUL \wcncacacndec 1.40.08 0.1-—2.2 0.50+.02 5 i ew ly Ded
(NH,).80..
Surface .......... 5.00.10 1.8—8.2 1.50+.08 29.4+ 1.6 2.0
Sc) oo 2.80.08 0.2-3.2 mW ON Doo mag OO 40.7 2.4 5
Blood.
eke: hee i 21.00.40 7.0—40.0 5/02: .30 oth Le 1.9
PRE BOLL: padvcteecice 10.70+.40 1.7—25.0 FE TN reas 1 49.4+ 3.1 4.0

Unless otherwise stated, the probable error of any value has been
used directly as found in the discussion which follows so that there is
simply an even chance that the results so treated fall within, or
without, the limits of their respective probable errors. The effect of
multiplying the probable error by two, three, or any higher number,
may be found by referring to the reference cited above.

DISCUSSION OF EXPERIMENTAL RESULTS

To express the results in concise form, table 5 has been inserted to
summarize briefly the data of the preceding tables. In the first column
the means of the various series are given with their respective probable
errors. In the case of residual nitrate, 2.7 milligrams in one hundred
grams of soil represent .0027 per cent of the soil or approximately
54 pounds of nitrate nitrogen per acre, considering only the upper six
inches of the soil mass. The probable error of the determination
amounts to .00005 per cent of the soil so that it is an even chance that
the mean of the eighty-one determinations is correct within one pound
per acre. In the subsoil, the mean of 14 pounds per acre, is within
0.6 pounds of the correct figure, on the same basis. The extreme range
amounts to 62 pounds in the surface soil and 18 pounds per acre in the
subsoil, both figures being of greater magnitude than the means of the
two series. It is not possible to translate the other figures into a
practical pounds per acre basis, since they represent laboratory treat-

ments.

254 University of California Publications in Agricultural Sciences | Vol. 3

The extremes recorded in column two are simply the extreme deter-
minations found in any one series. The extreme range may be deter-
mined by taking the difference between these two figures. The greatest
extremes are shown by the samples to which dried blood was added,
with the ammonium sulfate samples a close second. The results for
any one series emphasize the very large difference found between a
large number of samples treated as uniformly as possible.

It will be noted that the coefficients of variability as regards the
surface samples with their various treatments differ but little among
themselves, this difference amounting to only 5.3 per cent. The differ-
ence is greater with the four series in which the subsoil was used, being
15.7 per cent or nearly three times that of the surface samples. The
point is again emphasized here that we are dealing with the summations
of all the errors to which the samples are subject, both field and
laboratory. One source of error has been allowed for, which is of a
purely mechanical nature, namely, that of making the readings with
the colorimeter. This error will be considered in the following section,
and the coefficients of variability discussed at greater length there.

The percentage ratios given as the probable error of the mean place
all the results on a comparable basis as regards the error to which the
various means are subject. Attention is called to the fact that these
figures are of similar magnitudes in the four series of surface samples
while showing much larger differences in the subsoil samples with their
various treatments.

It will be noted from tables 1, 2, and 3 that in a number of samples
there was less actual nitrate nitrogen found in the subsoil samples
after incubation without the addition of anything but water, or with
the addition of 0.2 gram of ammonium sulphate, than was present in
the soil of corresponding samples as they came from the field. This
result was not anticipated and no explanation to account for this loss
of nitrate nitrogen is offered at the present time. It is, however,
regarded as of biochemical interest largely and not of importance as
regards the variation between samples at the time the determinations
were actually made.

ERROR OF THE DETERMINATIONS DUE TO THE COLORIMETER

Reference has already been made to the absolute accuracy of the
nitrate determination and its bearing upon the results reported in the
present paper. Aside from the absolute accuracy of the determina-

1918 } Waynick: A Statistical Study of Nitrification in Soil 255

tions, it is desired to consider briefly the error in making the readings
on the colorimeter due to the inability of the eye to detect small
changes in the depth of color between the standard employed and the
unknown solutions. All workers in soil chemistry are familiar with
the Kenicott-Sargent colorimeter, so that the instrument itself needs
no description here. To check the readings on the unknown solutions,
a solution was prepared of the average strength of the residual nitrate
determined in the first series reported. Sixteen equal volumes of this
solution were taken and treated exactly as the soil extracts were treated.
The average amount of nitrate nitrogen found in the sixteen portions
was the same as that for the series referred to above, namely, 2.7
milligrams. The actual determinations, together with the calculated
statistical constants, are reported in table 6. The probable error of
the mean of sixteen samples, together with the error to which both
larger and smaller numbers of samples are subject, is given in table 7.
The calculations have been made by the use of the formulae already
given. It is evident that the calculation of the probable error from
sixteen, instead of a larger number of samples, makes it less reliable
than if a larger number had been used, but since the error from
this source is relatively small as compared to the error due to field
sampling, it is deemed of sufficient accuracy for the purpose in hand.
This error will be referred to as the laboratory error to distinguish it
from the error due to sampling.

TABLE 6
COEFFICIENT OF VARIABILITY AND PROBABLE ERROR OF COLORIMETER READINGS
Nitrate Deviation Nitrate Deviation
No. nitrogen from mean+ No. nitrogen from mean +
Milligrams Milligrams Milligrams Milligrams
] 2.5 0.2 9 2.6 0.1
2 2.8 0.1 10 2.8 0.1
3 2.8 0.1 1] 3.0 0.3
4 2.9 0.2 12 2.6 0.1
5 2.5 0.2 13 2.4 0.0
6 2.6 0.1 14 yy | 0.0
7 2.8 0.1 15 2.6 0.1
8 2.6 0.1 16 2.7 0.0
Mean 2.7+.02 0.1
ee = eee
C.V. —48+.5%
E = 0.8%

M

256 University of California Publications in Agricultural Sciences | Vol. 3

It will be noted that the probable error of a single nitrate deter-
mination is 2.7 + .09 milligrams or 3.2 per cent of the amount deter-
mined. The error for a single determination, expressed on the field
samples as a percentage, is 17.4 or about 5.1 times greater than the
laboratory error, even after making allowance for this error. With
sixteen determinations, the probable error becomes 2.7 + .022 milli-
grams or 0.8 per cent. Further, with eighty-one samples, the probable
error is only 2.7 + .009 milligrams or 0.3 per cent.

In allowing for this laboratory error in the various series reported,
it is evident that it becomes relatively larger the smaller the amount
of nitrate determined within the lmits of the amounts found in the
present study. In other words, the probable error will remain the
same while the amount of nitrate determined decreases, so that the
probable error will form a larger percentage of the determination.
On the other hand, the probable error becomes relatively smaller as
we increase the actual amount of nitrate nitrogen again within the
limits of the amounts reported here. The same is true for the ¢o-
efficient of variability. This increased ratio is brought out in table 8,
which is simply a reconstruction of table 5, after making allowance
for the laboratory error.

The coefficient of variability computed from the standard deviation
(.18 + .01 mg.) and the average amount, of nitrate nitrogen reported
for the various series is given in column one. This figure is the largest
for the subsoil samples in the field and the smallest for the surface
samples treated with blood, the mean of the eighty-one readings being
0.7 and 21.0 milligrams, respectively, in the two eases. In the second
column, the corrected coefficients of variability for the field samples
are given, these being the difference between coefficients of variability
before the laboratory error was allowed for and the various coefficients
of variability given in column one. It will be noted that the same

TABLE 7

SHOWING THE DECREASE OF LABORATORY ERROR AS NUMBER OF
DETERMINATIONS INCREASE

Number Probable Probable Number Probable Probable
of error of error of of error of error of
samples mean mean samples mean mean
Milligrams Per cent Milligrams Per cent
1 2.700+.087 &.2 36 014 0.5
4 .043 1.6 49 .012 0.4
9 .039 i Fa 64 O11 0.4
16 .022 0.8 81 .009 0.3

25 017 0.7

1918 | Waynick: A Statistical Study of Nitrification in Soil 257

qualitative relations hold as between the various treatments in every
case except the incubated subsoil samples which are somewhat less
variable than the surface samples. With the other three series, the
subsoil samples still show a much higher coefficient of variability than
the surface samples, as do the samples treated with fertilizers in the
laboratory in contrast with the untreated field samples. The per-
centage probable errors or laboratory errors are shown in column
three, while the corrected figures for the field samples are given in
eolumn four.

Referring again for a moment to table 6, it is evident that the
laboratory error increases as the square root of the number of deter-
minations made, so that the mean of any number of readings on the
colorimeter becomes less reliable, the fewer the number, exactly as the
mean of a fewer number of samples is less accurate than the mean
of a larger number. In other words, the curves of the errors of the
various determinations are parallel, as will be seen by reference to
figure 2. This fact must be kept in mind in considering the results
given in the following section.

RESULTS OF RANDOM SAMPLINGS

It is of very direct interest to consider for a moment the accuracy
of the mean of a limited number of samples taken at random. Ten
surface samples are included in the first group (table 9) and sixteen
in the second (table 10), since about these numbers of samples have

TABLE 8

SUMMARY OF STATISTICAL DATA AFTER MAKING ALLOWANCE FOR THE
LABORATORY ERROR

Coefficient Corrected Corrected
of variability coefficient probable
(laboratory of Laboratory error of
error) variability error mean
Per cent Per cent Per cent Per cent
Residual nitrate.
oh oe 4.8+ 0.2 91 1 34 0.3 £5
ES eS ee 18.5 1.0 32.9 3.4 1.2 3.1
Ineubated blanks.
Le a oe 3.8 0,2 oT ae Lat 0.3 2.0
Le Re 9.2% 0.5 25.52: 2.1 0.7
Ammonium sulfate.
purines 2.5. 54... 2.6 0.1 26.8 1.6 0.2 1.8
So ee 4.6+ 0.2 36.1 2.4 0.4 3.0
Blood.
I Soci ecncnmeetcnss 0.6 0.03 26.5-= 1.56 0.05 1.9

2 | Se 1.2+ 0.10 48.2+ 3.1 0.09 3.9

258 University of California Publications in Agricultural Sciences | Vol. 3

frequently been used in making up a composite sample. It is assumed

— EEE

for the time being that the amount of nitrate actually found in a
composite sample is that expressed by the mean of any given number
of samples. All the calculations have been made upon the samples
reported in the tables below just as if these were the only samples
taken from the area, as would be done if such a number of samples
were used in an independent investigation. In this case, however, we
have a much larger number of samples to check the accuracy of the
results obtained with the fewer number. Table 9 gives the amounts

i i a i a i

of nitrate found in ten surface samples, numbered from forty-two to

TABLE 9

VARIABILITY OF TEN SURFACE SAMPLES TAKEN AT RANDOM }

Residual nitrate Incubated blanks (NH,)2SO, Blood .

Nitrate Devia- Nitrate Devia- Nitrate Devia- Nitrate Devia- :

: nitro- tion from _nitro- tion from nitro- tion from nitro- tion from

No. gen mean + gen mean —+— gen mean + gen mean +

Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs.

42 3.0 0 45 06 21 10 7.0 10.0 ;

43 3.4 0.4 3.8 0.1 6.2 3.1 18.0 1.0

44 1.8 1.2 3.0 0.9 5.2 2.1 18.0 1.0 |
45 2.5 0.5 4.0 0.1 2.3 0.8 21.0 3.0

46 2.1 0.9 3.0 0.9 1.8 13° > 138 4.0
47 4.0 1.0 3.8 0.1 2.5 0.6 18.0 1.0
48 3.1 0.1 3.3 0.6 2.5 0.6 20.0 3.0

49 4.4 1.4 5.2 1.3 2.0 1.1 21.0 4.0 f

50 3.5 0.5 4.8 0.9 2.3 0.8 20.0 3.0 ;

51 2.3 0.7 4.0 0.1 4.8 0.7 24.0 7.0 ;

Mean 3.0041.7 0.6 3.90+.15 0.6 3.10+.31 1.3 17.00.89 3.7 {

o 0.80+0.12 0.70+.10 1.50+.22 4.70+.63 ’

C.V. 26.7+4.3% 17.9+2.7% 48.4+3.9% 24.7+3.8% ’

E 5.7% 3.8% 10.0% 5.2% '

M

fifty-one, inclusive. It will be noted that these samples are taken in
a straight line (see fig. 1), while the sixteen samples are taken indis-
criminately over the area. Considering the residual nitrate alone, it
is seen that the mean of the ten samples is 0.30 milligrams above the
mean of the total number of samples. Further, the probable error of
the mean is increased from + .05 milligram to + .17 milligram or, in
terms of the probable error, the chances are about 3 to 1 that the
difference between the two results is a significant one.* The coefficients
of variability are very nearly the same in the two instances.

* The probable error of the differences between two results is caleulated from
the formula:

Probable error of difference = 2° ES E.

1918 | Waynick: A Statistical Study of Nitrification in Soil 259

In the incubated samples, the probable error of the difference be-
tween the samples is 0.50 + .17 milligrams, for the samples to which
ammonium sulfate was added 1.90 + .31 milligrams, and for dried blood
4.00 + .97 milligrams. It is worthy of note that the probable error of
the differences between eighty-one samples, to which ammonium sulfate
was added, and the ten samples given above is no less than 6 to 1.7
The coefficient of variability of the ten samples is greatly increased,

TABLE 10
VARIABILITY OF SIXTEEN SURFACE SAMPLES TAKEN AT RANDOM
Residual nitrate Incubated blanks (NH,)2SO, Blood
RE SE a
Nitrate Devia- Nitrate Devia- Nitrate Devia- Nitrate Devia-
nitro- tion from _ nitro- tion from _nitro- tion from _nitro- tion from
No. gen mean + gen mean + gen mean + gen mean +
Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Megs.
1 2.5 2.0 4.3 1.0 6.6 2.2 27.0 8.0
3 3.0 0.5 2.2 be 8.0 p.6 13.0 6.0
7 3.3 0.8 1.8 1.5 6.6 2.2 20.0 1.0
9 2.5 0.0 4.8 1.5 5.8 1.4 20.0 1.0
30 2.6 0.1 3.0 0.2 6.2 1.8 11.0 8.0
34 2.8 0.3 3.3 0.0 4.5 0.1 20.0 1.0
37 1.0 1.5 3.0 0.3 4.0 0.4 19.0 0.0
40 3.6 a i 4.0 0.7 6.6 2.2 13.0 6.0
42 3.0 0.5 4.5 1.2 2.1 2.3 7.0 12.0
46 2.1 0.4 3.0 0.3 1.8 1.6 13.0 6.0
49 4.4 1.9 5.2 1.9 2.0 2.4 21.0 2.0
53 2.3 0.2 3.1 0.2 6.4 2.0 27.0 8.0
57 1.8 0.7 1.2 2.1 2.2 2.2 27.0 8.0
59 1.3 1.2 2.0 1.3 2.2 2.2 14.0 5.0
60 2.0 0.5 3.0 0.3 3.5 0.9 30.0 11.0
72 2.7 0.2 3.6 0.3 1.8 2.6 27.0 8.0
Mean 2.50+.14 0.6 3.30+.17 0.9 4.40+.35 1.9 19.00+1.1 6.0
o 0.80+.10 1.00.12 2.10+.26 6.70.08
C.V. 34.444.5% 30.3+3.9% 47.7+6.4% 35.244.6%
E,, 5.6% 5.2% 7.9% 5.8%

being 48.4 + 3.9 per cent. On the other hand, it happens that the
incubated blanks vary even less than the eighty-one samples, the co-
efficients of variability being 17.9 + 2.7 per cent and 31.2 + 1.7 per
cent respectively. It is seen from these results that very wide varia-
tions may be found when only ten samples are used in making a
composite sample and that that number of determinations is by no
means enough to be an accurate measure of the actual nitrate nitrogen
content when the variations are of the magnitudes of those noted above.

Turning for a moment to the results given in table 10, we find that

+ For table of odds to aid in estimating the significance of differences between
two results, see Batchelor and Reed, Jour. Agr. Res., vol. 12, pp. 265-266, 1918.

260 University of California Publications in Agricultural Sciences [ Vol. 3

the probable error of the difference between the mean of the sixteen
samples taken purely at random, and the entire number of determina-
tions made, to be .20 + .15 milligrams, with a coefficient variability of
34.4 + 4.5 per cent as contrasted with 25.9 + 2.1 per cent for the total
number. The difference between the number of samples considered
here and the total number is not significant with the incubated blanks,
but with the ammonium sulfate samples the probable error of the
difference between the means is 0.66 + .33, and with dried blood
20+ 1.1. The chances are somewhat less than 2 to 1 that the differ-
ences between the sixteen samples here considered and the total eighty-

TABLE 11
EFFECT OF DISTANCE UPON THE VARIABILITY IN SAMPLING—RESIDUAL NITRATE
Five-foot radius Twenty-five foot radius Fifty-foot radius
Nitrate Deviation Nitrate Deviation Nitrate Deviation
No. nitrogen from mean No. nitrogen from mean No. nitrogen from mean
Milligrams Milligrams Milligrams Milligrams Milligrams Milligrams
2 2.8 0.4 6 2.7 0.3 1h 3.0 0.5
12 2.7 0.5 16 3.0 0.6 21 3.0 0.5
22 4.5 1.3 26 3.4 1.0 31 13 1.2
32 a 0.1 36 1.3 y R| 41 3.8 13
42 3.0 0.2 46 2.1 0.3 51 2.3 0.2
52 3.1 0.1 56 2.5 0.1 61 1.5 1.0
62 4.0 0.8 66 2.0 0.4 t 3.5 1.0
72 2.7 0.5 76 2.6 0.2 81 2.0 0.5
Mean 3.20+.14 a3) 2.40+.14 0.4 2.50.19 0.6
¢ 0.60+.10 0.60+.10 0.80.13
C.V. 18.7+3.3% 25.0+4.5% 32.0+5.8%
Ey 44% 5.8% 7.6%

one samples are significant. It is evident that caleulations made from
the mean of sixteen samples are of a higher degree of accuracy than
when only ten samples are used, but the number is still too few to give
results of a high order of reliability, and could by no means be taken
as truly representative of the entire area under consideration.

Other numbers and other groupings may be selected and the mag-
nitude of their means and their accompanying probable errors and
coefficients of variability computed from the data reported in tables
1 to 4.

EFFECT OF DISTANCE UPON VARIABILITY

To determine whether or not the distance apart the samples were
taken is a factor of importance in sampling, the arrangement given in
table 11 has been made. The results shown in the table are for residual

1918 | Waynick: A Statistical Study of Nitrification in Soil 261

nitrate in the surface samples only. The first group of determinations,
from numbers two to seventy-two, inclusive, by intervals of ten, were
recorded from samples lying within a radius of five feet of number
one. The mean of the eight readings is 3.20 + .14 milligrams or 0.5 —&
.15 milligrams above the mean for the whole number of samples. The
coefficient of variability is, however, relatively low.

The second group of determinations from numbers six to seventy-
six, varying as those of the group above, are of the samples on the
circle with a radius of twenty-five feet from the center. The mean of
this group of eight determinations is 2.40 + .14 milligrams or 0.3 + .15
below that of the established mean as already given. The coefficient
of variability in this case is nearly the same as for the total of eighty-
one samples, however.

The last group of determinations represents the nitrate found in
the samples taken as the fifty-foot radius. The mean of the eight
determinations is 2.50 + .20 milligrams; 0.70 + .24 milligrams and
10 + .24 milligrams. In two eases, the differences are significant; in
the third, the probable error is greater than the difference and holds
between the most widely separated samples taken on the twenty-five
and fifty-foot radii. Even though only eight samples are considered
in any one group, the conclusion seems justified that the distances
apart samples are taken is of little importance, except in so far as their
distribution be uniform over the area to be sampled. <A small area of
an apparently uniform field may lead to very erroneous results, as
evidenced by the high figures obtained for the mean of the determina-
tions made upon the samples on the five-foot radius. It is, of course,
taken for granted that we are dealing in every instance with a field
suitable for experimental work and hence not marked by changes in
the soil apparent to the eye.

ESTIMATE OF THE NUMBER OF SAMPLES REQUIRED FOR ANY

GIVEN DEGREE OF ACCURACY’

It is very desirable to know just how many samples it is necessary
to use to secure the degree of accuracy deemed desirable for the work
in hand. By the use of the probable error and the standard deviation
found from any representative number of samples, an estimate of the
number of samples which will give a lower or higher degree of accuracy
. than the number used may be computed. For example, in the case of

262 University of California Publications in Agricultural Sciences [ Vol. 3

the residual nitrate determinations, we have seen that the mean of the
eighty-one samples amounted to 2.70 milligrams, with a probable error
of + .05 milligrams and the standard deviation of the series (0.70 gram.
As already stated, the probable error of the mean is expressed as

: 6745 & o
1D M >—— a
Vn
30
I. Laboratory Error.
2. Residual Nitrate. 6224"
3. “ " 1-6"
4. Incubated Blanks 6" 24"
5 . " '- 6"
6 Ammonium Sulfate 6-24"
Z . - 76"
8 Blood 6"-24"
20 9. ” 1"--6"

mg. Nitrate. Nitrogen
a

1

eee rs
fe) 4S, Se —_——__= ————
14 9 16 25 36 49 64 8)

No. of Samples.

1918 | Waynick: A Statistical Study of Nitrification in Soil 263

and since the standard deviation in this instance is 0.7 gram, hence
6745 & 0.70
Vn

We can make Hy of any dimension desired and since our method of

4M—

determining nitrates allows of direct determinations only to 0.1 milli-
gram, we will use this number for the probable error of the mean of
the desired number of determinations so that

6745 & 0.70

0,40 ==
Vn

from which:n = 22. It must be remembered, however, that the labora-
tory error increases as we decrease the number of determinations in
the same manner as the probable error of our sampling, so that this
increased error must be taken into account in estimating the number
of samples necessary to ensure any desired degree of accuracy. Refer-
ring to table 7, we find that the probable error of making the readings
on the colorimeter for twenty-five samples is .017 milligram or very
nearly .018 milligram for twenty-two samples, so that for a probable
error of 0.1 milligram we have

__ .6745 & 0.13

= Vn

and n=1. Thus twenty-three samples are sufficient so that the
probable error in the mean is 0.10 milligram. The taking into

+().]

account of the laboratory error involves an extra calculation, which,
for all practical purposes, may be avoided by the use of a table, such
as shown by table 12 (represented graphically in figure 2), which has
been calculated from the data given in tables 1, 2, 3, and 4, after
the manner already outlined. It will be noted that this table is of
limited range and accounts for numbers of samples less than eighty-
one, but may be extended for a range greater than the one given if
desired. The approximate number of samples may be readily found
after the following manner. It is desired to determine the number ot
ammonium sulfate samples necessary to be taken to ensure the same
degree of accuracy as for twenty-three residual nitrate samples, of which
the probable error of the mean was calculated to be 0.10 milligram.
By reference to table 12, it is found that about eighty-one samples are
required without taking the laboratory error into account. This error
is .009 milligram (table 7) for eighty-one samples, an amount less
than one per cent of the error which we are allowing for and hence

264 University of California Publications in Agricultural Sciences | Vol. 3

negligible, for all practical purposes, when the probable error of the
sampling is of as great a magnitude as 0.1 milligram. It must be
recognized that the mean of the number of samples so calculated may
be found to have a greater or less probable error in practice so that
a greater number of samples than calculated should be taken. This
relation has already been brought out in the previous section, where
it was shown that the fewer the samples, the less representative
of the total area they became. By an inspection of table 12, it
is evident that the number of samples necessary to secure the degree
of accuracy which we established for the residual nitrate samples must
be very greatly increased, when we are dealing with ammonium sulfate
or blood treated samples.

TABLE 12
PROBABLE ERROR WITH VARYING NUMBERS OF DETERMINATIONS
Number’ Residual nitrate Incubated blanks Ammonium sulphate Blood
on 1"-6" 6”-24” 1"-6" 6-24" 1”"-6" 6”-24” 1”-6" 6”-24”
Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs. Mgs.
47 .24 ay mH} 1.01 74 3.8 3.5
+ .23 12 oT 16 oO .oT 1.9 BB
9 16 .08 25 af o 20 1.2 be
16 12 .06 18 .O8 .20 19 1.0 0.9
25 .09 .05 14 .06 20 15 .08 0.7
36 08 — .04 12 .05 me Wy 12 0.6 0.6
49 07 .035 10 .048 14 10 0.5 0.5
64 .06 .03 .09 04 12 .O9 0.48 0.45
81 05 .03 .08 .03 10 .08 0.4 .04

It will be remembered that throughout the discussion, we have con-
sidered the probable error of the mean of any given series of samples
directly, so that we have but an even chance that the mean for any
given number of determinations made will be of significance. It is
usual to consider about three times the probable error as a significant
difference between two given means, hence if we are to establish this
standard as regards the number of samples taken, we must increase
all the figures given by three times.* It is obvious that such a number
of samples in the case of dried blood, for instance, would be far beyond
practical limits as regards the making of the determinations. The
chances are that the use of a fewer number of samples means a low
degree of reliability for any determinations made. If soil biologists
are to continue to make beaker tests with fertilizers, the results must
be interpreted from this viewpoint.

* By multiplying the probable error found by 3.17 the chances are thirty to
one that a difference greater than the figure so found is significant.

1918] Waynick: A Statistical Study of Nitrification in Soil 265

While we are not justified in using the results obtained from labora-
tory treatments as direct criteria of what will happen in the field, it
is probable that greater variability will be found in field plots which
have been subject to treatment with fertilizers than in the normal soil
to which no fertilizers have been added, especially when the fertilizer
is of such a complex nature as dried blood.

It must further be emphasized that the figures as given above apply
only to the soil under discussion; each soil with the treatment applied
must be considered as a unit in a statistical study. It is evident that
a standard established for the residual nitrate, for instance, will not
hold for the nitrate produced from a one per cent application of blood.
The exact correlation between the various laboratory treatments and
between those treatments and results secured in the field is reserved
for discussion in a future publication.

REPRESENTATIVE AND COMPOSITE SAMPLES

It is evident from the results already presented in various group-
ings that a representative sample of any soil is a purely hypothetical
quantity whose constituents may only be determined indirectly. It is
also evident that determinations reported from only one sample of a
given area are practically worthless, when the errors to which it is
subject are of the magnitudes shown above. Composite samples made
up from a small number of single samples are of little more value.
Not until enough samples have been taken to enable the proper calcu-
lation of the probable error of the mean of a given number of samples
is the making of a composite sample justified, since the results obtained
from working with such a sample are of very limited value unless the
error to which the composite sample, itself, is subject, can be deter-
mined.

It seems, therefore that the use of the word composite as relating
to soil samples is only justified when the variations to which the
individual samples are subject are known and enough samples taken
to establish the error to which the composite, as a mean of all the
samples, is hable. The magnitude of the error which is liable to creep
into the determinations due to imperfect mixing in a composite sample
is no doubt worthy of consideration, but since its value is undetermined,
it has been assumed that a composite actually represents the mean of
all the samples taken. Just how reasonable such an assumption may be
remains for future investigations to bring out.

266 University of California Publications in Agricultural Sciences [ Vol. 3

GENERAL DISCUSSION

It has already been stated that the area under discussion was of
very limited extent and as free from apparent variations as any area
is likely to be. Also, that the treatment and climatic influences had
all tended toward a state of biologic equilibrium as regards nitrate
production in this particular soil. With this viewpoint in mind, the
importance of applying a statistical interpretation to results obtained
from working with a given soil type obtained under conditions much
less favorable, becomes doubly important. It is not at all improbable
that variations several times greater than those reported will be found
in many instances and the number of samples deemed sufficient in this
case must be increased to obtain any considerable degree of accuracy.
It is possible that areas more uniform than the one used will be found,
but it is hardly probable that such will be the case.

While the present paper deals only with the production of nitrates,
not only the variability of the products of microdrganic activities, but
the chemical constituents of any soil should be studied in a similar
manner to determine just how reliable past results in soil investigations
may be. It is beyond question that before we can have faith in future
results, we must apply the principles outlined. <A study of the prob-
lems of nitrogen fixation in the soil, which is to be as complete and
as carefully controlled as possible, is now under way at this station.
Statistical methods are to be applied to the variations in the total
nitrogen, total carbon, and nitrates, at least, in two representative
soils under observation before a treatment of any kind is apphed. In
other words, the experimental areas to be used are being standardized
as carefully as possible, making due allowance for field variations in
the constituents noted above. Further, the field errors due to varia-
tions between the samples must not be greater than the experimental
error due to the laboratory manipulations, since the increases (or
decreases) to be measured are themselves of small magnitude. To be
sure, this method of procedure takes much extra time and energy, but
it must be employed before the results of any treatments which are
made may be correctly interpreted or recommendations based upon
the experimental results safely made. It is hoped that some of the
results of these preliminary studies may be ready for publication in
the not far distant future.

1918 | Waynick: A Statistical Study of Nitrification in Soil 267

As regards the effect of seasonal variation upon the accuracy of
results which may be obtained at one season of the year upon those
secured at another period, no data are as yet available which are
extensive enough to warrant any conclusion. It is evident that if a

’

‘‘representative’’ sample must be found from time to time whenever
new work is undertaken, the procedure would become very laborious.
The prediction is made that the probable error of the mean as found
in any one sampling will be very nearly the same for other samplings
taken at other seasons of the year, so that it will only be necessary to
make a composite sample of a previously determined number of
individual samples and apply the probable error, as previously found,
to the results obtained.

The segregation of the causes of biologic variation in the deter-
minations as made, is of importance. Some evidence has already been
presented showing the increased variability due to laboratory treat-
ment. Variations in moisture present under incubator conditions, the
change in the medium due to the addition of various fertilizers, and
the mixing of the fertilizer with the soil are all causal factors in the
variations between samples as regards the amount of ammonia, nitrate,
or similar compounds finally measured. We are attempting, in this
laboratory, to determine the extent, and to limit as much as possible,
the variations due to manipulation. In the field the only possible
cause contributing to increased variability is the method of sampling,
and from unpublished results to be reported later the differences be-
tween different methods of sampling are of but little moment in a
study of field variability. Variations between field samples may only
be allowed for as already outlined and are no longer serious sources of
error when once recognized.

There can be no doubt that much of the work done in the past, as
regards nitrification at least, is open to very serious question in the
light of the results herein reported. Just how much of it can be
retained can only be determined by a careful checking of the actual
determinations made, taking into account the error due to sampling
and to the laboratory manipulations. If the data reported in table 4,
for instance, be arranged in any proper order, it will be found that
nearly any desired series of results may be secured, agreeing closely
in their relative range with any series of results obtained from plots
or tumbler treatments which have been reported by various investi-
gators. Individual investigations are not referred to here in detail,
since their large number precludes their discussion in the limited space

268 University of California Publications in Agricultural Sciences | Vol. 3

of this paper. It is beyond question that the soil is an extremely
variable quantity and that its variability must be measured and taken
into account before any determinations made upon it become of value.

SUMMARY

A study of variability as regards nitrate production of eighty-one
samples of soil taken from a limited area of an apparently uniform
soil, is reported. Both surface and subsoil samples were taken. The
nitrate present at the time of sampling, the nitrate produced from the
soil nitrogen, from ammonium sulphate, and from dried blood were
determined. Statistical methods were applied for the interpretations
of the results. The following conclusions seem justified from the data
presented :

1. The variability of the field samples of soil, even from an appar-
ently uniform area of limited extent, is high and is a factor of extreme
importance in an estimation of the reliability of any series of results.

2. The variability of the samples treated as in the tumbler method
for nitrification studies is increased over that found for the nitrate
produced in the field.

3. Subsoil samples vary more in the field, and when treated with fer-
tilizers in the laboratory, than surface samples taken from the same
area. No explanation of this fact can be offered at the present time.

4. A single sample of any soil is of little value as regards deter-
minations which may be made upon it.

5. A lmited number of samples as ten or sixteen, are subject to
wide variations and can only be used when the results are to be inter-
preted as having a low degree of accuracy.

6. A composite sample may be considered as of value only after the
probable error to which it is subject is known and this can only be
determined by the use of a large number of individual samples.

7. The distance apart samples are taken is of little importance as
long as the samples are uniformly distributed over an area which is
apparently uniform.

8. In the ight of these results, the conclusion seems inevitable that
much of the past work done, as regards nitrification at least, must be
critically examined to determine the degree of reliability, if any, it
may have.

1918 | Waynick: A Statistical Study of Nitrification in Soil 269

Attention is called to the fact that variations in other products of
microbrganie activity and in the chemical constituents of different
samples of the same soil may be as large or even larger than those found
in the present study; and that a much more comprehensive study of
variability than the one herein reported is now being carried out.

The writer wishes to express his indebtedness to Dr. C. B. Lipman
for suggestions offered during the progress of the work, and to Dr. L.
D. Batchelor for helpful suggestions in the preparation of the manu-
script. Also to Mr. Douglas Wright, Jr., for aid in taking the samples
and in making the calculations.

Transmitted April 18, 1918.

270 University of California Publications in Agricultural Sciences | Vol. 3

LITERATURE CITED

1 ALLISON, F. E., AND COLEMAN, D. A.
Biological variations in soil plots as shown by different methods of sampling.
Soil Science, vol. 3, pp. 499-514, 1917.

2 Auway, F. J., AND TRUMBALL, R. 8S.
On the sampling of prairie soils. Ann. Rep. Nebraska Agr. Exp. Sta., vol.
25, pp. 35-52, 1912.
ALway, F. J., AND FILEs, E. K.
On the sampling of cultivated soils. Jbid., pp. 52-56, 1912.

Auway, F. J., AND BISHOP, E. S.
The nitrogen content of some Nebraska soils. Jbid., pp. 129-160, 1912.
3 KASERER, H.
Beitrage zur Frage der Festellung des Nahrstoffgehaltes einer Ackerparzelle.
Ztsch. Landw., Versuchsw. Osterr., vol. 13, pp. 742-747, 1910. Cited from
E. 8. R., p. 320, 1911.
4 AMERICAN SOCIETY OF AGRONOMY.
Report of the Committee on Standardization of Field Experiments. Jour.
Amer. Soc. Agron., vol. 9, pp. 402-409, 1917.
5 LIPMAN, C. B., AND SHARP, L. T.
Studies on the phenoldisulphonie acid method for determining nitrates in
soils. Univ. Calif. Publ. Agr. Sci., vol. 1, pp. 23-37, 1912.
6 DAVENPORT, C. B.
Statistical methods (ed. 2; New York, Wiley, 1904).
7 ROBERTSON, T. BRAILSFORD, AND Ray, L. A.

Experimental studies in growth. II. The normal growth of the white mouse.
Jour. Biol. Chem., vol 24, pp. 374, 1916.

UNIVERSITY OF CALIFORNIA PUBLICATIONS
IN

AGRICULTURAL SCIENCES
Vol. 3, No. 10, pp. 271-282 June 22, 1918

DOES CaCO: OR CaSO, TREATMENT AFFECT
THE SOLUBILITY OF THE SOIL’S
CONSTITUENTS?

BY

C. B. LIPMAN anp W. F. GERICKE

In 1850, Thompson! showed that when soil is shaken with a solution
of sulphate of ammonia, calcium sulphate is brought into the solu-
tion. Using this observation as a basis, Way” proceeded, in a classical
investigation, to study the nature of the phenomenon. He found that
when the calcium sulphate goes into solution as observed by Thompson,
there is an amount of base in the form of calcium and of other bases
set free in the solution equivalent to the amount of ammonium base
which is absorbed by the soil. From this fact and his observation that
clay carries the constituent which thus reacts with the sulphate of
ammonia, Way argued that there exist in the clay certain ‘‘double
silicates’’ of the alkalies and alkali earths with aluminum, which are
the active bodies in the reaction under consideration. He never proved
that such double silicates actually exist in the ‘‘clay’’ of the soil, but
believed them to be present there because his artificially prepared
double silicates of calcium and aluminum, of sodium and aluminum,
and others, behaved toward salt solutions like the clay, and lost their
absorptive and reactive powers, like clay, on ignition. In contra-
distinction to Liebig’s view that the precipitation by soils of salts from
solution constitutes merely a physical phenomenon, Way believed that
the Thompson experiment, which typifies such soil-salt phenomena,
represents, really, a chemical reaction. Way’s view became generally

1 Thompson, H. 8., On the absorbent power of soils, Jour. Roy. Agr. Soc., vol.
11, p. 68, 1850.

2 Way, J. T., On the power of soils to absorb manure, ibid., vol. 11, p. 313,
1850, and vol. 13, p. 123, 1852.

272 University of California Publications in Agricultural Sciences | Vol. 3

accepted and has been taught and is still very largely taught in the
agricultural colleges today under the subject of ‘‘fixation’’ or ‘‘ex-
change’’ of bases in soils. The presence in the soil of double silicates
or zeolites was thus assumed by soil investigators, and Hilgard gave
the idea much prominence in connection with his methods and
hypotheses on soil analysis. Further, the idea served as a basis for
the use, by Lawes and Gilbert, of sodium sulphate and of magnesium
sulphate in connection with the application of fertilizers to their
experimental plots with the end in view of setting free potassium, from
its silicate combinations in the soil, for use by the plant.

All of this has led to the statement, universally employed by authors
of texts on soils, that the application of lime and gypsum to soils
results, among other changes wrought by them, in the making ‘‘avail-
able’’ of potassium and other ions* of a similar nature. As recently
as 1907, Hall and Gimingham*® adduced experimental evidence on the
interaction between clay and ammonium sulphate, which appeared to
mark that reaction as one obeying the mass law, thus seemingly lend-
ing support to the validity of Way’s hypothesis. Hall and Giming-
ham’s evidence was soon shown by Cameron and Patten* to be in-
complete, however. They demonstrated that the mass law does not hold
when a wider range of concentrations than that employed by the former
investigators is tested and a new hypothesis was necessary to explain
it. This was furnished by Van Bemmelen, who proved that absorption
by soils was closely parallel to that by colloids which he had studied,
and which may be explained by the formula y/m= Kce!/" in which
y is the amount absorbed by a quantity m of the absorbent, c the con-
centration of dissolved substance when equilibrium is attained, and
K and vn are constants depending on the nature of the solution and the
adsorbent. Such a formula has since been shown to hold for absorp-
tion of phosphates by Prescott® and for absorption of ammonium salts
by Wiegner.® In accordance with this conception of the soil as a
colloid-containing body, the colloidal particles possess the power of
holding ions which are adsorbed from salt solutions and give such ions
up with relative facility to new solutions containing other ions for
which they are substituted.

* In this case, and throughout this paper, the term ‘‘ion’’ is not used in the literal sense
It is not intended to convey the idea that the authors believe that a given ion by itself is
absorbed or set free, for we are actually inclined to the belief that in these cases, as in absorp-
tion by plants, not ions, but compounds, are absorbed as units.

3 Hall, A. D., and Gimingham, C. T., The interaction of ammonium salts and
the constituents of the soil, Trans. Chem. Soe., vol. 91, p. 677, 1907.

4 Cameron, F. K., and Patten, H. E., The distribution of solute between water
and soil, Jour. Phys. Chem., vol. 11, p. 581, 1907,

ull

to
~I

1918} Lipman—Gericke: CaCOs and CaSO, and Soil Solution

This idea has, however, been confused with the zeolitic hypothesis
from which, in some respects, it is quite distinct. Due to both concepts,
the teaching is still largely in vogue that CaCO, and CaSO, possess
as one function in soils a power to set potash and other bases free from
their insoluble combinations. In spite of the general acceptance of
this view, however, some practical agronomists have called it in ques-
tion and it seems necessary to determine if the hypothesis and the
laboratory experiments used in support thereof are valid. Briggs and
Breazeale’ have recently made an attempt to answer definitely the
question as to whether or not lime or gypsum applied to soils does
affect the potassium content of the soil solution produced by ortho-
clase, pegmatite, or orthoclase-bearing soils in contact with water.
They checked their results by growing young wheat seedlings in the
solutions produced by the treatment of the mineral or soil with hme
or gypsum and water. As a result of these experiments, they con-
elude that the ‘‘availability to plants of the potash in soils derived
from orthoclase-bearing rocks is not increased by the addition of lime
or gypsum. In some instances, a marked depression of the solubility
of the potash in the presence of gypsum was observed.’’ While the

ce

authors specifically refer to ‘‘soils derived from orthoclase-bearing

rocks, ’’

the statement carries the implication, owing to the stated
object of their investigation, that the potash-bearing silicates of any
kind in soil are not likely to be affected in solubility by the addition
to the soil of lime or of gypsum. The fact that this conception is con-
trary to what one would expect from theoretical considerations regard-
ing soil-solution reactions, appeared to render it desirable to investigate
the subject farther. We therefore planned and executed the following
experiment :

Calcium carbonate or calcium sulphate were each added to soils, and
throughly mixed with them in the different cases as further indicated
in the tables. The soils thus mixed were placed in pots in the green-
house. Water was added to make optimum moisture conditions and
such moisture conditions were maintained for a period of nine months.
Three soils were used, viz: Oakley blow sand, Berkeley clay adobe, and
a greenhouse soil, the latter having been originally made by admixing

5 Prescott, J. A., The reaction between dilute acid solvents and soil phos-
phates, Proc. Chem. Soc., vol. 30, p. 137, 1914.

6 Wiegner, Georg., Zum Basenaustausch in der Ackererde, Jour. Landw., vol.
60, pp. 110 and 197, 1912.

7 Briggs, L. J., and Breazeale, J. F., Availability of potash in certain ortho-

clase-bearing soils as affected by lime and gypsum, Jour. Agr. Res., vol. 8, p. 21,
1917.

274 University of California Publications in Agricultural Sciences | Vol. 3

barnyard manure with the Berkeley clay adobe soil. The applications
of CaCO, and of CaSO, were made on March 9, 1917, and in the
manner and quantities indicated in the tables. Control soils, untreated
with either lime or gypsum, were, of course, included in the experi-
ment, but were otherwise treated like the other soils. The soils in
all pots were sampled three times, at considerable intervals, as shown
in the tables. The samples were taken so as to represent the whole
depth of the soil layer in the pot and of different parts thereof. Eight
hundred gram portions of these samples, in air-dry condition, were
mixed with 1600 ee. of distilled water in large bottles and allowed to
digest for six days with occasional shaking during every day. After
six days, the solutions were filtered through Pasteur-Chamberland
pressure filters and analyzed by gravimetric or volumetric methods
for the constituents named in the tables. Large enough aliquots could
be employed, owing to the method which we have devised and described
above for mixing the soil and water, to insure accurate results by the
standard methods of analysis intended for larger quantities of the
same substances. We employed no checking system by means of
germinating plants, such as that used by Briggs, because (1) we do
not believe that a few days’ growth of plants constitutes any reliable
criterion regarding any factor in plant growth, and (2) the evidence
obtained by Burd, Hoagland, and Stewart has demonstrated that for
plants grown to maturity, an intimate relation holds between the
nature of the soil solution and absorption of nutrients by plants grow-
ing in such soil solutions in every stage of growth. In other words,
we contented ourselves with trying to determine whether or not the
soil solution is enriched with respect to potassium and other elements
by the treatment of soil with CaCO, or with CaSO, as indicated by
the composition of the soil extracts obtained by us. The results of the
analyses of the soil extracts are shown in the subjoined tables, in which
the amount of every ion sought and found in the solution is expressed
in parts per million of the soil.

For the sake of greater simplicity and brevity, we shall at first
discuss the tables separately.

In table 1, we see the results obtained with the Oakley soil, from
which it is clear that both hme and gypsum are without effect on the
amount of water soluble potassium in that soil. The latter behaves in
this respect like the Oatman soil from Riverside County in this state,
which Briggs and Breazeale have studied. There is little reason to
believe, likewise, from the data under consideration that the water

1918] Lipman—Gericke: CaCO, and CaSO, and Soil Solution

TABLE 1. OAKLEY SOIL

Treatment: Date Ke Ca Mg S K P
ag th nll acting In parts per million of dry soil
Control Ane. 9, "1% 1.0 16 2.3 17 9.1
500 CaCO, Ps eee ae Wy | 3.6 23 3.9 16 8.1
1000 CaCO, Apr. 9, 717 3.4 31 6.9 21 10.3
500 CaSO, Any. 9,717 1.4 32 3.1 21 9.7
1000 CaSO, Bene. 9.40 1.4 63 1.0 20 10.7
Control July 20, 717 1.2 13 3.6 10 7.9 6.9
500 CaCO, July 20, 717 2.0 27 OF 10 7.8 5.8
1000 CaCO, ~— July 20, 717 1.4 26 9.3 10 8.4 10.4
500 CaSO, = July 20, 717 1.4 26 1.6 23 8.3 5.5
1000 CaSO, July 20, 717 1.4 62 0.9 45 6.9 8.1
Control Dec. 24, 717 1.4 24 1.3 19 8.8 6.7
500 CaCO, Dec. 14, 717 1.4 3] 1.3 14 9.1 7.2
1000 CaCO, Dee. 24, 717 1.5 34 1.3 13 9.9 6.1
500 CaSo, Dee. 24, 717 1.0 44 ATs 30 1.3 6.7
1000 CaSO, Dee. 24, 717 0.6 61 1.3 64 8.0 6.3
TABLE 2. ADOBE SOIL
Treatment: Date Fe Ca Mg S K P
ce alia er In parts per million of dry soil
Control Apr. 23, 717 0.7 17 0.7 a 7.4
1000 CaCO, Apr. 23, 717 0.7 25 1.4 ae 12.8
1000 CaSO, Apr. 23, 717 0.8 50 ek axe 9.6
Control July 20, 717 0.7 32 2.1 32 9.7 7.2
1000 CaCO, July 20, 717 0.7 34 4.2 31 15.0 7.8
1000 CaSO, July 20, 717 0.7 78 2.1 124 12.4 7.5
Control Jan. 2, 718 1.6 47% 2.6 32 8.3 5.6
1000 CaCO, Jan. 2, 718 1.6 46 2.6 3] 8.8 6.1
1000 CaSO, Jan. 2, 718 1.0 84 ats 146 10.0 5.7
TABLE 3. GREENHOUSE SOIL
Treatment: Date Fe Ca Mg Ss K P
sg acl Bee cae In parts per million of dry soil
Control Apr. 20, 717 7.8 83 9.3 40 14.4
500 CaCO, Apr. 20, 717 15.5 112 19.5 42 15.3
1000 CaCO, =Apr. 20, 717 8.3 115 25.5 49 25.4
500 CaSo, Apr. 20, 717 7.0 157 17.8 91 20.4
1000 CaSO, Apr. 20, 717 7.8 210 6.7 106 27.0
Control July 20, 717 4.5 86 8.6 51 23.8 14.0
500 CaCO, July 20, 717 7.8 91 20.6 86 25.0 12.3
1000 CaCO, July 20, 717 5.6 104 24.3 82 38.6 12.3
500 CaSO, July 20, 717 4.5 129 9.3 130 28.2 11.4
1000 CaSO, July 20, 717 4.2 162 5.2 165 34.8 10.1
Control gan, 12, 718 11.9 93 3.9 5D 12.8 20.2
500 CaCO, Jan. 12,.718 9.8 128 5.0 76 15.4 19.6
1000 CaCO, Jan. 12, 718 9.8 142 5.4 76 32.0 18.4
500 CaSO, Jan. 12, 718 9.7 176 4.0 182 17,¢ 16.7
1000 CaSO, Jan. 12, 718 9.8 171 4.3 219 22.4 17.1

276 University of California Publications in Agricultural Sciences | Vol. 3

soluble phosphorus and the water soluble sulphur in that soil have been
affected by CaCO, and the first by CaSO, The calcium content of
the solution is affected by both CaCO, and CaSQO,, as would be ex-
pected, but which does not necessarily have to occur. On the other
hand, the water soluble iron content of the soil appears possibly to
be shghtly affected by the CaCO, treatment, at least in the first
sampling; and the magnesium content of the water extract shows, it
seems to us, very distinct accretions, through the CaCO, applications,
in the first and second samplings. The effect seems to have dis-
appeared, however, by the time the third sampling was made and a
new equilibrium is probably established. On the contrary, gypsum
seems to depress the amount of water soluble magnesium in the soil
solution of the Oakley soil. This appears to be definitely true by the
time the period of the second sampling has been reached, and less
definitely in the period of the first sampling with the larger gypsum
appheation. Just as the tendency to increase in amount in the soil
solution through the instrumentality of the treatment seems to char-
acterize both the ions, magnesium and iron, in the periods up to and
including the second sampling, a reverse tendency is manifested by
these ions by the time of the third sampling. In the soils treated with
CaCO,, there is a definite decrease in magnesium, in the solution, in
the period named and the iron content of the same soil solutions seems
to decrease simultaneously. . Yet the other ions do not seem to have
been affected in that way in the same period, but have either remained
stationary or have shown increases. These rather marked changes
evidenced by the figures of the second and third samplings are even
more distinct in the cases of the other soils, to which reference will be
made below.

In the Berkeley clay adobe soil, the data for which are given in
table 2, conditions are quite evidently not the same as in the Oakley
soil. While the potassium content of the latter soil’s solution remained
unaffected by the application of either CaCO, or CaSO,, that of the
former soil seems to us to be definitely increased by both CaCO, and
CaSO, in the first two samplings and by CaSO, alone in the last
sampling. The greater effect in that direction is clearly induced, how-
ever, by CaCO,. The iron content of the soil solution in the clay
adobe soil remains entirely unaffected by the treatment which is
accorded the soil. The phosphorus content of the soil solution affected
by CaCO, may, perhaps, be slightly increased in both the second and
third samplings, but the data do not give us leave to be certain on

1918] Lipman-—Gericke: CaCOs and CaSO, and Soil Solution 277

that point. The calcium and sulphur content of the soil solution behave
as one would expect without experiment in the clay adobe soil treated
with CaSO,, but the calcium content of the same soil treated with
CaCO, is affected to a small degree in some cases and not at all in
others. The magnesium content of the clay adobe soil solution behaves
similarly to that of the Oakley soil solution, but the increases due to
CaCO, treatment of the soil are not as large in the former as in the
latter. Again CaSO, seems to be without effect in that direction. In
general, the behavior of the clay adobe soil solution, as Judged by our
analyses, parallels that of the Oakley soil solution in the third samp-
ling, a condition of equilibrium, and, in general of a more dilute
solution, having been attained. That does not hold, however, for the
soil treated with CaSO,. In general, therefore, the results obtained by
us with the clay adobe soil, among other things, show a lack of agree-
ment between our results and those of Briggs and Breazeale regarding
the effect of CaCO, and CaSO, on the potassium content of the soil
solutions in question.

Coming finally to a consideration of the greenhouse soil, we find in
table 3 some very interesting data, and the most definite of any sub-
mitted in all the tables, inasmuch as the changes due to soil treatment
are so much larger than those characterizing the other soils. Con-
sidering the data for potassium first, we find that marked increases in
the amount of that ion in the solution of the greenhouse soil are
induced by the larger application of CaCO, and by both the smaller
and larger applications of CaSO,. Moreover, even the smaler appli-
eation of CaCO, seems to induce the solution of definitely larger
amounts of potassium than those found in the solution of the untreated
greenhouse soil. In the periods of the first two samplings, the iron
content of the soil extract seems to have been increased by the CaCO,
applications, but not by the CaSO, applications. Moreover, the smaller
CaCO, application seems to have been much more effective in that
direction than the larger application. By the time of the third
sampling, the effects just mentioned appear to have vanished, and in
fact, it is possible that they have been supplanted by a depression in
the amount of iron in the soil extract. The general direction taken
by the effects of the soil treatment on the calcium content of the soil
extract is what one would expect @ priori. The results indicate, how-
ever, the inaccuracy of the method of determination considered, in the
large, since the relations between the CaCO, and CaSO, applications
in small and large amounts do not maintain themselves constant.

278 University of California Publications in Agricultural Sciences | Vol. 3

This holds, of course, for the other soils as well as for the greenhouse
soil, indeed, more markedly so. The phosphorus content of the soil
extract is certainly not increased, in the two determinations made, by
the treatment of the soil under consideration. In fact, while it is
difficult to appraise it as such, there seems to be a slight depression
in the amount of the phosphorus present in the soil extracts of the
treated, as against those of the untreated soils. The magnesium is
affected in the greenhouse soil similarly to the manner in which it
was influenced in the other soils, but, as in the case of the potassium,
the results are much more emphatic. It is quite evident that large
amounts of magnesium go into solution through the influence on the
soil of CaCO, throughout the period of the experiment, but especially
in the periods of the first two samplings. CaSQO,, on the other hand,
only inereases the amount of magnesium when employed at the smaller
application and then only in the period of the first sampling. With
the larger application of CaSO,, in the first sampling and with both
applications in the second sampling, there seems to be evidence of a
depression in the magnesium content of the soil extract. In the third
sampling, the CaSO, treated soils seem to behave like the control and
furnish another instance of the phenomenon noted above in the case
of the other soils. The sulphur content of the soil extract is more
markedly affected by the treatment in question in the case of the green-
house soil than any other constituent thereof which we have deter-
mined. That is, perhaps, not surprisingly so in the case of the CaSO,
treatment, but it is to be particularly remarked how very great such
increases are even with the CaCO, treatment. Unlike the cases of the
other constituents of the soil extract, moreover, that of the sulphur
shows the effect of treatment even at the third sampling.

GENERAL DISCUSSION

From a general survey of our results, a few facts stand out clearly:
Of the seven ions which we have determined in the extracts of the
soils treated with CaCO, or with CaSO,, all, with possibly one excep-
tion—phosphorus—are affected by the treatment in one or more of the
three soils, in the directions either of increase or decrease in amount
in the soil solution. The ions are not all affected by the treatment in
any one soil, however. It appears that the nature of the soil minerals,
as well as the organic matter content of the soil, and hence probably
the partial carbon dioxide pressures, are important factors in deter-

1918 | Lipman-—Gericke: CaCOs and CaSO, and Soil Solution 279

mining how CaCO, or CaSO, will affect the soil reactions and the
precipitation or the greater solution of given ions in any soil. This
marked disparity between the nature of soil reactions and their results
in different soils, seems to have been but slightly appreciated, if at all,
among soil investigators. We therefore find, on the one hand, the
iterated and reiterated statements in our text-books respecting the
effect that lime or gypsum, or both, exert on the available potash
supply in the soil solution; and, on the other hand, such statements
as that by Briggs and Breazeale to which we have made reference
above, which deny directly or inferentially the effectiveness of lime
and gypsum, in that direction, for a certain soil or a certain mineral;
and through the absence of comparison with other soils imply the
denial of the existence of such effects in general. As is freqently the
ease in all matters, the truth hes between these extreme views. Potas-
sium from the soil minerals is rendered soluble in greater quantity
than normally by applications to the soil of both CaCO, and CaSO,
in some soils, but not in others. Of the three soils which we have
studied, two seem to us to show clearly the former and one the latter
effect.

Working also with only one soil (Dunkirk clay loam), Lyon and
Bizzell,s by the indirect method of studying drainage water from
lysimeters, and by the possibly direct method of studying absorption
by plants, showed, prior to the work of Briggs and Breazeale, that
lhming of soils does not increase the potassium content of the drainage
water, or of plant substance. But, it should be noted too, that in other
respects their results are also at variance with ours. For example,
they found that the application of lime to soil (to be sure it was CaO
and not CaCO,) did not increase, and in general, actually depressed
the amount of calcium in the drainage water and hence probably,
though not necessarily, in the soil solution; whereas we have found
the calcium content to be higher and distinctly so in all soil extracts
but one from soils treated with either lime or gypsum regardless of the
soil’s nature. In our opinion, these apparent disagreements are really
only manifestations of the marked differences characterizing the
physical-chemical systems which we eall soils in equilibrium with
water. When we consider soils as such systems, dynamic and not
static in nature, and in addition apply to them the Van Bemmelen
formula for absorption by colloids, it is not difficult to understand the

8 Lyon, T. L., and Bizzell, J. A., Calcium, magnesium, potassium and sodium

in the drainage water and from limed and unlimed soils, Jour. Amer. Soc. Agron.,
WoL, &;p. 81, 1916.

280 University of California Publications in Agricultural Sciences | Vol, 3

discrepancies in the reactions between different soils and CaCO, or
CaSO,, which we have been studying. While thus we are in apparent
disagreement with the principle of the indirect results of Lyon and
Bizzell regarding the effect of lime on the calcium content of the soil
solution, we are not actually so. On the other hand, we are in actual
agreement with them as regards the effect of calcium applications on
the magnesium content of the soil solution. In all soils studied by us,
we find increases of magnesium in the soil solution, due to CaCO,
applications, but this does not imply that the same would hold for
all other soils. Again, we are in agreement with the indirect results
of Lyon and Bizzell regarding the sulphur content of the soil solution
as affected by lime applications in the case of the greenhouse soil, but
not in the case of the clay adobe soil, and probably not in the case
of the blow sand.

If we may repeat, therefore, we are apparently forced to conclude,
from the results of our experiments and from such comparisons of
them with those of others as we can make, that no general idea of the
effect of CaCO, or of CaSO, on the potassium content of any other ion
in the soil solution can be adduced from any one soil or from any one
general kind of soil. In some soils, large accretions of soluble potas-
sium to the solution may be obtained by CaCO, or by CaSO, applica-
tions; in others no increases may be obtained. This may hold for any
ion, but does not preclude the probability that some ions may be
rendered soluble in larger amounts by CaCO, in any soil. Whether
or not the ions which are rendered soluble in greater amounts by the
application to the soil of CaCO, or CaSO,, or both, are also available in
such larger amount to the plant roots is another question, an affirmative
answer to which does not necessarily follow from such an answer to the
question which we are discussing here. It is to be noted from our
results, also, that the time of the year at which ions are sought in the
soil solution, or at least the period elapsing between the application
of CaCO, or of CaSO, to the soil and the sampling of the latter, are
important factors in determining the results of one’s findings and
cannot be overlooked in any such investigations.

In anticipation of queries which may arise from readers of the fore-
going discussion, we desire to make very clear and emphatic the follow-
ing general statement. We do not believe that all of the data given
by us in the tables are significant, because we appreciate the large
error which probably attaches to our method of obtaining the soil
extract and of analyzing it. Our calculations are such, therefore, as

1918 | Lipman-Gericke: CaCOg and CaSO,4 and Soil Solution 281

not to be dependent, in any large degree, upon the significance of any
isolated portion of our data. The table which we hold to be most
significant is table 3 and the two chief conclusions which we desire to
draw from our work are (1), that a soil may be distinctly affected, as
regards the solubility of its constituents through its treatment with
CaCO, or with CaSO,; and (2), that this is not necessarily so, however,
and may hold for one soil and one constituent in one case, and not in
another, depending on the nature of the physical-chemical systems
dealt with and upon the composition of the soil mineral complexes. In
these two conclusions from our experiment, one can find a reconciliation
of the two diametrically opposed views with regard to the effects of
CaCO, and CaSO, on soils and we offer our discussion as a contribu-
tion to such a reconciliation.

SUMMARY

From experiments to determine how CaCO, and CaSO, affect the
water soluble iron, calcium, magnesium, potassium, sulphur, and phos-
phorus in soils as determined by ordinary water extractions, the fol-
lowing outstanding conclusions were drawn:

1. All soils do not behave alike when treated with CaCO, or with
CaSO,. They should not be expected to do so, considering their
mineral composition, the law of chemical equilibrium, and the nature
of colloid action in soils. With this conception as a basis, the con-
flicting statements in our literature on the effect of CaCO, and CaSO,
on the soluble potassium supply in soils may easily be accounted for
and each view may be regarded as correct under certain circumstances.

2. Potassium was found to be rendered more soluble by CaCO, and
by CaSO, applications in clay adobe soil and in a greenhouse soil made
therefrom, but not in a blow sand soil.

3. The soluble calcium content was increased in all soils studied
by CaCO, or CaSO, applications. This does not prove that the same
will hold true for all other soils.

4. The soluble magnesium content of all soils studied was increased
by CaCO, treatment. It seems to have remained unaffected or even
to have been depressed by CaSO, treatment in all but one case in each,
the Oakley and the greenhouse soil with the small gypsum application.

5. The soluble iron content was probably increased in the solution
of the greenhouse soil by the treatment in question. It seems also to

282 University of California Publications in Agricultural Sciences | Vol, 3

have been so increased for a time in the blow sand, but not in the
clay adobe soil.

6. The soluble sulphur content was increased in the solution of the
greenhouse soil by CaCO, applications and probably also in that of
the blow sand, due to similar treatment.

7. The phosphorus content of the solutions of the three soils studied
seems to have remained unaffected by the treatments accorded the
soils. The indications are, however, that a slight depression in the
amount of the water soluble phosphorus may have resulted from the
CaCO, or the CaSO, applications in one case. In this case also no
generalization is attempted.

8. It seems that our current teachings on soils and plant physiology
should be corrected with these results as a basis.

Transmitted June 4, 1918.

UNIVERSITY OF CALIFORNIA PUBLICATIONS
IN

AGRICULTURAL SCIENCES
Vol. 3, No. 11, pp. 283-368, plates 25-42, 9 text figures April 4, 1919

AN INVESTIGATION OF THE ABNORMAL
SHEDDING OF YOUNG FRUITS OF THE
WASHINGTON NAVEL ORANGE*

BY
J. ELIOT COIT anp ROBERT W. HODGSON

INTRODUCTION

The genus Citrus is undoubtedly of tropical origin. Alphonse de
Candolle, after much investigation of historical and philological data,
concludes that the feral range of the sweet orange is South China,
Cochin China, Java, and Sumatra, with a possible extension into India,
which regions are classed ecologically as tropical rain forest. Morpho-
logical evidence of the tropical origin of the orange is abundant, its
tropical mesophytiec nature being indicated by glossy, broad, flat leaves
of rather loose and open cell structure, long life of leaves, absence of
stomatal devices for regulating transpiration, lack of root hairs, and
lack of a regular and non-interruptable period of dormancy. Living-
ston! has recently pointed out that the most efficient climate for plant
growth in the United States is peninsular or tropical Florida. The
significance of this is apparent when we remember that tropical
Florida is the only place in the United States where the orange has
run wild and been able so to maintain itself. In all countries where
the sweet orange has run wild after having been introduced into the
New World, such as Brazil, Paraguay, northern Argentina, and to
some extent in Florida, the climate is distinctly tropical.

Horticulturists have called attention to the fact that an environ-
mental complex which is most efficient as regards plant growth does
not necessarily conduce to the production of fruit of high commercial
value. On the other hand, some climatic factors, such as light and heat,

* Manuscript submitted January 17, 1918.
1 Physiol. Res., vol. 1, April, 1916.

254 University of California Publications in Agricultural Sciences [Vol. 3

which in excessive amounts tend to retard vegetative growth, intensify
certain characteristics of the fruit which greatly enhance its market
value. Thus we find that the Bahia or Washington Navel variety of
Citrus sinensis has comparatively little commercial value at Bahia,
Brazil, where it originated, or in any other tropical country where it
has been tested. In a semitropical desert environment, however, this
variety of orange is high in sugar content, has skin characteristics
which lessen decay in transit, and is possessed of a deep reddish orange
color which increases its salability. For these reasons the cultivation
of oranges under arid and semiarid conditions has developed into an
industry of large importance, in which many millions of dollars are
invested and upon which many thousands of people are dependent for
a livelihood.

When we consider the morphological characteristics of the more or
less xerophytic vegetation indigenous to the region now occupied by
orange orchards in California and note the striking dissimilarity
between the forms of native plants and citrus trees, we may reasonably
suspect that our orange trees may find it more or less difficult to adjust
themselves to the new and strange environment. Perhaps the under-
ground environment provided by soils which, on account of low rainfall
and consequent lack of leaching, still retain a large proportion of the
soluble salts resulting from the decomposition of soil minerals, would
be equally as disordered as the above-ground environment were it not
for the fact that water artificially applied by irrigation lessens the
asperity of the conditions met by the roots. Not only is the total
environmental complex to which our orange trees are exposed incon-
sistent with their natural requirements, but the trees of the Washing-
ton Navel variety are themselves decidedly abnormal. It is the
universal practice to place scions of the desired variety upon rootstocks
of other species of Citrus so that the reciprocal influences between
stock and scion come into full play. Moreover, the variety in question
bears some indications of hybrid origin. The blossoms are entirely
devoid of viable pollen, functional ovules are few, the fruits are
partially double, pecular in structure and seedless, and the vegetative
parts exhibit an erratic polymorphism which has so far proved
decidedly puzzling.

It is a matter of common observation that in the interior desert-like
valleys of the arid southwest the Navel orange is somewhat dwarfed
in stature, the leaves tend to persist to an unusual age, the volume of
bloom is abnormally large, shedding of the flowers and young fruits is

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 285

excessive, and various physiological derangements of nutrition are of
frequent occurrence.

In many interior localities where there are but few pests to hinder
the growth of the tree and where the climatic conditions favor the
production of early maturing fruit of good color and high sugar con-
tent, the excessive shedding of young fruits, or ‘‘June drop,’’ as it is
ealled, is particularly exasperating to growers, who would undoubtedly
make much greater profits if some way could be devised to prevent
that part of the drop which is in excess of the normal and necessary
amount. An investigation of this problem was undertaken by the
writers in response to a resolution passed by the California State Fruit
Growers’ Convention calling the attention of the university authorities
to the urgent need of an investigation of this subject. The results
secured from observations and experiments during the summers of
1916 and 1917 are brought together in his paper.

Most of the field experiments from which our data have been
obtained were carried on at two stations in Kern County; one at
Edison in the orchards of the Edison Land and Water Company, about
eight miles southeast of Bakersfield, and the other about two miles
and a half distant at East Bakersfield in the orchard of Dr. C. W.
Kellogg. Both stations, on account of being situated to leeward of a
considerable stretch of desert typical of the southern San Joaquin
Valley, experience the extreme climatic conditions referred to above.
The Navel orange matures early and is of excellent quality, and were
it not for the light crops borne this district would be considered
excellent for the production of Navel oranges. Under these climatic
conditions, unmodified, the drop occurs every year and is not de-
pendent on the occurrence of dry hot winds, as is the case in southern
California.

At Edison the Navel orange trees appear healthy and vigorous, the
leaves and branches being quite free from fungous parasites and scale
insects. Except for an occasional slight showing of mottled-leaf disease
the trees may be considered very thrifty and of good size for their age,
which is eight years. A general view in this orchard is shown in plate 25.

The soil conditions are good. The type is Delano sandy loam of
good depth. No general layer of hardpan exists. Although certain
bodies of hard conglomerate occur occasionally these are not in layer
formation and do not interfere with the drainage. The soil is rich in
most plant foods, though low in nitrogn, which, according to an
analysis kindly made by Dr. C. B. Lipman, runs from .025 per cent in

286 University of California Publications in Agricultural Sciences |[|Vol.3

the first six inches to .012 per cent at a depth of three feet. He also
reports the nitrifying power of the soil as fairly good and the
ammonifying power as high. The organic matter content is quite low,
much lower, in fact, than one would suppose from the healthy appear-
ance of the trees.

Irrigation water is pumped from wells situated on the tract and the
irrigation practice follows closely that of southern California. Water
is applied in four shallow furrows to each middle about once a month.
This is followed in a few days by shallow cultivation in both direc-
tions. The amount of water applied is sufficient to wet the soil five
feet deep and throughout the whole area except for a small space
between the trees in each tree row. In June the temperature of the
water as used is about 75° F. Hilgard advanced the idea that June
drop might be caused by low temperature of the irrigation water.
While it is entirely possible that cold water may influence drop, we
have found the drop to occur regularly where the water was not cold.

TABLE 1

MOISTURE DETERMINATIONS IN EpDISON SoIL
Furrows run north and south

Location of sample Per cent moisture based on
with reference water-free soil
to tree Depth Before irrigating After irrigating
North side 6 in. 5.70 6.38
North side 20 in. 5.04 6.95
East side 6 in. 6.72 12.61
East side 20 in. 7.99 10.25
South side 6 in. 5.70 6.04
South side 20 in. 7.87 7.29
West side 6 in. 7.52 11.48
West side 20 in. 7.06 11.60

A practical horticulturist after examining the trees and digging into
the soil would hardly conclude that the trees were suffering for water.
Moreover, Fortier states? that in sandy loam soils 6 per cent by weight
of free water is sufficient to keep citrus trees in a vigorous condition.
In the Riverside-Redlands districts the average moisture content of
the soils in citrus orchards runs from 4 to 9 per cent, depending on the
soil type. In spite of this it is possible, of course, that the average
moisture content of the Edison soil is below the optimum.

The management of the orchard consists of clean shallow cultivation
throughout the year with a fairly deep plowing in March. No cover
erops have as yet been grown. Light applications of manure and com-

2 Irrigation of Orchards, U. S. Dept. Agr. Farmers’ Bull. no. 404 (1910) p. 24.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 287

mercial fertilizers are given. The roots of the trees fully occupy all
of the middle spaces, and appear exceptionally healthy and vigorous.
A large number of healthy roots were taken from a hole dug at the
center of a square formed by four trees. The vertical distribution of
roots is good. <A hole two feet square was dug to the southwest of a
tree well beyond the spread of the branches. Each six-inch soil layer
was kept separate and the roots sifted out. On account of the dryness
of the air comparative weights were not made, but the root distribution
between the second and sixth six-inch layer is well shown in plate 42.

The general health and appearance of the trees at the Kellogg orchard
is in every way similar to that at Edison. The orchard is one year
younger than the plot used in the experimental work at Edison, but
there is no appreciable difference in the size of the trees, unless it be
in favor of the trees at the Kellogg place, which is to be explained
as due to the method of handling the orchard.

Soil conditions are fairly similar, except that the surface soil at
Edison is considerably heavier and more compact than at East Bakers-
field, where the soil would be classified as a medium sand. However,
it becomes heavier as one goes down until, at a depth of two feet, there
is no noticeable difference in the soil at the two stations. We are not
able to present analyses of this soil as to plant food, but there is no
reason to believe that it differs markedly from that at Edison.

A radical difference, however, is manifest in the management of
the two orchards. The main part of the Kellogg orchard is planted
to alfalfa (pl. 26), and the portions in which our experimental work
was done have had alfalfa grown between the trees for three or four
years. Before planting the alfalfa the orchard was carefully and
effectively laid out in small checks draining one into the other. The
trees are protected from having water standing about their trunks by
ridges thrown up just under the drip of the trees. These checks as
well as the ridges are occupied by a good stand of alfalfa, which is
eut for hay and hauled off. Irrigation water is pumped from wells
and is applied in copious amounts, the period between irrigations
averaging about three weeks, or a week to ten days shorter than that
at Edison. There can hardly be any doubt but that considerably more
water is applied to these trees than at Edison. Applications of com-
mercial fertilizers have been made to the orchard from time to time.
No detailed study of the root distribution was made but a few holes
dug for other purposes seemed to indicate that the roots tend to go
down or away from the surface in this orchard rather than to be
localized in the upper soil layers.

288 University of California Publications in Agricultural Sciences [Vol.3

Another distinctive feature of the Kellogg orchard is that it is
protected on three sides by a fairly efficient windbreak. On the north,
from which direction the prevailing winds blow, this consists of a
double row of pepper trees (Schinus molle), and a single row of
poplars. On the other two protected sides, the east and the west, there
are rows of eucalyptus.

THe NATURE OF JUNE Drop

A cursory investigation of the problem at once established the fact
that the young oranges are shed while still alive and actively function-
ing and as such the shedding constitutes true abscission. It is of
course quite a different process from exfoliation, which involves the
formation and activity of a phellogen. Before proceeding to a dis-
cussion of the process of abscission as determined by us, it may be
well to discuss the amount of bloom, time of abscission, reaction time,
and other important features.

Navel orange trees growing under the conditions studied always
bloom very heavily (pls. 27, 28, and 29). The blossoms are borne on
shoots of the current season’s growth, being preceded and accompanied
by new leaves. The old leaves do not fall until anthesis is well under
way or completed. It is evident, therefore, that during anthesis the
trees are under a heavy drain, Inasmuch as they are called upon to
support a heavy bloom in addition to both the new and old erops of
leaves. Shedding of the unopened flower buds occurs to a small extent
only. The opened flowers exhibit a certain amount of dimorphism.
Those capable of setting fruit possess large, fully formed ovaries, with
plump styles and stigmas. In many of the flowers, however, the
pistils show a varying degree of degeneration and shedding of the
flowers is largely confined to such individuals, beginning with the least
robust and grading off during petal fall and including many of the
most robust after petal fall. The period of maximum shedding takes
place when the young fruits are from one-half to two centimeters in
diameter. At first the point of abscission is always at the base of the
pedicel (pl. 30), but after the diameter of the fruit has reached one
centimeter or thereabouts it is usually at the base of the ovary. It is
interesting to note that where the larger fruits absciss at the base of
the ovary, abscission usually occurs also in the cortex at the base of
the pedicel; but on account of the formation of strengthening tissue
the process is not completed through the vascular elements and although
the pedicel dies, it remains very firmly attached to the twig. This is
shown in plate 31. It often happens that a certain amount of strength-

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 289

ening tissue at the base of the ovary may prevent the fall of the fruit.
These dead, dry fruits, as shown in plate 31, are often quite conspicuous
on the trees. Soon after the application of the stimulus, but several
days before actual separation, the larger fruits assume a characteristic
appearance, losing their luster and taking on a lighter green color. In
the case of exposed fruits the yellow color is deeper around the apex, but
this is not the case with shaded fruits. It is thus a simple matter to
select any number of fruits which are destined to absciss several days
before separation actually occurs.

Experiments carried on in the laboratory and observations made in
the field, both in a survey of the citrus districts of southern California
immediately following the heat wave of June 15-17, 1917, and at
Bakersfield during 1916 and 1917, have shown that the time inter-
vening between the application of the stimulus and actual separation
is from four to ten days. The shorter periods were obtained in the
laboratory, where the room temperature was uniformly high. Our
observations are that under field conditions abscission is ordinarily
complete within five to eight days after the application of the stimulus.

Normally, orange blossoms, being borne in cymes, open in succession,
beginning about March 20 in the San Joaquin Valley and continuing
about one month. Abscission varies with the season but usually it is
in evidence from April 1 to about July 1, a period of three months.
The period of maximum shedding occurs during the latter half of
April. It should be noted that the season of 1917 was unique in being
the latest on record. Protracted cool weather delayed the bloom fully
five weeks, with a consequent delay of the period of maximum shedding.
A comparison of the mean maximum atmospheric temperatures for the
years 1914-17 inclusive is shown in table 2. The comparative lateness
of the 1917 season is apparent from a study of this table.

TABLE 2

MontTHLY MEAN MAXIMUM TEMPERATURES FOR TEN MONTHS AT BAKERSFIELD
Compiled from U. S. Weather Bureau Records

1914 1915 1916 1917
January 61.2 60.3 57.8 59.3
February 67.9 65.2 69.9 68.2
March 75.8 71.8, 8 = 5
April 78.5 75.3 81.6 74.7
May 86.6 77.5 81.1 77.4
June 94.7 92.8 93.0 95.6
July 100.2 98.8 99.0 104.4
August 101.9 101.5 95.2 100.5
September 88.0 91.9 93.2 94.3

October 82.9 87.8 76.1 88.5

290 University of California Publications in Agricultural Sciences [Vol.3

Turning now to a more detailed account of the abscission process
itself we find that this subject has received considerable study and
investigation. The nature of the abscission process has been studied
and described in detail by Hannig* and Lloyd* for Mirabilis; Balls®
and Lloyd® for Gossypium; Loewi' for Ampelopsis; Kubart® for
Syringa and Nicotiana; Kendall® for Nicotiana; Tison’® and Lee™ for
many other plants, to mention only a few of the researches in this
interesting field. While the histology of abscission in Citrus has been
described in detail elsewhere’? by the junior author, it is appropriate
that a brief sketch be included here.

As previously indicated, there are two entirely distinct abscission
zones. One is at the base of the pedicel and the other at the base of
the ovary. In each case the zone may be considered to be situated at
the base of an internode where, on account of the power of forming
adventitious buds, it may reasonably be suspected that the tissue
retains, to a degree at least, its meristematic nature. The zones con-
sist of ten to eighteen layers of cells which in young tissue differ his-
tologically very little, if any, from adjacent tissues. In older material
differences involving shape, size, and content appear. That in the case
of young tissue differences of some kind do exist is shown by the fact
that after the stimulus has been applied, yet ten to fifteen hours before
visible indications appear, the walls of abscission cells are differentiated
by a marked inability to hold certain stains, such as methylen blue.
From six to eight hours before abscission the walls of the abscission
cells are refractive to a different degree.

The first indication of actual abscission is a marked swelling and
and gelatinization of the walls, which may amount to as much as 200

3 Untersuchungen tiber das Abstossen von Bliiten, Zeitschr. f. Bot., vol. 5
(1913), p. 417.

4 Abscission in Mirabilis Jalapa, Bot. Gaz., vol 61 (1916), pp. 213-80, pl. 13.

5 The Cotton Plant in Egypt (London, Macmillan, 1912), p. 69.

6 The Abscission of Flower-buds and Fruits in Gossypium, and its Relation to
Environmental Changes, Trans. Roy. Soc. Canada, ser. 3, vol. 10 (1916), pp. 55-61.

7 Blittablésung und verwandte Erscheinungen, Vienna Acad. Proe., vol. 1
(1907), pp. 166-983; S-B. d. math.-nat. Kl. d. k. Akad. Wiss., Wien, vol. 116,
abt. 1 (1907), pp. 983-1024.

8 Die organische Ablésung der Korollen nebst Bemerkungen iiber die mohlsche
Trennungschicht, [bid., vol. 115 (1906), p. 1491.

9 Abscission of Flowers and Fruits in the Solonaceae with special reference
to Nicotiana, Univ. Calif. Publ. Bot., vol. 5 (1918), pp. 347-428.

10 Recherches sur la chute des feuilles chez les Dicotylédones, Mém. Soe. Linn.
Normandie, vol. 20 (1900), p. 125.

11 The Morphology of Leaf Fall, Ann. Bot., vol. 25 (1911), pp. 51-106.

12 An Account of the Mode of Foliar Abscission in Citrus, Univ. Calif. Publ.
Bot., vol. 6 (1918), pp. 417-28.

7
}
¢
J
;

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 291

to 3800 per cent. This is followed by dissolution of the gelatinous
walls, thus freeing the cells which are now surrounded merely by the
very thin and delicate tertiary membrane. No elongation of the
tertiary membrane has been observed. Neither has any cell division
prior to separation been seen to oceur, although immediately following
separation this often takes place. So far as ascertained, therefore,
abscission in the orange conforms to the usual type, e.g., schizolysis™
representing dissolution of the middle lamellae of the abscission zone
cells by hydrolysis with subsequent separation.

STIMULI LEADING TO ABSCISSION

The direct cause of abscission in plants in general is considered to
be some stimulus which may be brought into play in a variety of ways,
depending somewhat on the nature of the plant involved. Lloyd’* has
taken pains to enumerate some of the different kinds of stimuli which
according to various writers have been found to cause abscission. It
is our purpose to consider these in turn as a possible cause of abscission
in the Navel orange and possibly by elimination to arrive at the true
cause or causes involved.

MECHANICAL SHOCK OR TRAUMATIC STIMULI

Fitting has shown that jarring or shaking the flower stalks of
Verbascum sp. and Geranium pyrenaicum will result in abscission
within a few minutes. We were unable to produce like results with
Citrus by this method. Moreover, abscission has been observed to
occur regularly under conditions which would preclude the possibility
of this cause being operative with oranges.

An effort was made to cause abscission by cutting and bruising the
young fruits in various ways. The result was a failure in every case.
Excission of the style and petals either separately or together, either
before or during anthesis, failed to produce abscission. Many of the
fruits from which the style had been removed developed to maturity
in a normal way. Others abscissed but the reaction time varied so
widely as to make it very improbable that the removal of the style
was the stimulus involved.

"18 Correns, Vermehrung der Laubmoose, Jena, 1899. (Cited from Lloyd.)

14 Abscission, Ottawa Naturalist, vol. 28 (1914), pp. 41-52, 61-75.

15 Untersuchungen iiber die vorzeitige Entblitterung von Bliiten, Jahrb., f.
Wiss. Bot., vol. 49 (1911), p. 187.

292 University of California Publications in Agricultural Sciences {Vol 3

In many plants insect injuries have been shown to be the cause of
abscission, ‘lhe case of the cotton boll weevil is perhaps the best known
example, though it is likely that young fruits of the plum and apple
react to injuries due to the curculio’® and codling moth" in much the
same way. In view of these observations it is interesting to find that
oranges are a marked exception to the rule, the young fruits being
particularly resistant to the effects of insect wounds.'* In the San
Joaquin Valley there are two insects at least which cause serious injury
to the fruit. The work of Scirtothrips citri results in an extensive
though superficial scarring of the fruit, yet the fruit develops to
maturity. The nymphs of the fork-tailed katydid, Scudderia furcata,
eat holes in the young fruits (see pl. 32), the holes sometimes extend-
ing entirely through the orange. This insect produces traumatic
stimuli of the first magnitude, yet they de not result in abscission.
Large numbers of the chewed, deeply scarred and distorted fruits
develop to maturity only to be discarded by the pickers at harvest time.

Mechanical shock produced by transplanting trees or the root
pruning incident to heavy spring plowing, such as is necessary to turn
under a rank-growing cover crop, is usually followed by more or less
dropping of the leaves and fruit. It is believed, however, that this
may be accounted for by the disturbance of the water relations which
follows root pruning rather than by the mechanical shock alone.
Balls,’ by root pruning cotton plants in Egypt, was able to cause
abscission of the bolls, which he explained on the ground of water
relations rather than shock. This particular phase of the problem will
be again referred to later.

AtR TEMPERATURES AND LIGHT CHANGES

Abnormally high air temperatures or sudden changes in the tem-
perature are by some investigators considered the cause of abscission
in certain cases. It is evident that the question of the influence of air
temperature is so involved with other important questions, such as the
influence of humidity, air movement, transpiring power and the like,
that it is inadvisable to assign specific influences to this factor alone.
The same is true of changes in lhght intensity. Suffice it to say, how-

16 The Plum Curculio, U. S. Dept. Agr. Bur. Ent., Cire. 73 (1906), p. 4.

17 The Codling Moth, ibid., Yearbook (1887), p. 90.

18 True in California, though Hubbard mentions the punctures of two insects,
Dysdercus suturellus and Leptoglossus phyllopus, as causing the dropping of
mature oranges in Florida. Hubbard, H. S., Insects Affecting the Orange, U. S.
Dept. Agr., Div. Ent. (1885), pp. 167-69.

19 Loe. cit., p. 68.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 293

ever, that while a sudden rise in temperature may be and often is
accompanied by increased shedding rates, it has been observed by the
writers that profuse shedding of the young Navel oranges takes place
during periods when no sudden changes or abnormally high tempera-
tures occur. It has also been noted that abscission of the interior
and well shaded fruits takes place simultaneously with that of fully
exposed fruits. It is altogether unlikely, therefore, that the June drop
ean be explained on these grounds alone. The relation between
abscission and tissue temperatures as affected by water deficits will
be discussed in another place.

Many investigators have noted the marked effect of increase in air
temperatures on the time involved in the separation process, and we
have noted the same phenomenon. The effect of course, as would be
expected, is an acceleration conditioned by the magnitude of the tem-
perature change. It appears therefore to the writers that abscission
following sudden increases in temperature, as noted by several investi-
gators, may be easily explained on the ground that the stimulus to
abscission had been activated at some time prior to the sudden change
in temperature, and the acceleration of the abscission process, produc-
ing marked results in a comparatively short period, has led them to
believe that the change in temperature is the causative stimulus.

LACK OF POLLINATION AND FERTILIZATION

While there is a general rule that pollination and fertilization is
essential to the setting and development of fruits, the rule is con-
spicuous for its exceptions. A number of our commercially important
fruits, such as bananas, Sultanina grapes, Japanese persimmons, and
Navel oranges, are distinctly parthenocarpic and do not require the
stimulus of pollination to insure the setting of fruits which are usually
seedless. The Navel orange does not produce viable pollen, and pollen
from other varieties will only occasionally accomplish fertilization for
the reason that nearly all of the embryo saes disintegrate instead of
developing into normal ovules capable of being fertilized.*° Occasion-
ally a few normal embryo sacs may be produced and seeds result pro-
vided the particular fruits having the normal embryo-sacs happen to
be pollinated with viable pollen from congenial varieties. It is the
remoteness of the chance of this occurring under ordinary field con-
ditions that accounts for the comparative seedlessness of these fruits.
Apparently there is nothing in the structure of the blossom of the

20 Ikeda, T., On the Parthenocarpy of Citrus Fruits, Jour. Sci. Agr. Soe. Tokyo,
vol. 63 (1904).

294 University of California Publications in Agricultural Sciences [Vol.3

Navel orange which would interfere with the germination of pollen or
the normal extension of the pollen tube. The exclusion of pollen by
the bagging method has shown that in setting fruit the Navel orange
is entirely independent of pollen. This experimental evidence is borne
out by the practical experience of growers who secure as abundant
crops from large isolated plantings of Navels as from mixed plantings.
It is therefore entirely safe to conclude that lack of pollination and
fertilization of the Navel orange does not result in the stimulus leading
to abscission.

RELATIVE POSITION ON STEM

There is some variation in the relation borne by orange fruits to
the main stipporting axis. As it has been suggested that with some
other plants this relation largely determines whether a given fruit
will be able to persist, it was thought worth while to investigate the
importance of this point in connection with oranges. A large number
of fruits were examined and divided into two classes: those which
terminated the axis, and those which did not. These two classes are
well illustrated in plate 33. It seems reasonable to suppose that in the
ease of the non-terminals, an organ of limited secondary thickening
(the pedicel) being in competition with one of unlimited secondary
thickening (the main axis) might suffer from an increasing prejudice
to its water supply. It was found by counts of large numbers of
fruits that the ratio of terminals to non-terminals was 5 to 6. The
new current season’s growth which bore terminal fruits averaged 3.8
leaves per shoot, while the non-terminals averaged 3.95 leaves per
shoot. In the latter case 1.85 leaves were below and 2.1 leaves above
the fruits. Counts of fruits which had successfully survived the
abscission period showed on one tree 16 terminals to 31 non-terminals,
but on another tree 25 terminals to 14 non-terminals. Counts of
dropped fruits also failed to support the above supposition, and it is
evident from our examination of large numbers of specimens that
abscission in this case is quite independent of such differences in the
relation of fruit to axis as is shown in plate 33.

THE GAs Factor

It has long been recognized that the subjection of certain plants to
an atmosphere containing traces of various narcotic or poisonous gases
is sufficient to cause abscission of leaves and other plant parts. One
of the first indications of smelter fume injury is the shedding of the
leaves of certain plants due to the presence of sulfur dioxide, which is

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 295

a combustion product in the reduction of sulfur-containing ores. G.
J. Pierce*! has shown that when SO, is present in as small quantities
as three to five parts per million abscission of the leaves of certain
forest plants occurs. Several investigators have reported abscission
of flowers and leaves of various plants when subjected to minute traces
of illuminating gas, ether, chloroform, ethylene, and other poisonous
gases. Further, two investigators have reported** ** abscission of the
leaves of citrus plants when subjected to an atmosphere containing
traces of illuminating gas. We have obtained similar results with
potted plants. Within four days after subjection to illuminating gas
all the leaves were shed.

The exhaustive work of L. I. Knight and W. Crocker** *° on the
effects of illuminating gas and smoke upon plants has shown rather
conclusively that the response is largely if not entirely due to the
toxicity of the ethylene present. It has been shown by E. M. Harvey”®
that as minute traces as one part per million are sufficient to cause
marked reactions on the part of the plant.

Preliminary experiments carried out in our laboratories with
excised citrus shoots subjected to various gases, including illuminating
gas, have indicated that under such conditions abscission is not appre-
ciably accelerated by any of the gases. The time at which shedding of
the leaves took place was approximately the same in ordinary room
atmosphere as in varying concentrations of illuminating gas.

Peirce?’ has shown that one of the effects of smelter fumes is to
cause excessive transpiration from certain plant parts prior to their
abscission. This is accounted for by the decomposition of the
chlorophyll in the guard cells of the stomata, resulting in decreased
stomatal regulation of transpiration. As will be pointed out later,
several investigators have concluded that abnormal water loss during
a part of the day, resulting in considerable fluctuations in the leaf

211. A Report of an Investigation econduteed for U.S. Department of Justice,

1913, unpublished manuscripts in the hands of U.S. Attorney General. 2. Report
of Selby Commission, to U.S. Bureau of Mines, 1913.

22 In Citrus limonia. Shonnard, F., The Effect of Illuminating Gas on Trees,
Yonkers, N. Y., Dept. Pub. Works (1903), p. 48.

23 In Citrus decumana. Doubt, Sarah S., The Response of Plants to Iluminat-
ing Gas, Bot. Gaz., vol. 63 (1917), pp. 207- "94,

24'The Effect of Tlluminating Gas and Ethylene upon Wioweriag Carnations,
Bot. Gaz., vol. 46 (1908), pp. 259-76.

25 Toxicity of Smoke, ibid., vol. 55 (1913), pp. 337-69.
26 Some Effects of Ethylene on Metabolism of Plants, ibid., vol. 60 (1915),
pp. 193-214.

27 Expert testimony incorporated in Records of Federal Court, District of
Utah, Salt Lake City.

296 University of California Publications in Agricultural Sciences | Vol. 3

water content, is sufficient in certain plants to cause abscission. In
the hight of these observations abscission of plant parts when exposed
to smelter fumes is explainable purely on the basis of abnormal water
relations.

In an effort to ascertain whether in the case of illuminating gas any
such relation holds true, we have made a careful study of the stomata
of citrus leaves and have to report that at an early period in the life
of the leaf they lose their power of functioning and remain practically
closed thereafter. This is significant in view of our findings mentioned
above, namely, that illuminating gas is not a direct stimulus to
abscission in Citrus, at least with excised shoots. In the case of potted
plants it seems probable that it works in an indirect manner through
disturbances in the physiological balance. In connection with the
question of the effect of illuminating gas upon the chlorophyll of the
cuard cells, it should be mentioned that H. M. Richards and D. T.
MaeDougal** have reported that chlorphyll formation is greatly
retarded when the plant is subjected to an atmosphere containing
traces of this gas.

The fumigation of citrus trees with hydrocyanie acid gas for the
control of scale insects is practiced quite generally and with marked
success in California. It is the general experience that under certain
conditions heavy dosages of this gas result in abscission of the older
leaves.?? Researches by Osterhout*®® and Moore and Willaman*' have
shown that when subjected to traces of this gas the permeability of
eytoplasmie septa is markedly altered, causing an increased loss of
water. In the light of these observations it is entirely possible to
explain dropping of citrus leaves due to fumigation on a purely water
relation basis.

Fumigation injury to the blossoms or fruit, whether large or very
small, consists of pitting and burning which results in sears on the
fruit. Apparently in no ease does fumigation of young Navel oranges
with hydroeyanie acid gas furnish a stimulus to abscission.

The whole subject of the effect of gases in causing abscission of
plant parts is in a very unsatisfactory state at the present time. In
view of the mass of conflicting data, as well as the fact that abscission

28 The Influence of Carbon Monoxide and other Gases upon Plants, Bull. Torr.
Bot. Club, vol. 31 (1904), pp. 57-66.
29 Woodworth, C. W., and others, School of Fumigation, Pomona, California,

pp. 162-64, August, 1915.

30 Similarity in the Effects of Potassium Cyanide and of Ether, Bot. Gaz.,
vol. 63 (1917), pp. 77-80.

81 Studies in Greenhouse Fumigation with Hydrocyanie Acid: Physiological
Effects on the Plant, Jour. Agr. Res., vol. 11 (1917), pp. 319-38.

|
|
.
|
|

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 297

of young Navel oranges occurs throughout the great interior valleys
of California and in districts very remote from any possible source of
noxious vapors, there is little possibility that the gas factor can be

operative in the case under consideration.

FUNGI AND BACTERIA AS A CAUSE OF ABSCISSION

Although the belief is commonly held by plant pathologists that
fungus parasites sometimes cause the shedding of plant parts, the
literature on this phase of abscission is very meager. Inoculations
with Bacterium citrarefaciens, the organism causing Citrus Blast,
carried on in our greenhouses have shown that when the organism is
inoculated into the tip of the young leaf the latter is shed within:a
few days. Rolfs has reported that shedding of mature oranges fre-
quently oeceurs in Florida, due to the common wither tip fungus,
Colletotrichum gleosporioides. However, we are concerned here with
the shedding of immature fruits and it is by no means clear that the
process resulting in shedding is the same in both eases.

For many years growers of Washington Navel oranges have ex-
perienced losses from a black rot disease of the fruit which manifests
itself as a stimulation of the fruit, causing it to grow to an extra large
size, ripen early and assume a deep red color, with a certain amount of
dropping. This disease was first noted by N. B. Pierce**? in 1892 and
was first described by him in 1902** as ‘‘Black Rot of the Navel
Orange’’ caused by the fungus Alternaria citri.

The fruit is infected when quite small, probably just before or
soon after the style is shed, through the cracks and imperfections in
the proliferations of the navel (pl. 34). The fungus is a weak parasite
and remains quiescent, or nearly so, during the growing period of the
young fruit, at which time the fruit is more or less resistant to the en-
croachments of parasites. With the decline in vigor incident to approach-
ing maturity the fungus becomes more active and exerts a stimulating
influence on the fruit, causing it to take on a deep reddish-yellow color
and to ripen earlier than the normal fruit. In a small and restricted
area the cells of the pulp are broken down and become a nauseating
mass of black fungus mycelia and spores. The rind is left uninjured
until the disease has made considerable progress within, but ultimately
a black and decayed spot appears on the surface near the navel end.
A certain proportion of the infected fruits early shows a yellow spot

32 U.S. Dept. Agr. Yearbook (1892), p. 239.
33 Bot. Gaz., vol. 33 (1902), pp. 234-35.

298 University of California Publications in Agricultural Sciences [Vol.3

about the navel end and drops from the tree when about one to two
inches in diameter, or even larger. The remainder persist to maturity,
the disease coming into evidence at picking time, in transit, in storage,
or not until in the hands of the consumer.

Early in 1916 our attention was directed to the fact that on dissee-
tion a relatively large number of the shed fruits and fruits about to
drop were found to have a discolored area under the navel end. In
many cases a dark colored, gummy mass was present, although in others
the tissue immediately under the navel was only slightly discolored
(pl. 35). In some fruits there was no evidence of any such spot or
area. <A few of the dropped fruits were sterilized in mercuric chloride
(1-1000) and placed in small moist chambers. To our surprise these
cultures showed practically 100 per cent infection with an Alternaria.
Other cultures were made with the same results. Therefore we con-
cluded that it was well within the realm of possibility that the June
drop was due to the same fungus causing black rot and decided to
investigate the matter more -thoroughly.

The fruits had reached a size of one or two centimeters and the
blooming period was entirely over, precluding any investigation as to
the source and manner of infection in 1916. Therefore our efforts in this
direction during 1916 were confined to attempts to determine, if pos-
sible, the extent of the infection. Cultures of many hundreds of
shed fruits, and fruits about to fall, from many districts of the state
were made both by the method above described and by inserting a
piece of tissue from the discolored area into slanted tubes of Shear’s
corn meal agar. The cultures uniformly showed a high percentage of
infection with Alternaria. A few cultures were then made using
healthy green fruits picked from the trees. The percentage of infec-
tion was small. Still later in the season dropped fruits from four to
five centimeters in diameter (pl. 35) were collected from districts as
far apart as Oroville in the Sacramento Valley and El Cajon near
San Diego. Cultures made from these fruits showed practically 100

per cent infection.

| Although the number of cultures made was too small to justify
a broad generalization, the work done in 1916 was sufficiently
productive to form the basis for a working hypothesis which was
advaneed as a theory to account for the June drop of Washington
Navel oranges. Other experimental work under way had indicated
the presence of certain abnormal water relations between the young
fruits and the leaves immediately behind them, which phenomenon

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 299

will be discussed more fully in a later section. Briefly, the theory
advanced was that excessive transpiration from the leaves caused
water together with enzymatic solutions secreted by the fungus in the
navel end to be drawn back through the vascular system of the young
fruits through the pedicel and thus provide the stimulus to abscission.**

That there is no mechanical difficulty involved in this theory was
borne out when by means of dyestuff solutions it was demonstrated
that the vascular system running to the navel or secondary orange
traverses the central pith or core of the primary fruit, which thus
serves as receptacle and stem to the smaller fruit (fig. 1).

Fig. 1. Structure of the Navel orange. The central pith containing fibro-
vascular bundles acts as the stem of secondary fruit.

Further evidence tending to support this theory lies in the fact
that black rot is much more prevalent in the interior valleys than in
the coast regions. In fact, there seems to be a certain correlation
between the amount of black rot and the amount of drop. The reason
for the greater prevalence of black rot in the hotter, more arid districts
was not uncovered until later; this will be brought out in another
section.

Alternaria citri, Ellis and Pierce

During the winter of 1916 a careful study of. the alternarias
obtained in our cultures was made and disclosed the fact that although
there were several strains of Alternaria obtained, one particular type
rather easily recognizable after a little practice, was by far the most

84 Coit, J. Eliot, and Hodgson, R. W., The Cause of June Drop of Washington
Navel Oranges, Univ. Calif. Jour. Agr., vol. 4 (1916), p. 10.

300 University of California Publications in Agricultural Sciences [Vol.3

common. In addition we obtained one strain possessing the ascigerous
stage, which of course classified it in the genus Pleospora. Several
Macrosporium strains were also isolated.

Considerable effort was made to identify the Alternaria strain
so commonly found, but we have been unable to satisfy ourselves
thoroughly in this regard. While the literature is indeed voluminous,
there is apparently no reliable monograph of the genus. Recently,
however, there has appeared a critical study of the taxonomic char-
acters of the genus.*° The genus Alternaria is one of the most uni-
versally distributed of the common forms of the Fungi Imperfectt.
It embraces about fifty species, although it has been shown by Elhott
that a large number of the species of the closely related genus Macro-
sporium really belongs to the genus Alternaria. Among these species we
find active parasites as A. solani (E. and M.) J. and G., weak or facul-
tative parasites as A. citrt Ellis and Pierce, and saprophytes as A.
tenuis Nees. Certain species have already been secured in the perfect
or ascigerous stage which has always proved to be Pleospora. Since
the strain under consideration was uniformly obtained from oranges in
a district where black rot is common it is probably the same form found
by Pierce and ealled Alternaria citri. We were unable to find the
original description by him, which does not seem to have been pub-
lished. However, after examining the literature and drawings of
Alternaria citri, particularly as given by Rudolph,** we feel reasonably
sure that we are dealing with Alternaria citri E. and P. and throughout
the remainder of the discussion we shall proceed on that assumption.

The spores of Alternaria citri are borne in long chains (pl. 36),
which readily break up, allowing the spores to float away in the air.
It seemed important to determine whether the infection of oranges was
accomplished by spores borne by the air or those carried by honey-
bees and other insects. The following methods were employed. Petri
dishes containing Shear’s corn meal agar were exposed for five minutes
in different localities. After a few days had elapsed in order to allow
the various bacteria, molds and other fungi to assume colony form
and the Alternaria, if present, to produce spores, the dishes being
inverted were placed under the low power of the microscope and the
colonies of Alternaria easily distinguished and counted. On account
of the length of the spore chains and certain other morphological

85 Elliott, J. A., Taxonomic Characters of the Genera Alternaria and Macro-
sporum, Am. Jour. Bot., vol. 4 (1917), pp. 439-76.

36 A New Leaf-Spot Disease of Cherries, Phytopathology, vol. 7 (1917), pp.
188-97.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 301

characters which became familiar with practice, it was easy to dis-
tinguish between various other species of Allernaria which were
occasionally met with.

The specialized cells lining the stylar canal of orange flowers secrete
a pure white sugary mucilage which is exuded upon the stigma in a
rather large drop. This material is an excellent medium for the growth
and sporulation of Alternaria, as was determined by trial, the fungus
fruiting heavily in a short time on smears kept in a moist chamber.
In order to determine the amount of infection of blossoms in the
orchard, the stigmas were clipped with sterile scissors on agar plates
and the resulting growths examined a few days later for the charac-
teristic spore chains. The data secured in this way are presented in
tables 3 and 4. In the interior valleys 89 per cent of the stigmas were
infected and in coast localities 76 per cent. It is found that the air
generally throughout the state carries Alternaria spores in abundance.
In interior localities Alternaria spores were taken in 78 per cent of
exposures with ten centimeter agar plates; in some places near the coast
in 63 per cent. It was also shown that while bees may and do carry
spores from one blossom to another the number of spores in the air is
sufficient to cause widespread infection without the aid of bees.

TABLE 3
NUTRIENT AGAR PLATES EXPOSED TO THE AIR, 1917

Alternaria Alternaria

Locality Date present not present
Whittier May 3 18 3
Highland May 6 10 0
Edison (under tent) May 3 I 2
Oroville May 14 10 2
Berkeley May 17 0 +
Fresno May 28 2 0
San Leandro June 3 1 4
Fair Oaks June 12 5 0
Edison (orchard) June 22 1 2
Edison (desert) June 22 3 2
Corona June 27 3 0
Whittier June 26 2 1
Riverside June 29 6 3
Berkeley Oct. 25 1 5

In this connection the question naturally arises as to why, if the
infection of the stigmas near the coast is as great as 76 per cent, there
is such a relatively small number of black rot oranges. The reason
apparently lies in the fact that the average configuration of the navels

302 University of California Publications in Agricultural Sciences [Vol.3

is more irregular, jagged and rough (pls. 34 and 37) in the interior
valleys than in the coast districts, where the navel formation is much
more commonly smooth or submerged and closed. This imperfect and
open condition of the navels in the interior valleys, as will be brought
out later, is due to the harsher environmental complex to which the
fruits are subjected during the growing period. Everyone is familiar
with the fact that fruits borne in exposed positions, particularly in
the top of the tree, are very apt to be coarse and rough with large
protruding navels, while the interior fruit is much finer in texture.
The prevalence of Alfernaria spores in the coast districts is certainly
not much less than in the interior valleys, but the amount of infection
is much less because of the smaller number of imperfect navels.

TABLE 4

MISCELLANEOUS CULTURES
Alternaria Alternaria

Locality Date Kind of material present not present
Whittier May 3 Navel blossoms 10 0
Whittier : May 3 Valencia blossoms 2 2
Highland May 6 Navel blossoms 14 0
San José May 25 Blossoms 4 2
Oroville May 14 Olive blossoms 1 0
Oroville May 14 Navel styles 8 0
Oroville May 14 Bees about trees 3 1
Oroville May 14 Lady bird (Vedalia sp.) 1 0
Berkeley May 17 Dead style from greenhouse 0 al
Berkeley May 17 Dead twig from greenhouse 0 1
Fresno May 28 Orange blossoms 5 0
Sacramento May 25 Orange blossoms 5 0
Fair Oaks June 12 Orange blossoms 9 0
Edison Apr. 24 Orange blossoms a! 1
Edison Apr. 25 Bees about trees 3 3
Riverside June 27 Citron styles 2 0
Edison May 2 Navel blossoms + 1
Edison May 2 Valencia blossoms + 0
Edison May 2 Pomelo blossoms 2 0
Edison May 2 Soil from under trees 0 2
Edison May 2 Bees about trees 1 1
Edison May 2 Navel blossoms from tented tree 6 0

As is shown in table 4, Alternaria spores are present on almost all
the styles, both in coast and in interior valley districts. In order to
ascertain whether infection occurred by the fungus growing down
through the style into the navel end, material known to be infected
with Alternaria was put up in paraffine, sectioned, and stained.
Although the fungus was conspicuous on the stigmatic surface no traces
of fungus mycelium could be found in the stylar tissues. This fact,
together with the fact that infection is definitely correlated with the

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 303

configuration of the navel end, renders it reasonably certain that
infection occurs some time after the style has been shed. The spores
are probably blown and find lodgment in ragged open navels where
they are held in the crevices till enfolded and overgrown by the rapidly
developing ovary (pls. 34, 37). Inasmuch as the configuration of the
navel as well as its size and degree of insertion are exceedingly variable,
it is evident that only in a comparatively small and variable number
of cases are the spores or mycelium so situated as to permit germina-
tion or growth. Alternaria citri is a weak parasite and cannot pene-
trate the unbroken skin of an orange. While it is not capable of pro-
ducing any widespread breakdown in the tissues of immature oranges,
it is able, after introduction into the fruit, to bring about a certain
stimulus or irritation which, according to our theory, results in abscis-
sion of a certain proportion of the young fruits. It is certain that as
the fruits grow and approach maturity the abnormal size, premature
ripening, and extra deep color are the direct results of this stimulation.
It is also considered highly probable that a certain proportion of the
splitting or dehiscence of the carpels which is so serious in interior
valleys is connected with the stimulation of these infections.

Referring again to the wide distribution and general prevalence of
Alternaria spores in the air, it is evident that the spores may be trans-
ported in large numbers for great distances. The source of infection
is by no means limited to the vicinity of orchards. The fungus grows
readily as a saphrophyte on dead leaves, weeds, twigs, and other plant
débris and it is entirely possible for spores to be brought in from
forest areas in the mountains many miles away. Spores have been
taken in the desert far from cultivated crops. In the dry air of the
San Joaquin Valley the black rot oranges which fall under the trees
are not immediately decomposed by Penicillia, Fusaria, and other fungi.
They tend to mummify and after the Alternaria spreads through the
interior it comes to the surface, and the spores there formed give these
mummies a black color, as shown in plate 38. These mummies, together
with the large number of abscissed styles from the blossoms, undoubt-
edly furnish a greatly increased supply of spores at the critical time
in the development of the fruit.

A rot of apples occurring in Colorado** has been described as caused
by an undetermined species of Alternaria. Judging from the draw-
ings presented in plate 4 of Longyear’s publication, the fungus is very
similar to if not the same as that with which we are dealing. Moreover,

87 Longyear, B. O., A New Apple Rot, Colorado Agr. Exp. Sta. Bull. 105,
1905,

304 University of California Publications in Agricultural Sciences [Vol.3

there is a marked similarity between the modes of infection. Accord-
ing to Longyear (p. 7):

The reason why certain varieties of the apple are particularly subject to
the blackened seed cavity is found in a structural peculiarity of such varieties.
Thus a longitudinal section through such an apple usually shows a very deep
calyx tube, which, in many cases, extends to or meets the core, or even opens
into it. In such cases the fungus has evidently reached the core through this
passageway by following the wnited styles and the inner wall of the calyx tube.
(Italies ours.)

Only certain varieties of apples, such as the Winesap, Ben Davis and
a few others which have the structural peculiarities above mentioned,
are found to be affected and in this connection Longyear’s remarks on
page 12 are of particular interest to us. :

Some of these varieties are among those which are reported as dropping

their fruit badly in some seasons during June and July, but whether or not the
fungus plays any part in this matter has not been determined.

The experimental work with Alternaria in 1917 for several reasons
gave quite different results from those obtained during the previous
season. As is shown in tables 3 and 4, cultures made from stigmas
early in the season showed a high per cent of Alternaria infection.
However, a very large series of cultures made somewhat later in the
season, from the young fruits one-half to two centimeters in diameter,
to our astonishment showed a very small per cent of infection. Culture
after culture showed no Alternaria at all. Somewhat later, when the
fruits were larger, cultures of the shed fruits showed a higher per cent
of infection, while a few cultures made when the dropped fruits were
four to five centimeters in diameter showed a high per cent of Alter-
naria infection.

Inasmuch as by far the greater part of the drop occurs while the
fruits are one-half to two centimeters in diameter, at which time our
cultures showed comparatively little Alternaria infection, it is evident
that the shedding of this part of the crop can not be attributed to
Alternaria. However, it is to be noted that, as was the case in 1916,
toward the end of the period of shedding the dropped fruits showed
a steady increase in the per cent of infection. Evidently, then, the
shedding may be divided into two parts, the first including small fruits
which may or may not be infected with Alternaria, the second includ-
ing larger fruits which are infected with Alternaria.

Inasmuch as the climatic conditions in the San Joaquin Valley
during the 1917 season were considerably more severe than in 1916

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 305

(fig. 6), and therefore the average configuration of the navels more
ragged and open, to what can we attribute this difference in the amount
of infection with Alternaria? We believe that this difference is easily
explained by a study of the mean maximum temperatures for the two
seasons. In table 2 these are shown for the years 1914-17 inclusive.
For the 1917 season, taking the months of January and February, we
see that they are about average for the last four years. March is four
or five degrees below the average, April still more, and even May is
below the average. June is several degrees above the average for the
last four years and July shows an average mean maximum temperature
of 104.4° F, considerably above the average. In other words, the
early part of the season was cooler than usual and the bloom was
delayed a month or more. Coincident with the end of the blooming
period the weather changed radically and became very hot and dry and
continued so for at least three months. Conditions were unfavorable
for infection by Alternaria; its growth was inhibited although the
spores were present. In fact, the amount of drop due to Alternaria
in 1917 is practically negligible, and this is supported by the fact that
there were very few black rot oranges at Edison at harvest time. On
the other hand, the season of 1916 was noted as a relatively cool,
pleasant summer and as such was favorable for infection by Alternaria,
with the result that there were many black rot oranges.

In this connection the question arises, why are not other citrus
varieties grown in these arid districts subject to infection by Alternaria
with a consequent shedding and loss due to black rot? The answer
apparently lies in two facts: that other varieties are not so susceptible
to shedding, which will be discussed later, nor are they morphologically
adapted to infection by the fungus. Plate 39 shows the apical end of
a small Valencia orange highly magnified and it is evident that there
is no favorable entrance for the fungus spores. Plate 34 shows a
similar view of a Navel orange with very favorable conditions for the
lodgment of fungus spores.

During the course of these investigations a great deal of time and
effort was devoted to attempts to ascertain by inoculation methods
whether the stimulus of Alternaria citri which manifested itself so
clearly in the change of color of the fruit might not also be the cause
of abscission of the young fruits. On account of several peculiar
difficulties inherent in this particular problem we have so far been
unable to secure conclusive results. The three most important of these
difficulties may be mentioned briefly as follows:

306 University of California Publications in Agricultural Sciences [Vol.3

1. Referring again to plate 29, it is apparent that the excessive
number of buds occasions a severe struggle for survival, only a com-
paratively small number being able to acquire water and food sufficient
for development. As it is impossible to determine in advance which
if any of a group of similar buds is destined to remain, it is evident
that if the sterile stigmas of all are inoculated just previous to open-
ing many will eventually fall from other causes. Moreover, the con-
siderable period of time involved and the frequent necessary opening
and closing of the bags in an atmosphere shown to be filled with spores
would introduce an element of serious error. Plate 40 shows one of a
number of trees used futilely in efforts to get results in this way.

2. Orange flowers are dimorphic, as before mentioned, a certain
number being destined to fall because the ovary is not capable of
development. The configuration of the navel is to a certain extent
fortuitous. In some cases the epidermal folds are so adjusted as to
admit infection, in others not. It is obviously out of the question to
examine each fruit frequently and with sufficient minuteness to deter-
mine whether during growth an opening sufficient for the entrance
of the fungus was or was not available.

3. A species of aphis is very common on Malva and other weeds
under the trees. For some reason not at present clear, the insect is
unable to increase to any extent. when feeding on the orange leaves
in the open. However, it was found that whenever a twig was enclosed
in a paper bag or a tree enclosed in a cheesecloth tent (pl. 40) the
aphis multiplied at an astonishing rate. In about half the bags on
the tree shown the twigs were defoliated and killed by the sudden
development of a mass of aphis from young and minute individuals
which were inadvertently included within the bags in spite of all pre-
cautions.

Summing up the relation between Alternaria and that part of the
June drop with which it is always associated, we have to conclude that
inasmuch as the presence of the fungus and its ability to provide a
certain stimulus have been demonstrated, it is not unreasonable to
suppose that abscission may be another manifestation of the same
stimulus both in the case of Navel oranges and in the apple varieties
referred to above. Satisfactory scientific evidence of this point, how-
ever, 1s lacking as yet.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 307

Tue RELATION OF ABSCISSION TO THE ENVIRONMENTAL COMPLEX

It has long been noted that there exists a marked correlation
between climatic conditions and the prevalence and amount of the
June drop. This correlation has been discussed somewhat by the Junior
author in another place®* and has been reflected in the general attitude
of erowers who are prone to assign June drop to hot north winds,
sudden changes in temperature, and other causes, most of which are
climatie in nature.

In order to obtain more accurate information in this regard an
investigation of the yield per tree in different citrus districts, where
all other factors except the climatic complex were comparable, was
earried out during the season of 1917. The results were striking and
show most pronounced correlation between climatic conditions and
yield when all other factors such as orchard management, etc., are
fairly comparable. It was found that, assigning a yield of 100 per cent
to the district averaging the highest crop, which district is character-
ized by considerable summer heat but moderate atmospheric humidity,
the farther inland the district lies the smaller is the crop. This is
precisely the order in which the asperity of the environmental com-
plex is heightened, the atmospheric humidity decreasing and the
average summer temperature increasing. Moreover, and more im-
portant, distance from the coast brings with it increasing lability
to sudden changes in the weather which react most unfavorably on
crops, particularly when in certain stages. The districts where these
climatic conditions are most severe, namely, the Coachella Valley and
the southern San Joaquin Valley, show a yield of approximately
25 per cent of that of the most climatically favored district. At
intermediate stations the extent of the drop and consequently the size
of the crop is easily correlated with weather conditions during the
critical period. This was exemplified by the almost total loss of the
Navel crop in the district between Corona and Redlands in 1917, when
a dry north wind of unprecedented severity was accompanied by maxi-
mum daily temperatures as high as 118°-120° F from June 15 to 17.

This correlation between asperity of climatic conditions and amount
of crop, or what amounts to the same thing, the prevalence of dropping.
was very apparent in the orchard where our experimental work was
done at Edison. The yield from the particular ten-acre tract used was

38 Hodgson, Robert W., Some Abnormal Water Relations in Citrus Trees of

the Arid Southwest and their Possible Significance, Univ. Calif. Publ. Agr. Sei.,
vol. 3 (1917), pp. 37-54.

308 University of California Publications in Agricultural Sciences [Vol.3

56 per cent less in 1917 than in 1916 though the trees were a year older
and should have yielded more. The asperity of climatic conditions
during the critical period in 1917 as integraded in the Livingston white
porous cup atmometer (pl. 41) was approximately 40 per cent greater
than during the same period in 1916. This fact is brought out in
table 5, where the water loss from atmometers at different stations in
the United States is shown. ‘‘Grove’’ station in 1916 is fairly com-
parable with ‘‘Cultivated’’ station in 1917, as is the case with the two
‘‘Desert’’ stations. Further evidence of this correlation is afforded
by the mean maximum temperatures obtaining during the critical
period in the development of the young fruit (table 2). During this
period in 1917 (June and July) the mean maximum temperatures
were 95°6F and 104°4F respectively, while those for the critical
period in 1916 (May and June) were only 81°91 F and 93°0 F.

TABLE 5

COMPARATIVE LOSS FROM CYLINDRICAL WHITE Porous Cup ATMOMETERS AT
DIFFERENT STATIONS IN THE UNITED STATES FOR THE MONTH OF JUNE

Average daily loss for

Station 24 hours in ce.
UPN PRT” eg ORC OTe Ine 15.9
{50 RES STC Cae Re pl Retinatens Abe Pa CP 2 aot 16.1
‘¢ Alfalfa’’ Station, East Bakersfield, 1917... 18.5
Whittier..Calit.,.1993: 3.62 icn eee 22.8
lee elem. att, 1987 oases cette 23.1
West Raleigh, North Carolina® ..................-.---- 28.0
Gaimeecilic, Florida oreo renesccteenwtcesenrcteeene 28.7
‘siPree” Station, Edison; 1916.2: 32.9
San Fringe. Omit oct eecsersaleeeennties 33.0
Cameron, Lovisians® csnccicnpee eee 33.4
‘¢Tree’’ Station, East Bakersfield, 1917 ........ 35.8
Riversias, Calif. 1912 28... chee 43.4
Dickinson, North Dakota* <......:<...24.2.2-< 45.0
‘¢Grove’’ Station, Edison, 1916 ....................-» 48.1
‘*Vard’’ Station, Edison, 1916 2.5.0.1... 55.1
“(Degsert’’ Station, Edison, 1916... 69.1
Renee Mevade.* 3.2 2 eee 69.5
‘‘Cultivated’’ Station, East Bakersfield, 1917 71.7
Meg ATIC OTR on oe et nae cat es 73.0
No lal We eT fl SR as ace, | RAO AE ROSE De 80.7
‘<Desert’’ Station, East Bakersfield, 1917...... 94.0

* Livingston, B. E., A Study of the Relation between Summer Evaporation Intensity
and Centers of Plant Distribution in the United States, Plant World, vol. 14 (1911),
pp. 205-22.

This correlation is again reflected in the comparative yields in
general throughout the state in the seasons of 1916 and 1917. The
latter season has been noted for its long continued, high temperatures

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 309

and low humidity, while the former was as equally marked by its rela-
tively low temperatures and equableness. The crop in 1917 over the
entire state is not estimated to be more than 40 to 50 per cent of that
in 1916.

All the more recent fundamental work in plant physiology has
indicated that for plants growing in the open the water relation is
the limiting factor. It is at once obvious that under the conditions
obtaining in the arid southwest it is the water relation which is most
likely to be strained. This is particularly to be considered in connec-
tion with the previously mentioned fact that the genus Citrus is
undoubtedly of tropical origin and therefore not well adapted by
nature to withstand the tremendous water loss incident to the severe
elimatie complex obtaining under arid conditions.

Evidence that abnormal water relations due to the influence of the
environmental complex may furnish the stimulus to abscission is not
lacking. In regard to the cotton plant Balls*® says: ‘‘It is certain
that the main factor, if not the only one, is the water-content of the
plant.’’ Lloyd,* also working with cotton, concludes that ‘‘the water
deficit is the cause of mse of temperature in the tissues, and this
constitutes the stimulus which directly leads to abscission.’’ Howard*?
has noted the fact that abnormal water conditions in the soil are
immediately shown in the indigo plant, Indigofera arrecta, by leaf-fall
or by the shedding of flowers without setting seed. His interpretation
of these results will be referred to later. The junior author has already
presented data to show that at Edison an abnormal water relation
does exist in orange leaves and young fruits during the critical
period.*? He has shown that a daily water deficit of 25 to 30 per
cent occurs in the young fruits, which deficit is made up at night.
These deficits are at their maxima during the afternoon, at which
period the atmospheric pull on the plant for water is at its maximum.
A eontributing factor to these water deficits lies in the fact that under
stress of the tremendous atmospheric pull for water the leaves actually
appropriate water from the young fruits. This strain on the plant is
not localized but extends throughout the tree. Tensions developed by
exterior foliage are transmitted quickly to interior fruits and even to
distant roots as was shown by several experiments; for the sake of
brevity only one will be described.

39 Loc. cit., p. 69.

40 The Abscission of Flower-buds and Fruits in Gossypium, and its Relation
to Environmental Changes, Trans. Roy. Soc. Canada, ser. 3, vol. 10 (1916), p. 61.

41 Soil Aeration in Agriculture, Agr. Res. Inst. Pusa, Bull. 61, 1916.
42 Loc. cit.

310 University of California Publications in Agricultural Sciences [Vol.3

On May 4, 1916, a large number of apparently healthy terminal
fruits about one-half inch in diameter were selected on six trees at
Edison. Lot A was left as a check, lot B was treated by clipping off
with scissors one-third of the leaves of the current season’s growth
behind the fruit. Lot C suffered excision of two-thirds of the leaf area,
and lot D had all of the leaves removed, leaving the fruit terminating a
bare stem about six inches long. Unfortunately, a few of the limbs
in these trees were removed by tree pruners. On November 16 the
remaining labels were located and a record made of the number of
fruits which persisted to maturity.

TABLE 6
Errect oF REDUCTION oF ADJACENT LEAF AREA ON ABSCISSION

Number Number labels Number of

labeled found fruit set
A. Check, not treated «.....:...4 200 165 29
B. One-third leaf area removed.... 200 163 19
C. Two-thirds leaf area removed 200 176 37
D. All leaves removed ................-- 200 167 21

Thus we see that the reduction of adjacent leaf area had no effect
on the drop and inasmuch as eosin solution was drawn through oranges
in situ to the stem in lot D very nearly as quickly as in lot A, it is
evident that the tensions referred to have to do with the tracheal
system as a whole, as is to be expected, and do not tend to be localized
in any particular part of the tree.

TABLE 7

PRESENCE OF LITHIUM NITRATE IN LEAVES BEHIND FRuUITS INJECTED WITH
Dry CRYSTALS AS SHOWN BY THE SPECTROSCOPE
Experiment began at 12 M.

First Second Third Fourth Fifth Sixth Seventh Twelfth

Time leaf leaf leaf leaf leaf leaf leaf leaf
12:30P.mM. Posi- Posi- Posi- Nega- Nega- _........... Noga- . scans
30 minutes tive tive tive tive tive tive

1:00 P.M. SG Sassen tne te aS ee Posi- Nega- .....:..... See
1 hour tive tive tive

2:00 P.M. | lens re POS 6 Sins viene, Jeeegeee Nega-
2 hours tive tive tive
3:00 P.M. ji) Ee Si a eee ae Pogis wc28 oe we
3 hours tive tive

4:00 P.M. MWe ee eae | es Posi- Posi- ........ ae
4 hours tive tive tive

12:00 m. Very: Very Nega- Traed s.ccc5 © siceccstn,) (occ)

24 hours slight slight tive (?)
trace trace

.Check I NOOR a sces, 1) ote 1 ait epaaa ako ereeninameal
tive tive

m..

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 311

The withdrawal of water from the fruits by the leaves has been
further substantiated by the use of dry crystals of lithium nitrate
injected into the navel end of the young fruits and testing for lithium
in the leaves proximal to the fruits at different periods following in-
jection by means of the spectroscope. These results are summarized
in table 7, where it can be seen that within a half hour, in spite of the
fact that the lithium nitrate was injected dry into the fruit and had
to go into solution in the freed cell sap, its presence was shown in the
leaves behind the fruits.

Water relations of this same general sort have been established by
a number of other investigators in plants where such deficits do not
constitute a stimulus to abscission. Under this category are to be
classed Renner’s**® ‘‘sitigungsdefizit’’? and the phenomenon of ‘‘in-
eipient drying’’ deseribed by Livingston and Brown‘ and established
in other plants by Lloyd*® and Edith B. Shreve.*®

To determine actually the ultimate connection between abnormal
water relations of the type noted and the abscission of young fruits has
constituted a most difficult problem, and the evidence indicating such
a connection has been obtained from several different lines of attack.
Although not as conclusive as could be desired, still we believe that it
is sufficient to indicate in general the relation between the two. It is
hoped that additional evidence can be obtained during the next season,
which evidence we were unable to eet during our investigation through
lack of sufficient equipment and apparatus.

As was mentioned in the description of the East Bakersfield station,
this orchard is planted to alfalfa, protected by an efficient windbreak,
and heavily irrigated. The noteworthy fact, however, is that this
orchard habitually bears crops in every way comparable to orchards of
the same age and general treatment located near the coast. Although
situated only three and one-half miles from the Edison station and
having the same exposure, the trees being one year younger, and all
conditions similar in every way with the exceptions noted, this orchard

43 Experimentelle Beitrage zur Kenntnis der Wasserbewegung, Flora, vol. 103
(1911), pp. 171-247.

44 Relation of the daily march of transpiration to variations in the water
content of foliage leaves, Bot. Gaz., vol. 538 (1912), pp. 309-80.

45 The Relation of Transpiration and Stomatal Movement to the Water Con-
tent of the Leaves of Fouquieria splendens, Plant World, vol. 15 (1912), pp.
1-14; Leaf Water and Stomatal Movement in Gossypium and a Method of Direct
Visual Observation of Stomata in situ, Bull. Torr. Bot. Club, vol. 40 (1913), pp.
1-26.

46 The daily march of transpiration in a desert perennial, Carnegie Inst.
Washington, Publ. 194, 1914.

312 University of California Publications in Agricultural Sciences [Vol.3

bears heavy crops (pl. 26), and has been profitable ever since it came
into bearing three to four years ago.

The conclusion cannot but be forced that in the exceptions noted
lies the secret of the heavy set of fruits. In order to obtain some idea
of the climatie conditions obtaining within this orchard as compared
with those under Edison conditions we had recourse to what metero-
90

80

70

40

30

20

10

23 MAY Sie! JUNE 8

Fig. 2. Comparison of daily atmometer water loss at four different stations
at Edison in 1916. Ordinates, water loss in e¢.; abscissae, days of the month.

logical instruments were available to us. While much more significant
results could have been obtained had we possessed more equipment, we
feel that our data, while possibly not accurately quantitative, at least
are qualitative enough to justify our conclusions. Air temperature
and humidity readings were taken by means of a Freiz thermo-hygro-
graph. We were particularly interested, however, in the integration
of all the climatic factors in their effect upon the plant and for this
purpose selected the Livingston white cylindrical porous cup atmo-

=

oo + «24

ee oe ee eee ee ee

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 313

meter*’ (pl. 41). We are cognizant of criticisms of this instrument
by Briggs and Shantz,** but believe that for our purpose it is suffic-
iently accurate. Due to a lack of a sufficient number of these instru-
ments we were unable to run a series simultaneously at Edison and
at East Bakersfield but we did operate them under as nearly similar
conditions at the latter place in 1917 as at the former in 1916. Know-

70 DESERT

60
YARD

4d GROVE

40

TREE

30

20

10

Fig. 3. Comparison of the average daily atmometer water loss from the
stations referred to in figure 2.

ing something of the relative harshness of the two seasons, both as
reflected in the amount of dropping and in the data taken by the U.S.
Weather Bureau observer at Bakersfield, we are able to approximate
fairly well the climatic conditions at Edison in 1917 for comparative
purposes. The water loss from our different stations at the two locali-
ties is well shown in figures 2, 3, 4, and d and in table 5.

At Edison our atmometer stations were selected as follows: ‘‘ Tree’
station was located underneath an orange tree near the center of the
orchard, about one-half mile to leeward of the edge of the orchard

?

47 The Relation of Desert Plants to Soil Moisture and to Evaporation, Car-
negie Inst. Washington, Publ. 50, 1906.

48 Comparison of the Hourly Evaporation Rate of Atmometers and Free
Water Surfaces with the Transpiration Rate of Medicago sativa, Jour. Agr. Res.,
vol. 9 (1917), pp. 277-96.

314 University of California Publications in Agricultural Sciences [Vol.3

which bordered the desert. ‘‘Grove’’ station was situated in the open
orchard midway between the tree just mentioned and its neighbor,

‘‘Desert’’ station was located on the open, bare desert about one-half

110

100

DESERT
90

CULTIVATED

60

40
TREE

30

” ALFALFA

10 12 JULY 21 23

Fig. 4. Daily evaporation from atmometers at four different stations at
East Bakersfield in 1917. Ordinates, water loss in ¢e¢.; abscissae, days of the
month.

mile to windward of the edge of the orchard and many miles to leeward
of any irrigated land (pl. 41)). The data accumulated for nineteen
days are shown in figures 2 and 3 and table 5.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 315

At East Bakersfield our atmometers were set up at the following

orn itd 5, 9)

stations: ree’’ station was similar to ree’’ station at Edison
except that the tree where it was located was in the orchard planted
to alfalfa. ‘‘Alfalfa’’ station was located similarly to ‘‘Grove’’

station at Edison but of course was surrounded on all sides by alfalfa,

DESERT

90
80
CULTIVATED
70
60
50
40
TREE
30
ALFALFA
10

Fig. 5. Average daily water loss from atmometers at the stations referred
to in figure 4.

to
oO

which averaged some twelve to eighteen inches high. ‘‘Cultivated”’
station was located in every respect similarly to ‘‘Grove’’
Edison and the two ‘‘Desert’’ stations were similarly situated. The
data accumulated for fourteen days are shown in figures 4 and 5 and
table 5.

station at

316 University of California Publications in Agricultural Sciences [Vol 3

It is at once obvious, looking at the stations, which are in every
way comparable, that the critical period in 1917 was considerably more
severe than in 1916 (fig. 6), which difference has been pointed out with
respect to the yield of the Edison orchard. It is also equally evident
that the water loss from the soil and plants has a most profound effect
in ameliorating the atmospheric evaporating power and that this effect
is cumulative with the direction of the prevailing winds. Thus at
Edison the ‘‘ Desert’’ atmometer lost an average of 69.1 ce. to 48.1 ce.
lost by the ‘‘Grove’’ station and at East Bakersfield the same stations
lost water in the ratio of 94.0 ee. to 71.7 ec. At Edison the orchard
environment during 1916 was sufficient to cut down the asperity
of the climate about 45 per cent, while at the Kellogg place in
1917 it was sufficient to reduce it 31 per cent. The atmometer
inside the tree lost only two-thirds of that lost by the instrument at
‘‘Grove’’ station or only 45 per cent of that at the ‘‘Desert’’ station.
Thus we can see the marked effect of an orchard in modifying its -
own environmental complex. It is undoubtedy this influence which
the orchard manifests per se which explains to some degree why it is
that as orchards planted in exposed districts grow older, the percentage
of yield increases more than the increase in size of tree. The fact that
inside fruit is subjected to an entirely different climate than exposed
fruit serves to explain why it is notably of better texture and grade
and why it possesses so few large and protuberant navels. We have
observed that Navel oranges grown in the University of California
greenhouses are of markedly superior texture and navel conformation
to those produced outside, where conditions are not so mild or uniform.
Again, it is this cumulative modification of the climatic complex fol-
lowing the direction of the prevailing wind which explains the fact
that a notably heavier set of fruit occurs on the south and east side
of the trees. This condition has been frequently mentioned and was
quite marked at Edison in 1917.

But the most striking modifications in climatie conditions are to be
seen with reference to the situation at East Bakersfield. Although the
Desert station atmometer lost an average of 94.0 ee. the Alfalfa station
instrument lost only 18.5 ce. or only 20 per cent as much. Reference
to table 5 serves to show that here is a climatic change within a
half mile in the San Joaquin desert of the same magnitude as that
between Miami, Florida, and Tueson, Arizona. The effect is, of course,
largely due to the fact that the alfalfa transpires at a tremendous rate
and the atmometer cup at that station was continuously bathed in an

{bnormal Shedding of Washington Navel Orange

Coit—Hodqson:

1919]

110

100

70

f A Lath v
: NA ;

1916

HH 1917

APRIL MAY JUNE JULY

Fig. 6. Maximum daily temperatures for period April 15 to August 1, 1916 and 1917.

318 University of California Publications in Agricultural Sciences [Vol. 3

almost saturated atmosphere. The windbreak served to prevent the
blanket of moist air from being rapidly dissipated. The loss from
Tree station is seen to be 35.8 cc., or only 30 per cent of that lost by
the Desert instrument. Although the effect of the alfalfa cannot be
exerted at any very considerable height above the ground, still it is
certain that the orange trees (with the young developing fruits) sur-
rounded by this transpiring alfalfa are literally bathed in a damp
atmosphere; at any rate so far as the tree is concerned it is subjected
to a very different climate from that which obtains on the desert. The
influence of the alfalfa in modifying the atmospheric humidity can
clearly be seen when the crop of oranges is picked, for under these
conditions most of the fruit is borne near the ground and less in the
tops of the trees. At Tree station, East Bakersfield, thermo-hygro-
graph readings were taken for a period of twenty days. A study of
the record for the period of the investigation shows some interesting
results. At no time did the temperature rise above 107° F although
in the laboratory, a quarter of a mile away, temperatures of 110° to
112° F were registered several times. The most significant feature,
however, is the relative humidity curve. The lowest humidity reached
was 25 per cent, which occurred at the time that the 107° F tempera-
tures were recorded, July 9 and 21. The average relative humidity
during the day was between 40 and 50 per cent. In 1916 at Edison
we recorded humidities as low as 10 per cent and the average relative
humidity was between 25 and 35 per cent. It is unfortunate that we
were not able to obtain simultaneous temperature and humidity read-
ings at the Desert station in 1917, but in view of the fact that the
1917 season has been shown to be much more severe than the 1916
season there is little doubt that in 1917 the relative humidity was
somewhat lower and the temperature somewhat higher than in the
former season.

We recognize clearly that in agricultural enterprises it is unsafe
to rely upon climatic averages. It is well known that with some crops
success or failure depends largely upon the extremes of climatic con-
ditions experienced during a certain critical period in their growth.
However, it should be borne in mind that conditions which tend to
ameliorate the environmental complex not only raise the general
average favorably, but also have a distinct modifying effect upon
extremes in weather conditions which may occur. Indeed, it seems
probable that this is the most important effect of the alfalfa and
windbreaks in the Kellogg orchard. It is not so much the higher

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 319

average humidity as it is the greater freedom from extreme variation
in climatie conditions which serves to enable the young fruits to
survive.

As referred to above, the junior author*® has shown in another place
that a marked water deficit occurs both in the young fruits and the
leaves under the climatie conditions obtaining at Edison and has sug-
gested that these abnormal water relations furnish the stimulus to
abseission. If this be so, then when there is little or no dropping of
the fruits and consequently a good crop, such abnormal water relations
should not be found. An effort was made at the East Bakersfield
station in 1917 to establish such abnormal water relations, but it was
found impossible to do so (table 8). Instead of there being a regular

TABLE 8

AVERAGE MOISTURE CONTENT AT DIFFERENT TIMES OF DAY

Average water content in
per cent, calculated on
basis of dry weight

Kind of material 1916 1917
Normal fruits one-third to three-fourths inch in diameter
DURRANT OTE: LOGON oe Sats asc eee nsec oodles 260.2 285.3
eM, OU PALUOTEE, BEVEL MOON). ocesicc dae eenscadadeendacmennnmsinne 247.0 283.9
Leaves of current season’s growth, gathered before noon 164.9 174.9
Res WG PANTO BLVGN DOO xn costa cote a docesnaeegenaet ne teec- 157.2 182.6

decrease in water content of similar leaves and fruits during the day,
which is made up during the night, no such relation was found. At
East Bakersfield the leaves and fruits, in the first place, averaged
somewhat higher in moisture content than those taken at Edison.
Secondly, although as nearly similar in every respect as possible,
duplicate series showed an absolute lack of uniformity, the variation
sometimes being as much as 30 to 40 per cent. Finally, no average
decrease in water content either of the fruits or leaves was found
to occur during the day. It should be mentioned that irrigation at
the Kellogg place is not uniform, relatively small tracts being irri-
gated at one time and these thoroughly soaked. As it was found in-
convenient to take all the leaves and fruits from the same trees it is
possible that some of the variation in moisture content noted may be
attributed to variations in soil moisture. However, under the marked
modification of climatic conditions which has been shown to occur as
a result of the management of the orchard, it is believed that such
abnormal water relations do not occur, at least to anything like the
extent to which they do under the unmodified climatic conditions.

49 Loc. cit.

320 University of California Publications in Agricultural Sciences [Vol.3

As to the ultimate stimulus beyond abnormal water relations we
can do little but speculate. Lloyd®® has expressed the idea that increase
in temperature following water deficits may be the ultimate stimulus
to abscission. It has long been known that plant parts, when for any
reason deprived of a normal supply of water, suffer an increase in
internal temperature. In an effort to furnish additional evidence as
to the presence of abnormal water relations, as well as to obtain some
idea of the temperature changes incident to such water deficits, we
took some temperatures of fruits destined to fall, fruits suffering
from a water deficit by reason of the fact that the tree was permitted
to suffer for lack of irrigation, and temperatures of normal fruits.
These are found summarized in tables 9 and 10. It will be seen that

TABLE 9
INTERIOR TEMPERATURES OF FRUITS, FAHRENHEIT
Fruit destined Normal

Hour to drop healthy fruit Air
9 91.8 91.4 91.5
9:20 94.1 91.5 93.2
10 96.3 93.0 95.9
11 100.4 96.9 97.5
12 102.2 98.0 100.4
1 106.5 100.9 105.8
2 110.5 104.9 110.1
3 109.9 107.2 109.0
+ 111.9 110.3 110.8
5 111.2 110.3 107.2
5:30 107.6 107.6 106.2
Average 103.8 101.0 101.6

TABLE 10
INTERIOR TEMPERATURES OF FRUITS, FAHRENHEIT
Fruit suffering Normal

Hour from drought healthy fruit Air
8 87.3 86.9 90.1
9 91.4 90.5 92.1
10 95.5 95.0 97.5
11 98.6 97.2 100.2
12 102.9 100.4 103.6
1 104.2 103.5 105.2
2 104.9 104.0 107.6
3 106.2 105.8 107.6
+ 104.0 104.0 104.0
5 101.3 101.3 101.6
6 98.6 98.6 98.2
7 93.2 93.2 94.1
Average 99.0 98.2 100.1

50 Loc. cit.

bo
~

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 3

the normal fruits average somewhat lower in temperature than the
air, and in turn those destined to drop are somewhat higher in tem-
perature than the air. Fruits permitted to suffer for lack of water
show a temperature approximately that of the air surrounding them.
It may be that increase in temperature due to water deficits is the
ultimate stimulus to abscission, still it should be pointed out that the
increases in temperature as recorded by us are of a much smaller
magnitude than the daily range in temperature changes. We are
fully aware, of course, that strictly accurate temperatures of plant
tissues can only be obtained by thermo-electric means, the mercury
thermometer being too subject to fluctuation and variation for very
delicate work.

FACTORS OPERATIVE IN CAUSING WATER RELATION STRAINS

It is of course obvious that, given a plant transpiring a certain
amount of water vapor daily, unless there be a sufficient water supply
in the soil within reach of the absorbing roots to make up for that lost
by the plant and in addition supply enough for its metabolic processes,
water deficits of the kind mentioned must eventually occur. That
under these conditions such do occur and that they are followed by an
abnormally severe shedding of the young fruits when in the critical
period, is the observation of the authors and the experience of many
growers. In the season of 1916 the junior author had under observa-
tion a ten-acre block of orange trees in the Oroville district which
had been top worked to the Washington Navel variety five years
previously. They bloomed very heavily and set an excellent crop.
Through an accident to the irrigation system preventing a sufficient
supply of water these trees were allowed to suffer for lack of water
at the time when the young fruits were about one centimeter in
diameter. At the time of irrigation several days later the fruits had
not fallen and it was hoped that the crop could be saved. Within a
week practically every fruit was shed, although the trees looked well
and had entirely recovered from the drought.

Observations, confirmatory in every respect to those given above,
were made on a row of trees at the Kellogg place in 1917. These trees
were permitted to suffer for lack of irrigation. Although the only
trees in the row which at the time bore fruits in the critical stage were
of the Valencia variety, which variety is much less subject to shedding
than the Washington Navel, still within a week after the application
of the water many of the young fruits had fallen. The desirability of

322 University of California Publications in Agricultural Sciences [Vol.3

a proper moisture supply in the soil at the blooming and setting period
is reflected in the practice of many growers who irrigate their orchards
heavily at such times as well as during the periods of hot, dry north
winds. °

In this connection it should be noted that Fowler and Lipman*!
have recently shown that under conditions of a soil moisture supply
somewhat below the optimum the visible effects upon the citrus tree
are a great deal less than under conditions of the same percentage
above the optimum moisture content. In other words, these authors
have shown that the citrus tree does not exhibit the effects of a deficient
soil moisture supply to the same extent that it does an excess of
moisture in the soil. It may well be, therefore, that many of our
citrus orchards are underirrigated and the irregular water relations
above discussed accentuated by reason of this fact. The authors feel
that many of the orchards studied in this investigation would probably
do better with heavier irrigation. : Manifestly it would be useless to
attempt methods of modifying the climatic complex with the end in
view of cutting down daily water deficits, if the soil moisture supply
is deficient. Therefore, the grower should first make certain that
sufficient soil moisture is available.

It has long been known that the presence of sufficient moisture in
the soil is not conclusive evidence that the plant is enjoying optimum
moisture conditions. Plants inhabiting salt marsh regions possess their
xerophytic adaptations by reason of the fact that although growing
with their roots in water or mud they are unable to obtain water in
any large amounts and are foreed to economy in the use of it. This
inability to absorb water has been traced to the ratio between the
osmotic concentrations of the soil solution and the cell sap of the roots,
and such a condition is called ‘‘ physiological drought.’’ Physiological
drought may be induced by the inhibition of absorption through the
action of factors other than the osmotic concentration of the solutions
involved.

Among the most important factors conditioning absorption is that
of aeration. It has long been known that when grown in water cul-
tures many plants make very unsatisfactory growth. Hall, Brenchley,
and Underwood® have recently shown that this unsatisfactory growth
is due to lack of aeration and can be remedied by passing a stream of

51 Optimum Moisture Conditions for Young Lemon Trees on a Loam Soil,
Univ. Calif. Publ. Agr. Sci., vol. 3 (1917), pp. 25-36.

52 The Soil Solution and the Mineral Constituents of the Soil, Jour. Agr. Sei.,
vol. 6 (1914), pp. 296-301.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 323

air through the solution. The economic applications of this principle
are many, but are of course particularly evident in regions where
through special conditions lack of soil aeration is emphasized, as is the
ease in certain parts of India. The soil is naturally very heavy and
easily packed by the torrential rains. Lack of aeration is accentuated
during certain portions of the growing season by the occurrence of
monsoons and tropical rainstorms of great severity. MHoward*® has
shown most conclusively that under these conditions the production
of the gram or chick-pea, Cicer arietinwm, grown to the extent of over
eighteen million acres, is absolutely conditioned by the soil aeration.
If the soil is permitted to become packed by summer rains and the
air supply cut off, the plants wilt down with water actually stand-
ing on the surface of the soil. Absorption is cut down to practically
nothing, while transpiration is not reduced in the same ratio, resulting
in ultimate wilting. While not extensive, all the experimental data
available on the production of this crop in California show this same
intolerance of lack of soil air. Howard has shown this same condition
affecting fruit trees and other crops, among which is the indigo plant.
Free®* has shown that with Coleus bluwmei ‘‘even a very small decrease
of oxygen below that normal to the atmosphere is injurious to the
plant. Thus a plant, the roots of which were supphed with gas con-
sisting of 75 per cent air and 25 per cent nitrogen, was injured within
three days and killed within 45 days. With lower oxygen content in
the soil atmosphere injury and death are still more prompt.’’ In
many cases the lack of aeration is first evidenced by the shedding of
the leaves and flowers. Soils of arid regions in general are well
aerated, and especially soils of open structure such as sands and
sandy loams. Therefore it is not likely that lack of soil aeration is
the factor conditioning absorption of water by citrus trees. However,
this problem is now under investigation and will be reported on later.

Under most conditions of lack of aeration not only is oxygen
deficient but carbon dioxide is present in excess. The experimental
data available seem to indicate that. while in general lack of oxygen
and excess of carbon dioxide in the soil atmosphere are detrimental,
there is no set rule. Cannon,*® and Livingston and Free®® have shown

53 Soil Aeration in Agriculture, Agr. Res. Inst. Pusa, Bull. 61, 1916.

54 Cannon, W. A., and Free, E. E., The Ecological Significance of Soil Aera-
tion, Science, n.s. vol. 45 (1917), pp. 178-80.

55 On the Relation between the Rate of Root-Growth and the Oxygen of the
Soil, Ann. Rep. Dir. Dept. Bot. Res., Carnegie Inst. Washington, Yearbook 15
(1916), pp. 74-75.

56 Relation of Soil Aeration to Plant-Growth, ibid., p. 78.

324 University of California Publications in Agricultural Sciences [Vol.3

that there is considerable variation in this respect, some plants, such
as Salix sp., growing and thriving in a soil containing no oxygen.
Apparently the limiting concentrations of these gases must be worked
out for each plant separately. As to the specific effect of lack of
oxygen and excess of carbon dioxide resulting in changes in absorption
rate little is definitely known. The first effect seems to be a slowing
down of growth, which in turn being ordinarily accompanied by the
imbibition (in the case of the embryonic growing regions of the root)
of water in considerable amounts, reduces absorption markedly. The
exact relation between growth and absorption is not well understood
at the present time; but it has been shown by MacDougal®* and others
of the Carnegie Institution that growth of embryonic tissues is mainly
accomplished by the imbibition of large quantities of water. It can be
readily seen, therefore, that if conditions are unfavorable for growth,
imbibition and absorption must necessarily be reduced.

Another factor which acts in a very similar way to lack of aeration,
and one little appreciated up to the present time, is that of soil tem-
perature. Every year adds more confirmatory evidence to prove that
the temperature relations of physiological processes follow certain
typical curves, which seem to be identical or closely related for processes
of the same fundamental nature in different organisms. The effects
of temperature on physiological processes, both in plants and animals,
have been investigated by many workers and in general a modified
curve of the Van’t Hoff type has been obtained where the most careful
work has been done. In such curves several cardinal points can be
determined, namely, the minimum temperature at which the process
goes on, the maximum temperature beyond which the process no longer
continues, and the optimum temperature at which the process is most
active. This last term has been superseded by what is known as the
maximum rate temperature, representing that temperature above which
the rate is ultimately decreased and below which the same occurs.
Blackman®® has shown that the term optimum temperature is in-
definite, since at certain temperatures physiological processes are very
rapid for a time but then slow down, due to the introduction of a time
factor. The maximum rate temperature is that temperature above
which a time factor is introduced resulting in an ultimate retardation
of the process.

These cardinal temperatures differ somewhat for different processes
but still more markedly do they differ for the same process in different

57 Ibid., Yearbook 15, 1916.
58 Optima and Limiting Factors, Ann. Bot., vol. 19 (1905), pp. 281-95.

co
bo
a) |

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange

organisms. Thus Howard®® has shown with wheat that at the germi-
nating period a fall of 10° to 12° F from 84° to 72° may mean the
difference between success and failure in obtaining a stand, since the
growth rate is almost inhibited at the former temperature. On the
other hand, Cannon"’ has shown that the maximum rate temperature
for the mesquite, Prosopis velutina, and Opuntia is about 93° F.
Tobacco is another plant which thrives in hot soils. Leitch®' has shown
that for the garden pea, Pisum sativum, 85° F is the maximum rate
temperature and above 110° F no growth whatever occurs. Appar-
ently, as in the case of the aeration factor, no general rule for these
eardinal temperatures can be laid down. They must be determined
for each plant separately. Since growth conditions absorption we
are justified in assuming that the cardinal temperatures for growth
are approximately those for absorption.

The genus Citrus, as mentioned elsewhere, is native to the tropics,
where it grew in the shade of other trees. Under these conditions the
soil was damp and soil temperatures certainly not high. It therefore
seems logical to assume that the temperatures favorable for root growth
in Citrus are not very high. As grown under clean cultivation in the
arid southwest we believe that the absorbing roots are subjected
during a certain portion of the day to temperatures above the optimum
and that during such periods absorption is actually reduced.

TABLE 11

Sor. TEMPERATURES (F.) AT EDISON, JUNE 7, 1916

Hoa Avoeas OS? SIS tede 2:15 21s.» ands Bais
Six-inch dust mulch ....... 80:6 842 S82. 923 941 960 995 99.0
Pare, © mehes ................ 77.0 783 800 842 89.6 88.8 88.6 87.0
Second 6 inches .............. "70° Ter “Tol FSO 82.4 824 82.4 - 806
Thard 6 inches .........-.....- 76.1 75.0 75.0 75.3 79.2 77.2 78.3 78.0
Fourth 6 inches .............. (aoe oes ee eee OTT. 76.6. P70 418
Six-inch dust muleh in
Shade of tree ...........: 7.6) 4aer, tou es.0 86.1 8682.5 82.2.) BAe

To obtain an idea of the soil temperatures prevailing in the
upper two feet of soil in 1916, a comparatively cool season, we made
a series of hourly readings at six-inch intervals. These may be found
summarized in table 11. This table shows that during the afternoon

59 Influence of Weather on Yield of Wheat, Agr. Jour. India, vol. 2 (1916),
part 4.

60 Relation of the Rate of Root Growth in Seedlings of Prosopis velutina to
the Temperature of the Soil, Plant World, vol. 20 (1917), pp. 320-33.
_ £1 Some Experiments on the Influence of Temperature on the Rate af Growth
in Pisum sativum, Ann. Bot., vol. 30 (1916), pp. 25-46.

326 University of California Publications in Agricultural Sciences [Vol.3

the temperature of this upper layer of soil does not fall below 75° F.
As was brought out previously, under clean cultivation practices the
absorbing roots of citrus trees are largely located in the upper two
feet of soil (pl. 42). It therefore seems quite probable that during
the afternoon at the very period when water loss by transpiration is
greatest, absorption is inhibited by high soil temperatures. A study
of the cardinal temperatures for absorption by citrus roots, which is
expected to throw considerable hight on this question, is now under
way and will be reported on later.

But granted that a condition of physiological drought existed, due
to the action of the factors just discussed, still the citrus tree might

Fig. 7. Citrus stoma showing maximum opening. From orange leaf just
reaching full size.

maintain itself in a proper water balance were it not for the fact that
it is not provided with efficient means of conserving its water by
regulating its loss through transpiration. A preliminary study of the
relation of cuticular transpiration to stomatal water loss has brought
out the fact that from 40 to 50 per cent of the water loss from
citrus leaves occurs through the upper epidermis which does not con-
tain stomata. These studies have shown that the young leaves are
more efficient than the older leaves but that even the youngest leaves
lose as much as 25 per cent of their water through the upper epidermis.

A study of the stomatal condition in citrus leaves has brought out
some interesting facts. By the use of Lloyd’s method® the amplitude
of stomatal movement was studied. It was found that very early in
the life of the leaf the stomata lose their power of opening and closing
and remain practically closed thereafter (fig. 7). In some cases the

62 Physiology of Stomata, Carnegie Inst. Washington, Publ. 82 (1908), p. 26.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 327

closure is not complete and the stomata remain slightly open. Heil-
bronn®™ has established this same condition in the leaves of the
Camelia. It is interesting to note in this regard the results obtained
by Shreve in a study of the transpiration of rain-forest plants carried
on in Jamaica.

The true stomatal transpiration is thus found to be from 42 to 48 per cent
of the total water-loss of the leaf. The close relation of transpirational behavior
to evaporation is thus shown to have its basis in the fact that rather more than
half of the water-loss of the plant goes on through the epidermal surfaces. .

The amplitude of stomatal movement in rain-forest plants under shade con-
ditions has been found to be relatively small. ... The weakness of the move-

Fig. 8. Cross-section of stoma from old coriaceous orange leaf. Note resin-
ous deposit in the substomatal cavity.

ments, together with the high cuticular water-loss, serves to give the stomata a
very negligible réle as regulators of transpiration rate, particularly during the
daylight hours.

It was found that a varying percentage of citrus stomata are
occluded by deposits of a resinous, gummy nature (fig. 8) in the sub-
stomatal cavity. Haberlandt® points out that physiological degenera-
tion of stomata takes place in a number of shade-loving hygrophytes,
doubtless because members of these ecological classes never require
much protection against excessive transpiration. Therefore it can be
readily appreciated that the citrus plant has relatively little control

63 Ber. d. deut. bot. Ges., vol. 34 (1916), pp. 22-31. (Cited from Exp. Sta.
Record.)

64 The Transpiration Behavior of Rain-forest Plants, Ann. Rep. Dept. Bot.
Res., Carnegie Inst. Washington, Yearbook 12 (1913), pp. 74-76.

85 Physiological Plant Anatomy (London MacMillan, 1914), p. 272.

328 University of California Publications in Agricultural Sciences [Vol.3

over its water loss. This condition itself constitutes strong evidence
of its tropical origin.

[f there be any regulatory action upon transpiration it should be
brought out in a study of the transpiration curve as compared to the
evaporation curve. These two curves for a typical day in July are
shown in figure 9, and it will be seen that the general form is very
similar and that the maxima of the two were reached at the same

i~

4P.M. JULY 21 12 P. M. 5 JULY 22 12 M.

Fig. 9. Comparison of Citrus transpiration curves with the evaporation
curve for the same period. Nos. 1, 2, 3, and 4 are transpiration curves obtained
by the potometer method. No. 5 is the evaporation curve obtained from a
Livingston white cylindrical porous cup atmometer. Ordinates represent water
loss in ec.; abscissae, hours of the day.

period. Were there any regulatory action the transpiration curve
should reach its maximum some time before the evaporation curve.

SUSCEPTIBILITY OF CITRUS VARIETIES TO ABSCISSION

Tt is well known that when grown under similar conditions the
Valencia variety of orange and the pomelo do not shed the young
fruits in anything like the same proportion as the Washington Navel.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 329

If the stimulus leading to abscission be abnormal water relations, why
then do not these two other members of the genus shed their fruits
to the same extent as the navel variety? Our observations made in the
field in orchards where these varieties are mixed have shown that such
is not the case, and experiments performed in our laboratories have
shown that abscission is much more easily induced in the navel variety
than in the others. Shoots bearing flowers and young fruits of each
variety have been placed in moist chambers and kept at room tempera-
ture. In the case of the navel variety abscission of all the flowers and
fruits has invariably occurred within sixty hours, while in the
Valencia variety and with lemons frequently no abscission occurred
within five to eight days. Apparently the navel variety is much more
susceptible to stimuli which lead to abscission. In this connection it
seems desirable to call attention to the fact that other investigators
have found in the case of hybrids abscission is much more prevalent
and much more easily brought about than in the case of the parent
varieties. Thus Goodspeed and Kendall*® have shown that in the case
of certain tobacco crosses in which only a small proportion of the
ovules are normally matured and capable of fertilization, which con-
dition obtains in the navel orange variety, practically all the flowers
and young fruits are abscissed. May not this sensitiveness to stimuli
which cause abscission constitute further evidence that the Washing-
ton Navel variety is of hybrid origin ?

MetuHops oF AMELIORATION

From the preceding discussion it is obvious that all methods of
preventing the June drop of our present strains of Washington Navel
oranges must be in the nature of modifying the environmental complex
either above ground, below ground, or, as is usually the case, both.

If the cause underlying these water deficits les in the asperity of
the atmospheric complex then practices tending to ameliorate climatic
conditions should work out to produce heavier crops. Such has been
found to be the ease. The planting of windbreaks to prevent the
dissipation of blankets of moist air; a moderate winter pruning to
reduce the total leaf surface area; and the planting of intercrops, such
as alfalfa, sweet clover, or buckwheat, which transpire large amounts
of water vapor; all these are methods of modifying the atmospheric
environmental complex.

66 On the Partial Sterility of Nicotiana Hybrids made with N. sylvestris as a

Parent, III: An Account of the Mode of Floral Abscission in the F, Species
Hybrids, Univ. Calif. Publ. Bot., vol. 5 (1916), pp. 293-99.

330 University of California Publications in Agricultural Sciences [Vol.3

In this connection it should be emphasized that the beneficial effect
of a summer cover crop does not seem to be due so much to the raising
of the average humidity as it does to the buffer effect which it plays
when sudden extremes in climatic conditions are experienced. The
increase in the average humidity occasioned by the use of a summer
cover crop is probably considerably smaller than the difference which
may exist from one season to the next. It does not seem so important
that the average humidity has been increased somewhat by its use as
that when sudden hot, dry spells are experienced their effect is
modified by the use of such a crop. This would seem also to explain
the effect of the straw mulch which of course does not affect the atmo-
spheric humidity to any extent.

If the limiting factor causing these abnormal water relations be
high soil temperatures then methods of orchard management which
will reduce such temperatures may be expected to result in heavier
crops. Such practices as mulching and the growing of intercrops are
known to reduce the soil temperatures. Moreover, such practices in
many cases have resulted in notably heavier yields. The junior author
had under observation a twenty-acre orchard in the Oroville district
in the 1917 season. This tract was planted out to purple vetch in the
late fall and was not plowed until the following June. It was heavily
irrigated during April and May. Although situated in a most exposed
position this orchard bore a much better crop than any other orchard
in this district, notwithstanding the extremely heavy fall of fruits
experienced in this season. It is possible that the heavy crops borne
at the Kellogg place are partly attributable to a reduction in soil
temperature during the growing season.

Some data have been published on the effect of straw mulches on
the setting of Navel oranges. Briggs, Jensen, and McLane report
as follows:

The set of fruit was very light throughout the Riverside district in 1915,
owing apparently to cold weather following the bloom. In the Sunny Mountain
tract, where the mulched basins were first installed in 1913, the average number
of oranges per tree on the check trees in 1915 was 116, while on the muleched-

basin trees the average number of oranges per tree was 281, or two and one half
times as many as on the check trees.

Similar results are reported from other tracts. It should be remem-
bered, however, that the trees used in this work were not healthy but
were badly mottled, and the increased setting may be attributable to

67 The Mulched-Basin System of Irrigated Citrus Culture, U.S. Dept. Agr.,
Bull. 499 (1917), p. 30.

1919] Coit-Hodgson: Abnormal Shedding of Washington Navel Orange 331

their improved health brought about by better soil moisture and humus
conditions as well as improved temperature conditions. It has not yet
been satisfactorily shown that the mulched-basin system alone will
reduce the amount of drop on healthy trees, although in the light of
the discussion above we believe it probable.

The determination of the specific factor, if it be a single factor,
which produces the abnormal water relations established, is yet to be
made. It is hoped that investigations planned for the coming season
may aid in solving this question. The orchard management practices
described above which result in heavier crops, unfortunately for in-
vestigational purposes, involve the modification of both the above-
ground and under-ground environmental complex.

The fact that by proper means man is able to change the climatic
conditions from those obtaining at Tucson, Arizona, to those at Miami,
Florida, within the space of a half mile, augurs well for the successful
control of the June drop. Measures of an anticipatory nature le in
the proper selection of the site before planting. The exposure to pre-
vailing winds, the nearness to large irrigated tracts, the possibility of
planting windbreaks; all these should be considered in the selection
of a site for a Navel orange grove. Growers should accustom them-
selves to thinking of climate not in terms of great valleys and states
but in strictly local terms. As has been pointed out above, the judicious
selection of the site, coupled with proper methods of orchard practice,
make it possible to secure marked modifications in our arid climate.
The question of the advisability of the measures suggested is purely
one of farm economics and does not le within the province of this
paper.

In view of the relatively small amount of shedding which is con-
nected with the Alternaria fungus alone and because of the peculiar
manner of infection the authors are led to believe that spraying with
fungicides for the June drop will hardly pay for the materials and
labor involved.

Another promising line of investigation looking toward control of
the June drop lies in the selection and propagation of dry heat resist-
ant strains of the Washington Navel variety. This variety, it is well
known, is constantly throwing off bud sports or mutations and it is
entirely possible that mutations may arise which are less sensitive to
abseission stimuli, but at the same time satisfactory otherwise. Every
grower should be on the lookout for such strains.

332 University of California Publications in Agricultural Sciences [Vol.3

SUMMARY

1. Citrus trees as grown in the interior valleys of the arid south-
west are subject to an environment entirely abnormal to them in their
natural habitat.

2. Moreover, the principal variety grown in these regions, the
Washington Navel orange, is itself decidedly erratic and unstable.

3. Among other troubles incident to the abnormal climatic con-
ditions is that heavy dropping of the young fruits, with consequent
light crops, known popularly as the June drop.

4. A study of the shedding has established the fact that it con-
stitutes true abscission, involving the separation of living cells along
the plane of the middle lamellae.

5. Exhaustive investigations as to the stimulus or stimuli responsible
for the abscission have narrowed them down to two: a fungus, Alter-
naria citrt KE. and P., and climatie conditions.

6. It is considered highly probable that a certain varying per cent
of the drop, occurring relatively late in the season, is brought about
by the stimulation of this fungus, which is also responsible for a black
rot of those infected fruits which remain on the trees to maturity.

7. This fungus is of very wide distribution and infection of the
young fruits is made possible through the peculiar structure of the
navel orange.

8. The amount of infection is dependent upon weather conditions
and the more or less fortuitous configuration of the navel end of the
young fruits.

9. On account of the peculiar manner of infection and the rela-
tively small amount of shedding due to the fungus, spraying will
probably not pay for the labor and materials involved.

10. By far the greater part of the shedding, which occurs earlier
in the season, is due to a stimulus to abscission arising from daily
water deficits in the young developing fruits, resulting from the
asperity of the climatic complex to which the trees are subject.

11. The prineipal factor in causing these abnormal water deficits
lies in the fact that citrus trees are not adapted to withstanding the
heavy water loss incident to the desert conditions under which they
are grown. The amplitude of stomatal movement is small and eutic-
ular transpiration very high.

12. It is further believed that under the prevalent clean cultivation
practice, the soil temperatures during a part of the day are so high as

1919] Coit—Hodgson: Abnormal Shedding of Washington Navel Orange 333

to result in the inhibition of absorption at the very time of day that
water loss by transpiration is greatest.

13. It has been found possible to modify climatic conditions in an
orchard so as to set crops in every way comparable with those produced
in much more climatically favored citrus districts.

14. Under these modified climatie conditions the abnormal water
relations referred to apparently do not occur.

15. Practical means of amelioration lie in heavier and more fre-
quent irrigation, the planting of intercrops, mulching with straw and
other materials, protection by means of windbreaks, and a reduction of
leaf area by moderate winter pruning.

16. Measures of an anticipatory nature lie in the judicious selec-
tion of the site for the orchard with reference to its exposure, nearness
to large irrigated bodies of land, and other features calculated to
ameliorate climatic conditions.

17. Orchardists should be on the lookout for mutant strains which
are dry heat resistant and satisfactory in other features.

This investigation had its inception with the senior author, who
began the experimental work in March, 1916. In May, 1916, the junior
author became connected with the Division of Citriculture and has been
associated in the study of this problem ever since. Early in the in-
vestigation it became evident that there were at least two distinct
promising lines of inquiry involved in the problem. The first, having
to do with the relation of a certain almost ever-present fungus to the
falling of the young fruits, is largely the work of the senior author.
The second, having to do with the relation of the shedding to environ-
mental conditions, although originating with the senior author and
receiving constant study by him, constituted the main problem of the
junior author, who moreover is responsible for the histological work
involved in the investigation. The combination of attack, both on the
pathological and physiological side, has given most satisfactory results
and it is the belief of the authors that when investigated in a some-
what similar manner many of our so-called ‘‘physiological diseases’’
may be better understood.

The authors wish to ackowledge their indebtedness to Drs. F. E.
Lloyd, W. A. Cannon, T. H. Goodspeed, and C. B. Lipman for sugges-
tions and assistance, and to Mr. W. W. Worden and Dr. C. W. Kellogg
for kindly codperation in placing their orchard facilities at their
disposal.

Transmitted January 17, 1918.

EXPLANATION OF PLATES

PLATE 25

The Navel orange orchard of the Edison Land and Water Company,
much of the experimental work was done.

[334]

UNIV, CALIF. PUBL. AGR. SCI, VOL. S [ COIT—HODGSON ] PLATE 26

-

iA

° A
. ory tN

eda
ei te Wael \"

PLATE 26 oe

Part of the Kellogg orchard at East Bakersfield, showing heavy stand of
alfalfa (just cut) between trees and also heavy crop of fruit. Photographed
November 25, 1917.

[336]

UNIV. CALIF, PUBL. AGR. SCI. VOL, S [ COIT—HODGSON ] PLATE 26

PLATE 27 ‘o>.
Typical Washington Navel tree in San Joaquin Valley, showing heavy bloon
oa

« Ms

UNIV. CALIF. PUBL. AGR. SCI. VOL. S [ COIT—HODGSON ] PLATE 27

PLATE 28 ry
Nearer view of same tree, showing details of heavy bloom,

“1ENd ‘dl

So 1A oS sal

> 3JiWid [ NOSDSGOH-LIOOD ]

PLATE 29
One branch with leaves removed, showing large number of buds produced.

_ [842]

PLATE 30 _
Typical abscissed fruits. Those to the right abscissed at the base of the
pedicel, those to the left at the base of the ovary. The two in the center a

healthy fruits picked from the tree for comparison.

q
Te

UNIV, GALIF. PUBL: AGR.USGI. VOL. Ss [ COIT—HODGSON ] PLATE 30

PLATE 31

Small dead orange persisting though abscissed both at base of ovary and
pedicel. Large fruit safely through both abscission periods. The dead style
abscissed much earlier but was retained in position by the ragged nature of the
break.

[346]

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Young Navel oranges, showing the ragged break of the style.
2 diameters.

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Showing the method of enclosing orange trees under the tents o
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Distribution of orange roots by six-inch layers at Edison station.
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UNIVERSITY OF CALIFORNIA PUBLICATIONS +6"
IN

AGRICULTURAL SCIENCE
Vol. 3, No. 12, pp. 369-498, 33 text-figs., pls. 43-74 June 30, 1919

ARE SOILS MAPPED UNDER A GIVEN TYPE
NAME BY THE BUREAU OF SOILS METHOD
CLOSELY SIMILAR TO ONE ANOTHER?

BY
ROBERT LARIMORE PENDLETON

CONTENTS
PAGE
I Be eh sect Wea 2c te aan da cab ove du acboccutanbankesupetecvidsinereenaiwennnmcuavexéeiibiepesnccesid Oe
EEE eR MERC: SUSAR Me Festa 1 Ser RAEe tens JdeN CE Oke ee ean nee es See 370
IS USE UE sg 0) |, ann Sl a 371
Historical development of the classification of soils .....................2---:ccscee-eeeeeees 371
emmeecen GG Prewent. Sey cc cee ig Ren iets ee. 376
ER gE USS SASSER eee Ope nS Ct Sl eee nee ae, See 377
CESS, 1 Sigg gO be RCE Ree ss Rn ee lee 380
ER Se A ee SP tet Sn Pe De ae ok ee eae: ROLE ee 395
ES SSE NS ORO ae Sere eee On | cS ee eee See 414
8 SIRE EERIE Se Ra ib ees (ieee | eee ne Se > a 432
NNER oe eis ar a A ae ac vigincndcaadenbeaghae ees 467
Ee A eee ae kee ee ene TCE de 2 ol rT Oa 481
(EE Eo TE RT ae On ne Renae Ue on 0 te er. © 483
) we Methods and technique: 02.) oo Soar euanctae. 483
yp OTST y 97 ana OR SU OE AL 2 nn ce ere 490

FOREWORD

It is due the author, as well as to the undersigned, that a few
words be said by way of preparing the reader for what follows in this
paper. It will be observed, first, that the manuscript was, for an
unusually long time, in the printer’s hands. Those who appreciate,
as few do today, the great rapidity with which the theories and the
methods in soil and plant study change, will readily catch the signifi-
cance of the foregoing sentence. Much of the work done by Mr.
Pendleton and some of the methods used may now properly be con-
sidered obsolete, or, conservatively speaking, at least obsolescent.
Nevertheless, I deem it of some importance to give the results obtained
in more or less detail, because of their historical value, and because Mr.

370 University of California Publications in Agricultural Sciences | Vol. 3

Pendleton’s residence in India since the paper was written by him
has rendered satisfactory changes and deletions practically impossible.
Under these circumstances, with the burden of preparing the paper
for the press and the reading of the proof falling to me, the author
cannot well be held responsible for the inaccuracies and the infelicities
of expression which have been carried over from the original manu-
script without change. Moreover, the investigation was carried out
under my direction, and the plan of attack on the problem, together
with the methods employed, were suggested by me. Much that, in the
light of present knowledge, is superfluous or patently inexact or
erroneous in the paper is due to points of view held by me in 1915,
but now happily discarded. For all these, I assume the entire
responsibility, and absolve Mr. Pendleton in that regard.

On the other hand, the work having been carried out at my sugges-
tion and under my direction, I feel constrained, in justice to myself,
to say that the views expressed in this paper, and the conclusions
drawn are wholly Mr. Pendleton’s and are not in agreement with those
held by me. I fail to see the cogency of the arguments set forth for
soil classification and mapping at this juncture in soil studies, and
cannot admit the pertinence of the analogy between classification of
other objects and of soils which the author of this paper employs.
My own general conclusion from the results obtaied by Mr. Pendle-
ton is that they cast grave doubt on the validity of the Bureau of Soils
method of soil classification and mapping, and, incidentally on all
methods devised for that purpose to date. I cannot see how such
methods can serve us in scientific work at all, and, from the practical
standpoint, it would surely seem that guides for the purchaser of land
could be arranged more cheaply and less elaborately than by the soil
mapping methods extant. This statement has particular reference to
the subdivision of types very minutely, such as, for example, sandy
silty clay, clay loam adobe, ete. Such minute classification and sub-
division in view of the present state of our knowledge of soils, is
analogous, in my opinion, to carrying figures out to four decimal
places when it is known that the accuracy of the method makes it
impossible for them to be correct beyond the first decimal place. In
support of this seemingly radical conclusion, the reader will find much
of interest in the recent studies of this laboratory on variability in
soils, which have already appeared in this same series.

Cnuas. B. LIPMAN.

INTRODUCTION

For several years the University of California has been cooperating
with the United States Bureau of Soils in the mapping of the soils of
the agricultural portions of the State of California. The system of
mapping used is that developed by the Bureau of Soils. During the
year 1914-1915 the writer, representing the University of California,
was engaged in some of this soil survey work. In that year, in the
field, many questions arose regarding the criteria used, the methods,

1919 } Pendleton: A Study of Soil Types 371

and the results of the scheme of mapping. It was thought that pos-
sibly some of the many questions could be answered through a labora-
tory study of some typical soils. This paper is a description of cer-
tain parts of the work done in this connection.

THE NEED OF A CLASSIFICATION OF SOILS

Since soils consist of a number of more or less distinct groups they
are fitting subjects for classification. In fact, it is my belief that it
is as necessary to have a classification for soils as for any other group
of natural objects in order that ‘‘the various and complex relations

1 and that there be a definite

may be shown as far as practicable,
basis for systematic and thorough investigations.” The advantages of
a classification of soils are apparent. But because soils grade gradu-
ally into one another, rather than exist as discrete individuals which
ean be more easily considered and treated from a systematic stand-
point, the problem of evolving a satisfactory classification has been
particularly difficult. The many and diverse classifications proposed,
and the difficulty of applying many of these classifications under con-
ditions other than those for which they were evolved, testify to the
difficulty of the task in question.

The mapping of soils without a classification is impossible, and
so a brief summary of the development of soil mapping will bear a
close relation to the development of soil classification.

HISTORICAL DEVELOPMENT OF THE CLASSIFICATION
OF SOILS

The early history of the making of soil maps is that of geologic
maps as well, when soils, from the agricultural standpoint, and the
less distinct geological formations as such, were not sharply distin-
guished. Blanck*® has an excellent treatment of the development of
soil mapping and of the modern continental European conceptions of
the nature and significance of soil maps. According to Blanck the
earliest record of a proposal to make a map to show something of the
nature of the actual material composing the surface of the earth is
that of Lister’s proposal, in 1683, to the Royal Society of London.
1 Coffey, G. N., Proc. Amer. Soc. Agron., vol. 1 (1909), p. 175.

2 Cameron, F. K., Eighth Internat. Cong. Chem., vol. 26 (1912), sees. Via—xiIb;

app. pp. 699-706.
3 Fihling, Landw. Ztg., vol. 60 (1911), pp. 121-45.

372 University of California Publications in Agricultural Sciences [| Vol. 3

But it was not until 1743 that Packe executed a map of Kent, showing
the occurrence of minerals by symbols. Apparently the next advance
was by the Germans, when Fiichsel, 1773, and Gloser, 1775, first used
colors to show granite, limestone, ete. This work constituted the first
real geologic map in the modern sense, There was not much activity
in this line of geologic work until 1870 or later. Such activity as there
was showed a lack of emphasis on soils in the agricultural sense of
the term.

The work on the geologic drifts of northern Europe, and studies of
the more recent lowland formations and soils of Germany led to soil
mapping. The first real soil map, according to Blanck, was prepared
by Benningsten-Forder of Halle, in 1864-67; while Carnot* states
that in 1863 M. Scipion Gras used superposable maps of the Depart-
ment of Isére, showing (1) geology, (2) agricultural soils, (3) alti-
tudes of agricultural regions, and (4) culture. The first true geologic-
agronomic map published by the Preussischegeologische Landesan-
stalt appeared in 1878.

The school of soil classification and mapping just mentioned, using
the geologic maps and methods as a point of departure have evolved
numerous though similar systems of recording the agrogeologic data
on the map. The geologic formation is shown by the color, and the
soil textures by symbols, while one or more of the following groups
of data appear and may be shown: topography by contours, subter-
ranean water by blue figures, location of borings in red with figures
referring to tables, amount of plant food elements or substances by
figures or hatchings, varying directions, color, or nature of lines, ete.
The nature and amount of the data shown and the manner of repre-
senting them vary a great deal. Some soilists, to use a term proposed
by Coffey,® advocate and use superposable maps to show one or more
eroups of data, thus avoiding unnecessary confusion on the main map.

Hazard® proposed a scheme of classification which is quite as
directly connected with the economie factors controlling the crops
erown, and with the assessable valuation of the land, as with the
actual or potential fertility of the soil itself. There are several classi-
fications of this type, involving the assessable values of the land.

4 Rapport sur les cartes agronomiques, Bull. Min. Agr. France, 1893, no. 8,
pp. 956-73.

5 Jour. Amer. Soc. Agron., vol. 8 (1916), p. 239.

6 Landw. Jahrb., vol. 29 (1900), pp. 805-911.

Gregoire, A., and Halet, F., Bull. Inst. Chem. et Bact. Gembloux, 1906, no. 75,
pp. 1-43.

al

1919 | Pendleton: A Study of Soil Types 373

This development of the mapping of soils as an outgrowth of areal
geology in France and Germany may be contrasted with the develop-
ment of soil classification from other viewpoints, such as that of the
Russian school. In Russia there is not the predominance of residual
and shallow soils which characterize much of western Europe and
which in France especially have led to the adoption of the geologic
basis of classification. Dokoutchayev and Sibirtzev have been the
chief proponents of a classification of soils based upon the ‘‘ conception
of a soil as a natural body having a definite genesis and a distinct
nature of its own.’

The genetie conditions of the formation of natural soils include
the following variable factors which cause variation :

(1) The petrographic type of the parent rock; (2) the nature and intensity of
the processes of disintegration, in connection with the local climatic and topo-
graphic conditions; (3) the quantity and quality of that complexity of organisms
which participate in the formation of the soil and incorporate their remains in it;
(4) the nature of the changes to which these remains are subjected in the soil,
under the local climatic conditions and physico-chemical properties of the soil
medium; (5) the mechanical displacement of the particles of the soil, provided

this displacement does not destroy the fundamental properties of the soil, its geo-

biological character, and does not remove the soil from the parent rock; and (6)
the duration of the processes of soil formation.

Upon this genetic basis there has been developed a series of soil zones,
ranging from the laterite soils in the tropics to the tundras in the
Arctie regions. The outstanding and controlling factor in the scheme
proposed is the relation of these zones to climate. For this reason the
statement usually seen is that climate is the basis of the classification.®
There are nearly as many groups of intra-zonal and azonal soils as
of those belonging to the zones proper. The former include alka,
marshy, alluvial, and other soils.

Hilgard, while actively interested in the genetic viewpoint of soil
classification, was the foremost proponent of a classification upon
the basis of the natural vegetation growing upon the soil.? This
criterion is not always available, though some groups of plants, as the
alkali tolerant ones, are almost invariably present where the condi-

7 Exp. Sta. Record, vol. 12 (1900), p. 704. .

See also Sibirtzev, Cong. Geol. Intern., 1897, pp. 73-125; abstract in Exp. Sta.
Rec., vol. 12 (1900-01), pp. 704-12, 807-18.
ee Tulaikof, N., The Genetic Classification of Soils, Jour. Agr. Sei. . Vol. 3 (1908),

8 Coffey, U. S. Bur. Soils, Bull. 85 (1912), p. 32; Jour. Amer. Soc. Agron.,
vol. 8 (1916), p. 241.

9 Hilgard, E. W., Soils (New York, Macmillan, 1906), pp. 487-549.

374 University of California Publications in Agricultural Sciences [ Vol. 3

tions are unfavorable for the less resistant plants. Later Hilgard
and Loughridge’® claimed that it is impracticable to attempt ‘‘a sat-
isfactory tabular classification in which each soil shall at once find its
pigeonhole prepared for it . . . because the subject matter is as yet

>?

so imperfectly known.’’ However, this does not dispute the justifica-
tion for making classifications for specific purposes or of specific
regions. With respect to this point there seems to be confusion. The
question is not whether soils can be classified at all or not, for every
observant farmer classifies the soil with which he is familiar, but
whether a satisfactory classification is possible over a large territory,
where soils are subject to the varying action of the important soil
forming agencies.

Still another type of soil mapping is that of Hall and Russell,
which is given in their admirable Report on the Agriculture and Soils
of Kent, Surrey, and Sussex.’’"! In this district the soils are largely
residual, and form quite distinct groups, depending upon the parent
geologic formation. These groups of soils, such as the Clay-with-
flints and the Thanet beds, have very definite agricultural properties ;
hence the treatment of all phases of agriculture upon. each separate
eroup of soils. Hall and Russell’? present an excellent discussion of
the methods of soil classification and the interpretation of the soil
analyses used in their study. Russell*® gives a very similar though
briefer treatment.

There are other more or less specialized classifications that have
been applied to local conditions and problems. As an example may
be cited Dicenty’s work on grape soils.*#

Various modifications of the above schemes of classifying and map-
ping soils are found in general texts on soils.1° Nowacki'® proposes a
curious system, Genera et Species Terrarum. It is in Latin terminology.
The genera are based on the quality of the soil, whether stony, sandy,
clayey, peaty, etc., and the species are dependent upon the quantities
of organic matter and clay.

10 The Classification of Soils, Second Intern. Agrogeol. Conf., Stockholm, 1910,
p. 231.

11 London, Bd. Agr. and Fish., 1911.
12 Jour. Agr. Science, vol. 4 (1911), pp. 182-223.
13 Soil Conditions and Plant Growth (London, Longmans, 1913), pp. 132-48.

14 Die ampelogeologische Kartierung. First Intern. Agrogeol. Cong., Budapest,
1909, pp. 257-71.

15 Ramann, E., Bodenkunde, Berlin, Springer, 1911.
Mitscherlich, E. A., Bodenkunde, Berlin, Parez, 1905.

16 Praktische Bodenkunde (Berlin, 1892), pp. 130-80.

1919 | Pendleton: A Study of Soil Types 375

Soil Surveying in the United States.—In a brief way, it has been
shown how there arose the different systems of soil classification.
Only a few typical systems of classifications, and something of the
reasons for the divergences, have been mentioned.’* Probably the one
agency that has carried on the most extensive soil classification and
mapping is the Bureau of Soils of the United States Department of
Agriculture. It is now proposed to discuss and in a measure criticize
the work of the Bureau of Soils, the one organization that has, more
than any other, succeeded in applying a detailed system of soil classi-
fication over extensive areas.

The problems that the Bureau had to face during its early exist-
ence were special studies of the soils of certain crops, especially of the
tobaeeo districts.‘ Later the soil utilization work of the Bureau of
Soils was transferred to other branches of the Department of Agri-
culture, leaving as the main task for the Bureau the systematic classi-
fication and mapping of the soils of the United States.

Coffey’? has so well discussed the present day conceptions of the
bases for the classification of soils, that it does not seem necessary to
repeat any portion of that excellent statement here. He showed that
the Bureau of Soils, in its method of classifying soils, uses a combina-
tion of a number of systems. This matter is dealt with more in detail
in an article by Coffey,?° and the Report of the Committee on Soil
Classification of the American Society of Agronomy.” The question
often arises as to the validity of making the close distinctions regard-
ing color, texture, geologic origin, ete., and is one which should be
dealt with in order to render less empirical the nature of most of the
criteria which are used at present. See the Report of the Committee
on Soil Classification and Mapping.””

Because of different views regarding soils and soil fertility from
those held by the Bureau of Soils, the Illinois Agricultural Experi-
ment Station has undertaken a soil survey and classification, under the
direction of Dr. C. G. Hopkins, which is independent of the Bureau
"47 Bee Coffey’s excellent treatment of the soil survey work in this country.

The Development of Soil Survey Work in the United States with a Brief Reference
to Foreign Countries, Proc. Amer. Soe. Agron., vol. 3 (1911), pp. 115-29.

18 Whitney, Extension and Practical Application of Soil Surveys, Off. Exp.
Sta., Bull. 142 (1903), pp. 111-12; The Purpose of a Soil Survey, U. S. Dept.
Agr., Yearbook, 1901, pp. 117-32.

19 A Study of the Soils of the United States, U. S. Bur. Soils, Bull. 85 (1912),
pp. 24-38.

20 Jour. Amer. Soc. Agron., vol. 8 (1916), pp. 239-43.
21 Ibid., vol. 6 (1914), pp. 284-88.
22 [bid., vol. 8 (1916), pp. 387-90.

376 University of California Publications in Agricultural Sciences [ Vol. 3

of Soils, and differs from its methods in a number of ways. Since the
soils of Illinois are of a much narrower range of variation than are
those of the whole of the United States, the system of classification
for the state need not be so elaborate. The soils are divided accord-
ingly as they have been glaciated or not, and if glaciated, in what glaci-
ation period. They are further divided according to color, topogra-
phy, and texture of soil and subsoil.** Correlation of the types of
soil mapped in the various areas, one of the greatest sources of criti-
cism of the Bureau of Soils survey methods, is more easily handled
in the Illinois work, since it is possible for the one in charge of the
work to pass personally, while in the field, upon all correlation and
the establishment of all new types. It is insisted that the field men
map accurately and in sufficient detail. This insures the accuracy of
the maps as regards the standards adopted, the information is specific,
and the local users of the maps are not misled.** In connection with
the field classification and mapping, pot and plot cultures are carried
on, not so much to test the relative fertility of the untreated soils, but
to determine the effects of the application of various sorts and quanti-
ties of fertilizers. Hopkins,”° to show the differences in detail between
the U. S. Bureau of Soils mapping and that of the Illinois Experi-
ment Station, compares a U. S. Bureau survey of 1902 with a state
survey published in 1911. This is not entirely fair, because with the
increase of field knowledge of soils gained by them and the realiza-
tion of the need of representing the soils in more detail, a survey
made by the Bureau in 1911 would almost certainly show much more
detail and show it with greater accuracy than the maps made in the
early period of the work. This point may be strengthened by the
notes given below on the comparison of a portion of an early survey
made in southern California by the Bureau of Soils with a recent
survey of the same soils made by the Bureau and the University of
California working in codperation.

PLAN OF THE PRESENT STUDY

The present study is an attempt to see if certain soil types mapped
as the same from different areas in the state of California, and judged
to be the same by the criteria used by the Bureau of Soils, are the —

23 Hopkins, Soil Fertility and Permanent Agriculture (Boston, Ginn, 1910),
pp. 54-57.

24 Ibid., p. 115.
25 Ibid., pp. 114-15.

oe,

a

1919] Pendleton: A Study of Soil Types 37

same or similar when examined from the laboratory standpoint. For
example, we may take the Hanford fine sandy loam, which is one of
the types that has been used in the present study. According to the
eriteria of color, mode of formation, origin (as judged by the presence
of mica), nature of subsoil, texture, ete., this soil has been found and
mapped in a number of areas that have been mapped in this state.
But will these various bodies of soil, from widely separated portions
of the state, when judged by laboratory and greenhouse studies on
samples as nearly representative as possible, appear to be the same or
similar ?

The types selected for such a study as this should fulfil the follow-
ing conditions: first, they should have at least a reasonably wide dis-
tribution in the state so as to have been mapped in a number of differ-
ent soil survey areas; and second, the several types should be repre-
sentative of different classes of soils (clays, loams, sandy loams, etce.),
so that contrasts could be obtained between the types.

In the collection of samples it was aimed to obtain representative
samples from each of a number of bodies of soil of the types selected ;
not to obtain possible variations from the ideal in any one body. In
the laboratory the soils were compared with regard to their physical
composition in the surface horizon, to their chemical composition in
three horizons, and to their relative bacteriological activities. In the
greenhouse the soils (surface horizon only) were placed in large pots
and their comparative ability to produce various crops was studied.

No claim is made that these criteria should be the ones used in
determining the systematic classification of soils or in determining
the relative fertility of the soils. They were merely used to determine
how nearly the soils classed under a given type name agree from the
standpoints named.

DISCUSSION OF RESULTS

The bacteriological and chemical determinations were run in dupli-
eate so that the figures presented are averages. It is considered that
this gives fairer figures for comparison, especially since the determina-
tions were run on separate samples, and not on aliquots of a single
solution from a single sample.

There is a very important factor which should always be kept in
mind especially when considering the bacteriological and greenhouse
comparisons. This is the factor of the probable error. Though the

378 University of California Publications in Agricultural Sciences [Vol.3

advisability of judging all results in the light of the probable error
is admitted, no attempt has been made to apply this factor to the
results reported in this paper. As the result of the effect which such
a factor might have upon the results of bacteriological determina-
tions carried on only in duplicate, or upon the results of greenhouse
work done in triplicate, one hesitates to draw conclusions, especially
those based upon minor variations. Hence in this work only the more
marked results will be considered of significance.

When planning the work it was thought that three or four samples
of a type would be enough to show whether or not a given type was
approximately uniform, or widely variable, and as to whether the
types were similar to one another, or quite dissimilar. But it now
seems, after comparing the determinations run on the larger number
of samples of the Hanford and San Joaquin types, 9 and 8 respec-
tively, with the determinations run on the Altamont and Diablo types,
of-which there were a much smaller number of samples, 3 and 4
respectively, that the larger series gives a much better insight into the
variations of a given type and affords a much better basis for con-
clusions.

Hence, as regards the laboratory work thus far carried out, the
emphasis has been placed upon the Hanford fine sandy loam and the
San Joaquin sandy loam. Determinations have not been completed
on the Altamont and Diablo series to the extent that they have on the
former two.

It is of no little significance that the Hanford fine sandy loam and
the San Joaquin sandy loam are very widely contrasted soils agricul-
turally. The Hanford is typical of good recent alluvial soil in this
state ; while the San Joaquin is typical of wide expanses of ‘‘old valley
filling’’ soils that are considered poor as regards crop producing
power and are underlain by compact iron-cemented hardpan. Conse-
quently, the results of comparing soils so different from an agricul-
tural point of view, and so radically different as regards soil survey
eriteria (though the textures are quite similar) will be of considerable
interest. They are of greater interest than the comparisons between
the Diablo and Altamont soils, as the latter are quite similar in agri-
cultural value and use, as well as in field appearances. Between the
Diablo or Altamont and the Hanford or San Joaquin one cannot
judge as closely regarding variations, for the soils are so radically
different. On the other hand, one can compare the soils of the heavy
and light types to see to what extent the chemical and bacteriological
results differ as compared with the physical results.

1919} Pendleton: A Study of Soil Types 379

See

O ee
025 AN I. ; Me 8. 16. 32. 64. Grits.
Size of Particles bi abd

Fig. 1. Graph showing the results of the Hilgard elutriator method of
mechanical analysis on the four samples of Diablo clay adobe.

380 University of California Publications in Agricultural Sciences [ Vol. 3

MECHANICAL ANALYSIS
Hilgard Elutriator Method.—That there is a wide variation be-
tween the samples is apparent (figs. 1-4). In fact, there is about
as wide a range of differences among the samples of the Hanford

Co

A
‘O
45

Fig. 2. Graph showing the results of the Hilgard elutriator method of
mechanical analysis on the three samples of Altamont clay loam.

fine sandy loam and among those of the San Joaquin sandy loam as
between the two types. The most outstanding differences are where
they ought to be, to show the differences that the type names presup-
pose, i.e., in the ‘‘coarse sand’’ (64 mm.) and the ‘‘grits.’’ The sam-
ples of the San Joaquin sandy loam average a larger proportion of
each of these separates than do the Hanford fine sandy loam soils.

1919] Pendleton: A Study of Soil Types 381

In the Hanford, no. 14 is notably heavier than the others, as shown
by its silt content, which is nearly half again as great as that of the
next highest sample.

The gravel content (sizes above 2 mm.) is interesting in its uni-
formity. In the San Joaquin soils the two samples above 1% are

40 o/,

Oo,
Play 0 oks & Ro a | VA 4 8 16 32 64 Grits
Size of Particles. mm.

Fig. 3. Graph showing the results of the Hilgard elutriator method of
mechanical analysis on the eight samples of San Joaquin sandy loam.

nos. 11 and 26. The material in the latter soil is composed almost
wholly of iron concretions, leaving sample no. 11 as the only soil with
more than 1% actual gravel. In the Hanford samples none were
found to have more than 1.5% gravel.

The Hilgard method does not include any precise subdivision of
the soils into groups or classes according to texture. Dr. Hilgard was
not in favor of making the fine distinctions in texture that other

382 University of California Publications in Agricultural Sciences [Vol.3

investigators have emphasized. But if there were such a scheme,
similar to that which the Bureau of Soils uses,*° it would be an easy
matter to compare the results obtained through the use of the elutri-
ator, and determine whether or not the soils examined belong to a

given class. The simple comparison of the quantities, in different

0.25 Q5 lO 20 40 80 14 32 64 Grim
Size of Particles. mm,

Fig. 4. Graph showing the results of the Hilgard elutriator method of
mechanical analysis on the nine samples of Hanford fine sandy loam.

samples, of any given separate or separates is not absolute. For it
must be realized that the conception of a soil class includes a certain
range in the quantities of particles of the various sizes. This must
be so since soils are ordinarily grouped into but ten or twelve class
textures, while there exist among soils those with all gradations in
the quantities of particles of the various sizes.

26 Instructions to Field Parties, U. S. Bur. Soils, Bull. 1914, p. 75; ibid.,
Bull. 85 (1912), p. 28.

Oe

og, A CE EE A ELE

:
a
‘
%
4

1919 | Pendleton: A Study of Soil Types 383

And because the ranges in the sizes of the soil particles separated
by the Bureau of Soils method cut across those of the Hilgard
method, it is impossible to regroup the results so that the Bureau of
Soils grouping into textures may be applied. But without any such
scheme, desirable as it may be, it has been pointed out that there is
clearly apparent a rather wide variation in the analyses of the several
samples of a type. All the soils representative of a given type are by
no means closely similar to one another.

TABLE 1—COMPARISON OF TEXTURES

Texture as judged

in the field

*1 Diablo clay adobe
2 Diablo clay adobe
3 Altamont clay loam
4 Altamont clay loam
5 Diablo clay adobe
6 Diablo clay adobe
7 Altamont clay loam

10 San Joaquin
11 San Joaquin

2 San Joaquin
13 San Joaquin
14 Hanford fine
15 Hanford fine
16 Hanford fine
17 San Joaquin
18 San Joaquin
19 Hanford fine
20 Hanford fine
21 Hanford fine
22 Hanford fine
23 Hanford fine
24 Hanford fine
25 Hanford fine
26 San Joaquin

sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam
sandy loam

Texture determined by
mechanical analysis
Clay
Clay

*Silty clay
Clay loam (sandy)
Clay
Clay
Clay loam (heavy)

*Fine sandy loam
Sandy loam (heavy)

*Tine sandy loam

*Fine sandy loam (heavy)

- Fine sandy loam (loam)

Fine sandy loam
*Sandy loam
Sandy loam
Sandy loam
*Sandy loam (heavy)
Fine sandy loam
Sandy loam
Fine sandy loam
. Fine sandy loam
Fine sandy loam
Fine sandy loam
Sandy loam

Note.—Textures not judged correctly in the field.

Mechanical Analysis by the Bureau of Soils Method—Among the
other determinations made by the Division of Soil Technology on the
surface horizons of the twenty-four soils used in this investigation
was that of making the mechanical analysis. The tables show the
percentages of the several separates. In all cases the figures represent
averages of duplicate determinations and in some cases the averages
of quadruplicate determinations. With this method, as well as with
the Hilgard elutriator, there are shown wide variations between the

384 University of California Publications in Agricultural Sciences [ Vol. 3

(O68 005: O85 .dA0° 425 os LO
mm =05 ~/0.:- 325 . “2 “LO -20
mm mm. mm mm MM. Wits

Fig. 5. Graph showing the results of the Bureau of Soils method of
mechanical analysis on the four samples of Diablo clay adobe.

1919] Pendleton: A Study of Soil Types 385

samples of a given type. But the graphs of the percentages (figs.
5-8), determined by the Bureau of Soils method for the several types
are not as closely similar as the graphs of the elutriator results for
the same types. That is, using the Bureau of Soils method, the graph
of the Hanford fine sandy loam does not resemble that of the San
Joaquin sandy loam as much as do the graphs of the results made

%
40

30

.005 .005-.05 .05-.10 .10-.25 .25-.5 .5-1.0 1.-2.

Fig. 6. Graph showing the results of the Bureau of Soils method of
mechanical analysis on the three samples of Altamont clay loam.

upon the same soils by the Hilgard elutriator method. This would
lead one to believe that the Bureau of Soils method of mechanical
analysis is the better suited for separating soils into groups; even
though these soils which were classified in the field according to the
differences which are the more prominent would be expected to show
greater differentiations when examined by the Bureau of Soils labora-
tory methods.

386 University of California Publications in Agricultural Sciences [ Vol. 3

Comparison of Textures.—Table 1 gives the texture as shown on
the soil survey map of the locality, as well as the results of the labora-
tory check. This texture as given on the map was also judged by me

50%

45%

40%

55%

%
005005 .05 406 25 5 LOmm
-O5 -10 “25 -=5 -10 2.0mm.

Size of Particles.

Fig. 7. Graph showing the results of the Bureau of Soils method of
mechanical analysis on the eight samples of San Joaquin sandy loam.

in the field to be more or less true to the type as mapped. I say more
or less true, for the field notes, as given in appendix B, show that in
several gases I was unable to obtain in the locality what I believed to

1919] Pendleton: A Study of Soil Types 387

be a sample of the soil thoroughly typical of the class and type in
question. Sample no. 3 had a large lime content which I thought
might more or less obscure the texture. ‘‘Slightly heavy, and barely
enough sand for a sandy loam’’ is the comment on sample 12, while
‘fa heavy sandy loam, approaching a loam’’ is found in the notes on
sample 138. The second column of the table shows the class sub-
divisions into which the soils were placed according to the mechanical
analysis. The words in parenthesis show modifying conditions but
do not indicate a change in the class. In considering the class groups
such as sandy loam, fine sandy loam, ete., it should be remembered
that though the groups are rather broad, the limits are arbitrary
and quite sharp. So the results of a mechanical analysis may place
a soil in the sandy loam class if 25% or more is fine gravel, coarse and
medium sand, while if less than 25% be present the soil belongs to the
fine sandy loam class, providing at the same time the amounts of silt,
clay, and fine sand are within the specified limits. The two soils may
be a great deal alike in texture though placed in different classes.
The failure of my judgment regarding the texture shows one of the
difficulties that the field man is continually facing. And his failure
to judge textures correctly is one of the causes of criticism of soil
survey work.

TABLE 2—MECHANICAL ANALYSES, HILGARD ELUTRIATOR METHOD
Diablo Clay Adobe

Separates

Samples
Velocity,

Diameter, mm. per 1-A 2—-A 5—-A 6-A

Name mm. second Jo Jo Jo Jo
Clay 01 0.25 44.16 35.81 44.97 64.63
Fine silt .01 —.016 0.25 23.91 34.08 25.57 25.13
Medium silt .016—.025 0.5 5.97 7.37 4.14 1.03
.025—.036 i 8.10 9.09 5.28 1.83

Coarse silt .036—.047 2 7.77 TAT 5.45 1.99
.047-—.072 + 6.05 4.09 6.18 2.13

Fine sand .072—.12 8 3.28 1.33 5.81 2.07
12 —.16 16 0.48 0.43 1.73 0.90

Medium sand 16 —.30 32 0.08 0.21 0.38 0.21
Coarse sand 30 —.50 64 0.18 0.11 0.49 0.11
Total weight of separates, gm. 19.18 19.62 19.30 19.68
Weight of original sample, gm. 18.83 18.88 18.66 18.16
Grits, % 0.5-2.0 mm, 0.26 0.29 0.57 0.10

Hygroscopic moisture, % 6.20 5.93 7.18 10.12

388 University of California Publications in Agricultural Sciences [ Vol, 3

“ : iO
fee Aa. -- OD : 25 Ro | LO mm.
“05, 310..-25 -5 0. 20mm
Size of Particles
Fig. 8. Graph showing the results of the Bureau of Soils method of
mechanical analysis on the nine samples of Hanford fine sandy loam.

re

1919]

Pendleton: A Study of Soil Types

389

TABLE 3—MECHANICAL ANALYSES, HILGARD ELUTRIATOR MetrHop

Aliamont Clay Loam

Separates
Velocity
Name GORE: | Lae
Clay 01 0,25
Fine silt OL —.016 0.25
Medium silt .016—.025 0.5
.025-.036 1
Coarse silt .036-.047 2
.047-—.072 4
Fine sand .072-.12 8
12 —.16 16
Medium sand .16 —.30 32
Coarse sand 230 —.50 64

Total weights of separates, gm.
Weight of original sample, gm.
Grits, % 0.5-2.0 mm,

Hygroscopie moisture, %

Samples

TABLE 4—MECHANICAL ANALYSES, HILGARD ELUTRIATOR METHOD

San Joaquin Sandy Loam

Separates
Velocity,
Diameter ar 10-A 11-A
Name mm. second % Jo
Clay .O1 0.25 11.14 15.46
Fine silt .01 -—016 0.25 20.24 31.88
Medium
silt .016-.025 0.5 1.44 2.73
.025-.036 6.54 SL}:
Coarse silt .036-.047 2 Soo)" | 10:23
.047-.072 9.50 8.41
Finesand .072-.12 8 10.66 7.47
12-16 16 10.30 5.97
Medium
sand 16-30 32 14.69 6.91
Coarse sand .30 —50 64 7.11 1.32
Total weight of separates, gm. 20.02 20.44
Weight of original sample, gm. 19.80 19.51
Grits, % 0.5-2.0 mm. 16.70 23.54
Hygroscopie moisture, % 0.98 2.48

12—A
To

8.99
26.57

Z.31
1.33
Lao
10.14

10.72

10.88

11.75
3.54
19.99
19.72
8.84
1.38

Notr.—aAll weighings made on the water free basis.

Samples
13-—A 17—-A
% 6
Pie > 30:53
24.04 16.20
4.64 1.81
9.86 5.89
9.59 5.82
10.05 8.46
10.92 12.04
16.14 13.438
1.96 19.21
2.12 6.60
20.10 20.38
19.76 19.85
8.10 23.12
1.22 0.75

390 University of California Publications in Agricultural Sciences [Vol.3

TABLE 5—MECHANICAL ANALYSES, HILGARD ELUTRIATOR METHOD

Hanford Fine Sandy Loam

Separates
Velocity, Samples
mm,
Diameter per 14-A 15-A 16-A 19-A 20-A 22-A 23-A 24-A
Name mm. second % Yo Jo %o Jo %o % %o

Clay O01 0.25 12.89 8.16 11.97 11.09 1055 7.97 868 6.47
Fine silt 01 -016 0.25 37.25 19.39 2461 595 22.09 1415 22.57 11.11
Medium silt .016—-.025 0.5 419 3.05 3.22 167 640 3.15 5.90 1.20
.025-.036 1 8.63 5.04 5.06 5.27 840 5.29 6.89 5.08

Coarse silt .036-.047 2 7.905 657 5.99 7.14 7.68 6.47 10.53 7.48
.047-.072 4 6.23 10.23 7.27 12.76 9.93 11.380 18.08 13.91

Fine sand 072-12 8 5.26 12.31 8.57 17.79 10.48 17.15 12.71 19.27
12-16 16 7.15 13.93 9.76 12.00 12.29 17.39 794 21.56

Medium sand .16— .30 32 8.81 15.29 16.05 24.20 10.03 14.87 9.88 12.36
Coarsesand .30— .50 64 148 602 751 218 3.70 237 ~s5, 2

Total weight of separates,gm. 20.19 20.23 20.53 20.08 20.27 20.06 20.30 20.26
Weight of original sample, gm. 19.46 19.90 19.69 19.82 19.73 19.81 19.78 19.83
Grits, % 0.5-2.0 4.12 13.23 25.47 7.85 6.71 3.07 17.24 6.85
Hygrosecopic moisture, % 2.73 049 154 089 1.34 094 1.10 £0.84

TABLE 6—MECHANICAL ANALYSES, BUREAU OF SOILS METHOD
Diablo Clay Adobe

Separates Samples
Diameter 1—A 2-A 5-A 6-A
Name mm. % % %o %

Clay .005 44.81 44.44 45.67 56.01
Silt .005— .05 32.00 42.51 23.01 14.28
Very fine sand .05 — .10 19.61 11.35 21.58 25.58
Fine sand 10 — .25 1.36 1,33 4.81 2.10
Medium sand 25 -— 5 0.26 0.69 0.95 2.05
Coarse sand 5 1.0 0.58 0.20 1.56 0.00
Fine gravel 1.0 -2.0 0.03 0.02 0.04 0.00

Nore.—Determinations made by the Division of Soil Technology.

TABLE 7—MECHANICAL ANALYSES, BUREAU OF SoILS METHOD

Altamont Clay Loam

Separates Samples
Diameter 3-A 4—A 7-A
Name mm. % Jo %

Clay .005 33.19 26.50 31.84
Silt .005— .05 31.76 17.35 37.40
Very fine sand .05 — .10 22.81 39.15 24.70
Fine sand 10 — .25 8.97 6.08 3.27
Medium sand 25 — 5 1.99 7.78 ~ 0.92
Coarse sand 5 -1.0 1.74 3.06 0.55
Fine gravel 1.0 -2.0 1.01 1.22 0.22

Nore.—Determinations made by the Division of Soil Technology.

1919] Pendleton: A Study of Soil Types 391

TABLE 8—MECHANICAL ANALYSES, BUREAU OF SOILS METHOD

San Joaquin Sandy Loam

Separates Samples
Diameter 10—-A 11—A 12-A 13—A 17—A 18—A 21-A
Name mm, % % %o Yo % %o To

Clay .005 10.78 15.77 16.16 16.94 Lat 10.49 8.28
Silt 005— .05 21.60 35.97 25.04 22.70 15.97 26.74 17.70
Very fine sand .05 — .10 28.07 18.53 27.42 47.01 20.42 12.02 15.92
Fine sand 10 — .25 19.96 2.66 17.07 3.99 22.57 16.61 21.27
Medium sand 25 — 9.20 6.96 5.80 4.69 10.75 138.85 13.57
Coarse sand o 1.0 9.08 8.51 6.52 2.96 13.81 16.52 21.41
Fine gravel 1.0 -2.0 1.34 12.52 2.15 1.81 3.13 4.07 2.07

NorTe.—Determinations made by the Division of Soil Technology.

TABLE 9—MECHANICAL ANALYSES, BUREAU OF SOILS METHOD

Hanford Fine Sandy Loam

Separates Samples
Diameter 14-A 15-A 16-A 19-A 20-A 22-A 23-A 24-A
Name mm. %o Yo %o % % %o %o Jo

Clay .005 14.10 12.08 16.84 15.28 15.95 7.79 10.61 9.83
Silt .005— .05 39.25 22.42 16.16 15.03 32.90 22.70 2438 11.42
Very fine sand 05 —.10 22.66 37.12 16.46 32.87 22.58 36.15 38.73 42.05
Fine sand 10 — 25 17.54 651 17.32 813 18.20 27.78 16.51 28.73
Medium sand 29 — wo 4,71 1140 :21.70 35.42 4.97 421 4.66, 427
Coarse sand » 1.0 1.99 649. 15.54 827 3:07 147 © 3.28) -3.01

Fine gravel 1.0 -2.0 Oise 091 6.27" *a.05. (0.20 0.20 148 £02

NoTEe.—Determinations made by the Division of Soil Technology,

Moisture Equivalent—The moisture equivalents of the surface
horizon samples were determined by the Division of Soil Technology
(table 10, and figs. 9, 10). The different types gave quite distinct
averages, though there was considerable variation within the type.
The Diablo clay adobe varied from 37% to 57%, with an average of
47%. The Altamont clay loam varied from 22% to 37%, with 28%
as an average. The San Joaquin sandy loam varied from 7% to
15%, with the average of 11%. The Hanford fine sandy loam varied
from 11% to 25%, with 15% as the average. These figures show
that as a whole the moisture equivalents of the several types are
distinct, though there is the usual overlapping in some cases. The
samples of a given type are in many instances closely similar, though
not always or even usually so.

To
17.38
18.17
13.84
10.26
14.72
24.26

2.02

25-A
%o

7.60
12.90
67.37

5.88

3.47

1.27

1.02

392 University of California Publications in Agricultural Sciences [ Vol. 3

Moisture
Equivalent

Moisture
Equivalent

Fig. 9. Graph showing the results of the determination of the moisture
equivalent and of the hygroscopic coefficient on the four samples of Diablo
clay adobe and the three samples of Altamont clay loam. .

1919 | Pendleton: A Study of Soil Types

TABLE 10—MOISTURE EQUIVALENT

San Joaquin Sandy

Diablo Clay Adobe Altamont Clay Loam Loam
A...

rac

Average Average Average
No. % % No. % % No. Yo %
1-A_ 49.70 3-A 38.10 10-A 10.30
48.90 49.30 37.80 37.95 10.10 10,20
2-A 37.40 4-A 23.41 11-A_ 15,52
36.80 37.10 22.30 22.88 15.54 15.53
5-A 46.55 7-A. 23.90 12-A 13.72
48.10 47.32 23.90 23.90 12.62 13.67
6-A 58.80 Average 28.94 13-A 14.50
56.80 57.80 14.60 14.55
Average 47.88 17-A_—-: 8.90
§.98 $8.94
18-A° =—s 7,92
1.87 7.89
21-A 7.16
7.09 7.12
26-A 11.30
Eiiea. 17.55

Average 11.18

Norr.—Determinations made by the Division of Soil Technology.

TABLE 11—HyGroscoric COEFFICIENT

San Joaquin Sandy

Diablo Clay Adobe Altamont Clay Loam Loam

Average Average Average
No. % % No. %o % No. * % %
1-A_ 15.88 3-A 17.48 -14-A_ 5.35
15.08 15.48 1845. 17:93 4.70 5.03
2-A = 9.90 4-A 9.60 15-A 1.31
9.48 9.69 7.00, 8.30 1.39 1:35
5-A 14.18 7A 7.92 16-A 3.90
13.90 14.04 5.92 6.92 3.60 3.75
6-A 15.20 Average 11.05 19-A 1.66
15.70 15.45 EA ee 1°73
Average 23.66 20-A_ 2.90
3.02 2.96
22-A 2.48
2.89 2.69
23-A 2.38
2.53 2.46
24-A 2.39
24-A 2.39
2.07 2.38
25-A 1.78
1.84 1.81

NorTe.—Determinations made by the Division of Soil Technology.

Loam

No. /,
14-A 25.80
25.20
5-A 11.50
11.20
16-A 15.60
15.60
19-A_ 13.30
14.30
20-A 18.41
18.38
22-A 12.73
12.22
23-A 11.08
19.90
24-A_ 16.30
16.17
25-A 11.17
12.72

393

Hanford Fine Sandy

Average
os
JO

25.50
11.35
15.60
13.80
18.39
12.47
10.99
16.23

11.94

Average 15.14

Hanford Fine Sandy

Loam
No. Jo
10-A_ 2.46
2.51
11-A_ 3.44
3.45
12-A_ 3.58
3.45
13-A_ 2.50
2.60
17-A_ 1.84
1.62
18-A_ 2.10
2.00
21-A 1.98
1.92
26-A 3.57
3.52

Average

Average
%

2.49

394 University of California Publications in Agricultural Sciences [Vol.3

Moisture
Equiv.

NG
Equiv.

14 15 16 19 20 22 23 24 25 Soils

Fig. 10. Graph showing the results of the determination of the moisture
equivalent and of the hygroscopic coefficient on the eight samples of San
Joaquin sandy loam and the nine samples of Hanford fine sandy loam.

Hygroscopic. Coefficient—The determination of this coefficient,
also by the Division of Soil Technology, shows no very distinct values
for the several types under consideration (table 11, figs. 9,10). The
Diablo clay adobe samples vary from 9.6% to 15.4%, with the average
of 13.6%. The Altamont clay loam samples vary from 6.9% to
17.9%, averaging 11%. The San Joaquin sandy loam varies from

1919] Pendleton: A Study of Soil Types 395

1.7% to 3.5%, with the average of 2.66%, while the Hanford fine
sandy loam varies from 1.3% to 5%, with the average of 2.68%.
There is no question that here the range of values within every type
is greater than that from type to type. Even excluding those sam-
ples shown by the mechanical analysis to be not true to name there
is a wide range within each type—a range too wide to allow one
to answer the question of this paper in the affirmative.

1 2 5 6 Soils

Fig. 11. Graph showing the percentages of nitrogen and of phosphorus in
the four samples of Diablo clay adobe.

THE CHEMICAL DATA

ToTAaL NITROGEN

Diablo clay adobe.—There is more variation in nitrogen content
between the different representatives of the type than one would
expect from a visual examination of the soils (table 12 and fig. 11).
No. 2 would be expected to contain less nitrogen than no. 5 because of
the lighter color, but such is not the case. In the A horizon, no. 5
shows the lowest notal nitrogen content with 0.084%, no. 2 is higher
with 0.092%, no. 1 with 0.104%, and no. 6 is the highest with 0.117%.
The decrease in the nitrogen content with the increase in depth is
normal. In the C horizon, no. 1 has the lowest total nitrogen content
with 0.057%, and no. 6 the highest, with 0.078%.

Altamont clay loam.—The agreement between the A samples is
fairly close (table 13, and fig. 12). No. 4 has 0.103%, no. 7, 0.104%,
and no. 3 has 0.123%. This gives an average for the surface soil of
0.110%, as compared with 0.099% in the Diablo clay adobe. It is to
be noted that the nitrogen content of the subsoil is relatively less
than that in the Diablo subsoils, 0.071% and 0.056% in the Altamont
B and C horizons, respectively, as against 0.076% and 0.065% in the

396 University of California Publications in Agricultural Sciences [Vol.3

B and C horizons of the Diablo. The average amount of nitrogen is
higher in the A horizon of the Altamont than in the Diablo, contrary
to what one would expect from the color of the soils, since the Alta-
mont is typically a brown soil and the Diablo a dark gray to black soil.

San Joaquin sandy loam.—The nitrogen content of these soils is
uniformly low (table 14 and fig. 13), from 0.03% to 0.05%, and is but a
third to a half of what Hilgard believed adequate for crop production.

3 4 7 Soils

Fig. 12. Graph showing the percentages of nitrogen and of phosphorus in
the three samples of Altamont clay loam.

Fig. 18. Graph showing the percentages of nitrogen and of phosphorus in
the eight samples of San Joaquin sandy loam.

The nitrogen content is seen to vary more or less directly with the
amount of the finer sediments present in the soil—nos. 11 and 12
being heavy members of the type, with 0.05% and 0.047% respec-
tively, and nos. 17 and 18 light members of the type with 0.029% and
0.027% respectively. It may be noted that the nitrogen content of
the various horizons are not as far apart as in the other types. The
averages for the three horizons are: A—0.037%, B—0.027%, and
C—0.026%. It must be borne in mind that the San Joaquin sandy
loam horizons are not full 12-inch samples, and that the total depth
of the sampling is less. wre

1919 } Pendleton: A Study of Soil Types 397

Hanford fine sandy loam.—Uere again in the A horizon the nitro-
gen content is fairly uniform (table 15, and fig. 14), with from 0.045%
to 0.072%, if the extra typical no. 14, with 0.119%, be left out of
consideration. One would suppose these soils to be higher in their

0.9 — pen
P20Os5
0.8 LSS PISRARS IRL aed Beene
|
| |
0.7 hE mae es |

: eee
: 2a
0.4 ae

a
} =
: ae
0.1

14 15 16 19 20 22 23 24 25 Soils

Fig. 14. Graph showing the percentages of nitrogen and of phosphorus in
the nine samples of Hanford fine sandy loam,

nitrogen content, as compared with the San Joaquin series, than the
results show. The B and C horizons of the Hanford samples contain
0.038% and 0.028% nitrogen, respectively, showing that with the
increase of depth there is a more rapid decrease of nitrogen than in
the San Joaquin samples, with the nitrogen content of the C horizon
of the Hanford only 0.002% above that of the C horizon of the San

398 University of California Publications in Agricultural Sciences [ Vol. 3

Joaquin. The greenhouse pot cultures showed the effect of the much
higher nitrogen content in no. 14 in giving better color and growth
to the plants and especially to the grains. The increase of the nitrogen
in the surface of no, 23, as compared with the B and C horizons,
might be ascribed to the fertilizers applied to the orange grove where
this sample was collected; yet no. 24 is a truck soil which has been
fertilized to a considerable extent with barnyard manure. The nitro-
gen content of this type, as judged by the previous standards, is
quite inadequate.

Compare the nitrogen content of the A horizons of the four types:
The Diablo has an average of 0.099%, with a range or from 0.084%
to 0.117% ; the Altamont has an average of 0.110%, with a range of
from 0.103% to 0.123% ; the San Joaquin has an average of 0.037%,
with a range of from 0.027% to 0.050%; and the Hanford has an
average of 0.062%, with a range of from 0.045% to 0.119%. Thus
the total nitrogen content of the several types is reasonably constant
within the type and rather distinct for the types.

/
TABLE 12—ToTAL NITROGEN
Diablo Clay Adobe

Horizon
A Average B Average C Average
Sample % %o % % Jo Jo
0.109 0.105 0.076 0.069 0.056 0.057
1 0.101 0.063 0.059
2 0.100 0.072 0.062
0.084 0.092 0.064 0.068 0.058 0.060
5 0.085 0.065 No sample
0.084 0.084 0.065 0.065
6 0.114 0.097 0.075
0.122 0.118 0.107 0.102 0.083 0.079
Average 0.100 0.076 0.065
TABLE 13—ToTaL NITROGEN
Altamont Clay Loam
Horizon
A Average B Average Cc Average
Sample % % % Jo % %o
3 0.123 0.089 0.069
0.124 0.123 0.087 0.088 0.067 0.068
4 0.103 0.054 "@04) 0.041
0.103 0.103 0.053 0.053 0.041 0.041
a 0.106 0.070 0.061
0.104 0.105 0.077 0.073 0.059 0.060

Average 0.110 0.071 0.056

1919]

A

Sample’ %
10 0.037
0.038
ll 0.051
0.051
12 0.049
0.045
13 0.040
0.040
17 0.028
0.030
18 0.028
21 0.029
0.030
26 0.041
0.041

Average

A

Sample %
14 0.113
0.126
15 0.052
0.055
16 0.058
0.054
19 0.046
0.044
20 0.062
0.058
22 0.057
0.061
23 0.075
0.071
24 0.050
25 0.045
0.047

Average

Pendleton: A Study of Soil Types

TABLE 14—ToTaL NITROGEN

San Joaquin Sandy Loam

Average
Yo

0.037
0.051
0.047
0.040
0.029
0.028
0.029

0.041
0.038

TABLE 15—ToTaL NITROGEN

Hanford Fine Sandy Loam

Average
/0

0.119
0.053
0.056
0.045
0.060

0.059

B

%
0.026
0.029
0.042
0.046
0.032
0.034
0.038
0.043
0.019
0.018
0.016
0.017
0.012
0.012
0.026
0.027

B
Jo

0.084
0.081

Horizon
“ee
0,027
0.044
0.033
0.040
0.018
0.016

0.012

0.026
0.027

Horizon

Average
(4)

0.082
0.041
0.030
0.025
0.033
0.034

0.029
0.034

0.031
0.038

©

%
0.022
0.020
0.038
0.040
0.042
0.040
0.033
0.033

Average
To

0.02]
0.039
0,041

0.033

No sample

0.018
0.021
0.014
0.014
0.016
0.017

Cc
%o
0.060
0.057
0.028
0.027
0.020
0.023
0.024
0.023
0.024
0.022
0.025
0.023
0.020
0.016
0.028
0.022
0.024

0.019

0.014

0.016
0.026

Average
oO

0.058

399

400 University of California Publications in Agricultural Sciences | Vol. 3

HuMUS

Diablo clay adobe.—The variations in the humus content of the A
samples (table 16, and fig. 15) are moderate, 1.1% to 1.4%, while the
B and C horizons do not agree so closely with each other or with the

Loss on
Ignition

4 K20

Tlumus

1 2 5 6 Soils

Fig. 15. Graph showing the loss on ignition, the amount of humus, and
the percentages of calcium, magnesium, and potassium in the four samples
of Diablo clay adobe.

surface foot. The average content of humus in the A samples is
1.26%, in the B samples 0.95%, and in the C samples 0.75%. It is
worthy of note that soil no. 2, with the lightest color of the four, and
what might be supposed to be a lower humus content, has next to the
highest amount. }

1919] Pendleton: A Study of Soil Types 401

Altamont clay loam.—Here the variations in the humus content
(table 17, and fig. 16) are small in the A horizon, 1.1% to 1.3%. The
average is 1.24%. The B and C samples show a good parallelism
among themselves, but not so good when compared with the surface.
The average of the B horizon is 0.84%, and of the © horizon 0.57%.

%
9

Loss on
Ignition

3 4 7 Soils
Fig. 16. Graph showing the loss on ignition, the amount of humus, and the
percentages of calcium, magnesium, and potassium in the three samples of Alta-
mont clay loam.

San Joaquin sandy loam.—This type contains a considerable quan-
tity of humus (table 18, and fig. 17) when one takes into considera-
tion the popular criteria for the presence of humus, for the red to
reddish brown San Joaquin soils are very different from the brown
Altamont or the black Diablo soils. The samples of this type gave

402 University of California Publications in Agricultural Sciences [Vol.3

light colored or nearly colorless humus solutions. But when the ali-
guots were ignited, after evaporation, there was a very noticeable
blackening and charring of the residue, together with a considerable

Loss on
Ignition

10 1l 12 13 17 18 21 26 Soils

Fig. 17. Graph showing the loss on ignition, the amount of humus, and
the percentages of calcium, magnesium, and potassium in the nine samples of
San Joaquin sandy loam.

loss in weight. This phenomenon, in the hight of the work of Gortner,?*
shows that these soils have a ‘‘humus’’ content above that which they
might be supposed to have, because of the almost complete absence of

27 Soil Science, vol. 2 (1916), pp. 395-442.

1919} Pendleton: A Study of Soil Types 403

the ‘“‘black pigment.’’ Soil no. 26, probably the only virgin soil in
the series, shows a particularly high content of humus for such a soil,
though from the color of the soil one would suspect but very little
humus. The agreement between the three horizons of the San Joaquin
sandy loam samples is close. The average content of humus was
0.68% in the A, 0.51% in the B, and 0.38% in the C horizon.

Hanford fine sandy loam.—The variations in humus content in this
type are greater than in any of the others (table 19, and fig. 18). This
is possibly because of two factors: the open texture of the soil, hence
the rapid loss of organic matter by oxidation processes ; and secondly,
the high agricultural value of this soil, which has led to a greater appli-
eation of fertilizers than has been the case with the other soils. The
actual variations in the humus content are large, 0.7% to 2.1% with
the average of 1.15% for horizon A, from 0.5% to 1.8% with the aver-
age of 0.81% for B, and from 0.44% to 1.07% with the average of
0.59% for C. The extra-typical sample no. 14 is above any of the
others in the total humus content. The variations in the subsoil
humus content are more or less parallel to those of the surface soil.

The following averages of the humus content of horizon A, Diablo
1.26%, Altamont 1.24%, San Joaquin 0.68%, Hanford 1.15%, show
that there is not much difference between the soils, except for the San
Joaquin sandy loam, which has an average of half the others. Within
the type the soils may be nearly alike, as in the San Joaquin and Alta-
mont, or may be variable to a large degree, as in the Hanford. The
variations in the humus content of the soils are small, considering the
diverse nature of the soils, and the usual methods for judging the
quantity of humus.

TABLE 16-—HuMus (AND Humus ASH)
Diablo Clay Adobe

Humus Humus ash
Horizons Horizons
Aver-
A Average B Average OC Average A Average B_ Average C age
Sample % Jo Jo Yo Jo Ye %o Jo Jo Je Ye Jo
1 1.08 0.51 0.18 0.55 0.75 0.45
1.08 1.08 0.51 0.51 0.24 0.21 0.56 0.56 0.73 0.74 0.46 0.46
2 1.40 1.16 1.09 1.01 0.96 1.09
1.38 1.39 1.15 1.15 1.02 1.06 1.03 1.02 0.96 0.96 0.96 1,03
5 a17 Case \aiees, 1.08 1. ees
hae 44S ODT - O.88)* ssc. - - s- 250-480-114. LAR as. ka
6 1.48 1.26 0.95 0.98 0.88 0.78
1.37 1.43° 1.26 1.26 0.99 0.97 0.95 0.96 0.91 0.90 0.85 0.81

Average 1.26 0.95 0.72 0.91 0.95 0.77

404 University of California Publications in Agricultural Sciences [Vol.3

Fig. 18. Graph showing the loss on ignition, the amount of humus, and
the percentages of calcium, magnesium, and potassium in the nine samples of
Hanford fine sandy loam.

1919]

Sample

3

4

Average

Sample
10

11
12
13
17
18
21
26

Average

A Average

f
%o

%

1.09

1,31

1.32
1.24

Average
Jo

0.64

0.77

0.51

0.58

0.52

1.02
0.66

Excluding no. 26

Pendleton: A Study of Soil Types

TABLE 17—Humus (AND Humus AsH)

Altamont Clay Loam

Humus Humus ash
Horizons Horizons

B Average © Average A Average B_ Average
Yo %o % % Yo To Yo Jo
0.89 0.59 1.29 1.08
0.84 0.86 0.58 0.59 1.28 1.26 1.28 1.18
0.69 0.59 0.80 0.98
0.71 0.70 0.28 0.43 0.85 0.83 0.98 0.98
0.95 0.68 0.72 0.87
0.96 0.96 0.68 0.68 0.75 0.74 0.88 0.88
0.84 0.57 0.94 1.01

TABLE 18—Humus (AND Humus AsH)

San Joaquin Sandy Loam

Humus Humus ash
Horizons Horizons

B Average C Average A Average B Average
Yo Jo %o Yo Jo To To Yo
0.53 0.27 1.31 1.33
‘ame O35 © xc) OLE es ls ES, SO 8 1
0.41 0.37 0.51 0.66
Wes. O30 seat War) -UGos 6.60 ..5 0.66
0.49 0.32 0.88 1.50
nem. 049 ...... 0.32 Goer ee os. LO
0.50 0.35 1.38 0.90
le O30) Sta Ae We AO oc O90
PES yd ll chats 0.53 1.23
ey Se Oe ees Gere PL LOD, cae ee
0.60 0.42 0.61 0.76
Gass U9". iss, 0.42 0.56 0.59 0.75 0.76
0.19 0.18 0.53 0.37
0.21 0.40 0.21 0.19 0.54 0.53 0.37 0.37
0.79 0.68 0.89 ' 3.57
0.79 0.79 0.82 0.75 0.76 0.83 3.63 3.60
0.51 0.38 . 0.83 1.24
Ct ye! ee | ae eee, 0.95

Loss ON IGNITION

0

%
0.95
0.95
0.91
1.03
1.09
1.08

Aver-

oe
0.95
0.97

1.08
1,00

The loss on ignition of the A horizon varies directly with the tex-

ture of the soil, the heavier soils losing more on heating.
the water of combination of the clay is a large factor in this loss.

Obviously

In

the San Joaquin sandy loam the loss on ignition was determined in

the three horizons.

only one examined (tables 20, 21, and figs. 15-18).

In the other three types the A horizon was the

406 University of California Publications in Agricultural Sciences | Vol. 3

TaBLE 19—-HuMus (AND HuMUS ASH)

Hanford Fine Sandy Loam

Hummus Humus ash
Horizons Horizons
je Ee [ E

A Average B Average C Average A Average B Average C age
4

Sample % % % Yo % % % % Yo % % Jo

14 2.11 1.81 1.10 1.14 1,24 1.01
8.00 2130 1.78.1.79 1.05 1:07 -1.27 136 3.37 1.36 100-35

15 1.79 0.88 1.04 1.88 0.94 0.92
1.77 1.78 0.93 0.90 0.67 0.86 1.85 1.86 0.89 0.92 0.91 0,92

16 1.20 0.73 0.41 0.91 0.93 0.90
1.20 1.20 0.73 0.73 0.46 0.44 0.91 0.91 1.47 0.93 0.90 0.90

19 0.73 0.51 0.45 0.48 0.57 0.78
0.74 0.73 0.50 051 0.55 050 047 048 0.58 0.58 0.76 0.77

20 1.08 0.86 0.59 0.52 0.90 0.79
1.06 1.07 0.89 0.88 0.50 0.55 0.56 0.54 0.90 0.90 0.78 0.78

22 0.96 0.73 0.58 0.59 0.60 0.58
0.96 0.96 0.71 0.72 0.56 0.57 0.59 0.59 0.60 0.60 0.63 0.61

23 1.04 0.59 0.38 0.58 0.45 0.39
1.07 1.05 0.62 0.61 0.38 0.38 0.57 0.58 0.41 0.43 0.37 0.38

24 0.73 0.55 0.56 0.58 0.69 0.82
0.73 0.73 0.61 0.58 0.51 0.54 0.56 0.57 0.69 0.69 0.80 0.81

25 0.71 0.58 0.45 0.57 0.67 0.74
0.69 0.70 0.56 0.57 0.42 0.44 0.61 0.59 0.71 0.69 0.78 0.76
Average £15 0.82 0.59 0.81 0.78 0.78

Diablo clay adobe-—The variation in these samples was from
5.6% to 8.6%, with the average of 6.8%. The Altamont clay loam
has a variation of from 5% to 8.7%, averaging 6.7%. The San Joa-
quin sandy loam has a range of variation between 1.6% and 4.2%,
with an average of 2.6%. The loss on ignition of the lower horizons
increases over that of the surface, because of the increase in texture.
The B horizon shows an average loss of 3.9% and the C horizon of
4.67%. The Hanford fine sandy loam range of variation in the loss
on ignition is, excluding no. 14, from 2.2% to 3.9%, with an average
of 3.4%. Thus the curve for this type is quite uniform, except for
no. 14, which shows a loss of 6.9%.

It is seen that the averages in the loss on ignition of the A horizons
of the Diablo and Altamont soils are close, and high, 6.8% and 6.7%
respectively. The averages of the San Joaquin and Hanford sam-
ples, 2.6% and 3.4% respectively, are low and not widely separated.
Since the values for the types overlap considerably, and the averages
are not distinct, except between the light and heavy groups, there is
no significant distinction between the four types by this determination.

1919]

Pendleton: A Study of Soil Types

Diablo Clay Adobe

% %
1-A 6.62
6.66 6.64
2-A 6.57
6.64 6.60
5-A 5.61
senee 5.61
6-A 8.67
8.71 8.69
Average 6.88
A
Sample %
10 2.13
2.17
11 3.23
3.20
12 5.37
3.22
13 2.94
2.96
17 1.85
1.88
18 1.82
1.83
21 1.68
1.69
26 3.30
Average

(Surface horizon only )

Altamont Clay Loam

3-A

San Joaquin Sandy Loam

Average
%

a)

2.15

%
8.74
8.82
5.05
5.05
6.58
6.46
Average

Horizon
B Average
Jo 0

2.32

2.27 2.29

6.33

6.16 6.24

2.97

3.18 3.07

6.58

6.75 6.66

2.54

2.61 2.57

2.18

2.18 2.18

1.60

1.56 1.58

6.97

6.95 6.96
3.94

% 1)

TABLE 20—Loss oN IGNITION

Hanford Fine Sandy
Loam

24-A

25-A

Yo
6.90
6.95
2.27
2.30
3.26
3.24
3.10
3.13
3.90
3.94
3.06
3.07
3.48
3.45
2.60
2.60
2.68
2.72

Average

TABLE 21—Loss oN IGNITION

6.07

5.02

No sample

2.90
2.89

%

6.92

2.28

40

408 University of California Publications in Agricultural Sciences [Vol.3

CALCIUM

The Diablo, Altamont, and Hanford soils were analyzed for their
calcium in the A horizon only, while the A, B, and C horizons of the
San Joaquin sandy loam were analyzed (tables 22, 23, and figs. 15-18).

Diablo clay adobe.—There is much divergence in the amounts of
CaO in this type, varying from 0.36% to 2.05%, with the average
of 1.23%.

Altamont clay loam.—In this type there is a little greater varia-
tion than in the Diablo samples, with a range of from 0.78% to 5.64%,
averaging 2.44% CaO. In both this soil and in the Diablo the wide
variation in the lime content is undoubtedly due to the nature of the
parent rock, since the soils are residual.

San Joaquin sandy loam.—In the CaO content there is no uni-
formity among the samples. The A samples of this type contain from
0.47% to 2.98%, with an average of 1.65%. It would seem that the
materials from which the soils were derived were of varying composi-
tion. For from the present climatic conditions soil no. 25 is the one
subject to the least leaching, and yet has the least CaO content. The
B and C percentages follow the surface very closely—sufficiently so
to necessitate no particular explanation. The range of variation in
the B horizon is from 0.11% to 2.42%, and the average is 1.42%.
The C samples vary from 0.17% to 2.81%, with the average of 1.52%.

Hanford fine sandy loam.—The A samples of this type contain
from 2.56% CaO to 4.69%, with 3.33% as the average. The varia-
tions are not so marked among the series of this type as in the cases
of the other three soils. The absolute range is nearly as great, but
the relative variation is less.

Even though there are differences between the average CaO con-
tent in the several types, the wide variation in the amount found in
the several samples of a given type, and the overlapping of these
amounts from the different types entirely preclude any statement
that as regards the calcium content the soils of any one type are
closely similar to one another, or that one type has a higher or lower
lime content than another.

1919] Pendleton: A Study of Soil Types 409

TABLE 22—CaLciuM AS CaO

(Surface horizons only)
Hanford Fine Sandy

Diablo Clay Adobe Altamont Clay Loam Loam
%o Jo Yo %o To Yo

1-A 1.86 3-A 5.64 14-A 2.91
1.80 3: i i i 5.64 2.99 2.95

2-A 2.12 4-A 0.92 15-A 2.98
1.98 2.05 0.88 0.90 3.22 3.10

5-A 0.56 7T-A 0.89 16—A 2.48
0.17 0.36 0.67 0.78 2.65 2.56

6-A 0.67 Average 2.44 19-A 3.28
ses 0.67 3.17 3.22

Average 1.23 20-A 2.69
2.73 2.71

22-A 3.80
3.92 3.86

23-A 2.88
3.00 2.94

24-A 3.88
4.00 3.94

25-A 4.58
4.80 4.69

Average 3.33

TABLE 23—CALCIUM AS CAO

San Joaquin Sandy Loam

Horizon
A Average B Average C Average
Sample %o %o %o % Jo Jo
10 0.67 0.82 5 a AY
0.62 0.64 1.03 0.92 1.12 itt
11 1.94 1.62 1.65
1.26 1.60 1.70 1.66 1.55 1.60
12 3.12 2.21 2.61
3.50 Bot eo ema 2.21 3.01 2.81
13 2.83 2.38 2.46
3.13 2.98 2.46 2.42 2.79 2.62
17 1.83 1.92 No sample
2.08 1.95 2.08 2.00
18 1.40 1.00 1.48
toe (aT 1.45 1.22 1.42 1.45
21 0.91 0.89 0.85
0.84 0.87 0.83 0.86 0.89 0.87
26 0.48 0.13 0.17
0.47 ~- 0.A7 0.10 0.11 0.17 0.17

Average 1.65 1.42 1.52

410 University of California Publications in Agricultural Sciences [ Vol. 3

MAGNESIUM AS MGO

Diablo clay adobe.—This type shows a moderate variability in the
magnesium content, with from 1.13% MgO to 3.26%, averaging
2.09%. The largest quantity is three times that of the smallest
(tables 24, 25, figs. 15-18).

Altamont clay loam.—Within the three samples of this type the
range in the MgO content is very great, from 0.07% to 1.90%, with
the average of 1.05%. The largest is twenty-seven times that of the
smallest.

San Joaquin sandy loam.—The total MgO in the samples of the
type is low, considering that some soils reported by Hilgard contain
from 1% to 3% magnesia by the acid digestion. The variation within
the A horizon is from 0.34% to 0.90%, with the average of 0.62%, i.e.,
the largest is three times the smallest. The quantities in the B horizon
are somewhat erratic as compared with those of the surface, yet in
both the B and C horizons the results approach those of the surface
sufficiently to give a rough parallelism. The greater amount of clay
and fine silts with the increase of depth gives, as one would expect,
an inerease of magnesium. The average MgO content in the B horizon
is 0.81%, and in the C horizon 1.05%.

TABLE 24—MAGNESIUM AS MGO

(Surface horizon only)
Hanford Fine Sandy
oam

Diablo Clay Adobe Altamont Clay Loam
i Tl are
Jo Jo Jo Jo Jo Jo

1-A 1.64 3-A 1.85 14-A 2.49
2.20 1.92 1.95 1.90 2.49 2.49

2-A 2.16 4—-A 1.21 15-A 0.93
1.95 2.05 1.17 1.19 1.02 0.97

5-A 1.25 7-A 0.09 16-—A 1.10
1.03 1.13 0.05 0.07 0.99 1.04

6-A 3.62 Average 1.05 19-A 2.11
2.90 3.26 1.99 2.05

Average 2.09 20-A 1.77
1.92 1.84

22-A 2.44
2.71 2.57

23-A 1.94
1.70 1.82

24-A 2.14
2.13 2.13

25-A 2.31
2.40 2.35

Average 1.92

1919 } Pendleton: A Study of Soil Types 41]

Hanford fine sandy loam.—The MgO content of the surface soil
varies from 0.97% to 2.57%, averaging 1.92%. The relative varia-
tion within this type is about that of the Diablo and San Joaquin
types.

Comparing the average amounts of magnesium oxide in the sur-
face horizon of the several types, we find the San Joaquin with 0.56%,
the Altamont with 1.05%, the Hanford with 1.93%, and the Diablo
with 2.09%. The averages do not signify much, however, because of
the wide ranges within the types. Therefore as regards magnesium
the types are neither distinct nor are the soils within the type
closely similar.

TABLE 25—-MAGNESIUM AS MaGO

San Joaquin Sandy Loam

Horizon

Sample %o %o % %o %o %
10-A 0.31 0.33 0.53

0.30 0.30 0.45 0.39 0.53 0.53
11-A 0.79 1.21 1.48

0.44 0.61 1.22 1.21 1.25 1.36
12-A 0.83 0.79 1.57

0.79 ln 00 0.79 1.62 1.59
13-A 0.90 1.70 1.67

0.80 0.85 1.63 1.66 1.82 1.74
17-A 0.53 0.51 No sample

0.74 0.63 0.77 0.64
18—A 0.50 0.40 0.64

0.48 0.49 0.69 0.54 0.75 0.69
21-A 0.29 0.28 0.52

barra! 0.29 0.31 0.29 0.56 0.54
26-A 0.50 0.52 0.52

0.52 0.51 0.44 0.48 0.53 0.52

Average 0.56 0.75 1.00

PHOSPHORUS AS P.O;

Diablo clay adobe-—The variations in the P,O,; content in the
samples of this type are relatively small, from 0.092% to 0.162%,
with 0.108% as the average (tables 26, 27, figs. 11-14).

Altamont clay loam.—The range of variation in the amount of
P.O, is large, from 0.031% to 0.265%, the largest quantity being eight
times the smallest. The average is 0.132%.

412 University of California Publications in Agricultural Sciences [ Vol. 3

San Joaquin sandy loom.—The variations in the P,O, content of
the surface soil are from 0.039% to 0.11%, with the average 0.068%.
The curve is fairly regular. The subsoils follow the surface in a gen-
eral way. The B horizon samples vary in the phosphoric acid con-
tent between 0.028% and 0.156%, and average 0.069%. The C sam-
ples vary between 0.03% and 0.109%, and average 0.067%. The
averages of the three horizons are seen to be almost identical. No
particular significance can be attached to the minor variations.

Hanford fine sandy loom.—The P.O, content in the samples of
this type is very variable, from 0.195% to 0.819%, with the average
of 0.363%. The average of the San Joaquin sandy loam samples is
0.069%, of the Diablo clay adobe 0.108%, of the Altamont clay loam
0.132%, and of the Hanford fine sandy loam 0.363%. Except between
the Diablo and Altamont types these averages would show considerable
differences, if it were not that the samples frequently show such wide
departures from the averages. The ranges of the several types fre-
quently overlap.

TABLE 26—PHOSPHORUS AS P.O;
(Surface horizon only)
Hanford Fine Sandy

Diablo Clay Adobe Altamont Clay Loam Loam
%o % %o Yo % To

1-A 0.088 3-A 0.278 14-A 0.373
0.096 0.092 0.252 0.265 | 0.292 0.333

2—-A 0.064 4—A 0.081 15-A 0.287
0.078 0.071 0.117 0.099 0.260 0.273

5-A 0.137 7T-A 0.034 16-A 0.260

0.082 0.109 0.028 0.031 0.277 0.268

6-A 0.143 Average 0.132 19-A 0.303
0.181 0.162 0.272 0.287

Average 0.108 20-A 0.190
0.200 0.195

22-A 0.397
0.401 0.399

23-A 0.242
0.270 0.256

24—-A 0.421
0.454 0.437

25-A 0.879
0.759 0.819

Average 0.363

1919] Pendleton: A Study of Soil Types 413

TABLE 27—PHOSPHORUS AS P,O,

San Joaquin Sandy Loam

Horizon
A Average B Average O Average
Sample % % % % % %

10 0.118 0.060 0.047

0.102 0.110 0.068 0,064 0.057 0.052
11 0.049 0.047 0.049

0.060 0.054 0.046 0.046 0.028 0.028
12 0.057 0.028 0.064

0.071 aoe? tt Pome 0.028 0.095 0.078
13 0.049 0.037 0.036

0.064 0.056 0.038 0.039 0.024 0.030
17 0.036 0.041 No sample

0.042 0.039 0.082 0.061
18 0.043 0.097 0.086

0.055 0.049 0.074 EES: swt. qigiten 0.086
21 0.069 0.088 0.094

0.068 0.068 0.066 0.077 0.062 0.078
26 0.117 0.130 0.120

0.092 0.104 0.182 0.156 0.098 0.109

Average 0.068 0.069 0.067

PoTASSIUM AS K,O

Diablo clay adobe—There is a moderate range in the variation in
the amount of K,O within this type, the lowest amount being 1.48%
and the highest 2.06%, the four samples averaging 1.71% (table 28,
figs. 15-18).

Altamont clay loam.—aA greater variation, from 1.09% to 2.14%,
of K,O, occurs in the three samples of this type. The average is
1.74%.

San Joaquin sandy loam.—This type shows the greatest variation,
from 0.98% to 2.84%. But even so, the the largest quantity of K,O
is less than three times the smallest. 1.88% K,O is the average of
the eight samples. Nos. 11 and 12 of this type show the smallest
amounts of K,O of any of the twenty-four samples.

Hanford fine sandy loam.—The variation in the K,O content of
the samples of this type is not great—from 1.73% to 3.16%, with
the average of 2.33%. This is the highest average, as the Diablo clay
adobe samples show 1.71%, the Altamont clay loam 1.74%, and the
San Joaquin sandy loam 1.88%. Because of the considerable range
in the amounts of K,O for the several samples of a type, and because
of the many overlappings of the values for one type over another,
the averages do not mean much and do not show the soils within a
type to be closely similar, nor do they show the types distinct.

414 University of California Publications in Agricultural Sciences [| Vol. 3

TABLE 28—PorTassiuM as K,O

(J. Lawrence Smith Method)
Hanford Fine Sandy

Diablo Clay Adobe Altamont Clay Loam San Joaquin Sandy Loam Loam

Average Average ta Average Average
No. % % No. % % No. Yo % No. Io oe

1—-A 1.68 3-A 1,06 14-A 1.79 10-A 2,14
1,67 1.67 1.13 1.09 1.67 1.73 2.12 2.13

2—-A 1.62 4-A 1.92 15—-A 2.54 11-A 0.99
169 1.65 2.86 2.14 2.62 2.58 0.98 0.98

5-A 1.45 7-A 1.90 16—A 2.42 12-A = 1.03
1.51 1.48 2.10 2.00 2.46 2.44 1.02 1,02

6-A 2.01 Average 1.74 19-A_ 2,10 13-A=s-:1.50
2.12 2.06 2.03 23.06 «» /j0e 1.50

Average 1.71 20-A 2.00 17-A = 2.40
1.81 1.90 2.24 2.32

22-4 = 2.68 18-A 207
2.62 2.65 2.28 2.17

23-A = 3.10 21-A 2.81
3.23. 3.16 2.88 2.84

24-A=s-_- 2.29 26-A 2.04
2.21 2.25 2.09 2.06
25-A 2.18 Average 1.88

2.21 2.19

Average 2.33

BACTERIOLOGICAL DATA

The bacteriological work was not entirely satisfactory, partly be-
cause the conditions in one of the incubators were not all that might
be desired, and partly because of the refractory physical properties
of some of the soils. The Diablo and Altamont types, in all three
horizons, were very heavy and hard to mix and keep in even fair
physical condition. The San Joaquin soils were predominantly of a
heavy texture in the B and C horizons, while the surface horizon
was light and the crumb structure was entirely lost if even a small
excess of water was added to the culture.

AMMONIFICATION

There are very marked differences between the various types in
this determination, though the samples in a given type vary among
themselves to a large extent.

Diablo clay adobe-——The highest ammonia production was about
three times the lowest, 7.7 mg. and 26 mg. In both this type and
the following, the B and C horizons follow the surface horizon quite

1919 | Pendleton: A Study of Soil Tyves 415

Mg N.as NH; Produced

Fig. 194. Graph showing ammonification in the four samples of Diablo clay
adobe. The quantities are expressed in terms of nitrogen produced per 100
grams of soil with 2% of dried blood.

10

“5

50

Mo N Fixed

Soils.

Ria, Io
Fig. 198. Graph showing nitrogen fixation in the three horizons of the four

samples of Diablo clay adobe. The quantities are expressed in terms of milli-
grams of nitrogen fixed per gram of mannite in 50 grams of soil.

416 University of California Publications in Agricultural Sciences [Vol.3

closely from sample to sample (table 28 and fig. 194). This may be
due to the textures, which are quite similar throughout the soil column.
The averages for the three horizons were: A, 18.6 mg.; B, 12.6 mg.;
and C, 8.9 mg.

7 Soils

Meg N. as NHs3 Produced

Fig. 204. Graph showing ammonification in the three horizons of the three
samples of Altamont clay loam.

3 + 7 Soils
Mg N. Fixed

Fig. 208. Graph showing nitrogen fixation in milligrams in the three horizons
of the three samples of Altamont clay loam.

Altamont clay loam.—As regards horizon A the amount of am-
monia produced in one soil is three times that in the lowest, 10 mg.
nitrogen and 33 mg. nitrogen as ammonia, with 8.9 mg. as the average
(table 30 and fig. 20a). The amount of nitrogen as ammonia pro-
duced in the B horizon averaged 12.6 mg., in the C horizon 8.9 mg.

1919 | Pendleton: A Study of Soil Types 417

San Joaquin sandy loam.—The amount of ammonia produced in
the A horizon varied between 30.4 mg. of nitrogen and 57.1 mg., the
average was 40.2me. (table 31 and fig. 214). The production of
ammonia, in milligrams of nitrogen, by the B samples varied between
4.5 mg. and 38.1 mg., with 20 mg. as the average. In the C samples
the variation was nearly as great, between 5.7 mg. and 32 mg., with
the average of 20.9 mg. Thus there are notable variations among the

26 Soils

Mg N. as NHs3 produced

Fig. 21a. Graph showing ammonification in the three horizons of the eight
samples of San Joaquin sandy loam,

samples of this type, the proportional variation being very great, con-
sidering the three horizons. Possibly the reason that the B and C
horizons are so divergent from the surface is that there is a very
marked variation in the texture between the surface horizon and
those below the surface.

Hanford fine sandy loam.—The variation is large here also (table
32, fig. 224), the largest quantity of ammonia produced in the surface
soil is twice that of the smallest production, 72 mg. and 35 mg. The
subsoil variations, in a general way, parallel those of the surface.
The average production of ammonia in the three horizons is as fol-

418 University of California Publications in Agricultural Sciences [ Vol. 3

lows: A, 56.9 mg. nitrogen; B, 46.3 mg. nitrogen; and C, 38.7 mg.
nitrogen. In attempting to correlate the variations in ammonifying
powers with the known variations of the soils, or with the known his-
tories of the soils, there seem to be no relations of significance.

The Altamont and Diablo types are about alike in their low am-
monifying power. The Hanford and San Joaquin are both higher
and nearer to each other than to the two heavy types, yet the Hanford
is noticeably higher than the San Joaquin. This is as one would ex-
pect, from a knowledge of the soils in the field. Considering the types
as a whole, as represented by the A horizon, there are more marked
variations between the types than between the samples of a given type
though the variations within a given type are very large.

TABLE 29—AMMONIFICATION
Diablo Clay Adobe
Milligrams N as NHg Produced

A B Cc
Increase Increase Increase
Checks over Checks over Checks over
Samplé Cultures average checks Cultures average checks Cultures average checks
1 31.48 28.58 24.24
40.32 252 33.38 22.98 2.28 23.50 14.99 2.42 17.19
2 19.81 9.45 8.41
17.07 1.68 16.76 9.84 1.91 7.73 9.95 1.05 8.13
5 15.90 11.55 No sample
acme 1.75 14.15 12.54 1.54 10.50
6 12.33 7.76 12.33
ae 2.11 10.22 13.55 2.07 8.58 12.33 2.03 - 10:30
Average 18.63 12.58 11.87

. TABLE 30—AMMONIFICATION
Altamont Clay Loam
Milligrams N as NHg Produced

A B Cc
Increase Increase Increase
Checks over Checks’ over Checks over
Sample Cultures average checks Cultures average checks Cultures average checks
2 8.14 6.97 5.89
10.58 1.68 7.68 ito.” ~ KAO 5.16 4.91 1.54 3.86
+t 19.75 6.59 5.41
19.12 2.66 16.77 6.67 136 5.27 5.12 1.19 4.07
7 28.66 19.66 8.00

27.53 2.03 26.06 16.25 1.75 16.20 12.37 1.33 8.95
Average 16.84 8.88 5.63

1919] Pendleton: A Study of Soil Types
TABLE 31—AMMONIFICATION
San Joaquin Sandy Loam
Milligrams N as NH, Produced
A B
Increase Increase
Checks over Checks over
Sample Cultures average checks Cultures average checks
10 54.24 42.63
41.95 1.72 46.73 36.11 1.28 38.09
11 44.47 7.47
73.23 1.70 57.15 12.52 1.81 8.18
12 44.48 18.73
40.07 1.56 40.71 21.81 1.50 18.77
13 41.66 5.41
45.94 1.30 42.50 5.36 0.86 4.52
17 30.19 27.59
33.88 1.66 30.37 20.68 1.51 22.62
18 35.04 30.56
35.24 1.48 33.66 22.81 1.30 25.38
21 34.44 37.41
30.89 1.48 31.18 37.74 1.388 36.19
26 40.81 7.50
tices 1.64 39.17 8.41 1.44 6.51
Average 40.18 20.03
TABLE 32—AMMONIFICATION
Hanford Fine Sandy Loam
Milligrams N as NHzg Produced
A B
Increase Increase
Checks over Checks over
Sample Cultures average checks Cultures average checks
Horizons
14 37.35 27.96
43.57 1.78 38.68 48.46 1.46 36.75
15 33.11 45.68
ai.vo.° 17D 35.68 48.38 1.70 45.33
16 56.59 44.08
56.77 1.83 54.85 42.10 1.61 41.48
19 52.92 46.70
51.85 1.47 650.91 as.ga. . dS" 45.68
20 72.49 45.49
74.21 1.36 71.99 38.52 1.03 40.97
22 64.92 57.44
67.56 1.75 64.49 55.384 1.51 54.88
23 71.56 50.84
68.66 1.61 68.50 43.01 1.37 45.55
24 65.02 50.09
59.51 1.50 60.76 46.54 1.32 46.99
25 68.20 69.29
67.29 1.43 66.31 60.03 1.25 63.41
Average 56.91 46.34

419

0
——
Increase
Checks over
Cultures average checks
28.89
38.25 1,59 31.98
6.05
6.78 1.68 4.78
10.91
6.1] 1.14 7.87
3.80
15.17 0.88 8.60

No sample

21.96
16.92 1.47 17.97
25.72
29.66 1.42 26.27
9.08
5.43 1.54 5.71
" 12.89
Cc
Increase
Checks over
Cultures average checks
14.39
41.70 1.24 26.80
59.90
52.59 1.62 54.62
44.58
52.10 1.69 46.65
24.56
28.12 1.24 25.10
22.05
30.35 1.00 25.20
46.08
47.55 1.60 45.21
35.15
35.23 1.35 33.84
37.56
40.21 1.33 37.55
61.01
47.70 1.22 53.13
38.67

420 University of California Publications in Agricultural Sciences | Vol. 3

NITROGEN FIXATION28

Diablo clay adobe.—This type shows the highest quantity of nitro-
gen fixed, 9.6 mg., with the subsoil quantities, much lower than the
surface. The variation within the type is seen to be the largest of that
in any of the types.

Altamont clay loam.—The surface samples have 1.0, 4.7, and 9.1
mg. nitrogen (table 34 and fig. 20B). The soils shows a wide diver-
vence between the surface samples and between the surface and sub-
soils. This is to be expected in the heavier soils.

Mg N. Fixed

Fig. 218. Graph showing nitrogen fixation in the three horizons of the
eight samples of San Joaquin sandy loam.

San Joaquin sandy loam.—The quantity fixed in the A horizon
(table 35 and fig. 218) is small and quite variable. It is between
nothing and 5.5 mg., with the average of 1.9 mg. Instead of nitrogen
fixation denitrification took place in a number of cases, especially in
horizon C. Considering the wide variation in textures of the horizons,
it is rather odd that there should not be a greater variation between
the soils from the various depths.

Hanford fine sandy loam.—The amount of nitrogen fixed by the
surface soil (table 36, and fig. 228) averages much higher, 5.7 mg.,
than that in the San Joaquin sandy loam, though the range of varia-
tion is about the same. It is noticeable that the amounts of nitrogen
fixed by the B and C horizons of the soils nos. 14 and 19 are much

28 All of the figures on nitrogen fixation refer to the milligrams of nitrogen
fixed per gram of mannite in 50 grams of soil (table 33 and figs. 9-13).

1919]

Pendleton: A Study of Soil Types

421

less (even to denitrification) absolutely and relatively as compared

with the surface horizons, than the amount fixed by the B and ©

horizons of the soils nos. 20 to 25 inelusive.

Comparing the nitrogen fixation of the various types, there seem

to be no characteristic differences between the heavy Altamont and

Diablo types, while the lighter Hanford and San Joaquin types are

considerably different from each other.
degree of similarity between the samples of a given type.

of variation within types is large.

A B
ee Increase
Checks over Checks’ over
Sample Cultures average checks Cultures average checks
1 60.25 31.52
63.40 02.22 9.60 29.56 34.67 -4.13
2 55.34 32.92
49.39 45.88 6.48 38.18 33.80 1.75
5 48.68 35.73
48.68 41.92 6.76 37.12 32.389 4.03
6 45.88 39.64
46.86 58.49 —12.12 42.72 50.77 9.59
Average 1 1.44
TABLE 34—NITROGEN FIXATION
Altamont Clay Loam
Milligrams N fixed per gram of mannite
A B
Increase Increase
Checks over Checks over
Sample Cultures average checks Cultures average checks
3 71.26 49.04
70.40 61.71 9.12 51.84 43.78 6.66
4 60.25 28.02
52.19 51.49 4.73 27.32 26.48 1.19
7 52.95 37.75
53.44 02.12 1.08 37.40 36.60 1.00
Average 4.98 2.95

TABLE 33—NITROGEN FIXATION

Milligrams N per gram of mannite

Diablo Clay Adobe

As a whole there is but a fair

The degree

C
Increase
Checks over
Cultures average checks
22.77
24.87 28.61 -4.79
30.47
32.22 29.77 1.57
No sample
35.02
39.01 39.05 -2.03
0.52

0
Increase
Checks over
Cultures average checks
37.13
38.51 33.76 4.06
20.31
21.01 2048 018
30.81
27.18 29.94 -0.94
1.41

422 University of California Publications in Agricultural Sciences [ Vol. 3

14 15 16 19 20 22 23 24 26 Soils
Mg N. as NHs produced
Fig. 224. Graph showing ammonification in the three horizons of the nine
samples of Hanford fine sandy loam.

Meg N. Fixed

Fig. 228. Graph showing nitrogen fixation in the three horizons of the nine
samples of Hanford fine sandy loam.

ne Poe ge @

1919]

—
Sample

10 25.01

23.47

11 27.25

31.87

12 25.85

23.82

13 22.77

21.58

Le 13.52

13.45

18 15.55

13.24

21 14.85

16.11

26 19.54

19.34

Average

Sample
14 71.52
63.05
15 38.18
29.56
16 30.33
32.92
19 25.56
26.41
20 38.04
38.11
22 35.59
31.80
23 38.95
43.57
24 28.79
34.61
25 26.55
26.41

Average

A

Checks

Cultures average

A

Checks

Cultures average

59.61

26.55

27.84

22.49

29.66

29.17

36.10

Pendleton: A Study of Soil Types

TABLE 35—NITROGEN FIXATION

San Joaquin Sandy Loam

Milligrams N fixed per gram of mannite

2.
ae, |

Increase
over
checks

0.66

0.98

—0.94
1.91

-~

B

Checks

a a
Increase

over

Cultures average checks

17.16
16.67
22.91
22.84
20.17
17.09
18.49
17.86
9.46
10.23
8.76
8.20
7.98
6.44
12.61
12.82

13.34

1.25

—0.72
1.09

TABLE 36—NITROGEN FIXATION
Hanford Fine Sandy Loam

Milligrams N fixed per gram of mannite

Increase
over
checks

7.67

7.32

3.78

4.49

8.41

4.52

5.16

6.03

3.78
5.69

B

Checks

Increase
over

Cultures average checks

41.61
41.69
22.07
21.09
16.46
16.04
14.43
13.59
22.84
23.61
22.20
23.40
19.19
20.25
19.89
21.52
17.86
17.93

41.01

20.12

14.85

0.64

1.46

1.40

3.21

423
0
a,
Increase
Checks over
Cultures average checks
15.83
18,14 10.33 §.65
21.72
22.00 19.43 2.43
18.98
20.10 20.41 —0.87
13.31
14,50 16.35 -2.45
No sample
9.18
11.42 9.74 0.56
6.58
7.28 7.01 -0.07
7.14
7.36 8.24 -0.99
1.20
Cc
Increase
Checks over
Cultures average checks
31.10
30.19 29.07 1.57
12.40
14.08 13.87 -0.63
9.67
8.97 10.61 -1.29
Bite
12.33 11.80 —-0.25
17.09
20.60 11.52 7.32
17.30
16.46 11.87 5.01
11.90
11.98 8.90 3.04
18.52
17.51 13.91 4.11
15.55
13.87 11.31 3.41
2.27

424 University of California Publications in Agricultural Sciences [Vol.3

NITRIFICATION 29

The most noticeable thing about the nitrification results is the
very wide range of variation in the various representatives of the
Hanford fine sandy loam as compared with the quite uniform and
consistent results obtained with the other types.

Diablo clay adobe—The percentage of nitrogen nitrified (table
37, 38, and fig. 23) is uniformly low. The B samples showed a less
vigorous nitrifying flora (except in the case of no. 6) than the sur-
face ones. Dried blood in the quantities used seems to depress the

A S.N.+Cottonseed Meal

A S.N.+ (NH4)2S04

A S.N.+ Dried Blood
A Soil Nitrogen

1 2 5 6 Soils
Percentages of N. Nitrified

Fig. 23. Graph showing the percentages of nitrogen in various nitrogen
containing materials nitrified in the four samples of the Diablo clay adobe.

normal activity (A horizon average 0.81%), while the (NH,).SO,
(A horizon average 3.03%) and the cottonseed meal (A horizon
average 2.91%), as compared with the incubated control tend to in-
crease the percentage of nitrogen nitrified. It should be kept in mind
that an absolute increase in the nitrogen content may accompany a
deerease in the pereentage, due to the greatly increased amount of
nitrogen present after the addition of a nitrogenous substance. The
variation of the samples within this type is very moderate as compared
with the San Joaquin and Hanford types.

29 The figures used in the discussion shows the percentages of the nitrogen in
the cultures which were nitrified. There are two tables for the samples of each
type. The percentages of nitrogen nitrified are rearranged in a second table for
greater ease in comparing results.

ad

1919 } Pendleton: A Study of Soil Types 425

Altamont clay loam.—The percentages of nitrogen nitrified (tables
39 and 40, fig. 24) are as a whole lower than in the Diablo soils. A
similar relative effect of the several nitrogenous materials is seen, for
(NH,).SO, is first, cottonseed meal, second, the soil’s own nitrogen
third, and dried blood fourth in the percentages of nitrates produced.
As in the Diablo soils the variation is not great from soil to soil.

San Joaquin sandy loam.—A wide range of variation (tables 41,
42, and fig. 25), from 1.2% to 4.5%, is found in the incubated control,
possibly due, in part, to the considerable variations in the physical
nature of the samples. The relative action of the nitrogenous ma-

YA S.N.+ (NH4)2S0x
A 8. N. +Cottonseed Meal
; |A Soil Nitrogen
—“JA 8. N.+ Dried Blood
3 4 7 Soils
Percentages of N. Nitrified

Fig. 24. Graph showing the percentages of nitrogen in various nitrogen
containing materials nitrified in the three samples of the Altamont clay loam.

terials in the soils of the San Joaquin samples as compared with that
in the Diablo and Altamont soils is well shown by the following aver-
ages of the A horizon: dried blood had 0.02%. cottonseed meal had
0.33%, and ammonium sulfate had 0.56% of the nitrogen nitrified,
while the incubated control had 2.47% nitrified. The soils are normally
low in nitrogen, and this, together with the poor physical condition,
made an unfavorable medium for any bacterial activity. This applies
especially to horizons B and C.

Hanford fine sandy loam.—This is by far the most inexplicable
set of results in the nitrification studies (tables 48, 44, and fig. 26).
The physical nature of this type is admirably suited for bacteriological
tumbler cultures, the soil being friable, not puddling readily, and
while in the incubator may be kept at the approximately optimum
moisture content with little difficulty. This property is fairly con-

426 University of California Publications in Agricultural Sciences [Vols3

stant throughout all the samples (except no. 14) and cannot well
be supposed to affect the results greatly. No. 14 has a low nitrifying
power throughout, but it is not representative of the type, for it is
heavier in texture than the rest. Moreover, it had been submerged
by river overflows shortly before the collection of the sample. One
would expect these factors to influence the numbers and the activity
of the bacterial flora. There is but little similarity in the way the
different samples of the A or B horizons behave toward any given

A Soil Nitrogen

A S.N.+ (NHa)2S0O«

A S.N. +Cottonseed Meal ©
26 Soils

Percentages of N. Nitrified

Fig. 25. Graph showing the percentages of nitrogen in various nitrogen
containing materials nitrified in the eight samples of the San Joaquin sandy
loam.

nitrogen containing material. Variations from 1% to 50%, from
0% to 14%, from 4.5% to 8%, or from 15% to 15.5% from soil to
soil, without regularity, give shgeht basis for generalizations. The
average effect of the A horizon samples of the Hanford fine sandy
loam as regards the several nitrogenous materials is as follows: dried
blood, 5.62% ; cottonseed meal, 13.72%; ammonium sulfate, 3.29% ;
incubated control, 1.55%. In a general way there is a similarity
between the effects of a given nitrogen containing material on the
surface sample, and on the B horizon. This should be so, since these
soils are very deep and uniform in texture. However, in the C
horizon there were still greater decreases in the bacterial activity.

Sample

1-B

6-A
6-B

| AP

1919 } Pendleton: A Study of Soil Types 427

As regards nitrification in general there is difficulty in showing
any greater resemblance between the samples of a type than there is
from type to type. In certain features, however, the types are some-
what distinct: (1) The relation of the nitrification of the soil’s own
nitrogen to the soil’s action upon added nitrogen is rather distinct
for the types. The normal soil in the San Joaquin type gave a much
larger per cent of nitrogen than did the soil plus the added nitrogen
containing materials. In the Diablo type (fig. 25) the normal soil
was about midway in its production as compared with the soils to
which the nitrogenous materials were added. In the Hanford fine
sandy loam the normal soils gave a much lower percentage nitrifica-
tion than in the greater number of instances where the soils were
treated with nitrogenous materials. (2) The relative nitrification of
the various nitrogenous materials is somewhat distinct for the types.
The Diablo, Altamont, and San Joaquin show the ammonium sulfate
first, with the cottonseed meal second, and the dried blood third. The
Hanford type shows cottonseed meal first, with dried blood second and
ammonium sulfate third.

TABLE 37—NITRIFICATION

Diablo Clay Adobe

Soil nitrogen and Soil nitrogen and Soil nitrogen and
Soil nitrogen ammonium sulfate dried blood cottonseed meal
5 5 5 5

im” «(ee & Su oe s Sea 0S SS me 88 SS
Ce eS ay ey
Pees se a
Ba ec. £5 Hin tl ee eee Es Z|. SS 53 25. Ss
eee “hee re eee es fe”. UR” a ar | ao
0.90 104.43 0.86 5.35 146.82 3.65 2.20 347.22 0.63 5.00 198.42 2.50
0.28 93.34 0.30 0.77 135.74 0.57 Jee k | Se Te. EST aa) ce
0.19 - 57.22 0.33 0.25 99.62 0.25 0.07 300.02 0.02 Ogi6.” Sig 23 enor
0.47 91.76 0.51 3.47 134.16 2.58 4.07 334.56 1.22 6.82 185.76 3.77
0.33 67.60 0.49 1.17 110.00 1.06 0.08. 210.40... 0.19 161.60 0.12
0.59 59.54 _...... 26 SOL08 ok. 0.80 302.34 _...... 0.80 153.44 °°

0.47 83.82 0.56 3.81 126.22 3.02 1.66 326.62 0.51 3.76 177.82 2.1

0.36 64.78 0.56 0.42 107.18 0.39 0.19 307.58 0.06 0.97 158.78 0.6

0.59 116.58 0.51 4.58 158.98 2.88 3.13 359.38 0.87 6.88 210.58
1.65 101.54 1.63 3.00 143.94 2.08 1.19 344.34 0.35 4.55 195.54
0.96 78.10 1.23 1.01 120.50 0.84 0.37 320.90 0.01 0.47 172.10

.

428 University of California Publications in Agricultural Sciences | Vol. 3

Percentages of N. Nitrified

Fig. 26. Graph showing the percentages of nitrogen in various nitrogen
containing materials nitrified in the nine samples of the Hanford fine sandy
loam.

1919 | Pendleton: A Study of Soil Types 429
TABLE 38—NITRIFICATION——PERCENTAGES OF NITROGEN NITRIFIED
Diablo Clay Adobe
Soil nitrogen and Soil nitrogen Soil nitrogen
Soil nitrogen ammonium sulfate and dried blood cottonseed meal
a, i a ———_—_—
Sample A B © A B © A B © A B 6)
1 0.86 0.30 0,33 3.65 0.57 0.25 Ch Se 0,02 Sasa .cn2t. a aero
2 On ee 2. 258° P06 - oo 5 ee OST. “OAS ss ataies
5 0.56 666’ ..... G:08 O38 <s.0s POR ARUO: ‘tics Bale UE) ee
6 0.61 1:68 1,28 2.88 2.08 0.84 0.87 0.35 0.01 3.26 232 0.27
Average 0.61 0.74 0.52 3.03 1.02 0.36 Os. 0,L0. O01 2.91 0.76 0.09
TABLE 39—NITRIFICATION
Altamont Clay Loam
Soil nitrogen and Soil nitrogen and Soil nitrogen and
Soil nitrogen ammonium sulfate dried blood cottonseed meal
= i
=] r= e =
& dp ae xs ee ei xs & be Z s by i s
RS ee en ey aa ee NOR) ek BR.) Ren cae
23 AS ene eg Aire ae og Arm esl ss Acm ae
Bs @* 8 Bos. at) See A ir ah ier ent 3
= $A a= = $4 Seo 5S = She S05 $A Sip
Sample %~ aha a ne a > A a ee oie alee EF oe
3-A 0.60 123.42 0.49 4.12 165.82 2.49 1.17 ~~ 366.22 0.32 3.57 217.42 1.64
3-—B 0.04 87.56 0.05 0.39 129.96 0.32 (dt ees 1 O08 161 56%) 322
3-C 0.27 67.52 0.40 0.20 109.92 0.18 eieeatUse Se ik tbe
4A 1.30 102.58 7 2.95 144.98 2.05 2.34 345.38 0.68 4.83 196.58 2.46
4B 0.45 52.96 Si Ob .eO.. ick ee O iaccas SN Uccgs 146.965.
eT A ee a eae eae Bao: onbckey +. tees i 0.20 134.96 0.15
7-A 0.50 104.24 0.48 1.35 146.64 0.93 0.40 347.04 0.12 1.27 198.24 0.64
7-B 0.25 73.20 0.34 O32: 116:60) 028 Vw ae = 185) | a a eee LOT.2Ory eis
| a ae Wacten? our Slack: TUS.) aac Cheers Se enn, Fee 153.88
TABLE 40—NITRIFICATION—PERCENTAGES OF NITROGEN NITRIFIED
Altamont Clay Loam
Soil nitrogen and Soil nitrogen Soil nitrogen and
Soil nitrogen ammonium sulfate and dried blood cottonseed meal
Sample A B C A B CO A B C A B C
3 0.49 0.05 0.40 2.49 0.32 0.18 ee aaa DGG * cul Fee
4 ter 0.80 . SV ee horn et J aie 3:46 0.15
7 0.48 0.34 ..2.. ive, OSE «22. Lo) ee OUGS = kn eee
Average 0.75 0.41 0.13 1.82 0.20 0.06 i = ieee OO ee eaten 0.05

450

Sample
10-A
10-B
10—C

11—A

Sample

10

7

12

13

uf

18

21

26
Average

University of California Publications in Agricultural Sciences

Soil nitrogen

pro-

duced, mg.
; Total N present

bo
~“

lor)

& - jp in soil, mg.
oo

w © nitrified, %

S © © Nitrate

ow w
ww
DS b& oo
Oo © & Nitrogen

i

~]

ior)

on
S
wo
i)
bo
Or

ad
~ |

oo
wouwn

_
bo

foot ,
Oo jw}

4.5

4.3

2.3

TABLE 41—NITRIFICATION

San Joaquin Sandy Loam

Soil nitrogen and
ammonium sulfate

-~ Nitrate pro-
duced, mg.

—_)
bo
rs

otal N present

in soil, mg.

122.26
111.98
105.46

135.10
126.36
123.66

131.32
117.92
125.62

124.80
125.21
117.50

113.72
103.22

112.26
100.98
104.28

113.80
96.72
98.82

125.48
111.48

trified, %

2 © t& ni

oC © © © Nitrogen
ior)

Soil nitrogen and

dried blood

© Nitrate pro-
duced, mg.

i)
ior)

otal N present
n soil, mg.

1

2.46
292.18
285.66

Sy

315.30
306.56
303.86

311.52
298.12
305.82

305.00
305.41
297.70

293.92
283.42

292.46
281.18
284.48

nitrified, %

© Nitrogen

=)
bo

eeeeee

(Vol. 3

Soil nitrogen and
cottonseed meal

> Nitrate pro-
duced, mg

_
i)

TABLE 42—NITRIFICATION—PERCENTAGES OF NITROGEN NITRIFIED

Soil nitrogen

A B Cc
14 09 0.3
25 .... 04
17 0.5 0.3
1.2 2
1.9
4.5
4.3
2.3

2.47 0.17 0.3

San Joaquin Sandy Loam

Soil nitrogen and
ammonium sulfate

A

0.56 0.03 0.18

Soil nitrogen

and dried blood

B

waeeee

weeeee
weeeee
aeeeee
aeeeee

Soil nitrogen and

A B Cc

0.
0.33 0.01 0.01

© Total N present
in soil, mg
nitrified, %

© Nitrogen,
°
®

weeeee

cottonseed meal

lL

1919]

Sample
14—A

14—-B
14—C

15-A 1.

15-—B
15-C

16—-A
16—B
16—C

19-A
19-B
19-—C

20-—A.
20-B
20-—C

22—A
22-B
22-C

23-A
23-B
23-—C

24-A
24-B
24—C

25-A
25-B
25-C

Sample
14
15
16
19
20
22
23
24
25

Soil nitrogen

Nitrate pro-
duced, mg.

i
°

= bo
or

0.07

Average

Total N present
in soil, mg.

Nitrogen

nitrified, %

45.40 1.2
31.01 1.0

22.62 0.5

Pendleton: A Study of Soil Types

TABLE 43—NITRIFICATION
Hanford Fine Sandy Loam

Soil nitrogen and

Soil nitrogen and
4
ammonium sulfate

g.

“1 £& db duced, m

So © CO Nitrate pro-
op oO

0.32
0.16

SE as Cee, |
:
tb s
R - a3
Bs =A
161.62 0.1
ct ba
100.54 0.7
95.50 3.4
$2.64. .02
70.14
98.08 2.5
7210 8.
63.62
87.38 2.3
66.98 0.2
66.00 0.2
IOI 2 Aye
Toole: + AH
65.44
100.74 6.4
76.86 0.3
66.14 82
114.6 78
71.54 12.5
60.20 20.6
93.74 4.4
76.30 0.5
70:29 - 05
S780) (71:5
73.41 0.4
65.02

0.2

to duced, mg.

© Nitrate pro-
or

_

dried blood

Total N present
in soil, mg.

254.22
217.02
193.14

188.10
175.24
162.74

190.68
164.70
156.22

179.98
159.58
158.60

194.32
167.78
158.04

193.34
169.46
158.74

207.20
164.14
152.80

186.34
168.90
162.82

180.40
166.01
157.62

ww Nitrogen
iu nitrified, %

oS;
Saad

0.2
0.2
0.1
4A
9.2

1.4

0.02

0.3

hieo
0.3

0.01

11.9
0.3
0.4

0.7

Soil nitrogen and
cottonseed meal

Nitrate pro-
U1

0.07

13.58
Lv
2.50

18.25
2.65
1.30

14.35
5.91
0.73

8.65
0.05
Ji 2

TABLE 44—NITRIFICATION—PERCENTAGES OF NITROGEN NITRIFIED
Hanford Fine Sandy Loam

Soil nitrogen

A B
2.7 0.4
16 0.4
2.2 0.3
13 0.4
14. 0.8
2.0 2.6
te: la |
hee 61.0
1.55 0.66

C
0.1

0.1
0.1
0.7
3.6
1.8
1.1
0.5
0.88

Soil nitrogen and
ammonium sulfate

A
0.1
3.4
2.5
2.3
1.2
6.4
7.8
4.4
1.5

3.29 1.59 3.38

B

0.2
0.1
0.2
0.1
0.3
12.5
0.5
0.4

Cc
0.7

0.2
8.2
20.6

0.5
0.2

B
4.1
0.2
0.2
8) (ee
14.1 9.2
14 0.02
17.9 0.3
11.9 0.3
0.7 —_
5.62 1.09

Soil nitrogen
and dried blood

C
0.1

0.3
0.01
0.4

0.09

otal N present
in soil, mg

e
166,22
129.02
105.14

100,10
87.24
74.74

102.68
76.70
68.22

91.98
71.58
70.60

104.32
77.78
68.04

103.34
79.46
68.74

117.20
74.14
62.80

96.34
78.90
72.82

90.40
76.01
67.62

-,

nitrified, %

Nitrogen,

0.1

13.1
2.4
3.6

15.5
3.6
2.1

14.9

Soil nitrogen and
cottonseed meal

A B
1 | a
4.5 4.8
45 4.8
8.1 0.3
59 1.9
13.1 2.4
15.5 3.6
1449 75
9.6 0.06
13.72 2.55

C
0.1
0.2
0.2
0.3
0.1
3.6
2.1
1.0

0.82

432 University of California Publications in Agricultural Sciences | Vol. 3

GREENHOUSE DATA

There are objections to all greenhouse work due to somewhat un-
natural conditions for the usual indicator crops, the lack of a normal
water supply, the small amount of root space, ete. Crowding of the
pots is also apt to cause variations. Even the slight change in the loca-
tion of a pot on the bench will affect the growth of plants, as some of
the elaborate precautions for moving the pots daily, and in a given
order, testify. The outstanding advantage of greenhouse work is that
with a given indicator crop a group of soils, or soil conditions, may be
compared under very similar conditions.

In the present case, the leaks in the sash allowed rain water to fall
into some of the pots to a considerable extent. The pots’ so affected
showed a poorer growth in the cases of the heavy Altamont and
Diablo samples, where the soil was readily compacted, while in the
poor Hanford and San Joaquin soils the pots receiving leakage water
showed markedly better growth.

To minimize such errors, as much as possible, triplicates were
used, as above explained, besides repeating the series. In working
out the final averages of the crop it was suggested that a selection be
made of the crop dry weights, in case that there was a marked varia-
tion between the triplicates, using the two weights close together, and
excluding the third if it were widely divergent. However, when one
begins to select certain figures from a series, and bases comparisons
upon these alone, there is apt to be the tendeney to select those figures
that will prove the point in question, unless there is some known dis-
turbing factor causing the divergence and which warrants the exclu-
sion of certain figures.

Other cases that are rather hard to deal with are those in which
the number of plants reaching maturity was not up to the standard to
which the series was thinned when the plants were young. This fail-
ure may have been due to poor germination, or to accidental destrue-
tion of the plants during growth. Sometimes less than the standard
number of plants will give a much greater dry weight per plant than
the normal number. It was not deemed advisable to use the weight
per plant, but rather to use the total dry weight of the crop, and only
consider of value the series in which the number of plants per pot
was practically constant.

In the greenhouse work the Diablo clay adobe, the Altamont clay
loam, and the Hanford fine sandy loam samples were compared by

1919] Pendleton: A Study of Soil Types 433

two croppings, while one crop was grown on the San Joaquin sandy
loam soils. The infertility of the San Joaquin soils, in some cases
extreme, greatly retarded crop growth.

Diablo clay adobe. First crop.—Due to the presence of wild oat
seed in all the four samples of this soil, and the inability to distin-
guish the young wild oat plants from the planted oats, wheat, or
barley when thinning, the value of the results of the grain crops in
this series is much decreased. The averages plotted include the total

ds)
20 rane
Bur Clover
05 Bur Clover
£
‘a
oO
lO
Oats
5 Barley
Wheat
O Phaseolus
| 2 Ss 6
Soils

Fig. 27. Graph showing the total dry matter produced by wheat, barley,
oats, Phaseolus, bur clover, and oats and bur clover on the four samples of
Diablo clay adobe. First crop.

crop, whether pure or with a greater or less quantity of the wild oats,
though the number of plants harvested was usually six or less.
Planting the oats and bur clover together was not a success. In three
of the soils the crop of bur clover alone was greater than that of the
six bur clover plants plus the six oat plants. Plate 44 shows how, in
some cases, the oats dominated, and in others the bur clover was
superior. On the soils of this type bur clover was the most satisfactory
crop, while the white beans were the most unsatisfactory of all.
Comparing the total crops (see fig. 27 and tables 45-50), it will
be seen that 1, 5, 2, 6 is the order for bur clover, soil no. 1 giving the

434 University of California Publications in Agricultural Sciences [Vol.3

best crop and soil no. 6 the poorest, while nos, 5, 1, 2, 6 is the order
for barley and wheat. Oats show nearly double the crop on soil 5
that it does on any of the other three soils. There is thus a general
agreement between the indicators that the soils are not of the same
productivity.

TaBLE 45—DraBLo CLay ADOBE, First Crop
WHEAT

Planted, November 6, 1915. Harvested, July 10, 1916

Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight ; Notes
1-1 Wheat 2 3.65 0.25
Oats 4 2.15 0.69 6.74
i a, Xe es Oe
Oats 6 4.05 2.47 6.51

1-3. Wheat l 1! SS YR en ee Pe
Oats 5 5.20 5.62 1.64 1.68 8.66 7.30

2-1 Wheat 5 5.33 0.05
Oats 1 eee ee. NTE 5.81
2-2 Wheat 4 3.53 0.03
Oats 2 0.69 0.04 4.31

o- Whats: fon* °° oO L
Oats 3 1.39 4.63 0.49 0.21 4.43 0.84

5-1 Wheat 2 4.33 0.90

Oats 4 1.56 0.42 7.21
5-2 Wheat 3 7.28 1.81

Oats 2 3.23 1.02 13.44
5-3 Wheat 3 7.09 «0.48

Oats 2 0.64 8.04 0.47 1.70 8.68 9.74

6-1 Wheat 2 2.19
Oats 4 1.03
ee ee,
“aco ll 1.72
2 Wheete 880 = nc: o
Oats 4 251 325 0.70 O17 £5.58 3.49

oh 3,29

1919] Pendleton: A Study of Soil Types 435

TABLE 46—Drasio Cray Apose, First Crop

BARLEY
Planted, November 6, 1915. Harvested, April 28, 1916
Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
1-1 6 5.19 1.06 6.25
1-2 + Barley 5 4.79 0.75
mee Se earl 6 Wy |) on! AM ee 5.54
1-3 Barley 4 5.75 1.34
Oates) <2" - 2:5. 5.24 0.98 1.38 8.07 6.62
2-1 6 5.12 1.05 6.17
2-2 6 4.87 5 IO 6.58
2-3 Barley 5 2.78 0.49
Oats 1 0.69 4.49 0.23 1.16 4.19 5,65
5-1 6 6.59 2.12 8.70
5-2 Barley 5d 3.01
Oats 1 2.56 0.25 3.25
5-3 Barley 5 3.01

Oats 1 8.43 5.86 0.04 1.95 11.48 7.81

6-1 6 GR: ti 1.26 5.88
6-2 6 4.36 1.25 5.61
6-3 Barley 5 0.33
Oats 1 3.49 4.16 0.24 1.02 4.06 5.18

TABLE 47—DIABLO CLAY ADOBE, FIRST CROP
OaTs

Planted, November 6, 1915. Harvested, May 8, 1916

Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
1-1 6 4.11 1.24 5.35
1-2 6 6.56 2.59 9.15
1-3 6 4.76 5.14 1.34 1.72 6.10 6.86
2-1 6 4.36 1.10 5.46
2-2 6 total only total only 6.92
2-3 6 6.66 5.01 2.06 1.58 8.72 7.03
5-1 is 7.55 2.59 10.15
5-2 6 10.66 4.38 15.04 _ One barley plant
5-3 6 10.10 3.12 13.22
6-1 6 4.70 1.48 6.18
6-2 6 6.81 1.42 8.22
6-3 6 6.78 1.09 7.88

436 University of California Publications in Agricultural Sciences [Vol.3

TABLE 48—D1aBLo CLay ApbosBe, First Crop
Burk CLOVER
Planted, November 6, 1915. Harvested, May 8, 1916

Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
1-1 5 11.01 15.13 26.32
1-2 + 9.07 14.15 23.22
1-3 6 12.18 10.75 18.02 1416 25.20 24.91
2-1 6 8.26 9.89 18.16
2-2 5 7.45 8.93 16.39
2-3 6 7.97 7.89 8.02 8.98 15.99 16.84
5-1 7 11.14 12.33 23.48
5-2 8 10.67 13.05 23.72
5-3 7 10.55 10.79 9.76 L372 20.31 22.50
6-1 6 7.96 8.73 16.69
6-2 6 8.26 9.76 18.02
6-3 6 6.87 7.69 6.04 8.18 12.91 15.87
TABLE 49—D1ABLo CLAY ADOBE, First Crop
OaTs AND BuR CLOVER
Planted, November 6, 1915. Harvested, May 8, 1916
Straw Grain Total dry matter
No. ye Average Average
Pot plants Weight -weight Weight weight Weight weight Notes
1-1 Clover 3 10.37 11.93 22.30
Oats 6 2.38 0.14 2.52
1-2 Clover 6 8.19 9.28 17.47
Oats 6 3.48 0.70 4.16
1-3 Clover6 13.53 9.81 23.34
Oats 6 2.65 13.53 0.27 10.71 2.92 24.24
2-1 Clover 6 2.13 2.57 4.70
Oats 6 5.77 1.81 7.08
2-2 Clover 6 4.24 4.62 8.87
Oats 6 4.56 1.26 5.82
2-3 Clover 6 3.43 4.51 7.94
Oats 6 3.20 7.75 0.46 5.08 3.66 12.85
5-1 Clover6 10.88 9.78 20.66
Oats 6 2.45 0.27 2.71
5-2 Clover5 10.52 9.32 19.84
Oats 6 2.19 0.51 2.79
5-3 Clover 5 8.31 8.36 16.66
Oats 6 3.45 12.60 0.66 9.63 4.10 22.26
6-1 Clover 6 8.90 9.56 18.46
Oats 6 3.10 0.35 3.45
6-2 Clover 6 9.01 5.82 14.83
Oats 6 2.09 0.52 2.61
6-3 Clover 6 6.51 10.45 16.97

Oats 5 2.33 10.65 0.47 9.06 2.80 19.71

1919] Pendleton: A Study of Soil Types 437

TABLE 50—DraBLo CLAY ADOBE, FIRST. Crop
Phaseolus vulgaris

Planted, April 4, 1916. Harvested, October 7, 1916

Straw Grain Total dry matter
i Tl aie Tt
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
1-1 8 2.05 0.58 2.63 Growth poor and
1-2 1 0.94 0.87 1.81 slow through-
1-3 12 2.86 1.95 1.37 0.94 4,23 2.89 out
2-1 3 0.53 0.21 0.74
2-2 10 ie ey 8) Sepak 0.83
2-3 17 1.26 0.87 Ott 0.10 Lol 0.98
5-1 3 0.53 0.40 0.93
5-2 2 0.46 0.41 0.87
5-3 eevy UN PEs a=)”, aed eed Ve te ce 0.60
6-1 2 eee 4 a oe areds 0.22
ORL apes a ee a ey OP eae
6-3 i 0.23 eB 3, i Abzcas) whe es 0.23 0.15

Diablo clay adobe. Second crop.—The erops used in this plant-
ing were milo (two series, one following oats and bur clover, and the
other following oats alone), cowpeas, millet, and soy beans. The
crop was thinned as follows: milo to eight plants, millet to twelve,
soy beans to six, and cowpeas to six. The total dry weight (tables
51-55) of the largest leguminous crop in this planting is about one-
third of that of the bur clover in the first planting; though the grains
are proportionately not nearly so much less than in the first crop.
Soil no. 2 has the least pronounced adobe structure, but was the most
easily puddled. The plants in one of the pots of soy beans of soil
no. 2 were entirely killed by too much water.

Comparing the relative growth on the soils, the notes made while
the crops were growing coincide very closely with the dry weights.
As to the relative crop production (fig. 28), it can be said that soils
nos. 1 and 5 produced larger crops than soils nos. 2 and 6. Thus the
second crop results substantiate those of the first crop.

438 University of California Publications in Agricultural Sciences [ Vol, 3

10
¥ Soy Beans
Es Milo B
GS) pa Cow Peas
Milo A

Soils

Fig. 28. Graph showing the total dry matter produced by milo (two
series), millet, soy beans, and cowpeas on the four samples of Diablo clay

adobe. Second crop.

Te)
_ Wheat
€ FS + Bur Clover
oF arley
85 ee Pal
Se
O Phaseolas
Ka ram
Soils

Fig. 29. Graph showing the total dry matter produced by wheat, barley,
oats, bur clover, Phaseolus, and oats and bur clover on the three samples of

Altamont clay loam. First crop.

Fig. 30. Graph showing the total dry matter produced by milo (two series),
cowpeas (two series), and soy beans (two series) on the three samples of
Altamont clay loam. Second crop.

1919 | Pendleton: A Study of Soil Types 439

TABLE 51—D1ABLO CLAY ADOBE, SECOND Crop
Mito A (following oats)
Planted, June 8, 1916. Harvested, November 16, 1916

Straw Grain Total dry matter
No. ae Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
1-1 8 8 Te a ee 4.87 Excluded from
1-2 8 SASS hy. Sere evaae 10,00 average
1-3 7 4.50 mioec 1.) ath © Rae 4.50 4.68
2-1 8 Bo Se ee he ee oe 2.59
2-2 8 Dietee eye i) acces 3.73
2-3 8 2.92 os le ee aa ae oe 2.92 3.08
5-1 8 7 A a one hit acne 4.03
5-2 6 Bane A 8 eee: 5.13
5-3 7 Oe ee Hy dates 8.44
6-1 9 Ee a) es oe 3.49
6-2 8 Bie Oe iy hee 3.08
6-3 8 2.98 Sets a lck ¢ ees 2.98 3.18

TABLE 52—D1ABLO CLAY ADOBE, SECOND CROP
Mito B (following oats and bur clover)
Planted, June 3, 1916. Harvested, November 16, 1916

Straw Grain Total dry matter
No. Average Average Average

Pot plants Weight weight Weight weight Weight weight Notes
1-1 8 SAA ee Sas 6.41
1-2 8 EA eee 8.78
1-3 8 6.21 Gis” SO Been ae eee 6.21 7.14
2-1 8 ery Mee | Ee Ae 3.92
2-2 8 oi gi i AAT Baeeaee 4.52
2-3 8 3.63 <A gi a get A 3.63 4,02
5-1 8 Pee ote A E. 10.34
5-2 8 i alas La ere 6.17
5-3 8 5.20 Mea OS -cisin's AA tree 5.20 7.24
6-1 8 Pe, Pie Sees 9,29
6-2 8 le i ie oe eee 3.70

6-3 8 4.09 Oe Fe cesta, mith 4.09 5.69

440

University of California Publications in Agricultural Sciences [Vol.3

TasLe 53—D1asBLo Clay ADOBE, SECOND CRoP
Miter (following bur clover)

Planted, June 3, 1916. Harvested, October 6, 1917

Straw Grain Total dry matter
No. Average Average Average
plants Weight weight Weight weight Weight weight Notes
12 1,52 1.44 2.96
11 1.34 0.90 2.24

11 2.03 1.63 1,15 1.16 3.18 2.79

12 1.26 1.29 2.55
11 1.49 1.32 2.80
12 0.93 1.23 0.88 1.16 1.80 2.39

10 2.26 2.19 4.45
12 3.35 3.36 6.71
12 2.02 2.54 1.51 2.35 3.53 4.90

11 1.19 0.99 2.18
12 1.59 1.23 2.82
13 1.26 1.35 1.04 1.09 2.29 2.43

TABLE 54—D1aBLo CLAY ADOBE, SECOND CROP
CowPeEas (following wheat)

Planted, August 10, 1916. Harvested, November 16, 1916

Straw Grain Total dry matter
No. Average Average Average
plants Weight weight Weight weight Weight weight Notes

7 Bee Bee ness 2.66
7 nse arene 5.30
7 3.73 ee oe a 3.73 3.89
6 Soe skeen 2.57
6 Gene ann 4.24
6 2.86 MES Fake | hateea 2.86 3.22
6 te ok SNe 5 eae 2.74
6 ht) | en 4.30
6 3.64 0 a en eee set 3.64 3.56
6 eo een 3.28
7 Sil =” ese 4.10
6 3.41 Be a ee ra 3.41 3.60

1919 | Pendleton: A Study of Soil Types 441

TABLE 55—D1aBLo CLAay ApDoBE, SECOND Crop
Soy Beans (following barley)
Planted, June 6, 1916. Harvested, November 14, 1916

Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
1-1 6 8.48 0.29 8.77
1-2 6 8.58 0.06 8.64
1-3 6 6.87 7.98 0.41 0.25 7.28 8.23
2-1 6 te Tee el Mecca 2.12 Excluded from
2-2 4 3.62 0.40 4.02 average
2-3 5 6.07 4.84 0.38 0.39 6.45 5.23
5-1 6 5.84 0.16 6.00
5-2 6 7.96 0.64 8.60
5-3 6 6.47 6.76 0.69 0.49 7.16 7.25
6-1 6 7.61 0.24 7.85
6-2 6 7.99 0.45 8.43
6-3 6 7.26 7.62 0.17 0.28 7.43 7.90

Altamont clay loam. First crop.—The crops planted in this soil
were wheat, barley, oats, bur clover, Phaseolus, and oats and bur
clover together. The standard number to which the plants were
thinned was six, except in the oats and bur clover series, where three
plants of each were allowed to remain.

With regard to the comparative crop producing power of these
soils under these conditions, soil no. 4 is the best, with soil no. 3 as
the second, and soil no. 7 was the poorest (tables 56-60, fig. 29). The
dry weight data decidedly corroborate the impression given by the
greenhouse appearance of the crops. However, as all the crops were
so small on all the series, the figures do not show as much as they
might have shown had the growth been more nearly optimum for the
several crops.

TABLE 56—ALTAMONT CLAY LOAM, FIRST CROP

WHEAT
Planted, February 25, 1916. Harvested, July 10, 1916
Straw Grain Total dry matter
No. Average Average Average

Pot plants Weight weight Weight weight Weight weight Notes
3-1 6 2.62 1.23 3.85
3-2 6 2.93 1.09 3.92
3-3 6 2.86 2.80 1.04 1.12 3.91 3.92
4-1 6 4.20 1.78 5.97
4-2 6 4.03 1.22 5.25
4-3 6 6.20 4.81 1.13 1.38 7.34 6.19
7-1 6 2.64 eh! 3.76
7-2 6 2.58 0.99 3.64
7-3 6 2.90 2.71 0.71 0.93 3.61 3.64

University of California Publications in Agricultural Sciences [Vol.3

TABLE 57—ALTAMONT CLAY LoAM, First Crop

Planted, April 4, 1916.

No.

Straw

Averag

plants Weight che hy
1.10
1.45

7 SOc). 332
1.99
1.90

2.39 2.09
0.98

1.06 1.00

Straw

No. Average
plants Weight woh des

1.36

1.60

1.70 1.55

3.05

2.62

3.46 3.04

1,21

1.00

0.88 1.03

Straw
No. Average
plants Weight weight
1.50
0.88
0.63 1.00
2.48
2.57
2.50 2.52
0.47
0.53
0.37 0.46

ADD PADAADQNH

AAA PRA ARAM

BARLEY

Grain

Avera

Weight ae

0.76
1.40
1.18

1.43
1.57
1.85

1.62

0.90 |

0.59

0.71

Harvested, July 11, 1916

Total dry matter

Weight
1.86
2.85
2.57

3.42
3.47
4.25

1.88
1.64

Average
weight

2.43

3.71

1.71

TABLE 58—ALTAMONT CLAY LoAM, First CRoP

Oats

Planted, February 25, 1916. Harvested July 11, 1916

Grain

Average

Weight a he

0.38
0.67
0.47

1.42
1.13
1.81

0.29
0.42
0.35

0.51

1.45

0.35

Total dry matter

Weight
1.74
2.27
2.17

4.47
3.76
5.27

1.51
1.42
1.23

Average
weight
2.06

4.50

1.38

TABLE 58—ALTAMONT CLAY Loam, First Crop

Bur CLOVER

Planted, February 25, 1916. Harvested, July 8, 1916

Grain

Avera

Weight molar:

1.03
1.17
1.34

1.47
1.57
1.31

0.66
0.24
0.20

1.18

1.45

0.36

Total dry matter

Weight
2.53
2.18
1.96

3.95
4.14
3.81

1.13
0.78
0.57

Average

weight

2.18

3.97

0.82

Notes

Notes

Notes

1919] Pendleton: A Study of Soil Types 443

TABLE 59—ALTAMonT CLAy Loam, First Crop
OATS AND BuR CLOVER

Planted, April 14, 1916. Harvested, July 8, 1916

Straw Grain Total dry matter
yo. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
3-1 B.C. 3 0.98 1.25 2.23
Oats 3 0.77 0.10 0.88
3-2 B.C. 4 0.79 iT § 1.96
Oats 4 0.68 0.22 0.90
3-3 B.C. 4 0.48 0.91 1.38
Oats 4 0.78 1.49 0.30 1.32 1.07 2.81
4-1 B.C.3 0.67 0.32 0.99
Oats 3 2.42 1.75 4.17
4-2 B.C. 3 0.40 0.62 1.01
Oats 3 2.63 1.38 4.01
4-3 B.C. 3 0.51 0.21 0.72
Oats 3 2.77 3.14 1.09 1.78 3.86 4.92
7-1 B.C. 3 0.20 0.27 0.47
Oats 3 0.86 0.74 1.60
7-2 B.C. 3 0.28 0.22 0.50
Oats 3 1.27 0.95 2.22
7-3 B.C. 4 0.42 0.37 0.74
Oats 2 0.64 1.22 0.44 0.98 1.08 2.20

TABLE 60—ALTAMONT CLAY LOAM, First Crop
BEANS (Phaseolus)

Planted, February 25, 1916. Harvested, July 11, 1916

Straw Grain Total dry matter
No. Weerkee Average Average

Pot plants Weight weight Weight weight Weight weight Notes
3-1 6 2.82 0.13 2.96
3-2 6 1.24 0.35 1.59
3-3 6 1.32 L719 0.32 0.27 1.64 2.06
4—] 5 1.71 0.25 1.96
4-2 6 1.41 0.59 2.01
4-2 6 iok 1.64 0.59 0.48 2.41 2.12
7-1 1 0.11 0.09 0.20
7-2 6 URE Se Magee 0 il Pete 0.53
7-3 5 0.63 2": a ee 0.03 0.63 0.46

Altamont clay loam. Second crop.—aA slightly different scheme
was used in the planting of this series, only three erops were used,
ie., soy beans, cowpeas, and milo. Two sets of pots were planted to
each crop. one of the two sets having previously been planted to a
legume, and the other to a non-legume. The milo was thinned so that

444 University of California Publications in Agricultural Sciences [Vol,3

one pot of each triplicate set would have 8 plants, the second of the
set 12 plants, and the last 16 plants. It was found that the wide
variation in the number of plants had but little effect upon the dry
weight produced per pot (tables 61-66). The effect was indeed so
slight that the totals were averaged up as usual. Figure 30 shows
distinctly that there was very little variation as regards total produc-
tion among these soils, so little as not to warrant any conclusions as
regards substantiation of, or disagreement with, the first crop. It
will be noticed in the second crop of the Diablo series, as well as in
that of the Altamont series, that the maintenance of the soils under
the same conditions for a year or more seems to bring them quite
rapidly to an average crop producing power.

TABLE 61—ALTAMONT CLAY LOAM, SECOND CRoP
Mito A (following wheat)
Planted, August 10, 1916. Harvested, November 17, 1916

Straw Grain Total dry matter
ee
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
3-1 8 TF OS PES 0.77
3-2 12 eee wn 1.01
3-3 16 0.97 SE td ttn We ee 0.97 0.92
4-1 8 oe wee Ott Scot e 1.22
4-2 12 eee es > SE 2.32
4-8 16 2.08 aR eee i eae. 2.08 1.87
7-1 8 rl Ss aga amore 0.59
7-2 12 O007. = foe 1.29
7-3 16 1.29 Es Hi. ace aw ees 1.29 0.95

TABLE 62—ALTAMONT CLAY LOAM, SECOND CROP
Mito B
Planted, August 10, 1916. Harvested, November 15, 1916

Straw Grain Total dry matter
ee
No. Average Average Average

Pot plants Weight weight Weight weight Weight weight Notes
3-1 8 ee re i an 0.82
3-2 12 3 1 bs Tes 13
3-3 16 1.15 2 |< a ise ee ea 1.15 1.03
4-1 8 jist ge) 0S Si ee 1.28
4-2 12 eee gS So a 1.82
4-3 16 1.45 13S Ar SO Nem i dae 1.45 1.52
7-1 8 Jd 1 SS i aera 0.66
7-2 12 1 oS ih orca 0.96

7-3 16 0.92 ee)? 624.) Ree 0.92 0.85

1919 | Pendleton: A Study of Soil Types

Taste 63—ALTaAMoNnT CLay LOAM, SECOND Crop
Cowrras A (following barley)
Planted, August 10, 1916. Harvested, November 17, 1916

Straw Grain Total dry matter
—
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
3-1 6 nee ae 3.48
3-2 6 Gb Be 8 i ). Seisacten 4.50
3-3 6 3.00 a0) © C. Yascpae ae ae 3.00 3.66
4-1 6 i Oy OR i eee 2.44
4-2 6 Beer. Lk ee 2.59
4-3 6 3.40 Ba. acant, Lh. beeen 3.40 2.81
7-1 6 Bal hi secs 2.64
7-2 6 Lis? Ue Sela)» ees 1.93
7-3 6 2.15 rf ee aie a ae 2.15 2.24
TABLE 64—ALTAMONT CLAY LOAM, SECOND CROP
CowPEaSs B (following oats and bur clover)
Planted, August 10, 1916. Harvested, November 14, 1916
Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
3-1 6 ar Ly ee a 4.16
3-2 6 Seacaen o.:t eet iy ule 3.63
3-2 6 rat Bf Dida) _- cae 6 ees 2.77 3.52
4-1 6 3 Bsn SS ee eee 3.35
4-2 6 Bethe i. ee OP ede akces 2.70
4-3 6 1.94 OO. ihe ie ae 1.94 2.66
7-1 6 gee eye oO Ot oe 1.51
7-2 6 Et Whe jy Si) Sees 2.10
7-3 6 2.85 Be dieds GOR) gcthcccte BAe 2.85 2.15
TABLE 65—ALTAMONT CLAY LOAM, SECOND Crop
Soy Beans A (following oats)
Planted, August 10, 1916. Harvested, November 17, 1916
Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
3-1 6 Se 555 RON al Re ee Se ere 4.85
3-2 6 Baie iabeh Ul ixdéee 4.25
3-3 6 4.50 BGA AG coe |. Stak 4.50 4.53
4-1 6 Garo. 8) FIL We ohee 3.53
4-2 6 Bide wh hin abs ot) ° kee 3.59
4-3 6 4.88 ns eee 4.88 4.00 ©
7-1 6 li ae eee 3.42
7-2 6 i: SR ie ee 3.34
7-3 6 3.42 Bid fo ease ceskce 3.42 3.39

445

446 University of California Publications in Agricultural Sciences [Vol.3

TABLE 66—ALTAMONT CLAY LOAM, SECOND Crop
Soy Beans (following Phaseolus)

Planted, August 10, 1916. Harvested November 17, 1916

Straw Grain Total dry matter
een een eX _ mm see ss
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
3-1 6 Seale |e fk 5,64
3-2 6 4 | Oe) ee Ae caeeanes 4.94
3-3 6 4.84 ae SW eee 4.84 5.14
4-1 6 co. i a ae 4.74
4-2 6 ae ered exe 4.64
4-3 6 4.71 At | | jhe tO Cam yae Tee 4.71 4.70
7-1 6 OR ee ig My eek 5.29
7-2 6 at lw Quel fy -veeece, 3.28
7-3 6 4.39 Se + ge ee eee 4.39 4.31

Hanford fine sandy loam. First crop.—trThis soil type, with sam-
ples from nine different localities in California, gave a much wider
range of conditions and made a much more interesting series. The
plants used as indicators in this series were milo (twice), millet, cow-
peas (twice), and soy beans. The milo was thinned to eight plants
per pot, the millet to twelve plants, and the’ cowpeas and soy beans
to six plants. Set A of cowpeas, and set B of milo were unfavorably
located, so that the results of these sets should be discounted.

It is interesting to note the large differences in the average
weights from soil to soil (tables 67-72, and fig. 31), as compared with
the photographs, in which little variation appears. See especially the
soy bean series. In this series two things are to be noted:

1. Averages on soils nos. 15 and 25 are hardly representative be-
cause in both cases excess moisture, from a leaky roof and too heavy
watering, depressed growth. The tendency to become compact and to
remain wet and cold shown by soil no. 15 aided the milo and depressed -
the soy beans.

2. The loose, open texture of soil no. 22 seemingly favored the soy
bean growth, though the other plants did not do as well on this soil
as on most of the others.

1919] Pendleton: A Study of Soil Types 447

Comparing the more satisfactory grains, milo A and millet, it will
be seen that there is somewhat of a parallelism from soil to soil. The
legumes do not always respond similarly to the grains, as in the Diablo
first crop, yet in the Diablo second crop and the Altamont first and
second crops the response of grain and legume seems quite similar.
Hence, it is not safe in every case to judge as to the relationships
shown by legumes and non-legumes.

RS

Fid. Of

Fig. 31. Graph showing the total dry matter produced by millet, milo (two
series), cowpeas (two series), and soy beans on the nine samples of Hanford
fine sandy loam, First crop.

Considering all the variations, one might say that soil no. 23 was
seemingly among the better soils, and soils nos. 16 and 22 among the
poorer soils. Yet when discussing whether the soils be the same or
similar, according to the criterion of the dry weight, one of the Han-
ford groups will be similar according to one crop, and an overlapping
group similar according to the second crop. It can be said with rea-
sonable certainty that these Hanford soils are not closely similar to
one another.

448 University of California Publications in Agricultural Sciences [Vol.3

TABLE 67—HaAnrorD Fine Sanpy Loam, First Crop

Planted, June 10, 1916. Harvested, November 18, 1916

Straw

No. Average
Pot plants Weight weight
14-1 8 15.34
14-2 8 12.50
14-3 8 10.15 12.66
15-1 8 13.14
15-2 8 14.50
15-3 5 15.21 14.28
16-1 8 8.67
16-2 8 5.86
16-3 8 4.76 6.43
19-1 8 7.65
19-2 8 14.11
19-3 8 7.01
20-1 8 14.10
20-2 8 10.15
20-3 8 7.68 10.64
22-1 8 5.34
22-2 8 5.88
22-3 8 5.35 5.52
23-1 8 8.90
23-2 8 10.04
23-3 8 8.67 9.20
24-1 7 10.82
24-2 8 9.92
24-3 8 6.01 8.92
25-1 8 11.26
25-1 8 11.26
25-2 8 5.70
25-3 8 9.33 8.76

Mito A

Grain

Average
Weight weigh

t

Total dry matter

Average
Weight weight Notes
15.34 Most plants bore
12.50 no grain; some
10.15 12,66 8fain was im-

mature at har-
vest. These
cases noted,
but no grain
weighed.

15.21 14.28 Not mature

4.76 6.43

7.68 10.64 Not mature

5.35 5.592

8.90 Not mature
10.04 Not mature
8.67 9.20

9.92 Not mature |
6.01 8.92 Not mature

9.33 8.76

1919] Pendleton: A Study of Soil Types 449

TABLE 68—HANForD FINE SANDY Loam, First Crop
Mito B

Planted, June 10, 1916. Harvested, November 20, 1916

Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
14—. 8 PUM ok iy Si 10.75
14-2 8 RAS he ee ee ccins 10.95
14-3 8 8.84 PEs) h NG oe hee bs deka 8.84 10.18
15-1 5 te eee 5.25
15-2 4 Gyan WAL Sie Wy aeons 4.62
15-3 2 3.92 RA Se a eer 3.92 4.60
16-1 7 Tames). © AE & nacho 7.36
16-2 2 ML i ie Oper 2.18
16-3 4 2.74 Se ere ae ieee ee 2.74 4.09
19-1 3 78 9: ae ae a or 3.73
19-2 8 ene aT wal © 4 ye, 4.79
19-3 8 9.60 ht = oo. Bee we once 9.60 6.04
20-1 8 pee et te be chs 8.14
20-2 8 Ons eee 3.23
20-3 8 3.22 Wired © 2... 7.06 fon 3.22 4.86
22-1 6 a sae 4.74
22-2 5 ie on 8 py See 3.01
22-3 ff 3.19 7 A Wy MN Ne” pees 3.19 3.64
23-1 8 i Ve 5.68
23-2 5 ete soe) Big Sess 7.72
23-3 8 6.93 Cie 9 etl) be Rene 6.93 6.78
24-1 3 = a a eee 3.16
24-2 6 a ey ee eae 5.64
24-3 6 3.26 RCs Bo cczates We tess 3.26 4.02
25-1 - Rk ot or ee 3.07
25-2 3 Gaeees ) e go ue 2.34

25-3 8 4.34 os ee ae Tee 4.34 3.25

450 University of C

Planted, June 10, 1916.

Straw

No.
Pot plants Weight

14-1 12
14-2 13
14-3 14
15-1 12
15-2 12
15-3 12
16-1 13
16-2 12
16-3 12
19-1 12
19-2 12
19-3 12
20-1 12
20-2 12
20-3 12
22-1 12
22-2 12
22-3 12
23-1 12
23-2 12
23-3 12
24-1 12
24-2 12
24-3 11
25-1 12
25-2 12
25-3 12

3.75
4,23
3.46

3.63 .

4.63
3.86

1.96
3.10
1.52

1.85
1.71
2.00

6.54
1.70
6.57

2.04
2.32
4.44

6.12
6.13
6.01

4.18
2.80
4.89

2.06
2.01
4.31

Average

weight

3.81

4.04

2.19

1.85

6.55

2.93

6.08

3.96

2.79

MILLET

October 6, 1916

Grain

Weight
2.90
2.95
2.01

1.02
1.31
1.12

0.74
1.81
0.73

0.73
0.76
0.69

2.78
1.01
2.21

0.65
0.68
1.90

1.21
2.14
1.97

1.50
0.91
2.08

0.77
0.51
2.15

Average

weight

2.62

1.15

1.09

2.50

1.08

1.50

1.14

alifornia Publications in Agricultural Sciences

Total dry matter

Weight
6.65
7.18
5.47

4.65
5.93
4.98

2.70
4.91
2.25

2.58
2.48
2.69

9.32
2.71
8.78

2.69
3.00
6.34

7.33
8.27
7.99

5.69
3.70
6.98

2.83
2.52
6.46

Average

weight

6.43

5.19

3.29

2.58

9.05

4.01

7.86

5.46

3.94

[ Vol. 3

TABLE 69—HANFORD FINE SANDY LoaM, First Crop

Harvested: Nos. 15-25, September 20, 1916; No. 14,

Notes

Seed immature
Poor. Lack of
drainage?

Possible error in
grain weight.
Original shows
6 grams

ae

1919 | Pendleton: A Study of Soil Types 451

TABLE 70—HANFoRD FINE SANDY Loam, First Crop
Soy BEANS

Planted, June 10, 1916. Harvested, December 11, 1916

Straw Beans Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
14-1 6 RO ates 16.69 Immature seed
14-2 6 SMM hy) Pda, Vainde 16,28 Immature seed

14-3 6 11.89 14.95 0.44 0.15 12.338 15.10 Immature seed

15-1 6 14.08 0.23 14.31 Immature seed
15-2 6 a I eh nl So re 5.17 Immature seed
15-3 6 6.53 | ee 0.08 6.53 8.67 Immature seed
16-1 6 12.63 0.32 12.95 Immature seed
16-2 6 Te eg tS = ees 14.60 Immature seed
16-3 6 POO aOR adele 0.11 16.60 14.72 Immature seed
19-1 6 Pe as ah a ce 1. eee 12.84 Immature seed
19-2 6 ee rite UC at Re 11.68 Immature seed
19-3 6 pee: ve bebuehin | Pe ie 4 Ake 16.03 13.52 Immature seed
20-1 6 eT tl ih eee 8.77 Immature seed
20-2 6 Pact eel Ba. 16.33 Immature seed
, 20-3 6 Sh gay Rt ie a PR ce 14.27 13.13 Immature seed
22-1 6 ee Wii paar eee. 20.28 Immature seed
22-2 6 Ay ayn |e > hl aaan 19.44 Immature seed
22-3 6 rie: Maga © © Salar ng ra bai 15.60 18.44 Immature seed
23-1 6 Pier ee Wee 21.42 No seed
23-2 6 Re Pe) i Ba ae 20.75 No seed
23-3 6 Pees. C2OGo). . Bw () Se 20.68 20.95 Immature seed
24-1 6 iwc ul, 0. . foes 17.37 Immature seed
24-9 6 jh Ar 21.24 Immature seed
24-3 6 is: Pet hi 2c eT eg meee 13.70 17.43 Immature seed
25-1 6 atte Th ee 5.53 Rained on; exclud-
ed from average
25-2 6 ‘b's! i a aes 17.85 No seed

25-3 6 21.58 Te. 0 She Ss 21.58 19.71 Immature seed

LS
:

University of California Publications in Agricultural Sciences [Vol.3

TaBLe 71—HaAnrorD Fine Sanpy Loam, First Crop
CowPEas A

Planted, June 10, 1916. Harvested, October 21, 1916

Straw Beans Total dry matter
No. Average Average Average
plants Weight weight Weight weight Weight weight Notes

6 2.99 0.93 3.92

6 on * =.) Cee 3.52

6 4.18 WO” te lee 4.18 3.87

1 ee ee 8 2.98 Immature seed

3 3.05 1.50 4.58

2.60 2.88 2.16 1.22 4.76 4.10

6 1.49 0.27 1.77

6 1.54 0.28 1.82

2 1.10 1.38 0.47 0.34 1.57 1.72

6 2.86 0.32 3.18

6 2.08 0.58 2.66

6 2.99 2.64 0.33 0.41 3.32 3.05

5 1.80 0.23 2.02

2 1.96 1.88 0.39 0.31 2.35 2.19

1 1.80 0.76 2.57

pier 1.80 ee 0.76 ees 2.57

2 1.06 0.25 1.30

1 1.80 1.29 3.09

2 1.75 1.54 0.45 0.66 2.20 2.20

3 2.74 2.03 4.78

1 1.88 2.28 4.17

2 2.12 2.25 1.24 1.85 3.36 4.10

1919] Pendleton: A Study of Soil Types 453

TABLE 72—HANFoRD FINE SANDY LOAM, First Crop
COWPEAS B

Planted, June 10, 1916. Harvested, November 21, 1916

Straw Beans Total dry matter
Pe Peay. th aN
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
14-1 6 Siero 8) Oh 3.94
14—2 6 ier a’ a Pt iaeees 5.92
14-3 6 3.32 BOO 2 cccee ie eed 3.32 4.39
15-1 6 Fie he oe Ae 7.24
15-2 6 Romo wr wy Mas, Bau 5.34
15-3 6 4.61 ay” Sg ener ny pee 4.61 5.74
16-1 6 et he Ch he ee 5.90
16-2 6 Bites bt, 2 Oo po haenk 5.82
16-3 6 3.65 5.12 Nar OY ane ORR 3.65 5.12
19-1 6 et SE ae eae 3.34
19-2 6 ae pes 3% aioae 3.38
19-3 6 3.87 ee, int be me occa 3.87 3.53 1 died early
20-1 6 cl, See a eee 3.09
20-2 6 Sete ey ee 3.15 1 died early
20-3 6 2.80 Sa” Wi Sc we LS 2.80 3.01
22-1 6 CAN a ee Wie 3.12
22-2 6 i cr CC ie ee oer 3.61
22-3 6 4.92 pol: Den ETS gh me ates 4.92 3.88
23-1 6 Ree . Nahi ee 4.59
23-2 6 8: is ie © tk 6.04
23-3 6 4.08 | 6 Sk ee eI 4.08 4.90
24-1 6 ite nhl beh | Cece 3.81
24-2 5 ye ip eT ee So 4,28
24-3 6 6.42 S.G8 0 5 a eee 6.42 4.84
25-1 5 ee ee i nk kee 4.17
25-2 6 eee hata ty OC ae 3.93 1 died early
25-3 6 4.86 ee eee 4.86 4.32

Hanford fine sandy loam. Second crop.—Barley (twice), oats,
wheat, bur clover (Medicago sp.), and Melilotus indica were the indi-
eator crops used when the Hanford soils were planted the second time.
In all cases a sufficient quantity of seed was used to insure the growth
of more plants than would be raised to maturity. Later the plants
in each pot were thinned to six in number, good specimens and well

454 University of California Publications in Agricultural Sciences [ Vol. 3

spaced. The final number of plants varied, but was almost always six.
An attempt was made to reduce at least partially the shading and
exposure effects. ‘The pots were periodically changed from position
to position on the bench.

The total dry weights produced on the several soils are interesting
(tables 73-78, and fig. 33). The grains gave more uniform results in
this crop than in the first. Soils nos. 14 and 23 show the best crops,
and they are the ones that have the highest amounts of total nitrogen.
The legumes selected must have been particularly well adapted to the
erowing conditions and the soils, because the growth was enormous.
In the amount of dry matter produced the parallelism between the
two legumes from soil to soil is close. It is noteworthy that soil no. 14,

15 Wheat

2 ES Bur Clover
Oats
fe) Melilotus
lO. Ti 2p 15. If © 16 > Bf Pe e6 oe
Soils
Fig. 52

Fig. 32. Graph showing the total dry matter produced by barley, wheat,
oats, rye, bur clover, and Melilotus indica on the eight samples of San Joaquin
sandy loam. First and only crop.

which showed the highest total nitrogen and produced the most dry
matter from the grains, gave the poorest crop of legumes. The notes
taken during the growing period show that the relative appearances
quite early and throughout the period of growth are usually a good
index to the relative amounts of dry matter produced. This is so,
even though the photographs of the mature plants do not show dif-
ferences nearly as great in magnitude as do the dry weights.

This type does not show any marked tendency for the several soils
te approach a more uniform crop producing capacity through being
kept under the same conditions. In fact, the second crop shows
ereater variations than the first. And this type does not show that
these nine soils, mapped under a single type name, are closely similar
to one another in crop producing power.

1919]

Pendleton: A Study of Soil Types

455

TABLE 73—HANForD Fine SAnpy Loam, Second Crop

Wueat (following millet)

Planted, October 30, 1916. Harvested, June 21,

Straw Grain Total dry matter

Average Average Average

No.
plants Weight weight Weight weight Weight weight

ao

ao a

10.75 3.55 14.30
5.20 2.10 7.30
14.85 10.26 6.45 4.03 21.30 14.30

3.55 1.30 4.65
4.85 1.50 6.35
2.80 3.66 1.10 1.30 3.90 4.96

3.20 0.95 4.15
8.20 3.70 11.90

2.80 3.00 0.70 0.82 3.50 3.82

2.80 0.75 3.99
2.80 0.65 3.45
2.20 2.60 0.60 0.66 2.80 3.26

5.45 2.80 8.25
4.05 1.55 5.60
21.35 4.75- ~12.90 2.17 34.25 6.90

4.15 0.90 5.05
3.95 0.40 4.35
4.45 4.18 0.90 0.73 5.35 4,92

4.90 1.60 6.50
4.75 1.60 6.35
3.75 4.46 1.10 1.43 4.85 5.90

18.60 8.30 26.90
3.20 0.90 4.10

23.75 3.20 5.40 0.90 29.15 4.10

2.25 2.37 0.80 0.57 3.05 2.95

1917

Notes

Rained on, exclud-
ed from average

Rained on, exclud-
ed from average

Rained on, exelud-
ed from average
Rained on, execlud-
ed from average
Rained on, exelud-
ed from average

456

University of California Publications in Agricultural Sciences [Vol,3

No.
plants

6
6
6

6
6

ann ano a

aa oD

TaBLE 74—HaANForRD FINE Sanpy Loam, Seconp Crop
Oats (following milo A)

Planted, November 22, 1916.

Straw

Weight
3.80
3.40
3.20

2.45
1.75
2.00

11.15

2.15

1.15

1.75
4.55
1.35

10.45

1.55
1.65

1.65
2.10
2.50

2.70
1.90
3.20

4.80
16.75

3.39

1.95
2.25
1.80

Average
weight

3.47

2.06

2.15

2.55

1.60

2.08

2.60

4.07

2.00

Grain

Weight

2.90
1.85
2.40

1.35
1.25
1.50

8.40

2.30

Average
weight

2.38

1.36

2.30

1.02

1.25

1 ey 9)

2.73

1.30

Weight
6.70
5.25
5.65

3.80
3.00
3.50

19.55

4.45

1.85

3.00
7.50
2.30

16.75

2.60
2.65

2.75
3:25
4.00

425

3.50
5.20

7.90
26.55

5.70

3.25
3.65
3.00

Average
weight

5.86

3.43

4.45

4.27

2.62

4.32

6.80

3.30

Harvested, June 18, 1917

Total dry matter

Notes

Rained on, exelud-
ed from average

Pot saturated with

soluble salts, ex-
eluded from av-
erage

Rained on, exclud-
ed from average

Rained on, exelud-
ed from average

~

1919] Pendleton: A Study of Soil Types 45

TaBLeE 75—HANForD Fine SANDY LOAM, SECOND Crop
BarLEY A (following cowpeas A)

Planted, October 30, 1916. Harvested, May 20, 1917

Straw Grain Total dry matter
_
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
14-1 6 4.75 4.30 9.05
14-2 6 9.22 9.00 18.22

14-3 6 11.97 8.65 10.85 8.05 22.82 16.69

15-1 6 15.47 15.30 30.77 Rained on, exelud-
ed from average

15-2 6 3.78 3.29 1.07

15-3 6 5.00 4.39 4.12 3.70 9.12 8.09

16-1 6 7.28 6.42 13.70

16-2 2.55 2.55 5.10

16-3 6 2.20 4.01 At 3.96 3.91 7.57

19-3 6 2.89 2.70 2.25 1.98 5.14 4.68

20-1 6 3.57 2.90 6.47

20-2 6 3.32 2.80 6.12

20-3 6 19.35 3.44 7.45 2.85 26.70 6.29 Rained on, exclad-
ed from average

22-1 2.73 2.07 4.80

22-2 5.89 3.53 9.42

22-3 6 3.69 4.10 2.73 2.78 6.42 6.88

23-3 6 7.98 6.24 4.20 3.93 12.18 10.41

e§
Cw bo
a
bo
yh
“1 ©
wo On
Ko)
~
Or
is)
aa
for)
fan)

3.90 3.57 3.05 8.30 6.95

25-1 6 2.47 1.75 4.22 Rained on, exelud-
ed from average
25-2 6 eee ee ee ne OSs Pot broken, ex-

cluded from av-

erage
25-3 6 3.01 2.74 2.18 1.96 5.19 4.70

458 University of California Publications in Agricultural Sciences. [Vol.3

TaBLE 76—HANFORD Fine Sanpy Loam, SeconpD Crop
Baruey B (following soy beans)

Planted, January 31, 1917. Harvested, June 21, 1917

Straw Grain Total dry matter
No. Average Average Average ;
Pot plants Weight weight Weight weight Weight weight Notes

14-1 6 9.55 6.80 16.35

14-2 6 6.05 5.40 11.45

14-3 6 3.80 6.47 2.10 4.76 5.90 11.23

15-1 6 3.50 2.80 6.30

15-2 6 3.20 1.70 4.90

15-3 6 405 358 260 236 665 5.95

16-1 3.10 1.45 4.55

16-2 9.20 8.20 17.40 Rained on, exclud-
ed from average

16-3 6 7.35 3.10 4.50 1.45 11.85 4.55 Rained on, exclud-
ed from average

19-1 6 3.05 0.80 3.85

19-2 6 2.65 2.20 4.85

19-3 6 2.15 2.62 1.85 1.61 4.00 4.23

20-1 6 3.35 2.60 5.95

20-2 6 4.20 3.20 7.40

20-3 6 2.55 3.36 2.15 2.65 4.70 6.02

22-1 6 2.05 1.75 3.80

22-2 6 2.90 2.35 5.25

22-3 6 3.15 2.70 2.25 2.12 5.40 4.82

23-1 6 3.10 2.05 5.15

23-2 6 3.10 2.95 6.05

23-3 6 3.40 3.20 2.75 2.58 6.15 5.78

24-1 6 3.10 1.45 3.70

24-2 6 10.10 5.80 15.90 Rained on, exclud-
ed from average

24-3 6 3.05 2.65 2.35 1.90 5.40 4.55

25-1 6 3.35 2.90 6.25

25-2 6 3.10 1.85 4.95.

25-3 6 4.70 3.72 4.60 3.12 9.30 6.83

——

1919]

Pot
14-1
14-3
14-3

15-1
15-2
15-3

16-1
16-2
16-3

19-1
19-2
19-3

20-1
20-2
20-3

22-1
22-2
22-3

23-1
23-2
23-3

24-1
24-9
24-3

25-1
25-2

25-3

6

Pendleton: A Study of Soil Types

TABLE 77—HANFoRD Fine SAnpy LOAM, SECOND Crop

Melilotus indica (following cowpeas B)

Planted, November 22, 1916. Harvested, June 21, 1917

Straw Unhulled seed ‘Total dry matter

siaais Weight eh Fn Weight Sack Weight pra
17.00 15.80 32.80
13.25 16.45 29.70

6
6

4.40 15,12 3.10 1618 7.50 31.25

35.00 34.75 69.75
24.85 27.28 52.05
28.95 ' 29.60 32.70 /31.58 61.65 61.15

23.50 24.90 48.40
30.80 25.50 56.30
23.65 25.98 25.70 25.37 49.35 51.35

20.50 18.35 38.85
26.90 23.20 50.10
26.20 24.53 27.40 22.98 53.60 47.52

20.55 17.80 38.35
20.75 21.20 41.95
28.85 23.38 26.05 21.68 54.90 45.07

28.00 28.10 56.10
32.30 34.20 66.50
28.25 29.52 31.85 31.38 60.10 60.90

38.05 34.25 72.30
34.40 36.55 70.95
32.25 34.90 32.35 34.38 64.60 69.28

37.35 31.40 68.75
25.90 28.10 54.00

29.05 30.77 30.15 29.88 59.20 60.65 .

25.35 30.45 55.80
33.90 35.90 69.80
32.10 3045 36.65 34.33 68.75 64.78

Notes

Excluded from
average

459

460 University of California Publications in Agricultural Sciences [Vol,3

TABLE 78—HANFORD FINE Sanpy LoaM, SECOND CROP
Bur Ciover (following milo B)

Planted, November 22, 1916. Harvested, June 25, 1917

Straw Burs Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
14-1 7 6.70 17.55 24.25
14-2 6 7.00 16.85 23.85
14-3 6 6.10 6.60 14.50 16.30 20.60 22.90
15-1 6 13.30 29.10 42.40
15-2 6 14.45 33.10 47.55
15-3 6 17.10 14,95 26.65 29.62 43.75 44.56
16-1 6 8.85 15.40 24.25
16-2 6 12.25 29.60 41.85
16-3 6 10.05 10.38 21.90 22.30 31.95 32.68
19-1 6 9.90 19.90 29.80
19-2 6 7.70 17.80 25.50
19-3 6 8.20 8.60 22.40 20.03 30.60 28.63
20-1 6 7.90 22.50 30.40
20-2 6 9.75 23.30 33.05
20-3 6 8.70 8.78 20.50 22.10 29.20 30.88
22-1 6 15.90 38.00 53.90
22-2 6 13.20 23.40 36.60
22-3 6 14.50 14.53 31.30 30.90 45.80 45.43
23-1 6 14.45 37.40 51.85
23-2 6 13.55 27.30 40.85
23-3 6 12.05 13.35 28.00 30.90 40.05 44.25
24-1 6 10.60 24.30 34.90
24-2 6 12.10 34.10 46.20
24-3 6 10.25 10.98 24.00 27.46 34.25 38.45
25-1 6 17.90 40.00 57.90
25-2 6 14.60 30.80 45.40
25-3 6 13.35 15.28 26.40 32.40 39.75 47.68

San Joaquin sandy loam.—The samples of this type were the last
to be weighed into pots and planted, because of the lack of available
greenhouse space; therefore the time allowed for the growing of but
one crop, instead of two, on each pot of soil. The crops used were
wheat, barley, rye, oats, bur clover (Medicago sp.), and Melilotus
indica. As was done for the other types, an excess of seed was
planted. When the plants were well established, thinning reduced
the number to six plants per pot.

Since the specific gravity of this soil was high, because of the large
amount of quartz and the small amount of organic matter in its com-
position, six kilos of soil, instead of five, were weighed out into each
pot. The samples of this type have the very annoying peculiarities
of becoming very mushy if an excess of water be added, and of setting

1919] Pendleton: A Study of Soil Types 461

with a very hard surface on drying. This makes the soils hard to
handle in greenhouse pot culture work.

The variation in crop growth from soil to soil, as shown by the
total dry matter produced (tables 79-84 and fig. 32), is rather
marked. That the several samples do not show equal crop producing
powers is very evident, though with regard to the several indicator
erops the soils would frequently not maintain the same order. Soil
no. 26 gave the poorest yields with all six crops. Except for wheat,
the soils nos. 10, 11, and 12 gave low yields with both the grains and
the legumes. It is interesting to note that wheat gave relatively high
yields with a number of the soils, and wheat has probably been raised
on these soils more than any other one crop. This series shows that,
as far as the samples represent the type and the crops used represent
crops as a whole, the soils mapped under a given type name are not
closely similar in crop producing power under greenhouse conditions.

TABLE 79—San JOAQUIN SANDY LOAM

RYE
Planted, November 22, 1916. Harvested, June 21, 1917
Straw Grain Total dry matter
No. Average Average Average

Pot plants Weight weight Weight weight Weight weight Notes
10-1 6 1.70 0.30 2.00
10-2 6 2.30 0.35 2.65
10-3 6 2.05 2.02 0.65 0.43 2.70 2.45
11-1 6 Ps 0.70 3.85
11-2 6 2.25 0.70 2.95
11-3 4 3.20 2.87 0.70 0.70 3.90 3.57
12-1 6 1.65 0.45 2.10
12-2 6 2.45 0.85 3.30
12-3 6 2.40 2.17 0.65 0.65 3.05 2.82
13-1 6 4.20 1.25 5.45
13-2 6 4.30 0.80 5.10
13-3 6 aro 4.08 1.60 1,22 2.00 5.30
17-1 6 7.09 1.60 9.15 Rained on
17-2 6 1.95 0.55 2.50
17-3 6 1.80 1.87 0.45 0.50 2.25 2.00
18-1 6 2.35 0.85 3.20
18-2 6 0.90 0.30 1.20
18-3 6 3.70 2.32 1.20 0.78 4.90 3.10
21-1 6 2.20 0.80 3.00
21-2 6 2.70 0.95 3.65
21-3 6 6.55 2.45 2.35 0.87 8.90 3.33 Rained on
26-1 6 1.50 0.60 2.10
26-2 6 2.55 0.75 3.30
26-3 6 2.50 2.18 0.70 0.68 3.20 2.87

462 University of California Publications in Agricultural Sciences [ Vol. 3

Gr

Melilotus

14 15 16 19 20 22 23 24 25 Soils

Fig. 33. Graph showing the total dry matter produced by wheat, oats,
barley (two series), bur clover, and Melilotus indica on the nine samples of
Hanford fine sandy loam. Second crop.

1919]

Planted, October 30, 1916.

Pendleton: A Study of Soil Types

TABLE 80—SAN JOAQUIN SANDY LOAM

Straw

Average

No.
plants Weight weight

6
6
6

2.93
1.87
1.47

1.91
2.02
2.97

10.27

3.60
3.49

2.14
3.19
3.28

3.89
3.74
2.44

4.65
3.74
5.61

2.05
2.10
3.81

1.12
1.08
1.20

2.09

2.30

3.04

2.87

3.35

4.66

2.65

1.13

BARLEY

Grain

Weight
0.92
0.81
0.85

0.66
1.28
0.90

4.95

1.32
0.43

1.46
1.78
Le

2.17
1.80
0.80

1.93
1.94
2.34

1.53
1.80
2.33

0.63
0.41
0.70

Average

weight

0.86

0.95

0.87

1.67

1.59

1.88

0.58

Total dry matter

Weight

3.85
2.68
2.32

2.57
3.30
3.87

15.22

4.92
3.92

3.60
4.97
5.05

6.06
5.54
3.24

6.58
5.68
7.95

3.98
3.90
6.14

1.75
1.49
1.90

2.95

3.25

4.42

4.53

4.95

6.74

463

Harvested, June 17, 1917

Average
weight

Notes

Rained on; exelud-
ed from average

464 University of California Publications in Agricultural Sciences [Vol.3

TABLE 81—San Joaquin Sandy LOAM
WHEAT

Planted, October 30, 1916. Harvested, June 21, 1917

Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
10-1 6 3.59 0.85 4.80
10-2 6 3.45 0.45 3.90
10-3 6 6.35 4.58 0.75 0.68 7.10 5.26
11-1 6 5.60 1.15 6.75
11-2 6 2.75 0.60 3.35
11-3 6 3.45 3.93 0.70 0.81 4.15 4.75
12-1 6 6.85 2.00 8.85
12-2 6 7.50 1.35 : 8.85
12-3 6 4.45 6.27 1.35 1.56 5.80 7.83
13-1 6 3.90 0.85 4.75
13-2 6 3.25 0.45 3.70
13-2 6 3.95 3.70 0.75 0.68 4.70 4.38
17-1 6 2.70 0.25 2.95
17-2 6 1.20 0.45 1.65
17-3 6 2.75 2.21 none 0.23 2.75 2.45
18-1 6 5.90 1.50 7.40
18-2 6 7.90 2.40 10.30 Rained on
18-3 6 5.00 5.45 1.00 1.25 6.00 6.70
21-1 6 3.10 1.05 4.15
21-2 5 4.30 0.75 5.05
21-3 6 8.40 3.70 2.45 0.90 10.85 4.60 Rained on
26-1 6 2.35 0.55 2.90
26-2 6 0.40 none 0.40 Rained on
26-3 6 2.60 2.47 0.35 0.45 2.95 2.92

1919] Pendleton: A Study of Soil Types 465

TABLE 82—SAn JOAQUIN SANDY LOAM
OATS

Planted, November 22, 1916. Harvested, June 17, 1917

Straw Grain Total dry matter
No. Average Average Average
Pot plants Weight weight Weight weight Weight weight Notes
10-1 6 2.25 0.90 3.15
10-2 6 3.65 1.90 5.55

10-3 6 1.70 2.53 0.50 1.10 2.20 3.63

11-1 2.25 1.25 3.50
11-2 6 1.75 0.95 2.70
11-3 6 2.10 2.03 1.00 OY. 3.10 3.10
12-1 6 1.70 0.90 2.60
12-2 6 2.40 1.00 38.40

12-3 6 2.35 2.15 1.05 0.98 3.40 3.13

13-1 6 2.25 1.20 3.45
13-2 6 2.40 1.10 3.50
13-3 6 2.70 2.45 1.70 1.33 4.40 3.78

17-1 6 0.80 0.55 1.35
17-2 6 1.50 0.90 2.40
17-3 6 1.25 1.90 0.70 0.72 1.95 1.90
18-1 6 1.70 1.00 2.70
18-2 6 1.15 0.60 1.75

18-3 6 1.10 1.32 0.50 0.70 1.60 2.02

21-1 6 1.85 0.95 2.80
21-2 6 2.35 1.05 3.40
21-3 6 1.00 ite 0.55 0.85 1.55 2.58

26-1 6 1.55 0.60 2.15
26-2 6 1.35 0.80 2.15
26-3 6 1.65 1.52 0.70 0.70 2.35 2.22

466

University of California Publications in Agricultural Sciences [Vol.3

TaBLeE 883—San Joaquin Sanp¥ Loam
Bur CLOVER

Planted, November 22, 1916, Harvested, June 17, 1917

Straw Seed in burs Total dry matter
ome, weight ATSROS? weight “Weight Welght weight’ Notes
6 0.50 0.95 1.45
6 1.50 1.65 3.15

6 0.50 0.83 1.75 1.45 2.25 2.28

6 0.90 2.00 2.90
6 0.25 1.00 1.25
6 0.30 0.48 1.10 1.37 1.40 1.85

6 0.90 3.00 3.90
2.15 5.30 7.45
1.50 1.52 1.90 3.40 3.40 4,92

6 1.55 3.45 5.00
0.75 2.80 3.55
4.35 1.15 5.70 3.12 9.05 4.27 Excluded from av-
erage
6 0.70 2.05 2.75
6 2.35 3.85 6.20 Excluded from av-
erage
6 0.90 0.80 1.70 1.87 2.60 2.67
6 1.20 3.40 4.60
6 3.25 6.65 9.90 Excluded from av-
erage

6 1.80 1.50 4.85 4.12 6.65 5.62

6 3.35 3.70 7.05
6 2.00 3.90 — 5.90.
6 1.75 2.37 5.15 4.25 6.90 6.62

6 0.60 1.45 2.05
6 1.20 2.75 3.95
0.40 0.73 1.30 1.83 1.70 2.56

1919 | Pendleton: A Study of Soil Types 467

TABLE 84—SAN JOAQUIN SANDY LOAM
Melilotus indica
Planted, November 22, 1916. Harvested, June 21, 1917.

Straw Unhulled seed Total dry matter

No. Average Average Avirics
Pot plants Weight weight Weight weight Weight weight Notes
10-1 6 1.20 1.20 2.40
10-2 6 1.03 0.92 1.95
10-3 6 1.30 1.18 1.65 1.26 2.95 2.44
11-1 6 1.05 0.85 1.90
11-2 6 0.50 0.35 0.85

11-3 6 1.00 0.85 0.80 0.67 1.80 1.52

2-1 6 1.07 2.05 3.12

2—2 6 1.70 2.45 4.15

2-3 6 1.20 1.33 1.40 1.96 2.60 3.29
13-1 6 3.05 3.70 6.75
13-2 6 3.10 3.95 7.05

13-3 6 3.50 3.22 4.45 4.03 7.95 7.25

17-1 6 3.05 4.05 7.10
17-2 6 2.25 3.55 5.80
17-3 6 2.85 2.72 3.20 3.60 6.05 6.32

18-1 6 3.25 3.90 7.15
18-2 6 2.05 2.65 4.70
18-3 6 2.85 2.42 3.95 3.50 6.80 6.22

21-1 6 2.50 3.40 5.90
21-2 6 2.65 3.95 6.60
21-3 6 3.45 2.87 3.30 3.59 6.75 6.42

26-1 6 1.10 0.85 1.95
26-2 6 0.95 0.85 1.80
26-3 6 1.30 1.12 1.05 0.92 2.35 2.04

GENERAL DISCUSSION

The limited time available for this study made it impossible to
make all the determinations upon each of the several horizons of all
the soils collected for this study.

It was believed, however, that the additional data were not re-
quired, since that already at hand seemed to give ample evidence upon
which to base conclusions. Therefore, in many cases determinations
were run on the surface horizon only. This makes some of the tables
appear incomplete.

468 University of California Publications in Agricultural Sciences [ Vol. 3

On the basis of the preceding results and discussions some general
treatment is possible, as well as a more or less critical discussion of the
methods of soil surveying pursued by the Bureau of Soils.

The types and the localities of collection of the soils studied were
as follows:

Diablo clay adobe: Thalheim (17)
San Juan Capistrano (1) Madera (18)
Los Angeles (2) Merced (21)
Calabasas (5) Del Mar (26)
Danville (6) Hanford fine sandy loam:

Altamont clay loam Elk Grove (14)
Walnut (3) Acampo (15)
San Fernando Valley (4) Woodbridge (16)
Mission San José (7) Waterford (19)

San Joaquin sandy loam: Snelling (20)
North Sacramento (10) Basset (22)
Lincoln (11) Anaheim (23)
Wheatland (12) Los Angeles (24)
Elk Grove (13) Van Nuys (25)

Nore.—Figures following localities designate sample numbers.

COMPARISONS OF PHYSICAL Data

The mechanical analyses of the soils were carried out with both
the Hilgard elutriator and the Bureau of Soils centrifuge methods.
The tedious nature of the elutriator method has been emphasized else-
where. The results by this method show that the soils of each type
as a whole are somewhat similar, though no two are identical and
some samples of a type are widely divergent from the rest. The
Bureau of Soils method appears to give a sharper and more satisfac-
tory separation into classes than does the elutriator method. This is
to be expected since the separates represent greater ranges of particle
sizes. As a check on the texture of the samples collected, it shows that
some of the soils are not true to name, therefore that all soils mapped
under a given type name are not closely similar to one another. Of
course, this is the belief of many soil surveyors, but it seems strange
that in the present work, where there was the attempt to select soils
representative of the class and type chosen for study, that such diver-
gences developed. It is an interesting commentary on the personal
equation of the field worker, in this case of the writer, who collected
the samples.

1919 | Pendleton: A Study of Soil Types 469

With regard to the methods of mechanical analysis, one should not
overlook Mohr’s work on The Mechanical Analysis of Soils of Java,*°
which gives an excellent discussion of the relative merits of the better
known systems of mechanical analysis. He describes a modified cen-
trifuge method preferred by him.

l dis-

Under a discussion of the physical constants of soils, Free®
eusses the value of mechanical analysis as a soil constant, and shows
that there are three serious errors in the determination, all of which
impress themselves upon one making and using such analyses. They
are: ‘‘(1) disunity of expression; (2) failure to express conditions
within the limits of individual groups; and (38) failure to take

9)

account of variations in the shapes of the particles.’’ Yet he empha-

sizes, and rightly so, ‘‘that mechanical analysis is by no means useless
nor to be belittled as a means of soil investigation.’’**

Moisture equivalents—This determination showed quite distinct
averages for the types, though there was considerable variation within
each of the types. Eliminating those samples shown to be non-typical
according to the mechanical analysis, the variation within the type is
reduced considerably. Yet it cannot be said that as regards this con-
stant that all soils mapped under a given type name, or even those
soils under a given type name which the mechanical analysis has
shown to be true to name, have closely similar moisture equivalents.
Briggs and McLane** express the belief that ultimately moisture
equivalent determinations will replace mechanical analysis in the
classification of soils, because the determination is simple and the
result can be expressed as a single constant.

Hygroscopic coefficient—The two heavy types show averages dis-
tinct from those of the two light types, but the wide and erratic varia-
tion within the type, together with the nearly universal failure of
Briggs and Shantz’s formula** to convert these values into values
even approximating those of the moisture equivalent, leads one to
doubt the accuracy of these figures of the hygroscopic coefficient. It
is because of the ease of determining the moisture equivalent, and
because of the difficulties involved in correctly carrying out the hygro-
scopic coefficient, that the doubt is cast upon the latter determination.

30 Bull. Dept. of Agr., Indes Neerland, 1910, no. 41, pp. 33. _

31 Free, E. E., Studies in Soil Physics, Plant World, vol. 14 (1912), nos. 2,
oo, 7, 8.

32 Tbid., p. 29.

83 Proc. Amer. Soc. Agron., vol. 2 (1910), pp. 138-47.

84U. S. Bur. Pl. Ind., Bull. 230 (1912), p. 72.

470 University of California Publications in Agricultural Sciences [ Vol. 3

COMPARISON OF CHEMICAL Data

The total nitrogen content of the samples of each type varies
within somewhat wide limits. The average amounts for the several
types are distinct, though the variations are such that some of the
quantities of one type overlap those of another type. It is believed
that for the types selected the field differentiations do indicate dif-
ferences.

Regarding the humus content of the four types under considera-
tion, the results are somewhat different. The average amounts of
humus are almost alike in three of the four types, while the nitrogen-
poor San Joaquin soil has an average of about half that of the others.
Within the type the soils may be very nearly alike in the humus con-
tent, as is the case in two of the types, or may be widely variable, as
in the Hanford fine sandy loam. It should be noted that the amount
of humus as shown by the method used, is not indicated by the inten-
sity of the color either of the soil or of the resulting extract. This
confirms the findings of Gortner, which are cited elsewhere.

There was quite a wide range shown in the results of the deter-
mination of the loss on ignition. The Diablo and Altamont soils, be-
cause of the heavier textures and the relatively large amounts of com-
bined water, and of considerable amounts of CaCO, in at least one
case, gave high losses on ignition. The averages were close, 6.8% for
the Diablo, and 6.7% for the Altamont. The Hanford soils were
lower, though with a wider range. Soil no. 14, with 6.9% loss on igni-
tion, shows almost double that of any other soil in the type. The San
Joaquin soils, with an average of 2.6%, show the lowest average loss
on ignition. The smaller amounts of organic matter in these soils is
one reason for the smaller loss. The two heavier types have averages
close together, and the hghter types have averages not far apart, but
because of the wide variations within each type, the results of the
determination of the loss on ignition certainly do not show that all
soils classified in one type are closely similar.

Hall and Russell, in their discussion of the soils of southeastern
England,*° consider of value the ratio of PBatdoee he ht asl ee “but apply-

% loss on ignition,
ing this ratio to the California soils under consideration does not seem
to give any relations of value. The Diablo ratio varies from 0.0136 to
0.0158, the Altamont from 0.0141 to 0.0204, the San Joaquin from
0.0144 to 0.0232, and the Hanford from 0.011 to 0.0172.

35 Jour. Agr. Sei., vol. 4 (1911), pp. 182-223.

1919 | Pendleton: A Study of Soil Types 471

The calcium (as CaO) content of the soils is interesting especially
because of the variability. The Altamont samples show the greatest
variation, for the largest quantity of CaO is about seven times the
smallest. The San Joaquin samples are second, with the largest over
six times the smallest. The Diablo samples are third, with the largest
over five times the smallest, while the Hanford soils show the least
variation, the largest being less than twice the smallest. There are
quite marked differences between the averages of the Diablo, Alta-
mont, and Hanford soils (the San Joaquin samples are intermediate),
but the wide variations within the types greatly minimize any sig-
nificance the averages might have. Hence it is not possible to state
that one or another type, as represented by these samples, is charac-
terized by high, low, or moderate amounts of calcium.

As the analyses of the samples for calcium failed to point out any
striking characteristics, unless it be that of variability, so it is with
magnesium. Magnesium (as MgQ) is variable within each of the four
types. The largest quantity is about three times the smallest in the
Diablo, San Joaquin, and Hanford types, while in the Altamont the
largest is twenty-seven times the smallest. Considering the Hanford
and San Joaquin, or the Diablo and San Joaquin, it is seen that the
eurves do not overlap, while the Diablo and Altamont, or the Diablo
and Hanford curves do. The averages of the four types are distinct,
except between the Hanford and Diablo, which are quite close. But,
here again, because of the more or less wide range of values within
each of the types, the averages are of little significance. The lime-
magnesia ratio is very variable in these soils. Comparing the calcium
and magnesium curves for the several soils gives a good idea of the
relations. The Diablo curves are quite similar except for soil no. 6,
which shows 3% MgO and 0.5% CaO. In the Altamont soils the
curves are somewhat similar in direction, though the ratios differ
widely. In the Hanford and San Joaquin types the ratios of CaO and
MgO are also far from constant, yet it is readily seen from the graphs
that the amount of magnesium varies more or less directly with the
amount of calcium.

Respecting the total phosphorus (as P,O,), if the San Joaquin and
Hanford samples alone be considered, there would be no doubt as to
the significance of the field separation, the variations within the type
notwithstanding. But when the other two types are considered, the
case is not so good in favor of the field classification. The Diablo soils
show considerable variation in the amount of P,O.,, while the three

472 University of California Publications in Agricultural Sciences [Vol.3

Altamont samples show much variation. Therefore with reference to
the amount of phosphorus, and the types studied, the separation into
types may or may not be of significance.

If the results of the potassium (K,O) determinations are com-
pared, it is very evident that but one conclusion can be drawn, and
that is that the variations in the amount of potassium within each
type are great enough so that any differences between the averages
of the several types have no significance whatsoever. Therefore, with
regard to total potassium the field separation of soils as represented
by these twenty-four samples of four types means nothing.

COMPARISON OF BACTERIOLOGICAL DATA

The wealth of the data obtained from over nine hundred bacteri-
ological tumbler cultures is hardly of sufficient significance to com-
pensate for the effort involved. There is one outstanding conclusion
from all this work, namely, the lack of any very definite, distinct, and
constant bacteriological activity of the samples of one type that is not
to a considerable extent shared by the samples of the other types.
There are tendencies in certain types with regard to bacteriological
activity which show that some of the types as a whole are more or less
distinct from one or more of the others.

Ammonification.—The amount of ammonia produced from dried
blood varies to a great extent. The Altamont samples gave between
10 and 33 mg. nitrogen as ammonia; the Diablo samples gave between
7 and 26 mg., and the Hanford samples gave between 35 and 72 mg.
The Altamont and Diablo types are thus seen to be about alike in their
low ammonifying power, as compared with the higher ability of the
San Joaquin types and still greater ability of the Hanford types.
And since there are somewhat greater variations between the types
than between the samples of a given type, the ammonifying power
may be significant.

Nitrogen fixation—The two heavy types, Diablo clay adobe and
Altamont clay loam, show no characteristic differences, while the two
lighter types show considerable differences. As a whole the types are
different one from another, yet the variations within the type are
sufficient to prevent any statement that the rate of nitrogen fixation
is a function of the type as determined in the field, or vice versa.

Nitrification The nitrification data are the most puzzling. The
figures are extremely variable within a given type; the erratic way

1919] Pendleton: A Study of Soil Types 473

in which the Hanford samples behave is not paralleled by any other
type. There are certain ways in which the types are distinct :

The nitrification of the soil’s own nitrogen as compared with the
soil’s action upon added nitrogen is in some degree separate for each
type. The San Joaquin samples nitrified their own nitrogen to a
greater degree than they did the nitrogen added to the soil.

The relative nitrification of the several nitrogenous materials
(dried blood, cottonseed meal, ammonium sulfate) is in some measure
distinct for the several types. The Diablo, Altamont, and San Joaquin
types show ammonium sulphate to be nitrified the best, cottonseed meal
less, and dried blood still less. The Hanford samples show cottonseed
meal to give the highest percentage of nitrates, with dried blood less,
and ammonium sulfate still less.

When any one soil is compared through the three sets of deter-
minations there are no apparent similarities. The Hanford type
shows the greatest bacterial activity, while the San Joaquin shows
less, with the heavier types showing sometimes greater activity and
sometimes less than that of the San Joaquin.

WorK IN OTHER STATES

In connection with the original chemical work reported in this
paper, there should be mentioned the large amount of work done in a
number of states on the analysis of the types of soils as mapped by
the Bureau of Soils. Apparently, these analyses have been made
without any question as to the validity of the existing subdivisions
into types. The various analyses have been reported with some com-
ment, but that which does appear usually deals with the ‘‘adequacy’’
or “‘inadequacy’’ of the plant food present. Blair and Jennings*®
present a large amount of data on chemical composition, some of
which on rearrangement show interesting relationships (table 85).
From the data the four series of soils with the largest number of
analyses were selected (see following table). Under each series there
are from 2 to 4 soil types, and from 2 to 6 analyses under each type.
The averages from each type are tabulated, also the averages of all
the types within the series. This is both for the strong acid extraction
and the fusion methods of analysis for significant plant food elements.
There are no doubts but that each series of soils shows characteristic
chemical peculiarities, peculiarities which are to a great extent con-

86 The Mechanical and Chemical Composition of the Soils of the Sussex Area,
New Jersey, Geol. Surv. N. J., Bull. 10, 1910.

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en |

stant throughout the several representatives of the type. In some
cases, the differences or similarities are more clearly seen in the total
analyses, and in other cases, they appear in the acid analyses and not
in the fusion analyses. Within any series the variations between
analyses of any one type are about the same as the variations from
type to type. There are many other papers*’ which provide material
for similar comparisons.

A paper by Van Dyne and Ashton** reports chemical analyses for
lime, phosphorie acid, potash, and nitrogen on the samples collected
in the course of the survey of Stevens County, Washington. Though
sometimes there is a much greater range within a type than between
types, in a general way the analyses for any one type agree quite
well. As a whole the chemical analyses seem to show that the field
eriteria are also a basis for grouping soils into certain chemical
groups. It should be mentioned that the work of Blair and Jennings,
also that of Van Dyne and Ashton, deals with individual areas, and
not with samples from several scattered areas. The work of Fraps and
Williams, and the original work here reported represent scattered
areas.

‘ THE GREENHOUSE CULTURES

By far the most interesting results were obtained in the pot culture
work. It is realized that there are variations in the physical nature
of the samples of a given type, yet since these samples were collected
with considerable care by one familiar with field classifications, the
samples so selected should be fairly representative of the type. It is
probable that if all the soils in each of the types used were exactly the
same in texture, ie., if the mechanical analysis showed the same
results for the several soils, the crops produced on the several soils of
a type would be less divergent in appearance or weight. Yet it is
not at all likely that the crops would be the same. Pot cultures pre-
sume that the conditions in all the pots can be kept uniform, but this
is obviously impossible. Greenhouse work is subject to many interfer-
ing factors. Nevertheless, the results are believed to be significant,

37 Williams, and others, Report on the Piedmont Soils, North Carolina Dept.
Agr., Bull. 206, 1915.

Fraps, G. 8., Composition of the Soils of South Texas, Texas Agr. Exp. Sta.,
Bull. 161, 1913; Composition of the Soils of the Texas Panhandle, ibid., Bull.
173, 1915.

88 Van Dyne and Ashton, Soil Survey of Stevens County, Washington, Field
Operations, U. 8. Bur. Soils, 1913, pp. 2165-2295.

476 University of California Publications in Agricultural Sciences [ Vol. 3

despite the large correction that the consideration of the probable
error might introduce.

The differences in the crop producing power of the soils are very
marked in the Diablo clay adobe, where the second crop, as well as
the first, shows evident variations in the ability to support a crop.
In the Altamont clay loam the second crop almost loses the variations
seen in the first crop from pot to pot. The samples of both types
seem to show one thing in common—the approach of the several sam-
ples toward a uniform ability to produce crops, as the soils are kept
for longer periods under the same conditions. The Hanford soils did
not show, with the several crops, the parallelism in the fertility from
crop to crop as did the Diablo and Altamont soils. Some soils pro-
duced good crops of grain and poorer crops of legumes, others did the
opposite. The low nitrogen content in this type seemed to be a limit-
ing factor. This would account for the variation between the grain
and the leguminous crops. Also, the presence, or absence of Bacillus
radicuola inoculation in this connection might greatly affect the total
crop produced.

There does not seem to be much doubt but that the soils of the
several types compared in this way are not the same, though they are
in certain respects similar.

The Place of Soil Classification—With all these evidences that the
soils within the several types are not closely similar, though they are
classified the same by the Bureau of Soils, what conclusion is one to
reach as to the value of such a classification? If it were true that there
were no appeal from the findings of such laboratory and greenhouse
determinations as these, and that these determinations were a final
proof of the fertility or infertility of a soil, obviously there would be
but one thing to do—discard all such field classifications as useless.
But the writer is one of a great many soilists who are not willing to
rely on laboratory or even greenhouse results for an absolute deter-
mination of fertility, and for the grouping together of soils inte a
workable classification. Not enough is definitely known as to the mean-
ing of such findings, though there are certainly many valuable points
shown by laboratory analyses.*®

As examples of the value of natural classifications we may con-
sider those of botany, zoology, or mineralogy. If available, a wholly
satisfactory classification of soils would be equally useful. The appre-

39 Jordan, W. H., Measurements of Soil Fertility, New York Agr. Exp. Sta.,
Geneva, Bull. 424; 1916.

1919] Pendleton: A Study of Soil Types 477

ciation of this is shown in the many systems of soil classification that
have been proposed.

Despite the foregoing facts that have been obtained showing the
divergent properties of different samples of one type presumably
alike, yet it must be admitted that soil surveys, even such as are no
more refined than those of the Bureau of Soils, have considerable
value for field use.

It is felt that the additional effort required to modify the practices
of the Bureau of Soils in the mapping and classifying of soils would
be more than justified by the increased accuracy and usefulness of
the maps. To point out some of the causes of the present practices
and to give suggestions for possible methods of improvement, the
following discussion of the Bureau of Soils methods has been
prepared.

Discussion of the Bureau of Soils’ methods—The methods of map-
ping and classifying soils, as devised and used by the Bureau, have
resulted from some definite and important considerations.

1. The necessity for keeping down the cost of surveying and map-
ping prevents the use of laboratory and culture methods in the study
of the soils classified, even if it were not for the fact that one of the
outstanding policies of the Bureau apparently denies the validity of
such studies in the classification of soils. This does not include the
mechanical analysis of soils, which is not a separate laboratory deter-
mination, but a method of checking the field man’s decision as to the
texture. It should also be added that some of the reports as published
in the Field Operations of the Bureau of Soils, for 1913, show the
subdivision of the soils into two groups based upon the CaCO, content.
Keeping down the cost has also prevented the use of sufficient time to
map the soils correctly, even according to the criteria admittedly of
value in the system adopted. Many of the other methods of classify-
ing and mapping soils, even if applicable to most of the agricultural
regions of the United States, would be absolutely out of the question
on account of cost.

2. The large and widely diversified area of the United States, and
the attempt to map representative areas in various parts of the coun-
try, early led to difficulties. There seemed to be a lack of understand-
ing as to what criteria to use in the classification of the soils. Re-
cently, some of the areas first mapped in the state of California have
been resurveyed. The texture, series, and province differences of the
early mapping seem not to have been clear. For example, we may con-

475 University of California Publications in Agricultural Sciences | Vol. 3

sider the differences between the older and the recent survey of two
localities east of Los Angeles. The notes were made by C, J. Zinn,
a member of the party which made the recent survey:

Locality A—About 15 square miles with Eaton Wash on the west, center of
Monrovia on the east, mountains on the north, and a line about 3 miles south of
mountains as the south boundary. The old survey4® has four types of three series
and two miscellaneous types: San Gabriel gravelly loam, San Gabriel gravelly
sand, Placentia sandy loam, San Joaquin black adobe, and Riverwash and Moun-
tains. The new survey (1915, unpublished) has 13 types of 6 series and 3 mis-
cellaneous types: Hanford stony sand, gravelly sand, loam, sandy loam, fine
sandy loam, and sand; Tejunga stony sand; Zelzah loam and stony loam; Pla-
centia loam, Holland loam, Chino loam and silt loam. The miscellaneous types
are Rough Mountain land, Rough Broken land, and Riverwash.

Locality B—In the city of Pasadena, comprising about 3.5 square miles, with
the southwest corner at the center of the city. The old survey4! shows San
Gabriel loam occuping about 0.6 of the area, San Gabriel gravelly sand about 0.3,
and Placentia sandy loam about 0.1... The new survey (1915, unpublished) shows
Zelzah gravelly loam occupying about 0.9 of the area, Zelzah loam about 0.1, with
a very small body of Holland loam. The older survey showed a recent alluvial
soil where the recent one shows an old valley filling soil.

Besides these errors (detected as such by the practical man, who
might attempt to use the soil maps in the field) there are in addition
those of another nature which were the source of much eriticism in the
earlier history of the survey

the so-called ‘‘ procrustean classification ’’
eriticism of Hilgard.*? Due apparently to an insufficient study of the
soils of the United States, there was the attempt to classify in the same
series soils of widely differing properties—differences of an important
nature being ignored.

At the present time there is an increasing tendeney toward limit-
ing series groups of soils to a more or less definite climatological
region. In this connection see the later changes in the correlation of
many soils.** These changes tend to limit the geographic range of the
series, and make these series narrower and more exact. Moreover, it
is understood that as the knowledge of the soils has increased, the
changes in correlation have been proceeding rapidly since the above
list was issued. This indicates that as the facts accumulate the ‘‘pro-
crustean classification’’ criticism is losing its force.

40 Field Operations of the U. S. Bur. of Soils, 1901, San Gabriel sheet.
41 Ibid.

42 Hilgard, E. W., and Loughridge, R. H., Proce. Second Intern. Agrogeol.
Conf., Stockholm, 1910, pp. 228-29; Hilgard, E. W., U. 8S. Office Exp. Sta., Bull.
142 (1904), p. 119; Hilgard, E. W., Proc. First Intern. Agrogeol. Conf., Budapest,
1909, pp. 52-54.

43 U. S. Bur. Soils, Bull. 96, 1913.

1919 } Pendleton: A Study of Soil Types 479

3. There was a lack of trained men early in the work. This was
to be expected. As has been shown, the early surveys were very crude
in certain places. It must be added that some of the errors and omis-
sions made in the more recent maps are not due to a lack of training,
but to the carelessness of the field men with respect to details.

4. The policy of the Bureau has been to recognize the physical
characteristics of the soil as factors in fertility to the virtual exclusion
of the chemical or biological factors. Therefore the use of physical
eriteria is necessary. Besides, the criteria must be such as can be
applied in the field, and are: (1) color, (2) texture, determined by
rubbing between the thumb and finger, (3) structure, (4) nature of
subsoil, (5) presence of hardpan, (6) height of water table, (7) pres-
ence of alkali, (8) topography, (9) physiographic form and hence
mode of formation, and (10) source of material (sedimentary, igne-
ous, or metamorphic rocks). Humus, and the presence or absence of
appreciable quantities of lime, also the reaction of the soil (acid or
alkaline) are frequently guessed at. These criteria are practically
the only ones that can be applied in field work. It is believed that
these same criteria indicate the chemical nature of the soil, though
there has been no attempt to correlate some of the factors. However,
the original work reported in this paper would indicate that the chem-
ical nature is not the same, of soils classified the same by the Bureau
of Soils criteria.

5. The desire to limit the number of groups of soils is a wholly
sound one. In discussing the problems of classifying soils there
should always be kept in mind the fact that some of the problems are
not very different, fundamentally, from some of the problems that
have been causing perplexity among biologists for a long while.
The tendency, as seen in some of the recent surveys, to make the
series more inclusive and to introduce the term, phase, is heartily
commended. By making the series broader there will be less difficulty
in placing a soil in its proper group. The phase will take care of many
of the series differences between area and area.

6. It seems certain that if there were more emphasis placed upon
the inspection of the area, during the progress of the field work and
after its completion, there would be a much closer approach to
accuracy throughout the map and report. At the present time the
field man is not closely checked up. The careless or indifferent worker
can map more or less as he pleases, especially in the out-of-the-way
places.

480 University of California Publications in Agricultural Sciences [VoL 3

7. Whether the soil survey should include more than a simple
classification of the soils or not, is an unsettled question. It is thought
hardly possible that in a soil survey the field man could handle all the
phases of an agricultural survey of an area, when his energies should
be fully employed in the classification of the soils. It is believed that
the place of the survey, in this country at least, is to handle the
classification of the soils, leaving the study of the remaining factors
largely to other specialists, who would use the soil survey as a basis.**
But to make the soil maps of more general use for such work, they
must be more accurate. These maps never can become the basis of
other agricultural studies as long as many experiment station workers
ridicule them. Hence, the ultimate effort of the survey should be
toward better work, rather than covering a wide range of agricultural
studies.

8. There is not the incentive to make as many separations of the
soils in the field, as the field man might think best, because frequently
the feeling of the editors is that there would be too many small bodies
of soil shown on the manuscript maps which would not warrant the
additional cost of publication.

In conelusion, the Bureau of Soils’ system has much to commend
it as a field method, and the resulting maps and classification are be-
lieved to be of distinct value. It is felt that a more general under-
standing of: (1) the limitations under which the maps, the earlier
ones especially, have been made; (2) the difficulties under which the
field work is at present carried on; (3) the meaning of the correlation
of soils; and (4) the general policy of the Bureau of Soils would give
people more sympathy with their work.

44 Fippin, E. O., Proce. Amer. Soc. Agron., vol. 1 (1908), pp. 191-97.

a

1919] Pendleton: A Study of Soil Types 48]

SUMMARY

Presumably typical samples of four soil types were collected for
laboratory and greenhouse study from widely distributed localities in
the state of California. The field appearance of each sample was

usually sufficient to warrant the classification as it exists.

PHYSICAL RELATIONS

1. The mechanical analysis by the Hilgard etutriator shows that
the soils of a given type are in some cases quite divergent from each
other in their content of certain of the sizes of particles. The mechan-
ical analysis by the Bureau of Soils method shows that 6 of the 24
soils were not true to their type names, and that of those soils within
the type there is considerable variation.

2. The moisture equivalents for the several types show distinct
enough values to substantiate the field separation.

3. The hygroscopic coefficients vary widely within each type and
the types are not shown to be distinctly different by this criterion.

CHEMICAL RELATIONS

1. The total nitrogen averages vary markedly from type to type,
with the Altamont clay loam containing three times that in the San
Joaquin sandy loam.

2. The average humus content of the San Joaquin samples is
about half that of the other types. The variations in the humus con-
tent between the types are small, considering the diverse nature of the
types and the large range in the amount of humus within the type.

3. The loss on ignition shows a considerable variation within the
type and no significant distinction between the four types.

4. The average total calcium content of the types is distinct,
though the wide range within each type minimizes the significance of
the variation in the averages.

5. With regard to magnesium, the types are neither distinct nor
are the soils within the type closely similar,

6. The average phosphorus content of the types is. distinct, though
the ranges within the several types frequently overlap.

7. The total potassium results do not show the types to be distinct
nor the soils within a type closely similar.

482 University of California Publications in Agricultural Sciences [ Vol. 3

BACTERIOLOGICAL RELATIONS

1. The ammonifying power shows rather larger variations from
type to type than between the samples of a type.

2. The nitrogen fixation data do not show characteristic differences
for the several types.

3. Regarding nitrification as a whole there may be a greater
divergence between the samples of a type than between types. The
relative nitrification of the soil’s own nitrogen varies with the type,
as does the relative nitrification of the several nitrogenous materials
added.

Por CULTURES IN THE GREENHOUSE

In addition to the effect of the probable error, the impossibility
under the conditions herein described of growing the same crops on
all the soils, during the same season of the year in the greenhouse,
prevents close comparisons between the types, or between the first and
second crops on a given soil. The comparison of several samples of a
given soil type and the comparisons of various soil types, according
to the previously outlined greenhouse methods show that:

1. Different representatives of a given type are not the same in
their ability to produce crops.

2. The arrangement of the samples of a given type according to
their fertility may or may not vary with the special crops used as the
indicators.

3. The types are distinct with respect to their fertility, considering
their average production.

Therefore it is concluded that with regard to the 24 soils of 4
types examined, all soils mapped under a given name by the Bureau
of Soils method may or may not be closely similar, depending upon
the criteria used. The greater number of the criteria show the soils
of a type to be not closely similar, and the types to be but litle differ-
entiated from each other.

In connection with the results of the author’s study of the soils,
there is given an historical sketch of the development of soil classifica-
tion and mapping, also a discussion of certain of the methods em-
ployed by the Bureau of Soils of the United States Department of
Agriculture. It is pointed out that despite its defects, the work of
the Bureau of Soils is of value, and is practically the only type of soil
classification and mapping possible under the conditions imposed.

4

1919] Pendleton: A Study of Soil Types 483

APPENDIX A
METHODS AND TECHNIQUE

COLLECTION OF SAMPLES

There was difficulty in finding types that would meet the requirements of wide
distribution and of differing from one another as to series as well as texture. The
types chosen were:

Diablo clay adobe, a residual soil.

Altamont clay loam, a residual soil.

San Joaquin sandy loam, an ‘‘old valley filling’’ (old alluvial soil).

Hanford fine sandy loam, a recent alluvial soil.

The first task was the collection of the samples of soil for study in the labora-
tory and in the greenhouse. Of course, there were kept in mind the errors and
difficulties involved in the collection of representative samples. The selection of
the localities in which to collect samples was frequently made in consultation with
the persons who had originally mapped the areas under the Bureau of Soils.
This was done so that the soil chosen might as nearly as possible represent what
the surveyor had in mind as characteristic of the type within the area. It was to
be expected that the ideal type which one man would use as a guide as he did the
mapping in one area would not always be identical with that which another man
might use in mapping another area, despite the aid of the inspector in keeping the
ideal types of the field men as nearly alike as possible. Some of the accompanying
index maps, showing the places where the soil samples were collected, are dupli-
eates of the same locality. As the dates show, one is a portion of a less recent,
and the other of a more recent survey. In many cases the index maps have been
copied from the manuscript maps, a number of surveys in this state not yet being
published. For a discussion of the differences in these maps, see below the section
on The Criticism of the U. S. Bureau of Soils Method of Surveying.

Not only were the field men questioned about the locality, but as nearly as
possible an exact designation was obtained on the soil map itself. In the collec-
tion of some of the samples the writer had the good fortune to have the assistance
of the man or men who actually mapped the soils in question. Sometimes there
was no trouble at all in locating a typical body of the soil where a sample might
be taken. On the other hand, as in the case of the collection of the Hanford fine
sandy loam from Woodbridge (nos. 15 and 16), more than two hours were spent
in driving about, trying to find a place that seemed a typical fine sandy loam.
Experience shows that the personal equation in field work is very important and
is hard to control.45

No special attempt was made to obtain virgin soil, for the types of soils that
had been selected for study were mainly agricultural, and most of the soils have
been at some time under cultivation, if they are not now. Also, there has been
little, if any modification of the agricultural soils by the addition of fertilizers.
Hence the small tracts of the Hanford fine sandy loam, for instance, that are still
virgin are largely non-agricultural, waste land areas, and would not illustrate the
properties of the type as a whole. Not so large a part of the San Joaquin sandy
loam is under cultivation now, though almost all of it has been farmed to grain
in the past. The two minor types studied, the Altamont clay loam and the Diablo
clay adobe, being of residual origin and occupying rolling to hilly or mountainous
land are also not very extensively farmed. The topography is the limiting factor
in most cases.

* Fippin, E. O., Practical Classification of Soils, Proc. Amer. Soc. Agron., vol. 3 (1911),

pp. 76-89; Increasing the Practical Efficiency of Soil Surveys, Proc. Amer. Soc. Agron.,
vol. 1 (1907-1909), pp. 204—06.

454 University of California Publications in Agricultural Sciences [ Vol. 3

The ideal way to collect a representative sample of soil for laboratory studies
is to make a number of borings scattered about the field or fields, so that the sam-
ple will approximate an average. But in the case of collecting the samples for this
study it was considered best not to attempt such a procedure, for the reason that
it was desired to have the samples for the greenhouse work and for the physical,
chemical, and bacteriological studies, come from the same lot of soil. The collec-
tion of such a large amount of soil, about 250 pounds in all, from a number of
places about the selected field would be very tedious. Hence as nearly a typical
place as possible was selected, close to a wagon road, in order that the samples
could be transported readily. Care was used that the location be far enough out
into the field to allow the sample to be representative of the conditions in the field.

The subsequent procedure was as follows: The selected spot was cleared of
grass or other surface material or accumulation that did not belong to the soil.
A hole was dug, usually one foot deep (the depth depending entirely upon the
nature of the surface soil and any noticeable changes toward the subsoil), and
big enough to give sufficient soil to make up the greenhouse sample of from 225
to 250 pounds. The soil was shoveled directly into tight sugar or grain sacks, no
attempt being made to mix the sample at this time. Some sacks of the soil would
contain more of the surface material, and others more of the lower portion, but a
later thorough mixing and screening at the greenhouse gave a uniform sample.
After the large sample was collected, the hole was usually dug two feet deeper,
giving a hole three feet deep. One side of this hole was made perpendicular, and
from this side the small samples were collected. The A, B, and C horizons were
marked off on this wall, and the samples collected by digging down a uniform
section of the designated portion, using a geologic pick and catching the loosened
material on a shovel. About ten pounds of soil were so collected, and placed in
clean, sterile canvas sample sacks. Care was used not to contaminate the samples,
so that the bacterial flora might remain nearly unaltered. It seemed imprac-
ticable to attempt to collect the laboratory sample under absolute sterile condi-
tions, especially since some of the deeper (B and C) samples were obtained by
means of the soil auger. When the auger was used to collect the samples from
greater depths the boring was done from the bottom of the hole made in collect-
ing the larger sample. The size of the laboratory sample required the boring of
five or six holes with the usual 1.5 inch soil auger. The laboratory sample of the
first foot, or the A sample, was always collected from the side of the large hole.
Notes regarding the sample, field condition, the place of collection, together with
photographs and marked maps are given in appendix B.

As described above, the soils were collected in separate portions from the sur-
face to the 12 inch, from the 12 to 24 inch depth, and from the 24 to 36 inch
depths where there were no abrupt or marked changes in the color, texture, or the
like, as in the Hanford fine sandy loam. But since in some cases, as most fre-
quently in the San Joaquin sandy loam, the samples do not represent the first,
second, or third foot depths, as the case might be, the term, horizon, has been
used. Horizon A indicates the surface sample, horizon B the second sample, and
horizon C the third sample.

LABORATORY PREPARATION OF SAMPLES

The large samples were stored in the greenhouse until ready for use. The lab-
oratory samples were allowed to remain in the sacks until air dry, when they were
passed through a 2 mm. screen. This was a difficult matter, with the heavy soils,
as well as with the heavy subsoils of the San Joaquin sandy loam. Cautious use

———————

1919 | Pendleton: A Study of Soil Types 485

of the iron mortar was necessary to supplement the rubber pestle.” The samples
were thoroughly mixed after screening, when they were weighed and placed in
sterile containers—glass jars and large bottles. Precautions were taken as far
as possible to avoid contamination of the samples during this preparatory process.
The screens, mortars, scoop, and pans were flamed out between samples. Obvi-
ously contamination could not be avoided absolutely without too great a prolonga-
tion of the work.

The material not passing the 2 mm. screen was subsequently washed on the
screen, with a stream of water to remove the finer material. The residue not
passing the screen by this treatment was dried and weighed. It seemed unneces-
sary to adopt elaborate precautions, like those described by Mohr," to obtain the
exact quantities.

MECHANICAL ANALYSIS

The Hilgard elutriator was used for the purpose of making the mechanical
analysis of the samples (surface horizon only). For the purpose of this work
the method described by Hilgard® has been modified in several respects. The pre-
liminary preparation by sifting through the 2 mm. sieve in the dry state, and
through the 0.5 mm. sieve by the aid of water was used. One hundred grams was
sifted with the 0.5 mm. sieve, and the fine material plus the water was evaporated
to dryness on the water bath. The dry material was broken up and from this
the samples were weighed out for the analysis.

The samples were not disintegrated by boiling, since it was believed that such
treatment would affect the ‘‘colloid’’ content of the sample. Instead, the samples
were shaken with water in sterilizer bottles for three hours, similar to the treat-
ment preparatory to the mechanical analysis by the Bureau of Soils method.
However, not boiling the samples caused more work later.

The colloidal clay was removed by placing the previously shaken sample in a
large precipitating jar and stirring up with several liters of distilled water. (Dis-
tilled water was used throughout the analysis.) The quantity of water was not
important, but rather the depth of the suspension, which was 200 mm. After
allowing to stand for 24 hours the supernatant turbid water was siphoned off,
when the residue in the bottom of the jar was again stirred up with water and
the clay again allowed to settle out of a 200 mm. column. This was repeated
until the supernatant liquid contained practically no material in suspension after
standing for 24 hours. The clay suspensions were placed in large enamelware
preserving kettles, and the solutions reduced in volume by boiling. The final
evaporations were carried on over the water bath, so as to avoid too high a tem-
perature.

A large portion of the finest sediment (0.25 mm. hydraulic value) was removed
as follows: After the greatest portion of the clay had been removed by the 24
hour sedimentation and decantation, the sample was placed in a 1 liter beaker and
stirred up with sufficient water to make a 100 mm. column. After standing 6
to 8 minutes the suspended material was decanted off. This was repeated until
the supernatant solution was practically clear. The entire time for these decanta-
tions usually occupied 2.5 or 3 hours. The decanted material was allowed to stand
for 24 hours, as before, and the 200 mm. column decanted as with the original
clay suspension. This was continued until the clay was practically all removed.

46 Hilgard, Calif. Agri. Exp. Sta., Cire. 6, June, 1903.
‘7 Bull. Dept. Agr. Indes Neerland., no. 41, 1910.

8 Calif. Agr. Exp. Sta., Cire. 6 (1903), pp. 6-15; see also Wiley, Agricultural Analysis,
vol. 1 (1906), pp. 246-62.

456 University of California Publications in Agricultural Sciences | Vol. 3

The residue constituted the main portion of the 0.25 mm, hydraulic value sep-
arate. The residue from the 6 to 8 minute decantation was placed in the elutri-
ator, and separated by the usual method into the various sizes. Since, however,
the sample was not prepared by boiling previous to the separation of the clay, the
clay was never as thoroughly removed from the coarser particles and the finer
aggregate particles were not completely broken down, Hence when the sample
was placed in the elutriator and subjected to the violent agitation of the stirrer
an appreciable amount of clay passed off with the finest separate. Therefore,
instead of allowing the water to return to the carboy from the settling bottle,
during the running off of the finest separate, the following procedure was em-
ployed: The water was run into precipitating jars and allowed to stand for 24
hours, and the clay water was then decanted off and boiled down with the other
clay water.

A further modification of the Hilgard method was found advisable after the
change from the large elutriator tube to the small one, preparatory to running off
the coarser separates. The mechanical defects in the elutriator always allowed
for the collection of a portion of the sample in crevices where the stream of water
could not reach to carry off the particles. Hence, when the large tube was
removed, and cleaned, there was found an appreciable amount of the finer sedi-
ments that had not passed over. These were all added to the small tube of the
elutriator, and the additional material of the smaller sizes run off, using an hour
or so for each size. This seemed a better method than the separation of such
sediments by the beaker method, as was done by Dr. Loughridge.

The separates, after decanting most of the water, were dried first on the water
bath and later in the drying oven at 100°C—110°C and weighed. All of the deter-
minations were made on the water free basis.”

ADDITIONAL PHYSICAL DETERMINATIONS

Upon the surface or A horizon samples of the 24 soils considered in this study
additional physical determinations were made by the Division of Soil Technology,
through the courtesy of Professor Charles F. Shaw. These determinations were
of the mechanical analysis by the Bureau of Soils method,” of the moisture equiva-
lent by the Briggs and McLane method," and of the hygroscopic coefficient accord-
ing to Hilgard’s method.”

CHEMICAL METHODS

At first the chemical work was based upon the ‘‘strong acid extraction’’
method, so well known through the work of Dr. Hilgard.” There are some very
pertinent objections, as well as advantages, to the method of acid extraction for
the purpose of comparing soils among themselves.”

In the analysis 2.5 gram samples, air dry, were used throughout. The acid
extraction results are not included in this paper.

49The writer wishes to emphasize the tedium of the elutriator process, and to advise
strongly against the use of the apparatus for the comparison of the soils as to texture. The
elutriator is excellent from a theoretical point of view, but the results do not at all warrant
the extravagant use of time in the laboratory that the apparatus requires.

5°U. S. Bur. Soils, Bull. 84, 1912.

51 Jbid., Bull. 45, 1907; Proc. Amer. Soc. Agron., vol. 2 (1910), pp. 138-47.
52 Calif. Agr. Exp. Sta., Cire. 6 (1903), p. 17; Soils, pp. 197—99.

53 Calif. Agr. Exp. Sta., Cire. 6 (1903), pp. 16ff; Soils, pp. 340ff.

54 See Hissink, Intern. Mitt. fiir Bodenkunde, vol. 5 (1915), no. 1.

1919 | Pendleton: A Study of Soil Types 487

The sodium peroxide fusion method® was carried out on the two larger series
of soils, the Hanford and the San Joaquin. The elements sought were phosphorus,
calcium, and magnesium. Five gram samples, air dry, were used throughout.
The general method of analysis, as set forth by Hopkins, was employed, though
there were a number of refinements used to increase the accuracy of the results.
As such might be mentioned the double precipitation of the iron, aluminum, and
phosphorus.

Phosphorus was determined volumetrically, according to the method of Hib-
bard.”

Total nitrogen was determined by the modified Gunning-Kjeldahl method,
using ten gram samples.

Loss on ignition was determined upon the 10 gram, air dry samples that were
used for the determination of the hygroscopic moisture of the samples used in
the chemical analysis. The soils were ignited in a muffle furnace to constant
weight.

Humus was determined by the Grandeau-Hilgard method,” using 10 gram
samples, air dry.

Potassium was determined by the J. Lawrence Smith method, using one gram
samples.

BACTERIOLOGICAL METHODS

The only bacteriological methods employed were the determination by the tum-
bler or beaker method of the ammonifying, the nitrifying, and the nitrogen fixing
powers of the soils.* All cultures were run in duplicate.

Ammonification tests were made using 50 grams of soil and 2 grams (4%) of
dried blood. The checks were distilled at once, and the cultures kept in the incu-
bator at 24°C-30°C for one week. (The incubator thermostat was unsatisfactory
in its action, hence the variation in the temperature. )

The nitrifying power of the soil was tested as regards the soil’s own nitrogen,
dried blood, cottonseed meal, and ammonium sulfate. In the Diablo clay adobe
and the Altamont clay loam 50 grams of soil were used, to which was added 1
gram (2%) of dried blood, or of cottonseed meal, or 0.1 gram (0.2%) of am-
monium sulfate. In the case of the San Joaquin sandy loam 50 grams of soil were
used, together with 1 gram (2%) of dried blood or of cottonseed meal, or 0.2 gram
(0.4%) of ammonium sulfate. In the series run on the Hanford fine sandy loam
100 grams of soil were used, to which were added 1 gram (1%) of dried blood or
of cottonseed meal or 0.2 gram (0.2%) of ammonium sulfate. It is to be regret-
ted that the several series could not all be run on exactly the same basis as the
Hanford series. But the small amount.of stock soils of the samples of the earlier
series precluded the use of larger original samples, not to speak of the impossi-
bility of repeating these series. The cultures were incubated for four weeks at
24°C-30°C. At the end of this period the cultures were dried in the oven at about
90°C and the nitrate content determined by the phenoldisulfonic acid method
according to the modifications of Lipman and Sharp.”

Nitrogen fixation. For this determination uniform quantities of soil were
used throughout—50 grams, to which was added 1 gram of mannite. These cul-

55 Hopkins, Soil Fertility and Permanent Agriculture, pp. 630-33; Hopkins and Pettit,
Soil Fertility Laboratory Manual (Boston, Ginn, 1910), pp. 42—45.

56 Jour. Ind. Eng. Chem., vol. 5, pp. 998-1009.
57 Calif. Agr. Exp. Sta., Circ. 6 (1903), p. 21.

_.*% Burgess, P. S., Soil Bacteriology Laboratory Manual, Easton, Pa., The Chemical Pub-
lishing Co., 1914.

59 Univ. Calif. Publ. Agr. Sci., vol. 1 (1912), pp. 21-37.

485 University of California Publications in Agricultural Sciences [ Vol. 3

tures were incubated for four weeks at 24°C-30°C, at the end of which time bae-
terial action was stopped by drying in the oven for 24 hours. Subsequently, the
samples were broken up in a mortar, and 10 grams weighed out for the determina-
tion of the total nitrogen.

Por CULTURES IN THE GREENHOUSE

The large samples of the surface foot of soil were stored in the greenhouse
until used. The preparation of the samples was in most cases as follows: The
sample was placed on a large table and screened through a quarter inch sieve.
This treatment of screening was attempted with the Diablo clay adobe and the
Altamont clay loam, but was abandoned as practically hopeless. The samples of
these two types had been collected in the late summer, when the ground was very
hard and dry, hence the clods defied any efforts to break them up. As an alterna-
tive the samples were as thoroughly mixed as possible and weighed out into the
pots. Several waterings during a week, together with carefully breaking up the
lumps by hand, rendered the soils finely divided enough to permit the planting of
the seeds. The Hanford and San Joaquin types were readily screened.

All the soils were weighed out into nine inch flower pots. In most cases the
pots had been previously paraffined. Care was taken to clean the pots thor-
oughly, as far as surface material was concerned; many of the pots were scrubbed
with a brush and water. All previously used pots were examined to exclude the
use. of such as had formerly been used for soils containing high percentages of
soluble salts, but such examination was not always successful in eliminating the
undesirable pots, as was afterwards evident. In the Diablo, Altamont, and Han-
ford soils the quantity of soil used was five kilos per pot. In the San Joaquin
soils six kilos were used.

Enough soil was collected to fill eighteen pots. This would allow for the
arrangement of six sets of triplicates of every sample; and the planting of a dif-
ferent crop in each of the sets would allow for the growing simultaneously of six
different crops on every soil. For example, there were placed together in the
greenhouse and considered as a unit in the culture work the series of the Diablo
clay adobe, including three pots of the sample taken from San Juan Capistrano,
three from that taken near Los Angeles, three from that of the San Fernando
valley, and lastly three from the sample taken in the Danville region. This group
of pots was planted to oats, barley, bur clover, or any one other crop. The pots
were kept together in the greenhouse, that the conditions for each one in the set
would be as nearly uniform as possible, for even a slightly different location in
the greenhouse was found to affect the crop appreciably. The other five sets of
pots were similarly treated. No fertilizing materials were added to any of the
soils. All were used in their normal condition. The aim was to compare the crop
producing power of the representatives of a given type of soil from various
localities.

Several crops were grown, as the desire was to get a series of plants that
would grow well under greenhouse conditions, and act as indicators. It was
known that barley was about the best crop to use, but supplementary plants were
desired. Barley, wheat, oats, rye, millet, milo, cowpeas (black eye beans), soy
beans, beans (small white), bur clover (Medicago denticulata), sweet clover (Meli-
lotus indica), and oats and bur clover in combination were tried. Some were
a marked success under greenhouse conditions, and others were practically total
failures; the better crops were given by barley, soy beans, bur clover, and millet.
Sweet clover gives excellent results. This wide range of varieties of plants was

1919 | Pendleton: A Study of Soil Types 489

necessary because of the fact that it was desired to grow two crops a year on the
soils. The winter crops will not do well in summer, and vice versa, even though
the summers in Berkeley are relatively cool, and though the greenhouse was
whitewashed during the summer months.

The seed was obtained in most cases from the Division of Agronomy of the
Department of Agriculture of the University of California. Such varieties as
were not available from this source were obtained from the commercial seed
houses in San Francisco.

Usually the seed was planted directly in the pots, using sufficient seed to be
sure that enough would germinate and grow to give the desired number of plants
per pot, usually six. After the plants were well established, and before there was
any crowding in the pots, the plants were thinned. In some cases an insufficient
number of plants germinated to give the desired number per pot. Difficulty was
found in getting the soy beans and cowpeas to germinate, especially in the
heavier soils. This was overcome by sprouting the seeds in an incubator and
planting them when the radicle was half an inch long or more. An excellent stand
was thus obtained.

No actual measurements of the height of the plants, or the length of leaves
were made in the greenhouse work. But photographs were taken, and in these
photographs the attempt was made to secure representative records of the entire
series, without photographing the crop in every pot. The usual procedure in the
Altamont and Diablo series was to photograph two pots out of each set of tripli-
cates, an attempt being made to select average, representaiive pots. In the large
Hanford series one representative pot of each set of triplicates in each crop
series was photographed, and three representative sets of triplicates were also
photographed. Thus some of the pots appear twice, and allow of comparisons.

If any doubt be entertained as to the relative weights of the crops in the pots
photographed as compared with those not so recorded, the relative weights of the
crops may be easily obtained by referring to the tables of dry weights. In prac-
tically every case the pot label can be read from the photograph. The method of
labeling is exemplified as follows:

6 Soil sample no. 6 (Diablo clay adobe from Danville).

W_ Wheat, first crop.

2 Pot 2 of the triplicate set first planted to wheat.

CP Cowpeas, second crop.

During the growth of the crops, notes were taken as to the relative growths and
the general conditions of the plants.

When the crop had ceased growing it was harvested, whether or not it was
mature in the sense of having set and developed seed. The plants from a given
pot were put in a paper bag, labeled, and placed in the drying oven for 24 hours.
The plants were weighed when dry and cool. If any mature seed was produced
it was weighed separately.

Between the first and second crops the soil was allowed to rest from two to
three weeks or longer. Each pot was emptied and the soil passed through a
quarter inch screen before replacing in the pot. This broke up the lumps and
removed most of the roots. The roots were not saved. The weight of the roots
would have been interesting, but their recovery, especially from the heavy soils,
would have involved careful washing, and the loss of much ofthe soil. It was
thought that some washing would be necessary, even in the Hanford series, in
order that the resulting figures might be at all accurate.

490 University of California Publications in Agricultural Sciences [ Vol. 3

APPENDIX B
SOIL SAMPLE LOCATIONS

FieLtp NOTES ON THE Sort SAMPLES COLLECTED

No. 1—Diablo Clay Adobe

Location: A little over a mile east of San Juan Capistrano, Orange County. On
the lower slopes of the hills to the south of San Juan Creek. Sample sta-
tion is on a little shoulder running northwest, between Mr, Echenique’s
house and the fence following the road to Prima Deshecka Canada. Ap-
proximately one-quarter mile from the above house.

Soil: 0-12 inches—Dark gray adobe; much cracked.

12-36 inches—Soil becomes gradually lighter in color, approaching a light
bluish gray mottled with brown.
36 inches—The subsoil becomes a silty clay loam in the lower depths.

History: The field was pastured up to and including 1906. From 1907 to date
the field has been annually planted to barley. Data from Mr. Echenique,
the owner. Sample collected August 19, 1917.
Depths of horizons:
1-A 0-12 inches. 1-B 12-24 inches. 1-C—_-. 24-36 inches.

No. 2—Diablo Clay Adobe

Location: One and three-quarter miles east of southeast of Eastlake Park, Los
Angeles. Station is 0.7 mile by secondary road south of Pacific Electric
railroad crossing, and 1.2 miles southeast of the Southern Pacific railroad
crossing. Station is about 150 feet up the hill to the west of the road, in
grain field, and 75 feet south of a 10 or 12 year old eucalyptus grove.
The road, going south, emerges from the grove, and is then flanked by pep-
per trees.

Soil: 0-12 ineches—Dark gray to almost black, but with a shade of brown rather

than a bluish gray.

12-24 inches—Dark grayish brown clay adobe, becoming a little lighter with
depth.

24-36 inches—Dark brown with soft, whitish fragments. Fragments probably
the partially weathered parent rock, though no outcrops of the rock were
seen in the vicinity. Previous to the collection of the sample, Mr. E. C.
Eckman, who mapped the area as the Bureau of Soils representative, said
in substance: ‘‘We have no good Diablo in the area; the body I am
directing you to is as good as any, but it is pretty brown.’’

History: Property owned by Mr. Huntington. Farmed to grain the past 2
years; pasture previously. Data from the son of the tenant. Sample col-
lected August 20, 1915.

Depths of horizons:
2-A 0-12 inches. 2-B 12-24 inches. 2-C = 24-36 inches.

No. 83—Altamont Clay Loam

Location: 1.4 miles southeast of Walnut, Los Angeles County, on the shoulder of
a low hill, about 200 feet east of the wagon road running south through
the hills. The station was selected so that the texture was about right,
for in a very short distance there were variations from a heavy dark clay
loam or clay adobe to the light clay loams.

1919] Pendleton: A Study of Soil Types 491

Soil: 0-36 inches—A medium textured brown friable clay loam. The soil column
throughout was more or less filled with small soft whitish fragments, por-
tions of the parent rock.

36 inches—The weathered parent rock was encountered.

History: A. T. Currier, owner. The field is in pasture, and has not been eculti-
vated for forty years, to the knowledge of the ranch foreman. The soil is
probably virgin. Sample collected August 20, 1915.

Depths of horizons:

3-A 0-12 inches, 3-B 12-24 inches. 3-C 24-36 inches,

No. 4—Altamont Clay Loam

Location: On a hillside a few feet above the Cahuenga Pass (Burbank road),
near Oak Crest, Los Angeles County. _Just a few feet from the U. 8.
Bureau of Soils station for the type in the San Fernando area. (For map,
see the map under sample no. 25.)

Soil: 0-14 inches—A dark brown clay loam.

14-36 inches—A yellowish brown loam, grading into the weathered, thin bed-
ded shales at about 36 inches.

History: Roadside, above the big cut on the road, probably never tilled. The sur-
face is not so steep but that it could be well tilled; some of the soil in
the immediate vicinity is cultivated to grain. Sample collected August 21,
1915.

Depths of horizons:

4—A 0-12 inches. 4-B 12-24 inches. 4-C 24-36 inches.

No. 5—Diablo Clay Adobe

Location: About % a mile north of Calabasas, San Fernando Valley, Los Angeles
County. The station is some distance up the hill to the west of the road
running north from the Calabasas store. The sample was collected near
the top of the hill, to the northeast of the oak tree.

Soil: A dark gray to black typical clay adobe. Distinctly heavy. Digging was
very difficult, the soil coming up in large, very hard clods. The soil was of
about the same color and texture down to the bedrock at 26 inches. The
bedrock is a heavy claystone or shale.

History: John Grant, Calabasas P. O., owner. The land has been dry farmed
to grain. Presumably there had been no additions of fertilizing materials
to the soil. Sample collected August 21, 1915.

Depths of horizons:

5-A 0-14 inches. 5-B 14-26 inches. 26 inches. Parent rock.

No. 6—Diablo Clay Adobe

Location: In Contra Costa County, % mile west of Tassajero; 6 miles east
and a little south of Danville. Station about 150 feet up the hill to the
south of the road, that is, about one-third of the way up the hill.

Soil: 0-34 inches—A black or dark gray clay adobe, moist at 10 inches.

34-72 inches—A dark grayish brown subsoil, becoming lighter below the third
foot. No bedrock within the 6 foot section, nor was there any sign of any
outcrop in the vicinity. The slope of the hill moderate, the exposure
north. The sample was collected with the assistance of Mr. L. C. Holmes
and Mr. E. C. Eckman, both of the U. S. Bureau of Soils. They pro-
nounced the station typical.

492 University of California Publications in Agricultural Sciences [ Vol. 3

History: Property owned by J. J. Johnson. The field has been farmed to grain
for probably 60 years. Formerly the rotation was pasture one year, and
grain one year; now the practice is grain two years, and pasture one year,
Sample collected September 2, 1915.

Depths of horizons:

6-A O-12 inches. 6-B 12-24 inches. 6-C 24-36 inches.

No, 7—Altamont Clay Loam

Location: On the Mission Pass road, a little less than 2 miles south and a little
west of Sunol, Alameda County. About 100 feet above the road, between
wooden electric power poles nos. 92/30 and 92/31.

Soil: 0-34 inches—A medium brown clay loam, considered typical by Mr. L, C.
Holmes and Mr, E. C.:Eckman of the U. 8. Bureau of Soils. There were
slight changes in texture. |

34 inches—A stiff clay horizon. |

Inspection of a deep cut on the roadside near the location of the sample
station showed that at 6 feet and deeper there existed a heavy reddish clay.
In the immediate locality the road sections showed that the parent rock
was deeper than the 6 foot section. The slope of the land at the sample
station was quite steep.

History: Tom Burns, Irvington, owner. Field has been in pasture for the past 3
years at least, and probably for a much longer time. Sample collected
September 2, 1915.

Depths of horizons:

7T-A 0-12 inches. 7-B 12-24 inches. 7-C =. 24-36 inches.

No. 10—San Joaquin Sandy Loam

Location: North Sacramento, Sacramento County; 144 mile east of tile factory,
across the road; opposite poles 57/32 and 57/33, 75 feet southeast from the
State Highway.

Soil: 0-26 inches—A brownish red sandy loam, slightly hog wallowed, and very
slightly rolling.
26-36 inches—A sandy clay loam.
36 inches—A hard hardpan.

History: Owner not known, the district now being subdivided, the property being a
portion of the old ‘‘ Hagan Grant.’’ A near-by resident gave the following
information: ‘‘The land has not been cultivated for the past 15 years or
more. The land is said to have been farmed to grain at one time for a few
years, but the ‘soil is too light for wheat, it grows nothing but filaree.’ ’’
The principal use has been for cattle and sheep pasture. Sample collected
March 28, 1916.

Depths of horizons:
10-A 0-12 inches. 10-B 12-24 inches. 10-C 24-36 inches.

No. 11—San Joaquin Sandy Loam

Location: Four miles west of Lincoln, Placer County, at the ‘‘Road Corners,’’
in the southeast field, 10 feet east of the west fence and 60 feet south of
the north fence.

1919 | Pendleton: A Study of Soil Types 493

Soil: A gently hog wallowed, sandy loam, with some deeper depressions, prob-

ably stream channels, Sample slightly gravelly.
0-12 inches—Brownish or reddish brown sandy loam.
12-17 inches—Sandy clay loam or clay, color the same.
17-23 inches—A stiff reddish brown clay.

23 inches—A hard hardpan.

History: Mr. Frank Dowd, owner. The land has been planted to wheat for the
past 20 or 25 years; previous to that time it was used for pasture. Six
to 10 or 12 bushels of wheat, and 8 to 20 bushels of barley is the production
of this soil in the locality. The soil is usually fallowed on alternate years.
Land held at from $30 to $50 per acre. Sample collected March 28, 1916.

Depths of horizons:

11-A 0-11 inches. 11-B~ 11-17 inches. 11-C 17-23 inches.

No. 12—San Joaquin Sandy Loam

Location: About 6 miles west of Wheatland, Sutter County. Near a road corner,
in a little swale west of a knoll, 15 feet east of the westerly fence of field,
and 150 feet south of the north line of the westerly road.

Soil: Texture slightly heavy, and barely enough sand for a sandy loam, but the
best found for several miles. Color brownish red, the same throughout the
entire depth.

0-18 inches—Light, fine textured, sandy loam.
18-31 inches—Heavy sandy clay loam, running into a stiff clay.
31 inches—Hardpan, sandy and somewhat soft. The ground was very
moist at this time.

History: Very evidently pasture for sheep and cattle. No signs of having been
cultivated for several years, at least. The cover is of a number of low
annuals—Orthocarpus, Trifolium, Centaurea, and others. Sample collected
March 29, 1916.

Depths of horizons:

12-A 0-12 inches. 12-B 12-18 inches. 12-C 18-31 inches.

No. 183—San Joaquin Sandy Loam

Location: Three and three-quarters miles east of Elk Grove, Sacramento County.
On the Sheldon road, about 30 feet northwest from the fence on the north
side of the road. About 200 feet southwest from where a house formerly
stood.

Soil: A reddish brown sandy loam, approaching a loam; becoming redder in
color with increasing depth.
0-14 inches—Heavy sandy loam.
14-22 inches—Clay loam.
22-29 inches—Heavy clay loam.
29 inches—Compact hardpan.
History: Wackman Brothers, Elk Grove, owners. The land has not been plowed
or farmed for at least 15 years. The land is held at about $50 per acre.
Sample collected March 30, 1916.

Depths of horizons:
13-A 0-12 inches. 13-B 12-22 inches. 13-C 22-29 inches.

494 University of California Publications in Agricultural Sciences [ Vol. 3

No. 14—Hanford Fine Sandy Loam

Location: One mile southeast of the Sheldon road, 34% miles east of Elk Grove,
Sacramento County. On the southwest side of the secondary road, in al-
falfa field, about 25 feet from the fence. Station on a little rise.

Soil; 0-11 inches—A medium brown micaceous heavy fine sandy loam,

11-24 inches—A dark gray to black fine sandy loam, grading into the fol-
lowing.
24-36 inches—Brown fine sandy loam. Water table at 32 inches.

History: Mrs. A. C, Freeman, Elk Grove, owner. Land planted to alfalfa. Good
growth. No irrigation. Willows as well as alders and river ash along the
sloughs. Many scattering valley oaks. The land is subject to overflow
from the Cosumnes River, as it lies low in the river bottom, and shallow
stream channels and sloughs are frequent. Sample collected March 30, 1916.

Depths of horizons:
14-A 0-12 inches. 14-B-_- 12-24 inches. 14-C 24-36 inches.

No. 15—Hanford Fine Sandy Loam

Location: North of Woodbridge, San Joaquin County, along the State Highway,
less than 4 mile south of the road running westerly from Acampo to the
highway. Station in a vineyard, with almond trees along the roadside, 20
feet northeast of ‘‘change telephone pole,’’ 200 feet north of pine tree
at the gateway on the opposite side of the highway. (For map, see under
sample 16.)

Soil: Texture a rather coarse fine sandy loam; it was hard to find a good fine
sandy loam. Color when moist was a medium brown throughout the 3 foot
section; the field color was a light grayish brown.

History: Mike Nolan estate, owner. The vineyard is of Tokay grapes, 10 to 12
years old. The land is held at $300 to $400 per acre. It is said to be a
losing game to farm this land to grapes at this valuation. Sample col-
lected March 30, 1916.

Depths of horizons:
15—A 0-12 inches. 15-B 12-24 inches. 15-C 24-36 inches.

No. 16—Hanford Fine Sandy, Loam

Location: Along the road north of Woodbridge, San Joaquin County. In a young
pear orchard about 65 feet west of the highway, and about 95 feet north »
of the north abutments of the bridge over Mokelumne River.

Soil: A medium brown fine sandy loam, similar throughout the soil column of
three feet. This soil is of the recent, flood-plain phase of the type, though
this station is not known to have been under water for a number of years,
at least. There is only a comparatively narrow shelf of this phase between
the older, higher phase, and the river.

History: A. Perrin, Woodbridge, owner. The land had always been in brush
and pasture until it was cleared and planted to pears in 1911. Value
about $500 per acre. Sample collected March 30, 1916.

Depths of horizons: i

16-A 0-12 inches. 16-B =: 12-24 inches. 16-C 24-36 inches.

1919 | Pendleton: A Study of Soil Types 495

No. 17—San Joaquin Sandy Loam

Location: A short distance south of the east and west road that runs east to
Thalheim, San Joaquin County. The station was on a slight knoll 75 feet
south of a canal, and the same distance east of the secondary road running
north and south; not far from a vacant barn.

Soil: 0-12 inches—Reddish brown.

12-24 inches—Slightly redder.

24 inches—Hardpan.

The surface had the characteristic hog wallows, and the usual scant vegeta-
tion of grasses and herbs, ‘‘filaree’’ being abundant; yet all vegetation
was more abundant than that in pastured fields.

History: Rey. Frank Hoffman, Acampo, owner. Apparently, the land has not
been cultivated in recent years. Sample collected March 31, 1915,

Depths of horizons:

17-A 0-12 inches. 17-B = 12-24 inches.

No. 18—San Joaquin Sandy Loam

Location: Two and one-half miles northwest of Madera, Madera County. Along
State Highway, 75 to 100 feet southwest of the paved road, at telephone
pole 92/29; across the highway from the driveway to the house.

Soil: 0-5 inches—A light reddish brown sandy loam. A noticeable plow pan at
5 inches.

5-24 inches—A light brownish red sandy loam, becoming heavier below.

24-30 inches—Quite compact heavy sandy loam.

30 inches and deeper—A very compact hardpan.

Topography very gently rolling, hog wallows well developed, though consider-
ably degraded by cultivation. Barley grain not growing well in the lower
spots.

History: Cropped for probably 20 years to grains; barley at present. Land used
for pasture previous to grain farming. <A good yield is 8 sacks, varying
from that down to little or nothing. Miller and Lux, owners. Sample col-
lected April 11, 1916.

Depths of horizons:

18-A 0-12 inches. 18-—B 12-24 inches. 18-C 24-30 inches.

No. 19—Hanford Fine Sandy Loam

Location: Eight miles east of Waterford, Stanislaus County, near Robert’s Ferry
bridge. About 75 feet west of the road that runs south from the bridge
onto the bluff. About 450 feet north of the driveway to the Sawyer place.

Twenty-five feet inside of the fence, in the alfalfa field.

Soil: Medium brown fine sandy loam; a good brown color when moist. Texture
somewhat variable, some rounded gravels up to the size of a hen’s egg.
Topography undulating, and more or less terraced, due to the old stream
channels.

History: G. H. Sawyer, Waterford, owner. Alfalfa planted in 1915, looks well.
Land previously planted to barley and wheat, with a production about as
follows: barley, 14 sacks is considered good; wheat with 12 sacks is good,
with 6 sacks a low average. Value of the land as recently determined in
court, in a case of flood damage by a canal break, is $100 per acre. On an
adjoining piece of land young walnut trees are doing very well. Sample
collected April 11, 1916.

Depths of horizons:

19-A 0-12 inches. 19-B 12-24 inches. 19-C 24-36 inches.

496 University of California Publications in Agricultural Sciences [ Vol. 3

No. 20—-Hanford Fine Sandy Loam

Location: Near Hopeton, Merced County, 14 miles north of Merced. Less than
1, mile north from the road corners, 15 feet east of the east fence of the
road, and 150 feet south of irrigating ditch.

Soil: A good medium brown fine sandy loam. The color is especially good when
the soil is moist. The topography is slightly uneven because of the old
stream channels. Going north along the road from the cross roads the
soil is quite gravelly at first, but the texture gradually becomes heavier,
with less gravel. At the sample station the texture is a rather heavy fine
sandy loam.

History: J. G. Ruddle, Snelling, owner. The field is planted to alfalfa, as are
most of the Hanford soils in the locality. The land is not subject to
overflow. Sample collected April 13, 1916.

Depths of horizons:

20—A 0-12 inches. 20-B 12-24 inches. 20-C 24-36 inches.

No. 21—San Joaquin Sandy Loam

Location: Near Nairn Station, Merced County. About ™%4 mile west of the rail-
road, 50 feet north of the private ranch road, and 120 feet east of the field
gate across the road. About 4 miles northwest of Merced.

Soil: A good brownish red San Joaquin color. Texture a sandy loam, grading
into a clay loam or clay at about 24 inches.

Depths of horizons:
24-27 inches—A heavy clay.
27 inches—Hardpan.
The same was taken from near the top of one of the hog wallow elevations.
The topography is gently rolling.

History: F. W. Henderson, Merced, owner. At the present time the land is used
as pasture. It has been plowed at some time in the past. The present
growth of wild herbage (Lepidiwm, small grasses, Cryptanthe, ete.) is
meager. Sample collected April 13, 1916,

Depths of horizons:

21-A 0-12 inches. 21-B 12-24 inches. 21-C 24-27 inches.

No. 22—Hanford Fine Sandy Loam

Location: A short distance north of Basset, Los Angeles County, on the main
road north from Basset station. The sample was collected in a walnut
grove 100 feet east of the road and 250 feet south of the driveway to the
ranch house.

Soil: A good medium brown when moist, and a light grayish brown when dry.
Mr. L. C. Holmes, of the U. 8. Bureau of Soils, described the soil at the
time of collection as being ‘‘all a little browner, and with a little more
color than a good Hanford.’’ There was a very slight color change at
about a foot, the soil below was grayer. Texture a good fine sandy loam,
with practically no change in the 3 foot column. Topography smooth.
The texture varies quite rapidly from place to place in the field. Some
big washes of typical intermittent streams are found not far to the north
and west.

1919] Pendleton: A Study of Soil Types 497

History: C. N. Basset, of Basset and Nebeker, Santa. Monica, owner. The land
is planted to walnuts, and the trees are about 10 years old. They are
doing well, some replants are found, The trees are irrigated. Sample col-
lected May 22, 1916,

Depths of horizons:

22-A 0-12 inches, 22-B 12-24 inches. 22-C 24-36 inches.

No, 28—Hanford Fine Sandy Loam

Location: South and west of the town of Anaheim, Orange County. Within a
radius of 20 feet of where the official Bureau of Soils sample was taken.
Thirty feet east of side road, and 100 feet north of main east and west road.

Soil: Brown fine sandy loam, possibly a little more silty than no, 22, but not
heavy enough for a heavy fine sandy loam. Dry field color a light, grayish
brown. Topography smooth, no stream channels visible. Irrigation in fur-
rows. Soil similar to about 62 inches, a little more grayish at 18 inches,
the change being gradual. At 62 inches a gray clean sand, or fine sand,
was found.

History: 8. J. Luhring, R. F. D. no. 4, owner. The field was planted to Valencia
oranges in 1913; previously to grapes and miscellaneous crops. Sample
collected May 238, 1916.

Depths of horizons:

23-A 0-12 inches. 23-B 12-24 inches. 23-C 24-36 inches.

No. 24—Hanford Fine Sandy Loam

Location: Southeast of the center of Los Angeles, half way from Magnolia Ave-
nue on Fruitland Road, to Salt Lake Railroad on the east. South side of
the road about 60 feet from center, in edge of corn field. Just across
road from east end of east cypress trees.

Soil: A medium brown fine sandy loam when moist; color in the field is a grayish
brown. Micaceous. Topography level, no stream channels seen nearby.
Color of body variable. Sample location in the browner phase. Toward
south and east along the railroad and Arcadia Avenue the color is much
grayer, and even black when moist. Texture within the body is very vari-
able, though always within the fine sandy loam group.

0-36 inches—Fine sandy loam, grayer below.
36-37 inches—Layer of grayish sand and fine sand.
37-72 inches—Fine sandy loam, heavier in streaks.

History: C. D. Templeman, R. F. D. no. 2, Box 178, Los Angeles, owner. Land
has been in truck for 10 or 12 years. Only fertilizer, barnyard manure.
Sample collected May 24, 1916.

Depths of horizons:

24—A 0-12 inches. 24-B 12-24 inches. 24-C 24-36 inches.

No. 25—Hanford Fine Sandy Loam

Location: Near Van Nuys, Los Angeles County; near official sample station.
Seventy-five feet west of center of road, between fourth and fifth rows of
apricot trees north from boundary.

498 University of California Publications in Agricultural Sciences [VoL 3

Soil: A good medium brown fine sandy loam; the field color a grayish brown.
The texture uniform throughout the 3 foot section, with a little gravel occa-
sionally. Also the texture is variable to about the usual degree, in the
field distribution. The color is slightly lighter at about 2 feet and below
throughout the 6 feet, with a little variation in an increasing amount of
coarser sands,

History: Chase, Riverside, owner (?). Planted to apricots, 2 years old. Inter-
planted to melons. Sample collected May 24, 1916,
Depths of horizons:
25-A 0-12 inches. 25-B 12-24 inches. 25-C 24-36 inches.

No. 26—San Joaquin Sandy Loam

Location: On the high bluffs about 114 miles southeast of Del Mar station, San
Diego County, close to the road that runs back along the main ridge. About
50 feet north of the road where it swings south to get around the head of
the big arroyo from the north. ra

Soil: A brownish red sandy loam. Surface covered with a moderate growth of
the low chapparal common to these exposed ridges. Soil heavily laden with
iron concretions. Surface has the usual hog wallows characteristic of the
San Joaquin series.

0— 6 inches—Reddish brown sandy loam, many concretions. Dry.

6-13 inches—Clay (sandy), reddish in cracks, and bluish inside of lumps and
where not weathered.

13-22 inches—Clay, mostly bluish gray.

22-38 inches—Boring very difficult, due to the heavy nature of the clayey
moist material. Color bluish. .

About 40 inches—Hardpan. Very compact.

History: Probably never farmed. Recently streets cleared, and an attempt made
to sell lots for building. Value for agriculture—none without irrigation.
Sample collected May 25, 1916.

Depths of horizons:

26-A 0-6 inches. 26-B 6-13 inches. 26-C 13-22 inches.

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 [PENDLETON] PLATE 43

A general view in the greenhouse, where all the pot culture work was carried

on. The entire right hand bench was devoted to this study, also half again as
much space not visible in the print.

UNIV, CALIF. PUBL. AGR. SCI. VOL. 3 [PENDLETON ] PLATE 44

DIABLO CLAY ADOBE—FIRST CROP

Pots of same and different representatives of a given soil type compared.
Fig. 1. Oats and bur clover., Left to right—Soil 1, pot 1; soil 2, pot 2;
soil 5, pot 1; soil 6, pot 3.

I AS. Fig Th
ee

a

DIABLO CLAY ADOBE—FIRST CROP

Pots of same and different representatives of a given soil type compared.
Fig. 2. Oats. Left to right—Soil 1, pot 1; soil 2, pot 3; soil 5, pot 2; soil 6,
pot 2.

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 [PENDLETON] PLATE 465

DIABLO CLAY ADOBE—F IRST Crop
Pots of same and different representatives of a given soil type compared.

Fig. 1. Bur clover.. Left to right—Soil 1, pot 1; soil 1, pot 2; soil 1, pot 3.

DIABLO CLAY ADOBE—FIRST CROP

Pots of same and different representatives of a given soil type compared.

Fig. 2. Bur clover. Left to right—Soil 2, pot 1; soil 2, pot 2; soil 2, pot 3.

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 [PENDLETON] PLATE 46

-—
; a
. i
, h
-
7 f

tet

DIABLO CLAY ADOBE

First Crepe

Pots of same and different representatives of a given soil type compared.

Fig. 1. Bur clover. Left to right—Soil 5, pot 1; soil 5, pot 2; soil 5, pot 3

—

Seria
————

DIABLO CLAY ADOBE—FirRsStT CRopP

Pots of same and different representatives of a given soil type compared.

Fig. 2. Bur clover. Left to right—Soil 6, pot 1; soil 6, pot 2; soil 6, pot 3.

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 [PENDLETON] PEATE 47

wie
it BS OR

DIABLO CLAY ADOBE—FIRST CROP

Pots of same and different representatives of a given soil type compared.
Bur clover. Left to right—Soil 1, pot 1; soil 2, pot 2; soil 5, pot 2; soil 6,
pot 1.

=s

UNIV. CALIF, PUBL. AGR. SCI. VOL. 3 [PENDLETON] PLATE 46&

DIABLO CLAY ADOBE—SECOND CROP

Pots of same and different representatives of a given soil type compared.
ton) «
Fig. 1. Dwarf milo (a) following oats. Left to right—Soil 1, pot 2; soil 1,
y0t 3: soil 2, pot 1; soil 2, pot 3; soil 5, pot 1; soil 5, pot 3; soil 6, pot 2; soil 6,
) ’ b b b ’

pot 3.

SECOND CROP

D1ABLo CLAY ADOBE
Pots of same and different representatives of a given soil type compared.

Fig. 2.

Dwarf milo (b)following oats and bur clover. Left to right—Soil 1,
pot 1; soil 1, pot 3; soil 2, pot 1; soil 2, pot 3; soil 5, pot 1; soil 5, pot 3; soil 6,

pot 1; soil 6, pot 3.

WNiva CALIF. PUBL, AGR.- SCli VOL. S [PENDLETON] PLATE 49

way
i ibe,

r agen : 2S
ae ae =e Me : 3 r ro . 5 gee
— ee ue J ea * 7 ‘ne : ow. J i
Oe ee ETS a. oR ee

DIABLO CLAY ADOBE—SECOND Crop
Pots of same and different representatives of a given soil type compared.
Fig. 1. Cowpeas, following wheat. Left to right—Soil 1, pot 1: soil 1, pot 2;

’

so-l 2, pot 1; soil 2, pot 2; soil 5, pot 1; soil 5, pot 2; soil 6, pot 2; soil 6, pot 3.

DIABLO CLAY ADOBE—SECOND CROP

Pots of same and different representatives of a given soil type compared.

Fig. 2. Soy beans, following barley. Left to right—Soil 1, pot 1; soil 1,
pot 2; soil 2, pot 1; soil 2, pot 3; soil 5, pot 1; soil 5, pot 2; soil 6, pot 1; soil 6,
pot 2.

UNIV. CALIF, PUBL. AGR. SCI. VOL. 3 {PENDLETON ] PLATE 650

L.
t

ALTAMONT CLAY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.

Cowpeas B, following barley. Left to right—Soil 3, pot 1; soil 3, pot——-;

soil 4, pot 1; soil 4, pot 3; soil 7, pot 1; soil 7, pot 3.

ght
Pt
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¢

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=~ Wl a? i ,
et
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hee

UNIV. CALIF. PUBL. AGR. SCI. VOL, 3 LPENDLETONT PEATE 6%

ALTAMONT CLAY LOAM—SECOND Crop
Pots of same and different representatives of a given soil type compared.

Fig. 1. Soy beans A, following oats. Left to right—Soil 3, pot 1; soil 3,
pot 2; soil 4, pot 2; soil 4, pot 3; soil 7, pot 2; soil 7, pot 3.

ALTAMONT CLAY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.
Fig. 2. Soy beans B, following Phaseolus. Left to right—Soil 3, pot 2;
soil 3, pot 3; soil 4, pot 1; soil 4, pot 2; soil 7, pot 1; soil 7, pot 2.

UNIV. CALIF. PUBL. AGR. SCI. VOL. 8S [PENDLETON] PLATE 62

ALTAMONT CLAY LOAM—SECOND CROP
Pots of same and different representatives of a given soil type compared.
rb «

Fig. 1. Dwarf milo A, following wheat. Left to right—Soil 3, pot 2; soil 3,

pot 3; soil 4, pot 1; soil 4, pot 3; soil 7, pot 1; soil 7, pot 3.

ALTAMONT CLAY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.
Fig. 2. Dwarf milo A, following bur clover. Left to right—Soil 5, pot 1;

soil 3, pot 2; soil 4, pot 1; soil 4, pot 3; soil 7, pot 1; soil 7, pot 3.

UNIV: CALIF. PUBL. AGR, SCI. VOL. Ss [| PENDLETON] PLATE 66

‘e vi
A, - Me) se ct vee, <a) a we

Www

~ - - mee od —_ 2 r

ide wt.

EE te Rese = ee o

= a

HANFORD FINE SANDY LoAM—FirRsT CROP

Pots of same and different representatives of a given soil type compared.
Fig. 1. Dwarf milo A. Left ie right—Soil on pot 2; soil 15, pot 2; soil 16,
).

y0t 3: soil 19, pot 3: soil 20, pot 2; soil 22, pot 2; soil 23, pot 1; soil 24, pot 2;
] >} ] ] J >]

»
oO,
soil 25, pot 1.

HANFORD FINE SANDY LOAM—FIRST CROP

Pots of same and different representatives of a given soil type compared.
Fig. 2. Dwarf milo A. Left to right—Soil 15, pot 1; soil 15, pot 2; soil 15,
pot 3; soil 20, pot 1; soil 20, pot 2; soil 20, pot 3; soil 23, pot 1; soil 23, pot 2;

soil 23, pot 3

UNIV: GALIE. PUBL. AGR, SCI, VOL. S { PENDLE

TON] PLATE 64

HANFORD FINE SANDY LoAM—FIrst Crop

Pots of same and different representatives of a given soil type compared.
Fig. 1. Dwarf milo B. Left to right—Soil 14, pot 3; soil 15, pot 2

2: soil 16,
pot 1; so1 19, pot 3; soil 20, pot 2; soil 22, pot 3; soil 23, pot 3; soil 24, pot 2;

;
soil 25, pot 3.

SSR

HANFORD FINE SANDY LOAM—F IRST CROP

Pots of same and different representatives of a given soil type compared.
Fig. 2. Dwarf milo B. Left to right—Soil 14, pot 1; soil 14, pot 2; soil 14,

pot 3; soil 22, pot 1; soil 22, pot 2; soil 22, pot 3; soil 23, pot 1; soil 23, pot 2;
soil 23, pot 3.

UNIV. CALIF. PUBL, AGR. SCI, VOL. S [ PENOLETON ] PLATE

wie,
‘te.

P =Ty
, iV
ae
ae

Bai

HANFoRD FINE SANDY LoAM—Fi1rst Crop

Pots of same and different representatives of a given soil type compared.

Fig. 1. Soy beans. Left to right—Soil 14, pot 1; soil 15, pot 1; soil 16,
pot se) soil 19, pot 2; soil 20, pot 3; soil 22, pot 1; soil 23, pot 3; soil 24, pot 1;
soil 25, pot 3.

Pe
- b

ee : Sian: ae, su - She
lo, "14

see

First Crop

HANFORD FINE SANDY LOAM

Pots of same and different representatives of a given soil type compared.
Fig. 2. Soy beans. Left to right—Soil 14, pot 1; soil 14, pot 2; soil 14,
D> . b] ] ]
pot 3; soil 16, pot 1; soil 16, pot 2; soil 16, pot 3; soil 25, pot 1; soil 23, pot 2
soil 23, pot 3.

UNIVe GALI PUBL, AGA, SCl. VOL. s [PENDLETON ] PLATE 56

i
Penn aname

se ~~

HANFORD FINE SANDY LOAM—FiIrRST Crop
Pots of same and different representatives of a given soil type compared.
Fig. 1. Cowpeas B. Left. to right—Soil 14, pot 1; soil 14, pot 2; soil 14,
pot 3; soil 22, pot 1; soil 22, pot 2; soil 22, pot 3; soil 23, pot 1; soil 23, pot 2;

soil 23, pot 3.

-
ae 1

,

6 44

=e F

HANFORD FINE SANDY LOAM—FIRST CROP

Pots of same and different representatives of a given soil type compared.

Fig. 2. Cowpeas B. Left to right—Soil 14, pot 3; soil 15, pot 2; soil 16,
pot 2; soil 19, pot 2; soil 20, pot 2; soil 22, pot 2; soil 23, pot 2; soil 24, pot 1;
soil 25, pot 3.

UNIV... CALIF, PUBL. AGR. SCI. VOL..s [f PENDLETON ] PEATE 6&7

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Ly ? hi :

' i 4 |
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Vinee ap
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\

x

HANFORD FINE SANDY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.
Fig. 1. Barley, following soy beans. Left to right—Soil 14, pot 2; soil 15,
pot 1; soil 16, pot 3; soil 19, pot 3; soil 20, pot 1; soil 22, pot 2; soil 23, pot

soil 24, pot 3; soil 25, pot 1.

43

me Fes
as, am He <A te mer, OK AS

HANFORD FINE SANDY LOAM—SECOND CROP
Pots of same and different representatives of a given soil type compared.

Fig. 2. Barley, following soy beans. Left to right—Soil 14, pot 1; soil 14,

pot 2; soil 14, pot 3; soil 19, pot 1; soil 19, pot 2; soil 19, pot 2; soil 19, pot

soil 23, pot 1; soil 23, pot 2; soil 23, pot 3.

UNIV. CALIF. PUBL. AGR. SCI. VOl 3 [ PENOLETON ] PLATE

"

esx.
4 . ~
\ 7

HANFoRD FINE SANDY LOAM—SECOND CROP
Pots of same and different representatives of a given soil type compared.
Wheat, following millet. Left to right—Soil 14, pot 1; soil 15, pot 1; soil 16,
pot 1; soil 19, pot 3; soil 20, pot 1; soil 22, pot 1; soil 23, pot 1; soil 24, pot 1;

soil 25, pot 3.

UNIV. CALIF. PUBL. AGR. SCI. VOI 3 { PENDLETON ] PLATE 69

HANFORD FINE SANDY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.
Wheat, following millet.

Left to right—Soil 16, pot 1; soil 16, pot 2; soil 16,
pot 3; soil 22, pot 1; soil 22, pot 2; soil 22, pot 3; soil 24, pot 1; soil 24, pot 2
soil 24, pot 3.

ad 9

TON ] PLATE 60

[ PENDLI

3

ai
'

PUBL AGR. SCI. VOL

UNIV. CALIF

f WAISRY bi
NY maa

a

HANFOoORD FINE SANDY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.
Fig. 1. Barley, following cowpeas. Left to right—Soil 14, pot 2; soil 15,
pot 3; soil 16, pot 2; soil 19, pot 2; soil 20, pot 1; soil 22, pot 3; soil 23, pot 3;
soil 24, pot 3; soil 25, pot 1.

CROP

LOAM—SECOND

HANFORD FINE SANDY

Pots of same and different representatives of a given soil type compared.
3arley, following cowpeas. Left to right—Soil 19, pot 1; soil 19,

Fig. 2.
pot 2; soil 19, pot 3; soil 20, pot 1; soil 20, pot 2; soil 20, pot 3; soil 23, pot 1;
2; soil 23, pot 3.

soil 23, pot 2;

UNIV, CALIF, PUBL. AGR. SCI. VOI 3 PENDLETON ] PLATE 61

: ; t :
; /
My i
i | | i hie eat =
; j : | | } \\ !
| | f . eave | otis .
Phe cal VE cot LD ee gd Sie ET in es
a a Nn ee Co a
a ~evageraee

SECOND CROP

HANFORD FINE SANDY LOAM

Pots of same and different representatives of a given soil type compared.

Fig. 1. Oats, following milo. Left to right—Soil 14, pot 3; soil 15, pot 2;
soil 16, pot 2; soil 19, pot 1; soil 20, pot 2; soil 22, pot 1; soil 23, pot 3; soil 24,
pot 1; soil 25, pot 1.

aie

HANFoRD FINE SANDY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.

Fig. 2. Oats, following milo. Left to right—Soil 14, pot 1; soil 14, pot 2;
soil 14, pot 3; soil 15, pot 1; soil 15, pot 2; soil 15, pot 3; soil 24, pot 1; soil 24,
pot 2; soil 24, pot 3.

UNIV. CALIF, PUBL. AGR. SCI. VOL. S PENDLETON!) FEATEVSoe

HANForRD FINE Sanpy LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.

Melilotus indica, following cowpeas. Left to right—Soil 14, Pot 1; Soil 15,
Pot 3; Soil 16, Pot 2; Soil 19, Pot 2; Soil 20, Pot 1.

UNIV. CALIF. PUBL. AGR. SCI, VOL. 3 [ PENDLETON ] PLATE 63

HANFoRD FINE Sanpy LoaM—SECOND CROP

Pots of same and different representatives of a given soil type compared.
Melilotus indica, following cowpeas. Left to right-—Soil 22, Pot 2; Soil 25,
Pot 1; Soil 24, Pot 1; Soil 25, Pot 1.

*

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 [PENDLETON ] PLATE 64

HANFORD FINE SANDY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.

Melilotus indica, following cowpeas. Left to right—Soil 15, Pot 1; Soil 15,
Pot 2; Soil 15, Pot 3; Soil 23, Pot 1.

UMIViGALIF, PUBL, AGAR. SCI. VOU. S {[ PENDLETON ] PLATE 66

HANFORD FINE SANDY LOAM—SECOND CROP

Pots of same and different.representatives of a given soil type compared.

Melilotus indica, following cowpeas. Left to right—Soil 23, Pot 2; Soil 23,
Pot 3; Soil 25, Pot 1; Soil 25, Pot 2; Soil 25, Pot 3.

UNIV. CALIF. PUBL. AGR. SCI

+
- e

HANFoORD FINE SANDY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.

3ur clover, following milo. Left to right

Soil, 14,. Pot 2: Sou 15) Pot. 2:
Soil 16. Pot 2: Soil 19, Pot 1; Soi 20, Pot 1.

HANFORD FINE SANDY LOAM—SECOND

Crop

Pots of same and different representatives of a given soil type compared.

Bur clover following milo.

Left to right—Soil 22, Pot tf; Soil 2:
Soil 24, Pot 1; Soil 25, Pot 1.

22. Se Ot

UNIV: CALIF é PUBL, AGR. SCI; VOL, S L PENDLETON | PLATE Sf

HANFORD FINE SANDY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.
Bur clover, following milo. Left to right—Soil 19, Pot 1; Soil 19, Pot 2;
Soal 19. Pot 3:"Soil 23, Pot 1: Soul 23, Pot 2:

HANFORD FINE SANDY LOAM—SECOND CROP

Pots of same and different representatives of a given soil type compared.
3ur clover, following milo. Left to right—Soil 23, Pot 3; Soil 25, Pot 1;
Soil 23, Pot 2; Soil 23, Pot 3.

UNIV, CALIF. PUBL. AGR. SCI. VOL. 3 [ PENDLETON ] PLATE 68

SAN JOAQUIN Sanpy LOAM

Pots of same and different representatives of a given soil type compared.

Rye. Left to right—Soil 10, pot 2; soil 11, pot 1; soil 12, pot 2; soil 13,
pot 3; soil 17, pot 3; soil 18, pot 1; soil 21, pot 1; soil 26, pot 1.

UNIV, CALIF. PUBL. AGR. SCI. VOl 3 [ PENDLE

row
-

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.
”)

Fig. 1. Melilotus indica. Left to right—Soil 10, pot 1; soil 11, pot 3; soil 12,
2- goil 26, pot l.

pot 2; soil 13, pot 1; soil 17, pot 3; soi 18, pot 3; soil 21, pot 2

,

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.

Fig. 2. Melilotus indica. Left to right—Soil 13, pot 1; soil 13, pot 2; soil 13,
pot 3; soil 17, pot 1; soil 17, pot 2; soil 17, pot 3; soil 26, pot 1; soil 26, pot 2;

soil 26, pot 3.

UNIV. CALIF, PUBL. AGR. SCI. VOL. 3 [ PENDLETON ] PLATE 70

P<

: SCA ange!

he We

yf .

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.
Rye. Left to right—Soil 10, pot 1; soil 10, pot 2; soil 10, pot 3; soil 18,

pot 1; soil 18, pot 2; soil 18, pot 3; soil 26, pot 1; soil 26, pot 2; soil 26, pot 3.

SNivea GALL: PUBL, AGR, SCil, VOL: Ss [ PENOLETON ] PLATE 71

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.

Fig. 1. Barley. Left to right—Soil 10, pot 3; soil 11, pot 2; soil 12, pot 3;

soil 13, pot 1; soil 17, pot 3; soil 18, pot 2; soil 21, pot 3; soil 26, pot 1.

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.

Fig. 2. Barley. Left to right—Soil 10, pot 1; soil 10, pot 2; soil 10, pot 3;
soil 18, pot 1; soil 18, pot 2; soil 18, pot 3; soil 26, pot 1; soil 26, pot 2; soil 25,
pot 3.

—
. }
4
.
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UNIV. CALIF, PUBL, AGR. SCI. VOl 3 { PENDLETON PLATE 72

a SD Ba Ee 8 a
|

| |
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ea’ :
ie Nn ee

Mite Be

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.
at )

Fig. 1. Oats. Left to right—Soil 10, pot 1; soil 11, pot 1; soil 12, pot 2;
}

soil 13, pot 1; soil 17, pot 2; soil 18, pot 3; soil 21, pot 1; soil 25, pot 3.

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.

Fig. 2. Oats. Left to right—Soil 11, pot 1; soil 11, pot 2; soil 11, pot 3;
soil 17, pot 1; soil 17, pot 2; soil 17, pot 3; soil 21, pot 1; soil 21, pot 2; soil 21.
pot 3.

UNIV, CALIF. PUBL. AGR, SCI. VOL 3 [PENDLETON] PLATE 73

Bi dh dame a a a ek ld cea

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.
Fix

g. 1. Wheat. Left to right—Soil 10, pot 1; soil 11, pot 3; soil 12, pot 1;
soil 13, pot 1; soil 17, pot 1; soil 18, pot 2; soil 21, pot 1; soil 26, pot 3.

~

re Tari "<i: IPA, at “Ei
Dh. at Bi Sama. 1
“aS ater

2

_—

SAN JOAQUIN SANDY LOAM
Pots of same and different representatives of a given soil type compared.
Fig. 2. Wheat. Left to right—Soil 10, pot 1; soil 10, pot 2; soil 10, pot 3;

soil 13, pot 1; soil 13, pot 2; soil 13, pot 3; soil 17, pot 1; soil 17, pot 2; soil 17,
pot 3.

UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 [ PENDLETON ] PLATE 74

q
iy

“‘ s
SAN JOAQUIN SANDY LOAM
Pots of same and different representatives of a given svil type compared.

Fig. 1. Bur clover. Left to right—Soil 10, pot 2; soil 11, pot 2; soil 12,

pot 3; soil 13, pot 1; soil 17, pot 3; soil 18, pot 2; soil 21, pot 1; soil 26, pot 3.

SAN JOAQUIN SANDY LOAM

Pots of same and different representatives of a given soil type compared.
Fig. 2. Bur clover. Left to right—Soil 10, pot 1; soil 10, pot 2; soil 10,
)

pot 3; soil 18, pot 1; soil 18, pot 2; soil 18, pot 3; soil 26, pot 1; soil 26, pot 2;
soil 26, pot 3.

INDEX

Abbott, J. B., Connor, 8. D., and
Smalley, H. R., cited, 157.
Abnormal Shedding of Young Fruits
of the Washington Navel Orange,
An Investigation of, 283; loca-
tion of experiments, 285; condi-
tions: climate, soil, water, char-
acter of cultivation, 285-288;
nature of June drop, 288-291;
possible causes of abscission, 292—
306 (see Abscission; Alternaria
citri); influence of the environ-
mental complex, 307-821, and
methods of ameliorating, 329-331;
factors contributing to water re-
lation strains, 8321-828; summary
of results of the investigation,
332-333. See also Abscission;
Alternaria citri; Washington

Navel orange.

Abnormal Water Relations, Some, in
Citrus Trees of the Arid South-
west, and Their Possible Signifi-
cance, 37.

Absceission, studies in nature of, 290,
291; description of histology of,
in Citrus, 290-291; stimuli lead-
ing to, 291-306; traumatic stim-
uli (mechanical shock), 291-292;
air temperatures and _ light
changes, 292-293; lack of pollina-
tion and fertilization, 293-294;
relative position on stem, 294;
the gas factor, 294-297; fungi
and bacteria as a cause of, 297-—
306; relation of, to environmental
complex, 307-321; factors opera-
tive in causing water relation
strains, 321-328; citrus varieties
susceptible to, 328-329; methods
of amelioration, 329-331; illus-
trations of fruits, opp. 344, 346,
352, 354, 358, 362. See also Ab-
normal Water Relations in Citrus
Trees.

Absorption, studies in, 138-139, 140,
143, 148; by colloids, 272.

Aération, factor conditioning absorp-
tion, 322-324.

Africa, South, Phalaris bulbosa from,

Ageton, C. N., and Giles, P. L., cited,
140.

Air temperature, effect of, on ab-
scission in Washington Navel
orange, 292.

Alfalfa, influence on water relations
in Citrus, 316, 318, 329.

Altamont soil type, study of, 378,
498,

Alternaria, genus, 299, 300,

citri, cause of black rot disease in
Navel oranges, 297-306; descrip-
tion of infection, 298, 304-305;
theory regarding stimulus to ab-
scission, 298-299, 305-306; prob-
lem of identification of, 299-300;
futility of use of fungicides
against, 331; illustrations of in-
fected fruits, opp. 354, 360; photo-
micrograph showing spores of,
opp. 356,

solani, 300,

tenuis, 300,

Aluminum chloride, 138, 149, 156, 157,
158, 164, 186-191.

Aluminum nitrate, 157.

Alwood, W. B., cited, 116, 126.

Ammonia, used in experiments on
soil, 29, 271, 272.

Ammonification of soil field samples,
472.

Ammonium sulphate, 272.

Animal physiology, effects of salts
on, 64, 83, 87, 89, 90, 94, 96, 136.

Antagonism, in plant and animal
physiology, 88, 84, 86, 87, 89, 90,
92, 94, 95, 96, 136, 138-140. See
also Salts, toxic and antagonisti¢
effects of.

Antagonism and Cell Permeability,
The Chemical Composition of the
Plant as Further Proof of Close
Relation between, 135; phases of
the problem, 137; review of other
investigations, 137-140; methods,
140-144; solution used, 142; ex-
perimental data, 144-154, 155; ex-
ternal appearances of the plants,
154-155; results with salts of the
heavy metals, 156; effect on
plants of variation in solutions,
160; possible calcium-magnesium
ratio, 160-162; permeability and
antagonism, 162-165; summary,
165-166.

Tables and graphs: Calcium echlor-
ide, 168, 169, 170, 171, 172, 173,
174, 175, 178, 179, 188, 189, 194,
195; magnesium chloride, 170,
171, 172, 173, 174, 175, 190, 191,
196, 197; magnesium sulphate,
176, 177, 178, 179, 180, 181, 184,
185; ealeium nitrate, 180, 181;
potassium chloride, 182, 183, 184,
185; aluminum chloride, 186, 187,

s, 189, 190, 191; ferrie chloride,

193, 194, 195, 196, 197, 200,

208, 209, 210, 211, 214, 215,

217; copper chloride, 198,

, 200, 201, 202, 203; mercuric
chloride, 202, 203, 216, 217, 218,
219; copper sulphate, 204, 205,
206, 207, 208, 209; zine sulphate,
206, 207, 212, 213, 214, 215.

Plates showing plants as affected
by various salt solutions, opp.
220-242,

Apple rot, 303-304.

Arenicola, 87, 94.

Argentina, 283.

Arizona, 53.

Arntzen, V., acknowledgment to, 60.

Atmometer, plate showing, 366.

Auer, J., and Meltzer, 8S. J., cited,
87, 96.

Australia, grass seed (Phalaris bul-
bosa) from, 2, 3.

Bacillus subtilus, 69, 72.

Bacteria, antagonistic effects of salts
on, 84, 87, 90, 92, 94, 96; cause of
abscission, 297-306, 332.

Bacterium citrarefaciens, 297.

Bahia orange, 284.

Balls, W. L., cited, 39, 292.

Barium chloride, 140.

Barley, Beldi variety, used as plant
indicator in experiments with

salts, 140.

Bartlett, H. H., and True, R. H., cited,
139.

Batchelor, L. D., acknowledgment to,
269.

Berkeley clay adobe, used in soil ex-
periment, 273.

Bioletti, F. T., 103; acknowledgement
to, 65

Binary salts, experiments with, 81.

Biologie variation, causes of, 267.

Bizzell, J. A., cited, 279.

Black rot of the Navel orange, 297—
299. See also Alternaria citri.
Blair, A. W., and Jennings, H., cited,

473.

Bokarny, T., cited, 65.

Brazil, 283.

Breazeale, J. F., cited, 139, 273, 277,
279.

Briggs, L. J., cited 273, 277, 279.

Briggs, L. J., Jensen, C. A., and Me-
Lane, J. W., quoted, 330.

Brooks, C., cited, 136, 165.

Bruce, D., 55.

Burger crops, figure showing, 123.

Calcium carbonate, 271, 282.

Calcium chloride, experiments with,
on wine yeast, 66, 68, 72-74, 77-
81, 81-84, 84-87, 94-96, 97-98,

Index

[500]

99-100, 101; used in study of re-
lation of antagonism and eell
permeability, 144, 145, 164, 168-
175, 178, 179, 188, 189, 195; effect
on soil constituents, 271, 273, 274,
276, 282.

Calcium nitrate 139,

Calcium sulphate, 139, 271-282.

California, New Grasses for, |.

Camelia, 327.

Cameron, F. K., cited, 272.

Cameron, IF, K., and Kearney, T. H.,
cited, 83, 89, 95.

Cannon, W. A., cited, 323; acknowl-
edgment to, 333.

Carbon dioxide pressures, 278.

Catawba grapes, 116, 124.

Cell permeability. See Antagonism
and cell permeability.

Chandler, W. H., cited, 52.

Changes in the Chemical Composition
of Grapes during Ripening, 103.

Chemical Composition of the Plant as
Further Proof of the Close Rela-
tion between Antagonism and
Cell Permeability, 135.

China, 2.

Chlorides used in_ investigation of
antagonism and cell permeability,
142.

Chlorophyll, 154.

Chlorosis, 37.

Chromium, 158.

Cicer arietinum, 328.

Citrus, genus, physiological diseases
of, 37; June drop in, 38-39; origin
of, 40, 283, 309, 325; moisture
content, 41, 42; effect of dye stuff
solutions on, 47; effect of environ-
ment on, 28, 284; influence of soil
moisture, 322, of soil tempera-
ature, 324-326, 330; stoma, and
transpiration, 52, 295, 326-328,
figures of, 326, 327; varieties of,
subject to abscission, 329. See
also Citrus trees of the arid south-
west.

Citrus blast, 297.

Citrus Trees of the Arid Southwest,
Some Abnormal Water Relations
in and Their Possible Signifi-
cance, 37; physiological diseases
of, 37-38; investigation of June
drop in, 38-39, 52; abscission,
and water relations, 39; influence
on hydrolysing enzymes, 51;
water content of plant organs,
39-40; manner of growth of fruit
in relation to its fall, 40; method
of study of water relations, 40;
comparative water content of
fruit and leaves, 40, 47-48; table

j

Index

showing, 41, conclusions, 41—42,
51-52; comparative water con-
tent of different kinds of fruit,
42-47, 49, experiments proving,
42-47, 49, illustrations of, 45, 46,
opp. 54; water transport studies,
47-52, method used, 47, deserip-
tion of experiments, 47-48, con-
clusions, 48-51.

Clay adobe soil, experiments on, 131.

Climate, in its effect on abscission
(June drop) in Navel oranges,
307-819, 331; basis for soil classi-
fication, 373.

Cochin China, 283.

Colby, G. E., cited, 103.

Coleus blumei, 323.

Colin, H., and de Rufz, J., cited, 140.

Colletotrichum gleosporiodes, 297.

Colorado, 308.

Coit, J. E., 38, 283; acknowledgment
to, 53.

Colloids, absorption by, 272.

Colorimeter, error due to, 254.

Conner, 8. D., cited, 157.

Copper chloride, 150, 151, 158, 180,
181, 198-203.

Copper hydroxide, 154.

Copper salts, 144, 150-152, 154, 155,
164, 165.

Copper sulphate, 138, 151, 152, 158,
159, 204-209.

Cornichon grapes, 119, 123.

Cover crop, 230.

Cruess, W. V., acknowledgment, 65,
66, 79; cited, 103.

Cucurbita pepo, 138.

Culberson, J. D., acknowledgment, 31.

Davi, H., 103.

Davis, California, weather conditions,
6; character of soil, 7; University
Farm at, 140, 244.

de Candolle, A., cited, 283.

de Heen, P., Gies and Micheels, H.,
cited, 156.

Dendrometer, A New, 55; disadvan-
tages of other volume tables, 55—
56; qualities needed in, 56; de-
scription of, 57; figure illustrat-
ing principle of, 57; method of
use, 57; advantages and disad-
vantages, 57-58; adjustment, 59;
error in, 59-60; figure showing
construction, 59, showing the in-
strument, 60; weight, 60; range,
and accuracy, 58, 61; field test of
sight lines, 61; modification for
timber surveying, 61.

de Rufz, J., and Colin, H., cited, 140.

Diablo soil type, study of, 378, 498.

Die-back, 37.

Dixon, H. H., cited, 50, 52.

[501]

Does CaCO, or CaSO, Treatment
Affect the Solubility of the Soil’s
Constituents?, 271.

Doubt, Sarah 8., cited, 295,

Dye stuff solutions, experiments with,
on citrus, 47.

Dysdereus suturellus, 292 note 18.

Edison Land and Water Company,
285, acknowledgment, 53; Navel
orange orchard, 285, picture of,
opp. 334,

Egypt, 292.

Electrolytes, 139,

Elliott, J. A., cited, 300.

Emperor crops, figure showing, 119.

England, 470.

‘nvironment, influence of, 38, 283,
284, 307-321, 329.

Eucalyptus rudis, 51,

tereticornis, 51.

Ferric chloride, 149, 150, 157, 158,
164, 192-197, 200, 201, 208-211,
214-217.

Ferric phosphate, 151, 154.

Ferric sulphate, 152, 153, 154, 155,
158, 159.

Fertilization, relation to fruit develop-
ment, 2938.

Florida, 283, 297.

Forage, furnished by Phalaris stenop-
tera, 7.

Forbes, R. H., cited, 150, 165.

Fortier, S., cited, 286.

Fouquieria splendens, 40.

Fowler, L. W., 25.

Free, E. E., cited, 323.

Free acid, changes in, 125, 129.

Fruit production, effect of soil mois-
ture content on, 29.

Fundulus, 69, 73.

Fungi, as cause of abscission, 297-306,
332.

Fungi Imperfecti, 300.

Fungicides and the June drops, 331.

Fusaria, 303.

Gas factor, as cause of abscission,
294-297,

Geranium pyrenaicum, 291.

Gericke, W. F., 271; cited, 150.

Gies, Micheels and de Heen, cited, 156.

Gile, P. L., cited, 162.

Gile, P. L., and Ageton, C. N., cited,
140.

Gimingham, C. T., cited, 272.
Goodspeed, T. H., cited, 329.
Gossypium herbaceum, 39.
Grammarus, 69, 73.

Grape juice, 66.

Grapes, Changes in the Chemical Com-
position of, during Ripening,
103; list of, 104; samples used in
investigations, 105; method, 105;

Index

effect of age of vine, 105; com-
parison of grapes on north and
south sides of vines, 106; effect
of location of bunch of, on cane,
106, table showing, 107; variation
in balling degree in must, 107,
table showing, 107-108; effect of
location of berries, 109, of thor-
oughness of pressing, 109; preser-
vation of samples, 109; methods
of analysis, 111; analyses of
must, 111, tables of, 112-115;
differences between total solids
and sugar, 126, graph showing,
126, table of, 127; variation in
protein, 128, graph showing, 128;
summary of changes, 129-130.
Varieties studied, and ripening tests

of:

Burger, 114, 116, graph of, 123.

Catawba, 115, 116, 126, graph of,
124.

Cornichon, 112, 114, 116, graphs of,
119, 123.

Emperor, 113, 116, graph of, 119.

Malaga, 112, 113, 125, graphs of,
117, 120.

Museat, 113, 115, 116, 1
graphs of, 120, 124.
Pedro zumbon, 113, graph of, 121.
Sultana, 113, 116, graph of, 121.

Sultanina, 114, graph of, 122.
Tokay, 112, 114, 116, 125, graphs
of, 118, 122.
Grasses, New, for California, 1.
also Phalaris stenoptera.
Grasses of California, conditions of
growth, 1. See also Phalaris
bulbosa.

Greenhouse soil, use of, in experl-
ments, 273.

Growth and absorption in plants, re-
lationship between, 148.

Gypsum, in relation to soil, 272, 282.

Haberlandt, G., cited, 327.

Hackel, E., quoted, 3.

Hall, A. D., cited, 272.
Hall, A. D., Brenchley, W. E., and
Underwood, L. M., cited, 322.
Hall, A. D., and Russell, C. J., cited,
470.

Hanford soil type, 378-498.

Harding, R. R., curator of Botanic
Gardens, Toowoomba, Queensland,

25,

126,

See

Harding grass, proposed name for
new grass, Phalaris stenoptera
(which see), 5.

Heilbronn, A., cited, 327.

Hilgard, E. W., cited, 108, 378, 374;
elutriator method of soil analysis,
380, 468.

[502]

Hodgson, R. W., 37, 283.

House, cited, 156,

Howard, A., cited, 325,

Ikeda, H. T., cited, 293.

Illinois Agricultural Experiment Sta-
tion, soil survey and classifica-
tion, 375-376.

India, 283; soil aération in, 323,

Indigofera arrecta, 309,

Insect injuries in relation to abseis-
sion, 392, 306,

Intercrops (intercropping), effect of,
on abseission (June drop), 329,
330.

Investigation of the Abnormal Shed-
ding of Young Fruits of the
Washington Navel Oranges, 283.

Iodine test of soils, 421.

Ion absorption, 138, 139, 140, 280.

Iron, 140, 144, 150, 151, 152, 1538, 154,
158, 164, 281; water soluble iron
content, 276.

Irrigation necessary to most Califor-
nia grasses, 1; moisture content
problem of, 25, 29.

Jamaica, 327.

Java, 283. .

Jennings, H., and Blair, A. W., cited,
473.

Jensen, C. A., acknowledgment to, 26.

June drop, physiological disease of
Citrus, 37, 38, 39-40; investiga-
tions of, 285; nature of, 288; time
of appearance, 304; methods of
amelioration, 329. See also Ab-
scission; Washington Navel orange.

Katydid, fork-tailed, 292; illustration

of work of, on oranges, opp. 348.

Kearney, T. H., and Cameron, F. K.,
cited, 83, 89, 95.

Kelhofer, W., cited, 103.

Kellogg, C. W., 285; acknowledgment
to, 333; picture of orange orchard
of, opp. 336.

Kenicott-Sargent colorimeter, 255.

Kennedy, P. B., 1.

Knight, L. I., cited, 295.

Kratzmann, E., 157.

Laboratory error in determining nitri-
fication in soils, 256, 257, 262, 264.

Leaf area, in Washington Navel
orange, effect on abscission, 310.

Leitch, I., cited, 325.

Lemon, not susceptible to abscission,
329.

Lemon Trees, Young, on a Loam Soil,
Optimum Moisture Conditions
for, 25; plan of experiment on,
26; results, 27-28, figure and
plates showing, opp. 32, 34, 36;
optimum per cent of moisture
content, 28; range of soil mois-

,
)

Index

ture percentages, 28-29; wilting
point, 29; ratio of growth to
moisture percentage, 30; sum-
mary, 31.

Leptoglossus phyllopus, 292 note 18.

Liebig, J., cited, 271.

Light changes, effect of, on abscis-
sion in Washington Navel orange,
292.

Lillie, R., cited, 83, 87, 89, 92, 96.

Lime, in relation to soil, 272-282, 475;
and iron, absorption relationship,
140,

Lime-magnesia ratio, 160-162.

Limoneira Company of Santa Paula,
California, 25.

Lipman, C. B., 25, 131, 271; acknowl-
edgment, 53, 166, 269, 285; cited,
64, 66, 69, 72, 73, 75, 78, 90, 92,
96, 150.

Lisbon lemon, used in moisture con-
tent experiment, 26, 31.

Literature cited, 101, 270.

Lithium nitrate, 310.

Litmus, solution, 66.

Livingston, B. E., cited, 323.

Livingston, B. E., and Brown, P. E.,
cited, 39, 311.

Livingston, B. E., white porous cup
atmometer, plate showing, 366.

Lloyd, F. E., cited, 39, 40, 311, 326;
acknowledgment to, 333.

Loeb, J., cited, 66, 69, 72, 73, 75, 79,
80, 85, 89, 90, 96, 136, 165.

Lyon, T. L., cited 279.

McCool, M. M., cited, 155.

MacDougal, D. T., cited, 324.

Maerosporium, genus, 300.

Magnesium chloride, experiments with
on wine yeast, 66, 68, 71, 72, 76,
87-90, 92-94, 97-98, 99-100, 101;
used in study of antagonism and
cell permeability, 144, 145, 159,
160-162, 163, 164, 170-175, 190,
191, 196, 197.

Magnesium sulphate, 146, 147, 148,
155, 156, 176-181, 184, 185, 272.

Magowan, F. N., cited, 69, 74, 75, 144.

Malaga crops, figure showing, 117,
120.

Maquenne, L., cited, 140.

Marsh, C. D., cited, 140.

Melilotus alba, 5.

Meltzer, S. J., and Auer, J., cited, 87,
96.

Mercurie chloride, 140, 144, 151, 154,
155, 159, 202, 203, 216-219.

Micheels, H., Gies, and de Heen, P.,
cited, 156.

Micro-organic activities, 266.

Mitra, 8S. K., 68.

Miyaki, K., cited, 156, 157.

[503]

Moisture Conditions Optimum, for
Young Lemon Trees on a Loam
Soil, 25; soil determinations, 26;
experimental results, 27; effect of
varying percentages of moisture
content in soil, 28, 29, 31, figures
showing, 32, 34, 36; wilting point,
29.

Moisture (water) content, 39, 40, 41,
42, 52, 319.

Moore, Anne, cited, 84.

Mottled-leaf, 37.

Mulches, straw, effect of, on setting
of Washington Navel oranges,
330-831.

Mulching, effect of, on soil tempera-
ture, and on abscission, 330-331.

Museat crops, figures showing, 120,
124,

Musts, analyses of, from grape-ripen-
ing samples, 111.

Narcosis, 139.

New Grasses for California. I, Phal-
aris stenoptera Hack., 1.

New Method of Extracting the Soil
Solution, 131.

New Zealand, grass seed Phalaris
bulbosa from, 2, 3.

Nickel, 158.

Nitrate nitrogen, amount of, criterion
of variability in soils, 246, 266—
269; statistical tables of nitrate
production, 249-253; laboratory
error, 254-258; sampling error,
259-265.

Nitrification in Soil, A Statistical
Study of, 243; calculations, 247;
experimental investigations, 253,
472; value of post work on, 267.
See also Variability in Soils and
Its Significance, ete.

Nitrogen fixation, in soil samples,
472, 481, 482.

Nutrient solution from pure materials,

66.
Orange. See Bahia orange; Valencia

orange; Washington Navel orange.

Oakley blow sand, used in experi-
ments, 273.

Optimum Moisture Conditions for
Young Lemon Trees on a Loam
Soil, 25. See also Lemon trees.

Opuntia, 325.

Orange, Bahia, 284; Valencia, 321, 328,
329, 362; Washington Navel,
which see. See also Abscission;
Alternaria citri; Citrus, ete.

Organie matter content of soil, 278.

Osterhout, W. J. V., cited, 64, 75, 87,
89, 90, 95, 138, 165, 296.

Ostwald, W., cited, 69, 73, 89, 92, 96.

Index

Pantaneli, E., work of, on ion absorp-
tion, 138-139.

Paraguay, 283,

Parkinsonia microphylla, 40,

Patten, H. E., cited, 272.

Peat soils, experiments on, 131.

Pedro zumbon erops, figures showing,
121,

Pendleton, R. L., 369.

Penicillia, fungus, 303,

Perennial canary grass, 1.

Permeability, cell, and antagonism,
the chemical composition of the
plant as further proof of the close
relation between, 135. See also
Antagomism and Cell Perme-
ability, ete.

Phalaris arundinacea, 4.

Phalaris bulbosa, name incorrectly
applied, 2,3; description of, under
correct name, P. stenoptera, 3-4;
original samples of, 4-5; eco-
nomic considerations, 5.

commutata, name incorrectly ap-
plied, 2-3.

Phalaris stenoptera, Hackel’s descrip-
tion of, 3-5; sterile florets of, 4;
common name for, 5; manner and
conditions of growth, 5-9; palat-
ability, 8; plates showing, opp.
10, 12, 16, 18, 20.

Phosphates, 272.

Phosphorie acid, 139.

Phosphorous content in soil solutions,
282; in soil field samples, 471.
Physiologically balanced solution, 64,

136.

Physiological diseases, 37.

Physiological drought, 322

Pierce, G. J., cited, 295.

Pierce, N. B., cited, 297.

Pisum sativum, 325.

Plant physiology, antagonistic effects
of salts on, 83, 86, 89, 90, 94, 95,
136, 188; correction needed in
current teachings on, 282.

Pleospora, genus, 300.

Pollination, relation to fruit develop-
ment, 293.

Pomelo, 328.

Potassium chloride, used in experi-
ments on wine yeast, 66, 68, 69-
70, 75-79, 80, 84, 86, 87, 90-94,
97—98, 99-100, 101; used in study
of relation of antagonism and
cell permeability, 139, 144, 147,
148, 182-185, 272, 274, 276-281,
472, 481; solubility, 281.

Potassium content and liming of soil,
279.

Potassium nitrate, 139.

Potassium sulphate, 139.

Prescott, J. A., cited, 272,
Prosopis velutina, 325,

' Protein content in grapes, 128.

Pruning to reduce leaf surface, 829.

Puffing of fruit, 37.

Quincke, G., data obtained by, 131,

Renner, C., cited, 311.

Rudolph, B, A., cited, 300.

Ruprecht, R. W., cited, 156.

Russell, C. J., cited, 470.

Saccharomyces ellipsoideus, 65; vari-
ation in physiological characters,
65

Saccharomyces ellipsoideus, Wine
Yeast, Toxic and Antagonistic
Effects of Salts on, 63; purpose
of investigation of, 64-65.

Method of experimentation, 65-68;
yeast selected, 65; salts tested,
66; choice of solution, 66; deter-
mination of activity of yeast,
67; salts used, 68.

Experiments with single salts, 68—
75; toxie effects of the salts, 75—
79, 99; literature cited, 101.

Experiments with combinations of
salts, antagonistic effects of the
salts, 99; literature cited, 101.

See also Calcium chloride; Magnes-
ium chloride; Potassium chloride;
Sodium chloride.

Salix, sp., 324.

Salts, binary, 81; of the heavy metals,
137, 148, 156, 160, 164.

Toxie and antagonistic effects of,
on wine yeast, Saccharomyces
ellipsoideus, 63; experiments with
single salts, 68-79, with combina-
tions of salts, 80-98; effects on
animal physiology, 83-86, 89, 90,
94, 96, 136, on plants, 83, 87, 89,
90, 94, 95, 136, on bacteria, 84,
87, 90, 92, 94, 96, 136.

Experiments with, in study of an-
tagonism and cell permeability

in plant physiology, 135-242;.

reasons for choice of, 144; sum-
mary of conclusions, 155-166;
tables and graphs illustrating,
167-219.
Absorption relationships, 138-140,

145-151, 158, 159, 164.

San Joaquin soil type, study of, 378—
498,

San Joaquin Valley, California, 292,
303, 304, 338, 340.

Schiffel’s formula, 56.

Schinus molle, 288.

Schizolysis, 291.

Schreiner, O., and Skinner, J. J., work
of, on ion absorption in plants,
139.

1
f

Index

Scirtothrips citri, 292.

Seudderia fureata, 292.

Seasonal variation, effect of, on soils,
267.

Sea water, 136.

Sharp, L. T., acknowledgment, 166.

Shaw, C. F., acknowledgment to, 26.

Shive’s three salt nutrient solution,
142,

Shreve, Edith B., cited, 40, 311, 327.
Skinner, J. J., and Schreiner, O.,
cited on ion absorption, 139.

Smalley, H. R., cited, 157.

Sodium earbonate, 139,

Sodium chloride, experiments with on
wine yeast, 66, 74, 81, 87-90, 90-
92, 94-100, 101; used in study of
antagonism and cell permeability,
139.

Sodium sulphate, 139, 271-282.

Soil, solubility of constituents of, as
affected by CaCO, or CaSO,
treatment, 271; accepted views on
soil-salt phenomena, 271-273; ex-
periment of adding CaCOs and
CaSO4, 273-278; soils used, 273-
274; results of experiment on
Oakley blow sand, 274, 275, 276,
on Berkeley clay adobe soil, 276—
277, on greenhouse soil, 277-278;

factors in determining results, .

278-279; significance of variation
in the soils, 279-281; summary,
281-282. See also Moisture con-
ditions, Optimum, ete.; Variabil-
ity in soils, ete.

Soil classification, deevlopment of,
371-376; value of, 476.

Soil Solution, A New Method of Ex-
tracting, 131; experiments, 131-
132; discussion of the direct pres-
sure method, 132-134.

Soil temperature, influence of, on
growth, 324-326, 330; means of
reduction of, 330.

Soils Mapped under a Given Type
Name by the Bureau of Soils
Method, Are They Closely Similar
to One Another? 369; plan of
the study, 376-377; methods and
technique, 483-489; discussion of
results, 377-467; types and loeali-
ties of soils studied (which also
see), 468; field notes on soil
samples, 490-498.

Mechanical analyses of the soil
samples, 380-395, 485-486; tex-
tures, 386-387; loss on ignition,
405-470; moisture equivalents,
391-394, 469, 486; hygroscopic
coefficient, 394, 395, 469; com-

parisons of physical data, 468—
469; physical relations, 481.
Chemical data, 395-414, comparison
of, 470-472; chemical methods,
486-487; chemical relations, 481.

Bacteriological data, 414-431, com-
parisons of, 472; bacteriological
methods, 487-488; bacteriological
relations, 482.

Greenhouse data, 432-467; green-
house cultures, 475-476, 482, 488,
489.

Solubility of the Soil’s Constituents,
Does CaCO, or CaSO, Treatment
Affect?, 271. See also Soil, solu-
bility of constituents of, ete.

South Africa, 1, 8.

Starch in abscission zone in Citrus,
421.

Stoma, in Citrus, relation to transpir-
ation, 395, 26, 328; figures of,
326, 327.

Straw mulches, effect of, on setting
of Washington Navel oranges,
330-331.

Sugar, in grapes, 126, 127, 129, 130.

Sulphur content in soil solutions, 282.

dioxide, 294, 295.

Sultana crops, figure showing, 121.

Sultanina crops, figure showing, 122.

Summer cover crop, beneficial effect
of, 230.

Sumatra, 283.

Synthetic solution, 66,

Szues, J., work of, on antagonisms of
salts in plants, 138.

Teague, C. C., acknowledgment to, 31.

Temperature, air, effect on abscission,
292; soil, influence on plant
growth, 324-326, 330.

Thompson, H. S., cited, 271.

Timber, a new dendrometer for esti-
mation of, 55. See also Dendro-
meter, A New.

Tokay grapes, figure showing, 118, 122.

Toowoomba grass, 1.

Toxie action of simple salts upon
plants, 64.

Toxie and antagonistic effects of salts
on wine yeast (Saccharomyces
ellipsoideus), 68, 70, 71, 73, 74,
75.

Transpiration, 40, 50, 52; stoma and,
295, 326, 328.

Traumatic stimuli leading to abscis-
sion, 291.

True, R. H., and Bartlett, H. H., cited,
on effect of salts on plant physi-
ology, 139.

U. S. Bureau of Soils, system of soil
mapping, 370, 375-376, 383, 473-
475, 477-480.

lndéx

University [of California] Farm, 140,
244,

Valencia orange, 321, 328, 329; plate
showing clean break between style
and ovary, 362.

Van Bemmelen, J, F., cited, 272.

Variability in Soil and Its Signifi-
cance to Past and Future Soil In-
vestigations, 243; literature on,
244; investigation, 244; in soil of
experimental area,, 266; seasonal
variation, 267; biologie variation,
267; variations of manipulation,
267; summary of conelusions,
268-269.

Methods of study, 244—247; criterion
of variability, 246; calculations
(mathematical treatment), 247-
248; statistical tables, 249-253;
discussion of experimental results,
253-254; errors due to colorimeter,
254-258, to sampling, 259-265,
267; representative and composite
samples, 265; variation, 267.

Verbascum, sp., 291.

Volume tables, defects in, 55, 56.

Washington Navel Orange, An In-
vestigation of the Abnormal
Shedding of Young Fruits of the,
283.

Washington Navel orange, problem of
the June drop, 37-40, 285-304;
effect of environment on, 283—
284; abnormal characteristics,
284; hybrid origin, 284, 329; soil
conditions in experiments on,
285; blooming of, 288; abscission
in, 288-291, 294, 297, 310, plate
showing effects of, opp. 358; tem-
peratures of fruit, 320; effect on,
of water deficits, 321, of straw
mulches, 330; dry heat resistant
strains, 331; purpose of pruning,
329; plates showing: orchards of,
opp. 334, 336, 338, 340; leaves re-
moved, opp. 342; wounds by katy-

did, opp. 348; terminal and axil-
lary fruits, opp. 350; apical end
of ovary, opp. 352; infection with
Alternaria citri, opp. 354; effects
of abscission, opp. 358. See also
Abnormal Shedding of Young
Fruits, ete.; Abscission; Alter-
naria citri; Citrus; Citrus trees;
Water relations; ete.

Water, holding power of soil over,
131.

Water (moisture) content, 39, 40, 41,
42, 53, 319. See also Moisture
conditions, ete.

Water relations, in Citrus, 37, 39, 43—
48, 50; literature on, 39; methods
of study, 40; as stimulus to abs-
cission, 309-321; factors operative
in causing strains in, 321-329.

Water transport studies, experiments
on Citrus, 47.

Way, J. T., cited, 271.

Waynick, D. D., 135, 243; acknowl-
edgment, 132.

Wiegner, G., cited, 272.

Wilting point in soil, 29.

Windbreaks in citrus orchards, 329.

Wine Yeast (Saccharomyces ellipsoid-
eus), Toxic and Antagonistic
Effects of Salts on, 63. See also
Saccharomyces ellipsoideus,

Wiskocil, C. T., acknowledgment to,
132.

Wolff, J., cited, 158.

Worden, W. W., acknowledgment to,
333.

Wright, D., Jr., acknowledgment to,
269.

Wyatt, F. A., cited, 162.

Yolo silt loam, 7.

Zeolites, 272.

Zine sulphate, 144, 152, 153, 158, 159,
164, 206, 207, 212-215.

Yeast. See Saccharomyces ellipsoid-
eus.

ERRATA

Page 126. For Muset read Muscat.
from bottom. For Pantelli read Pantaneli.

Page 138, line

2
Page 144, line 21. For MeGowan read Magowan.

Page 172, line 2
Page 178, line 2.
Page 180, line 2

Page 182, line 2.

For Magnesium Sulphate read Magnesium Chloride.

For Magnesium Chloride read Magnesium Sulphate.

For Potassium Chloride read Magnesium Sulphate +
Calcium Nitrate.

For Magnesium Sulphate + Calcium Nitrate read

Potassium Chloride.

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