The germination of seeds as effected by certain chemical fertilizers

SB

| | BULLETIN No, 24,
7 hey
H ©? : U. S. DEPARTMENT OF AGRICULTURE.

DIVISION OF BOTANY

DHE

S GERMINATION OF SEEDS

AS AFFECTED BY

CERTAIN CHEMICAL FERTI

“nw
puns
wo
&
—
pase
ep
a~
Op

He

or +
PELE
ie
fe g
b

WASHINGTON:
GOVERNMENT PRINTING - OFFICH I IBRARY OF Cc
Lae hE

I Qoo.

UNITED STATES OF #

.

BULLETIN No. 24.

Poe Oe PARTMENT OF AGRICULTURE.

‘

DIVISION OF BOTANY.

GO) es a>

GERMINATION OF SEEDS

AS AFFECTED BY

CERTAIN CHEMICAL FERTILIZERS.

BY

|
GILBERT H? HICKS.

VY RNUFA TURES
SVG

IN
SSS

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1goo,

Ty
2,

LETTER OF TRANSMITTAL.

U. S. DEPARTMENT OF AGRICULTURE,
DIVISION OF BOTANY,
Washington, D. C., January 25, 1900.

Sir: I have the honor to submit herewith, for publication as Bulletin
No. 24, of this Division, a manuscript entitled “The Germination of
Seeds as Affected by Certain Chemical Fertilizers,” by the late Gilbert
H. Hicks, Assistant Botanist. Mr. Hicks left with the manuscript,
which fortunately had been completed at the time of his death, a note
acknowledging his indebtedness to Mr. John C. Dabney, formerly an
assistant in the Division of Botany, for valuable help in conducting
the experiments. Dr. H. W. Wiley, Chief Chemist of the Department,
has courteously read the manuscript and suggested certain amendments
which have been incorporated in the text.

In the rapid extension of the use of chemical fertilizers in recent
years, our knowledge of the precise physiological effects of this kind
of fertilizers on different plants has not kept pace with the investiga-
tion of their purely chemical relationship with the crops and soils on
which they are used. The application of chemical fertilizers frequently
takes place at the same or nearly the same time as the sowing of seed,
and while experience has often shown the partial loss of a crop, appar-
ently from some injurious influence of the fertilizer on the seeds, little
definite practical knowledge has thus far resulted from these occasional
accidents. The general conclusion that a commercial fertilizer, unless
known to be of a noninjurious kind, should not be brought into direct
contact with germinating seeds should be made the basis of estabiished
practice.

Respectfully, FREDERICK V. COVILLE,
Botanist.
Hon. JAMES WILSON,
Secretary of Agriculture.
D, ot D.

pone

HINOCICUTOM << 56S SSeS Sees» See ey a ee
JEUEST OLY CHE DNHEN AIOE) 8 ee ee
WOM Gh Mio XPORUMON US: ecmers- ces so oS ee = Rae co weenlnn sles cewt ewes ccc eeecces

TMDLS) Syraltedan Ni AMERY Se ee See 2 ee

nla SavyoneCrimMs On), CLOVEL SOCO << sac, sec cs coc cbs. cc wicca tccccsaciecss cence
WonCGlimsvOns]—- 5 t~ ccc e ct lan cee eee a eee es ee 52 ge ot

ILLUSTRATIONS.

PLATE 1.—Fig. 1, Wheat experiment with potash. Right, check; left, potash
sown in the rows. Fig. 2, Wheat experiment with phos-
phoric acid. Right, sown in the rows; left, mixed with
GHESOll as 58 222 oo a Bose Se SS oslo see een eee

II.—Fig. 1, Wheat experiment with lime. Right, sown in the rows;
left, mixed with the soil. Fig. 2, Wheat experiment
with mixed fertilizers. Right, sown in the rows; left,
mixed with thesoil) -2252- . 22 see see ee ee soomee

Page.

11

THE (ERMIN ATION OF SEEDS AS AFFECTED BY
CERTAIN CHEMICAL FERTILIZERS,

INTRODUCTION.

A large number of germination experiments have been made to ascer-
tain the effect of different chemicals upon the sprouting of seeds. In
earlier times the object of these experiments was principally to dis-
’ cover, if possible, some chemical to assist in the germination of old,
weak, or naturally slow-germinating seeds. More recently such inves-
tigations have been conducted mainly in connection with the use of
fungicides and insecticides, to learn in what strengths chemicals might
be applied to seeds without seriously injuring their vitality. Asa rule
it has been found that the germination of seeds soaked in solutions of
bases or salts is retarded or even entirely prevented unless these are
extremely dilute, the injury being proportionate to the concentration of
the chemical employed.

In some instances it has been claimed that certain chemical solutions
quicken the germinating power of seeds, and occasionally these claims
have been quite startling.

But interesting and important as have been the experiments in which
chemicals were applied to seeds which were afterwards placed in a
germinator to sprout, conclusions drawn from the results of such experi-
ments are not to be relied upon as applied to seeds planted in soils to
which fertilizers have previously been applied. .

Here the problems involved are much more complex. In the former
case the seed is in contact for a short time only with a chemical solu-
tion and one whose nature is known, and rarely indeed is this solution
present after the radicle has appeared through the seed coat. Here
the chemicals remain in the soil in more or less direct contact with the
seed from first to last. Moreover, the chemical processes continually
taking place in the soil have themselves a marked effect upon germina-
tion. Add to this the hidden changes which the fertilizer constituents
are constantly undergoing in contact with the humic acid, carbon diox-
ide, and various salts in the soil, and we find that a study of the rela-
tion of fertilizers to germination involves one in problems of a very
difficult and yet withal of an exceedingly interesting and important
character.

6

Comparatively little research has been made in this field. The pres-
ent paper is intended to be merely suggestive, and is preliminary to
more extended research in the same line which the writer hopes to
undertake.

HISTORY OF PREVIOUS WORK.

One of the earliest important contributions to this subject was made
by Tautphceus in 1876. In his experiments such salts were employed
as are found to a greater or less extent in commercial fertilizers. They
were applied to the seeds in solutions of various strength from 0.5 to 5
per cent, and the seeds were then placed in a germinating apparatus.
Wheat, rye, rape, maize, beans, and pease were tested in this way, a
check test being conducted with distilled water. The checks always
germinated best, although rape seed showed scarcely any injury from
the use of chemicals, even in solutions concentrated to a strength as
great as 2 per cent. In the other seeds the vitality was seriously
injured whenever the salt content of the solution was greater than 0.5
per cent.

The chemicals employed by Tautphceus were potassium chloride,
sodium chloride, calcium nitrate, sodium nitrate, potassium sulphate,
and hydrie di-potassie phosphate. The plumule and radicle in all the
experiments showed a normal development. The seedlings, however,
were more vigorous in the checks, except in the case of sodium chloride,
where a 5 per cent solution gave stronger plantlets than where dis-
tilled water was used. He concludes that fertilizers which contain
plant food in an easily soluble form should not be used in large amounts,
at least immediately before the seeds are planted, lest their concentra-
tion in the soil become so great as, on the one hand, to destroy the
vitality of the seed, or, on the other, to injure the development of the
seedlings.

About the same time (1876) Henri Vilmorin published a short article
in which he states that when the upper stratum of the soil contains a
large proportion of mineral fertilizers, e. g., Chili saltpeter (sodium
nitrate), beet seed germinates very slowly or not at all. Vilmorin’s
experiments were conducted in pots containing earth, to which, after
weighing, different fertilizers had been applied in amounts varying from
0.5 to 5 per cent. The germination of wheat and beet seeds sown in
these pots was retarded to a marked degree when potassium nitrate,
zaleium phosphate, and especially sodium nitrate were used in amounts
equaling 5 per cent of the weight of theearth. With 10 per cent sodium
nitrate the wheat and nine-tenths of the beet seed failed to germinate.
It should be stated here that never in actual practice would the propor-
tion of fertilizer to soil amount to anything like 5 per cent. Sodium
nitrate is usually employed in quantities ranging from 150 to 300 pounds
per acre. The soil on one acre to the depth of 8 in. weighs approxi-
mately 2,000,000 pounds.' If, however, the fertilizers were drilled in

‘See Wiley’s Principles and Practice of Agricultural Analysis, vol. 1, p. 102.

ft

with the seeds, the percentage of saltpeter in the soil coming into
immediate contact with the seeds, might readily reach the danger point.

Hindorf claims that magnesium chloride and calcium chloride used
in proper amounts exercise a favorable effect upon the germination and
growth of wheat, rye, barley, oats, peas, red clover, and rape, and that
they never cause injury unless used in greater amounts than would
occur in agricultural practice. The injury which then results he
attributes to chlorine.

Nessler (in 1877) stated that he had noticed that hemp seed sown in
fields fertilized with ordinary cooking salt at the rate of 250 kilos per
hectare germinated unevenly and made a poorer development than in
other fields. Experiments led him to conclude:

(1) A 0.5 per cent solution of cooking salt is injurious to the germi-
nation of rape, clover, and hemp. Wheat withstands this solution,
but is injured by a 1 per cent solution, and hemp by a quarter of 1
per cent.

(2) A 1 per cent solution of ammonium sulphate had no appreciable
effect upon wheat grains, but the plants were injured somewhat by a
0.75 per cent solution.

W. Jarius (in 1885) studied the effect on germination of various salts
used in commercial fertilizers, and concluded that in general (with
some notable exceptions) solutions of these salts in strengths of 0.2 and
0.4 per cent favorably affected germination; also that no ill effects can
possibly result from the use of fertilizers, since their solution in the
soil can never exceed 0.4 per cent. In his paper the conclusions of
Tautphoeus and Nessler are criticised.

Jarius’s experiments were conducted in pots of pure sand previously
moistened for twenty-four hours with the solution. The seeds were
planted so that one-half of each, including the micropyle, projected
above the surface, “in order,” as the author says, “that observation
might be facilitated and an unimpeded access of air be secured.” This
impractical method of making the tests largely or quite invalidates the
conclusions drawn by the experimenter, at least from a practical
stand point.

A more important study of this subject, because conducted under
conditions nearer to those of the field, was published in 1896 by Claudel
and Crochetelle.! In order to make use of an inert substance which
would play the mechanical role of the soil without giving any chemical
reaction in contact with the dissolved salts, they employed chemically
pure (as nearly as obtainable) sterilized sand. Four hundred grams
of this sand were placed in a porcelain saucer and the seeds laid
equidistantly upon the surface; another layer of 400 grams of sand was
placed on top of them, the seeds of all the species being planted at a
uniform depth of 8 to 10 millimeters. In order to maintain as nearly
as possible the same degree of moisture in all the saucers, the amount

' Annales Agronomique, 1896, pp. 151 to 142.

8

of liquid supplied was based upon the amount of sand (800 grams)
rather than upon the strength of the solution. After ascertaining the
amount of liquid (200 cubic centimeters) necessary to moisten 800 grams
of sand, each of the lots after planting received this amount of dis-
tilled water, together with a solution of the chemical more or less
dilute, according to necessity. Readily soluble materials were used,
as potassium sulphate, ammonium sulphate, sodium nitrate, and potas-
sium chloride. Slag and superphosphates were mixed with the super-
ficial layer of the sand, direct contact with the seeds, however, being
avoided. The results of these experiments are worth a somewhat
extended mention.

Potash fertilizers under the form of sulphate or chloride of potassium
in general retarded germination, this retardation being greater for the
chloride than for the sulphate; the difference was especially noticeable
for the Leguminosae and flax.

Ammonium sulphate had a disastrous effect upon the sprouting,
though in unequal degrees, colza, flax, wheat, and mustard being very
sensitive to its influence, while sainfoin and wheat were less so than
any other seeds. To make sure that this injury was not due to too
large an amount of the fertilizer, the experiment was repeated with
wheat, oats, barley, colza, clover, and beans in solutions of 0.5, 1.2, and
5 parts per 1,000 of the sulphate of ammonia. The results showed that
wheat, barley, and oats are practically insensible to this salt in solu-
tions up to a strength of 2 parts per 1,000, but a 0.5 part per 1,000
affected colza slightly and clover to a marked degree. With 5 parts
per 1,000 of the salt, all germination was arrested.

Sodium nitrate acted in a manner similar to ammonium sulphate, but
less enegetically. The 1 part per 1,000 solution had no appreciable
effect upon wheat, barley, sugar beet, colza, and beans, but seriously
injured buckwheat and to a considerable extent clover. The 2 part
per 1,000 solution had but little effect upon wheat, barley, and colza,
but entirely prevented germination in buckwheat and beans, while
sugar beet dropped off considerably and clover was badly injured; all
the seeds germinated more slowly in this solution than in those of less
strength. In the 5 part per 1,000 solution no seeds sprouted except
barley, which germinated 100 per cent.

Phosphoric acid was used in the form of slag and superphosphate,
the former being alkaline and the latter acid. In very feeble amounts,
2 parts per 1,000 and less, the addition of superphosphate slightly
hastened germination; with 4 parts per 1,000, on the contrary, a con-
siderably less number of seeds sprouted. The authors conclude that
in acid soil the use of superphosphate does not retard germination, if
the free acid is quickly combined with the bases of the soil.

The slag favored germination in all cases, especially in those of the
Leguminosae. Anattempt was made to ascertain whether this advan-
tage was due to the phosphoric acid or to the lime, and it was found

9

that the basic phosphate of lime acted favorably upon the germination
of vetches, while the acid phosphates were injurious. I*ree lime gave
better results than the carbonate, but was inferior to the slag.

Summing up, the authors conclude:

(1) In the amounts employed, and leaving the seeds constantly in
contact with the material used, sulphate of ammonia, sulphate of soda,
chloride of potassium, sulphate of potassium, and the superphosphates,
exercised an injurious action upon the germination of seeds in general.

(2) Not all the species sown were influenced to the same extent; for
example, the wheat resisted the best among the species tested, whereas
lentils, lucerne, and flax were very sensitive to the action of the fertili-
zers used.

(3) Alkaline substances with a basis of lime or of potash favored in
a marked degree the germination of certain seeds, notably those of the
Leguminosae. The slag used produced better effects than the lime
alone.

In the same paper the authors give the results of experiments con-
ducted to obtain information concerning the acids set free or originat-
ing during the germination of seeds, which showed that the amounts
of acids thus formed are sometimes very great; hence it is concluded
that lime, slag, and liquid manure act by saturating these acids in pro-
portion to the amounts formed. Aso, that the loss of phosphoric acid,
which is excreted in considerable amount in the germination of wheat,
for instance, is hindered by these alkaline substances, and thus con-
served for the use of the young plant. These conclusions, in the opinion
of Claudel and Crochetelle, explain to a certain extent the beneficial
ettect of lime, slag, and ashes upon acid soils. Seeds of clover were
found to produce more acid for a given weight than any other seeds
studied, thus explaining the fact that clover does not appear in acid
soils prior to the addition of lime, ashes, or slag.

Professor Buffuin, of the Wyoming State Experiment Station, made
quite an extensive study of the effect of alkali soils upon germination,
and found that even small per cents of alkali in the soil retard germi-
nation, although as a rule about as high a per cent of seeds germinated
in a soil containing 1 per cent of alkali as in alkali-free soil, provided
the seeds were left long enough.

DEPARTMENT EXPERIMENTS.

In any study of the effect of fertilizers upon the germination of seeds
planted in the ground the following possibilities should be kept in :nind:
fertilizers may influence—

(1) The swelling stage.

(2) The nature-and availability of the reserve materials.

(3) The awakening and growth of the embryo.

(4) The young sprout before it reaches the surface of the soil.

We expect to show in this paper that the principal effect is upon the

10

sprout after it has broken through the seed coat. It has already been
established by Deherain and other investigators that plants in the
seedling stage absorb a proportionally greater amount of mineral mat-
ter than in more advanced periods of development. Indeed, in the
case of the bean, soda is taken up in the early life history of the plant,
whereas none whatever is used when the plant is fully developed.

In experiments conducted by us in one of the greenhouses of the
U.S. Department of Agriculture the following kinds of seed were used:
Jones’s Winter Fife wheat, Curled Simpson lettuce, French Breakfast
radish, and crimson clover. Previous tests had shown that all of the
varieties were of strong vitality. Common potting soil, sifted and
clean, was thoroughly mixed and placed in greenhouse “flats.” At the
beginning of the experiment each flat was given enough water to suffice
while the experiment was in progress, and all were treated alike
throughout the test except in the matter of fertilizers. A check flat
containing soil only was provided for each kind of seed.

The fertilizers used were the following: Nitrate of soda, muriate of
potash, bone black made soluble by treatment with sulphuric acid, and
lime made from powdered oyster shells. In addition to these, there
was employed a mixed or “ balanced” fertilizer consisting of bone black
(treated as above), 600 parts (by weight); muriate of potash, 100 parts,
and nitrate of soda, 200 parts. This fertilizer contained approximately
the following proportions of plant food: Nitrogen, 23.7 per cent; phos-
phorice acid, 54.7 per cent; potash, 21.5 per cent. It is to be noted that
all of these fertilizers are readily soluble in cold water. The seeds in
each test were plump and sound and approximately of the same size.

The varieties were all planted at the same depth in four rows, each
containing an equal number. In no case was the soil firmed after
planting. Fifty eubic centimeters of fertilizer were added to the soil
in the following manner: In one flat of each experiment 12.5 cubic cen-
timeters was equally distributed in each row, the seeds sown upon the
fertilizer, and a covering of soil added. In another flat the top inch
of soil was carefully removed and 50 cubic centimeters of the fertilizer
thoroughly mixed with this soil, which was then replaced and the seeds
planted therein. A third flat contained soil only, as above stated.

The weight of 50 cubic centimeters of each fertilizer was as follows:
Bone black, 43.5 grams; muriate of potash, 43.0 grams; nitrate of soda,
57.5 grams; lime, 31.0 grams; mixed fertilizer, 35.5. The fertilizers
were used in the following strengths by weight: Bone black, 1.52 per
cent; muriate of potash, 1.31 per cent; nitrate of soda, 1.75 per cent;
lime, 0.94 per cent; mixed fertilizer, 1.08 per cent. While these pro-
portions are greater than would obtain in ordinary practice, it is believed
that they were not too large to give reliable results.

.

}t

tet

Bul. No. 24, Div. of Botany, Dept. of Agr. PLate |.

Fic. 1.-WHEAT EXPERIMENT WITH POTASH. RIGHT, CHECK; LEFT, POTASH SOWN
IN THE ROWS.

Fig. 2.—WHEAT EXPERIMENT WITH PHOSPHORIC ACID. RIGHT, SOWN IN THE ROWS;
LEFT, MIXED WITH THE SOIL.

Bul. No. 24, Div. of Botany, Dept. of Agr. ; PLaTE Il.

FIG. 1.-WHEAT EXPERIMENT WITH LIME. RIGHT, SOWN IN THE ROWS; LEFT,
MIXED WITH THE SOIL.

Fic. 2.-WHEAT EXPERIMENT WITH MIXED FERTILIZERS. RIGHT, SOWN IN THE ROWS;
LEFT, MIXED WITH THE SOIL.

11

TRIALS WITH WHEAT.

‘4 °
in the experiments with wheat four rows of 50 seeds each were used
in each test (Pls. [, II). In the following table, which summarizes the
; results, the percentages given are the average of the four rows:
Effect of chemical fertilizers on the germination of Jones’s Winter Fife wheat.
Time re- | Average
quired for | 4 verace per | height of
Fertilizer. How fertilizer was applied. | germina. | “Verage per | sprouts
| tion of first cent sprouted. | Qnim.) on
| sprouts. | fifth day.
rs x , ins In 5 - 10 | ¢
Days: days. | days.
Sn [SOW IIT NONCONS = terete «cts cele ccc sco mcacs We iee ta sna as 00 ODI Wisden tan seme
Potash (KCl) -.---- NivinacedayiGleS0le eee once toes sce | RP ae Dees 00 11 ae) |e
Phosphoric acid |{Sown in the rows ..-...-..--..--------- | 3.0 S150) esod0 16.6
(bone black). (Mixed WILUHES OF lee sors Sactoas Stoo sa nace 2.5 87.0! 89.0 46.2
Se ONO erieccritiv coll cs-2s eee seee|stoseeeczese| 00 | 00 [2200200022
Sown i » rows 2.5] 8 3.5 31.5
Lime (oystershells) \Sriredwith soll -22.lssc| 2B) 85 | 90.8 8?
: ee jSown in therows......--.----. aeieers =e | 5.5 0) 9.0 00.0
; Mixed ...---.-+---- Wise divi Ghai SOil 222 << 2s ac etesls seme | BB 46,0 80, 0 15.4
: (HINDU < Sac cab eo goss Oe CBU OOOO OSE GOD CONDE nen Ae ae erate aan 2,5 89.5 90.5 54.0
:
: Analyzing these results we notice, first, that the potash and nitrogen
; - -

fertilizers prevented germination entirely.

Second, that in every case at the end of four days the germination
was greater when the fertilizers were mixed with the soil than when
they were sown in the rows and the seeds placed in direct contact,
although the difference in the case of lime was very slight.

Third, that germination was retarded when the fertilizers were in
direct contact with the seeds, except in the lime experiment.

Fourth, that on the fifth day the germination of the wheat sown in
soils mixed with the phosphorie acid and lime fertilizers was only
slightly less than that of the checks, and that it had nearly or quite

P| caught up with the checks on the tenth day.
Fifth, that lime in the rows gave a slightly greater percentage of
: germination than the check on the tenth day. The increase, however,

is not large enough to warrant the conclusion that lime is really
beneficial to germination. That it is, on the contrary, to a certain
extent detrimental if used in amounts equaling 0.94 per cent may be
inferred from the fact that the average length of the sprouts was con-
siderably less on the fifth day, even when the lime was mixed with the
soil, and much less when sown in the row.

The experiment teaches that care should be exercised in applying
muriate of potash and sodium nitrate to soils in which wheat is to be
sown, as an excess of these salts will seriously injure and may prevent
germination. Also, that a combination of sulphate of lime with acid
phosphate and a little free sulphuric acid is not likely to injure the
germination of wheat, even when used in some excess.

12

The serious damage caused by the mixed fertilizer was undoubtedly
due to the potash and nitrogen which it contained.

After the completion of the ten days’ experiment the unsprouted
grains of wheat were taken from the nitrogen and potash flats and
tested between damp blotters in the laboratory, with the following

results :
Laboratory test of residual wheat.

Per cent

Fertilizer. How fertilizer was applied. germi-
nated.
; (i: Mean SHOT OWS os erecinta cor ace a tates lee slo ate eysic ict c Sivas Srere ra ae ee ee nee eee 50
Potash......---.-- \| Mixed with soil........... 70
oa a AREA Gog Devers we), (2: eet Sian yh edn ee eR RE Be re aE at oe Ei 49
Nitrogen ...-.-..- We Boasts loti sto! bee she ae 3 5 ie ee 8 2 ee See eh ang Sapo aceunt 84

Many of the seeds were found to be decayed when taken from the
flats.
TRIALS WITH LETTUCE SEED.

Lettuce seed, if kept thoroughly wet for the first forty-eight hours
of a germination test, sprouts very freely, even as high as 98 or 100
per cent by the third or fourth day. In these experiments this excess-
ive moisture was not maintained, hence the low germination of the
check. The seed was planted in the afternoon of May 19. Four hun-
dred seeds were used in each test.

Effect of chemical fertilizers on the germination of Curled Simpson lettuce seed.
il ) : { , 1

Per cent

germinated | germinated

Fertilizer. How fertilizer was applied. First sprouts.

: on the on the
fourth day. | twelfth day.
Poth (Hee Gnti dbl (ease eo seers aeoscenScesuel Geaadondae sacsas No sprouts.) Nosprouts.
fix? Nemes IAMiixedswith ‘solo 4..< 25. coca ee sae [ese eeeeeeeeee No sprouts. | No sprouts.

awe ae fiplu, the TOWwss- 2-252 -2ccee eects see May °6,p.m..) No sprouts. 2.5

Phosphoric acid - -) Mixed with! soile2-220 2 otmecc seers May 21,p.m .. 2,5 45. 25
rage (\ Cin the mowss-ce see esuash toads aeaene te eee eee sae No sprouts., Nosprouts.
Nitrogen = ----2~-: Ul Misced “with«soil’ 2.6 22222022 eietacle see eee No sprouts.) Nosprouts.

TRme {\ploctheirOws-eo ees se eo eee May 23, a.m .. 0.75 | 36
a eh a ie Mixed swith is0il.2_f22cc5a- cece coe as) a yeoenoeeees 4.0 39. 75
sane ens oe Se NL GO-TO W Simca cmaice sos sores oc el ieee oe ee No sprouts.) Nosprouts.
Mixed fertilizer -- Mixed: with S01)... <.jece scene ese ce] - eee eee rnene No sprouts.| No sprouts.

Olid es Saat eo aoeeer b Sseesee Aen cs cGinmacon 2 eee ieeece May 21,2.m .. 40.5 | 73

Potash and nitrogen prevented germination entirely, as in the case
of wheat; furthermore the mixed fertilizer had the same effect. Phos-
phorie acid and lime greatly retarded germination, and even prevented
it toa large extent. It is noticeable, however, that although the phos-
phoric acid mixed with soil appeared to be slightly more favorable than
lime under the same circumstances, yet the latter really affected germi-
nation much less injuriously, as evidenced by the fact that when in
direct contact with the seeds the phosphoric-acid fertilizer almost com-
pletely prevented germination, giving only 2.5 per cent sprouts on the
twelfth day, while 36 per cent sprouted in the lime test within that
period.

13

At the close of the greenhouse experiment part of the sound lettuce
seeds were removed for a test between damp blotters in the laboratory.
The results are very interesting, since they indicate that the principal
injury from the application of the fertilizers, especially when mixed with
soil, accrued to the young sprouts after leaving the seeds and while
yet beneath the soil, rather than to the seeds themselves. The labora-
tory tests continued three and one-half days. One hundred seeds were

used in each test.
Laboratory test of residual lettuce seed.

Wet eae opt e1s ae + | Per cent
Fertilizer. How fertilizer was applied. | germinated.
, (UIE KT Gam O WSs aise iaiae er earstarme cic clo hos aioustaie wre ao aiete sieicvereimere'« | 62
Potash ..-..--------------+- Millia cd witnails. s6ce.08 5 G0. > oocadcactoc cous cea. 2ncan | 93
i ee [@ENiet ROMO WW Ste ace tec ape ee a: Swtnsee ria ge atorsievnceleicie yses | 80
Phosphoric acid ..-..------- WiMxedewabh sOllecceiecsccccceccvescecccccersc-.cces--ce-) Nottestad.
NGtrOS AVPLIE ONE TOW Secs ses- satan mater oe bee ee ee eee 36
nO Sees cn ae cn 2a: WED edawiGhySOllmencsicatccemasce nce cece ac dudes coc =o se 79
Time (MTN GIMOW Ses eccctc Sess car cpt ceceiet cece o-0eSecccecse| NOt tested:
HANG) BSCR SPOOR Bis ae ie tats MeVOE eur EGU SOI li iaccrsnc ciscin aise = Sas cs.cie ats Sis oc-d arene ertaisles | Not tested.
3 haere RUNGE NE LO WAe ae oe Be eee aes = ace cieucameel st cecces Sue 90
Mixed fertilizer ...-...-..-. Wea xedswiruhhSOtlet 2c. oo kc cnt Sesceeiawesee ees cacueeccece 93

The sprouts were mostly normal and healthy in the potash and
mixed fertilizer tests. Those derived from seeds which had been in
direct contact with the nitrogen and phosphoric acid were somewhat
sickly and weak. Unfortunately, the record is not entirely complete,
since neither the seed tested in phosphoric acid in rows nor the limed
seed was given a laboratory test; but the very high germination of
the two mixed-fertilizer lots, neither of which had sprouted at all while
in the soil, adds further evidence to the apparently established fact
that the injurious effects of the fertilizers were principally wrought
upon the hypogeous seedlings, and that owing to the protecting power
of their teguments, perhaps to some extent also to the dormant condi-
tion of the seed contents, the seeds themselves were not injured by the
fertilizers employed.

TRIALS WITH RADISH SEED.

The soil experiment represented in the table below occupied ten
days. Two hundred seeds were used in each trial. These were planted
in the afternoon of May 21.

Lffect of chemical fertilizers on French Breakfast radish seed.

. Per cent
| First sprouts er cent

Fertilizer. How fertilizer was applied. appeared. of germi-

| nation.
ae = es : == ”
Sa (eth etrows eecee ees ae has = oes chaz oe Sede ce se Re. pate } -
IQS in eae easec es cae saoes Wee acim) ek cae ce j; No sprouts. ...| 1/5
; ee (PICU EIU OW Sie eee cc cee tees 208 ees a ocie ch May 26, a.m . 19.0
Phosphoric acid .-..--....-.- Wits dnwithssoll.. css. 2 cic anise twee oe .---| May 24, a.m -. 95. 0
7 En @lnkthe molwWis estes cen Bcaecaas bees aon be May 25, p.m .. 2.0
Nitrogen -..-.-------.------- (Mixed with soil ...........: Ce ae oe oe ee ee May 26, a.m -. 6.5
. WETIAUH GIP OWS tents at et ese bcmelia: wedebesc.es May 24, a.m -- 37.5
Lime ...-.2.-.--2--+-+++--++- (Mixed WiAthrSOllem ens et eto te ees kc =| ences doy.224224: | 93.0
ye Eaten hee \fIn THSITO WS ye cies eats Bae ne May 25, a.m’ ..| 34,5
Mixed fertilizer -............ Mixed! withisoil 22, te. 06.-ke cto eo oe... May 24, p.m ..| 92.0

(CHIGES 2220 eB Saad aR GNG SSS GCE OB Eee Ea eee a er ee Seer me ae May 24,a.m .. 96:5

14

Here again it is seen that the potash and nitrogen fertilizers practi-
cally prevented germination. The fact is striking, however, that, while
the sprouting was seriously injured in all of the tests in which the seeds
were sown directly upon the fertilizers, when the latter were mixed
with the soil the germination of the radish seed was nearly as high as
in the check test.

An examination of the radish seeds remaining at the close of the soil
experiments revealed the fact that many of them which had been in
immediate contact with the potash and nitrogen were badly decayed,
while those taken from the soil-mixed fertilizer lots were generally, to
all appearance, quite sound. This I attribute mainly to the fact that
in the case of wheat and lettuce “seed” we are really dealing with
fruits, in which the proper seed is encased in external teguments, whereas
the radish seed has only the true seed coats.

Laboratory tests were made of radish seed taken trom the flats of the
potash and nitrogen experiments, with the following results:

Laboratory tests of residual radish seed.

| Per cent

Fertilizer. How fertilizer was apphed. | germi-

nated.
aye (Te ENS LOWS soe cece aie steioiolleinst eit eda dese e ieee eee eas 20
Potash. ...-.---------++---++- Mixed withisoilt 2202. h<e. see: Soe ee eee eee 56
NGETORET (In The: TOwS ass 2 se oo rie oes a eee Core eee eee eee | 32
aN LO BD rea 5 2 einige UMixed-withisolllo:.. secs ccoc. ete ee ee ee ee eer 68

These figures are in decided contrast with those given in the table of
germinations of radish seed in soil treated with the potash and nitrogen
fertilizers, and show that while radish seed is much more susceptible
to the action of fertilizers than the others tested, when in direct con-
tact, nevertheless the effect is mainly produced upon the seedlings.

TRIALS WITH CRIMSON CLOVER SEED.

A soil test was made with crimson clover seed which lasted eleven
and one-half days. Two hundred seeds were used in each trial. These
were planted May 20, p. m.

Effect of chemical fertilizers on crimson clover seed.

Per cent

First sprouts

Fertilizer. How fertilizer was applied. ge aad of germi-
| appeared. tine
> = 2
os \(in the TOWS: sss scecc sus ecieee e menreneoer IN O}SPLOWGS sere eeee mee
gee aes Poe Ryo WMixed.s....:sccecanten conse see seee aren |e sdoearees Keahrerone
, 3 (Tn the TOWS). <> .cn.2e= 505 oceceeee ereeeee ee eeeee OM aSa5s552 Baeso—ssce
Phosphoric acid ..-..-.------ {Mixed Spa Sere e a.ccce es Cee ae OEE eee | May 28, a. m.. 31
Pre Mn the Towsts sc sos foo See ee eee eee Nosprouts Sey Bea e ans
Nitrogen ..-..-.--------.+--. IMI x60' 322 2. ccac ce oz eae eee en ee | eee Chea aos Resor oon
Tas fdinithe rows’ <.22 - 22 220. Soe seeseaee ee oee eee May 28, a. m.. 1
Sa ee Se VME sede ae7 Sonor sce oe ee eee eee May 23, a.m.. 38
a See Ta theerows) occ csc oe eee Ee Pee INOISPLOUtSHe<<| senescent
Mixed fertilizer..-........... (Mixed Ee ne er ee ee Oe SAGE ot aDe Mayu a.m. ilo
Gheck 255 222.5 tc poco dame lee ticise sis canter een eset e (ene ee eee eee eet May 23, a. m.. 31

Pi ess

as)

The injurious action of the fertilizers upon the crimson clover seed
seems to have been much more marked than in the case of any other
seed tested, but any definite conclusions are precluded by the extremely
low germination of the check. This seed tested in the laboratory
between moist blotters showed a vitality of 974 per cent. The seed,
however, was 2 years old, as was the case with the wheat also, while
the lettuce and radish seed are supposed to have been grown in 1897,

As with wheat, lettuce, and radish (practically), the muriate of potash
and sodium nitrate prevented germination. Lime, too, was almost
prohibitive when sown in the rows, although it gave better results than
any other fertilizer when mixed with soil. Liebenberg claims that the
use of lime renders the reserve materials of the seed more available to
the developing seedling and therefore helpful to germination. This is
certainly not the case when an excessive amount is applied.

CONCLUSIONS.

Summing up the results obtained from these experiments, we may
safely conclude:

(1) That muriate of potash and sodium nitrate used as fertilizers in
strengths of 1 per cent or more are very detrimental to the germina-
tion of seeds, whether applied directly or mixed with the soil,

(2) That fertilizers composed of phosphoric acid or lime are much
less injurious to germination than sodium nitrate or muriate of potash,
and if not used in excess may be harmless.

(3) That commercial fertilizers should not be brought into direct
contact with germinating seeds.

(4) The effect of treating seeds with chemicals before planting is no
index to the action of those chemicals when applied as manures to the
soil.

(5) That the chief injury to germination from chemical fertilizers is
inflicted upon the young sprouts after they leave the seed coat and
before they emerge from the soil, while the seeds themselves are injured
only slightly or not at all.

(6) It is highly improbable that potash, phosphorie acid, nitrogen, or
lime used as fertilizers actually favor germination.

O

2

as

LIBRARY OF CONGRESS

SL

OO0ebs&o40as