.vV

5

Biological
^ Medjcai
•Serials

LAWES AGRICULTURAL TRUST.

Rothamsted Experimental Station,
Harpenden.

Annual Report for 1911

with the

Supplement

to the

'' Guide to the Experimental Plots,"

containiriK

The Yields per Acre, etc.

In every case the page, table, and plot nui ts refer to the " Guide," it being under-
stood that no change is made in f, manuring, etc., there described.

r-.rc

("a

A. D. HALL. Dir

HARPENDEN:

Printed by D. J. Jeffery, Vaughan Road

19 12

Laboratory Staff,

Director

Chemist

Goldsmiths' Company's Soil Chemist

Bacteriologist ...

Botanist

Organic Chemist

Biologist "...

Assistant Soil Physicist

Farm Manager

Mackinnon Research Student, R.S

Board of Agriculture Research Scholar

Voluntary Research Worker

Secretary

Private Secretary

Clerk

Chemical and General Assistant

>» M >»

Botanical Assistant

General Assistant and Caretaker

General Assistant

r

Laboratory I^oys

A. I). Hall, M.A., F.R.S.
N. H. J. Miller, Ph.D.

E. J. Russell, D.Sc.

H. B. Hutchinson, Ph.D.

Winifred E. Brenchley,
D.Sc, F.L.S.

W. A. Davis, B.Sc.

F. R. Petherbridge, B.A.
L. M. Underwood, B.Sc.

S. J. K. Fames.

T. Goodey, M.Sc.

J. A. Hanley, A.R.C.S.

J. Clayton, B.A.

A. J. Daish, A.C.G.I.

G. T. DUNKLEY.

G. Bates.
W. Wilson.
E. Grey.
A. OgOlesby.

A. Bowden.

Grace Bassil. -^

W. Pearce.

B. Weston.
P. Wilson.

W. Game and F. Seahrook.

INTRODUCTION

John Bennet Lawes was the founder of the Rothamsted
Experimental Station. He began experiments with various
manurial substances, first with plants in pots and then in the field,
soon after entering into possession of the estate at Rothamsted in
1834. In 1843 more systematic field experiments were begun, and
the services of J. H. Gilbert were obtained as Director, thus starting
the long association which only terminated with the death of Lawes
in 1900, followed by that of Gilbert m 1901.

The Rothamsted Experimental Station has never been connected
with any external organisation, but has been maintained entirely at
the cost of the late Sir John Lawes. In 1889 he constituted a Trust
for the continuance of the investigations, setting apart for that pur-
pose the Laboratory (which had been built by public subscription,
and presented to him in 1855), certain areas of land on which the
experimental plots were situated, and ^"100,000.

By the provisions of the Trust Deed the management is
entrusted to a Committee nominated by the l<oyal Society (four
persons), the Royal Agricultural Society (two persons), the Chemical
and Linnean Societies (one each), and the owner of Rothamsted.

It has latterly been the desire of the Committee to obtain addi-
tional funds for the extension of the work of the Station. In 1906
Mr. J. F. Mason, M.P., presented the Committee with /lOOO for
the building and equipment of the " James Mason " Bacteriological
Laboratory, together with a grant towards its maintenance. In 1907
the Goldsmiths' Company made a grant of ^"10,000 the income
from which is devoted to the payment of a special assistant for the
investigation of the soil. The Permanent Nitrate Committee have
also made a grant of /"2000 to the endowment. The Society for
extending the Rothamsted Experiments, founded in 1904, has also
collected donations amounting to ^3300 and annual subscriptions of
nearly /"1 50. This Society has recently been Incorporated under
the Board of Trade, thus giving it the power to hold money in trust
for the purposes of the Rothamsted Experiments.

During the year a scheme has been published from the Board
of Agriculture for the encouragement of Agricultural Research with
funds provided by the Development Commission, and this scheme
contemplates the establishment or assistance of a certain number of
institutes for fundamental research, each dealing with one great
branch of the subject. The Rothamsted Experimental Station is
recognised as the Institute for dealing Avith Soil and Plant Nutri-
tion problems. In accordance with this scheme a temporary grant
of ;f2000 was made for the year ending March 31st, 1911, and it

is expected that an annual grant of rather more than this amount
will be made to the Station in future. Certain scholarships have
also been instituted to provide the training in research work for
men who have already qualified in pure science and are desirous
of taking up an agricultural career. The holders of two of these
scholarships will do their work at Kothamsted.

The field experiments, wliich began in 1(S43, have on some of
the plots been continued without break or alteration up to the
present day ; on the Broadbalk Wheat Field certain rearrangements
were made in 1852, in which year also the Barley experiments on
the Hoos Field began. The leguminous crops on the Hoos Field
were started in 1848, the experiments on Roots have been continued
on the same field since 1843, and on the same plan since 1§56. The
grass plots began in 1856, and the rotation experiments in 1848.

It is impossible to exaggerate the importance of continuing the
experimental plots at Rothamsted without any change, as nowhere
else in the world do such data exist for studying the effect of season
and manuring upon the yield and quality of the crop, and for
watching the progressive changes which are going on in the soil.
Year by year these plots are found to throw light upon new problems
in Agricultural Science ; in all directions they continue to provide
material for investigations upon points which were not contemplated
in the original design of the experiments, so that it is impossible to
foresee when and how they will not become useful and provide
indispensable material for the solution of problems undreamt of at
the present time.

The maintenance, however, of the old data throws a heavy
burden upon the Experimental Station. There are 210 plots, and
every year 243 samples have to be taken with proper precautions
and put into store for future reference. In addition there are made
486 determinations of dry matter, 243 of ash, 170 of nitrogen, 50 of
phosphoric acid, and 24 of potash, also 180 determinations of nitrates,
etc., in rain and drainage waters, and 17 botanical analyses of hay.
This does not include examinations of soils, the complete grass
separations, and other extensive series of determinations which are
made at longer intervals. All the above determinations, however,
are part of the necessary routine which must be completed before
any new investigations can be undertaken.

It should be remembered that the object of the Kothamsted
Experiments is to ascertain " how the plant grows," and only
indirectly to find the most paying method and manuring; hence
both the nature and the quantities of material applied are not to be
taken as indicating the manures which should be used in practice.

5

ANNUAL REPORT

FOR THE YEAR 1911

THE season of 1911 will long be memorable for the exceptional
heat and drought of the summer. The closing three months
of 1910 were exceptionally wet, over 12 inches of rain being
registered at Rothamsted, but a dry January enabled the wheat plant
to recover from the bad start it had made. In February and March
the rainfall was about normal with no severe cold, though there were
very few nights during the first three months of the year in which a
little frost was not recorded on the grass. With April the droughts
began, there being then a period of 20 days in which never more
than a sprinkling of rain fell. In May the high temperatures began,
and there were two spells of dry weather, though the rainfall for the
month was considerably above the average. June again opened with
a period of drought and heat, but heavy thunder rain about the time
of the Coronation again made the total rainfall above the average.
July was remarkable for a period of 25 days without any rain at all,
and a succession of high temperatures which made the mean maxi-
mum for the month as high as 76*3°. The first 19 days of August
were almost al^solutely dry with very high temperatures, a maximum
of 92'3'' being registered on the 9th, the highest air temperature that
has ever been recorded at Rothamsted. The mean maximum for
the month was almost as high as in July, namely 75'9°. Another
period of drought extended from the 22nd of August to the 13th of
September, though on several days a measurable shower of fine rain
w^as recorded ; the weather broke in the middle of October, and from
that time to the end of the year there were only 6 days without some
rain being recorded.

The sunshine records were also well above the average, there
being an excess of 99 hours in July, 25 in August, and 66 in September
above the average of the 18 years, 1892 — 1910. Even these figures
hardly serve to express the exceptional character of the summer and
the severe conditions of drought which all the crops experienced
during comparatively long periods.

The wheat on Broadbalk Field was sown on October 21st, and
though it suffered a good deal during the early part of the wdnter, it
tillered and grew very w^ell during April and May; it also continued
to flourish through the heat, and like the wheat all over England,
became a very handsome crop, exceptionally clean and bright and
standing up everywhere. A new variety was grown for the first
time — "Little Joss" — one of the varieties raised by Professor Biffen
of Cambridge, distinguished by its resistance to rust, and whether

the variety or the season is responsible, it is certainly many years
since the Broadbalk wheat seemed so free from disease. The yields
were generally good without being exceptional, only Plot 16 reached
as much as 40 bushels to the acre. The unmanured plot yielded as
high as 1 22 bushels to the acre, but the crop on Plot 2 receiving
farmyard manure did not come to the front so much as might have
been expected in so dry a season. The weight per bushel was ex-
ceptionally high; the average of all the plots was 65*5 lbs., and Plot
16, with the highest yield, reached the exceptional figure of 66*8 lbs.
The highest weight of any individual bushel was 67*5 lbs. — also on
Plot 16 — while on the farmyard manure Plot grain was produced
weighing only a fraction less. These are the highest figures that
have ever been recorded.

The Half Acre Plot, grown after a bare fallow^ in alternate
years, also yielded well, 17 bushels to the acre, which is higher than
it has been for many seasons past. This result is rather remarkable
considering the heavy rainfall of the last 3 months of the year 1910,
which might have been expected to w^ash out of the soil the nitrates
accumulated during the summer fallow\ In an ordinary way the
yield of wheat after fallow^ is largely determined by the rainfall of
the preceding autumn.

If the season was exceptionally good for the wheat, it was
equally bad for the barley, which was sown on March 27th. The
highest yield was rather under 29 bushels to the acre, and the un-
manured Plot fell below 5 bushels to the acre. There was a con-
siderable attack of gout fly, but doubtless the great heat and drought
ripened off the barley too early and prevented the formation of the
grain from running its proper course, as may be seen from the
fact that the weight per bushel, although abo\'e the average, was
not good and the proportion of grain to straw was exceedingly low^
It is rare to find the weight of barley-grain falling as low as half
the weight of the straw; indeed in a dry year one generally
expects the two to be equal on the good plots, but in 1911 the grain
was less than half the straw on as many as 12 plots out of the 29.
In consequence of the very scanty growth on many of the plots
there was an enormous development of weeds, which indeed have
been increasingly troublesome on the barley plots for some years
past. So serious has the situation become that it has been decided
to leave the plots without crop during 1912, and by continuous culti-
vation under bare fallow to try and restore the i)lots to a reasonable
degree of cleanliness.

Like all other root crops the mangolds on the Barn Field suf-
fered from the season. They were first sown on May 9th and 10th,

but as the sowing was followed by rain and then drought, the surface
of the land caked very badly and the germinating seed was unable to
push through the ground. Only on Series 1 and 2, where farmyard
manure is supplied, was anything approaching to a plant attained,
and in June the field presented a remarkable illustration of the value
of farmyard manure in ameliorating the texture of the soil and en-
abling germination to take place. The plant was so scanty on the
other plots that they were scufHed over and re-sown on June 12th.
The second sowing germinated fairly well, but never grew freely.
The highest yield of roots was a little over 21 tons per acre on the
plot receiving farmyard manure and rape cake, but it was not more
than 4 or 5 tons per acre on the plots receiving a purely inorganic
manure with nitrogen in the form of nitrate of soda or sulphate of
annnonia. The yields seemed entirely dependent upon the amount
of organic matter supplied by the manure and its cumulative effect
upon the soil. It was characteristic of the season that the usual
attacks of Uroniyces betae on the high nitrogen plots was almost
entirely absent tliis year.

On the Agdell T^ield wheat was taken, this being the close of
the 16th complete rotation. A fine plant of wheat was to be seen
all over the fiekl, and the yield was especially remarkable on the
unmanured plots, where as much as 24 bushels to the acre, weighing
65 lbs. to the bushel, was obtained. Still more remarkable, perhaps,
was the yield of almost 32 bushels to the acre on the plot w^iich re-
ceives no nitrogen and on which clover is not grown ; indeed it is
not immediately obvious where the large amount of nitrogen neces-
sary for a crop of this magnitude can have come from, for the plot
has received no nitrogen since 1848, and has never grown clover or
any other leguminous crop (except the Medicago which is a very
abundant weed on occasions). The effect of the preceding clover
crop as compared with a preceding bare fallow was clearly visible,
raising the yield by about 5 to 6 bushels on Plots 1 and 3 which
had received fertilisers for the root crop at the beginning of the
rotation. Plot 1, on the portion of the field which receives a com-
plete fertiliser for the roots, suffered somewhat during the w^inter,
for water lay there badly during the heavy rains of December and
killed off some of the plants, which were only imperfectly replaced
by re-seeding in January.

The yield on the Permanent Grass Plots in the Park was below
the average, and the proportion of leguminous herbage was also
below the average. On most of the half plots the effect of the liming
w^as apparent in a considerable increase of crop, and the leguminous
plants were also more abundant on the limed portions. On the un-

8

limed portions of the plots receiving sulphate of ammonia, where the
soil is now markedly acid, the vegetation suffered considerably during
the drought, and the bare patches which have been developing of late
years are now very prominent.

The Little I loos F'ield, on which the residual values of
manures are being tested, was sown with mangolds, and though an
even plant was obtained it grew very indifferently through the
drought and yielded but a small crop of about twelve tons to the
acre. The effect of the manure applied in the current year was
very evident, but the manurial residues had but a small influence
upon the yield.

All experiments with root crops were unsatisfactory this year,
so that the yields were small and somewhat irregular on the plots
that are used to test the value of the new nitrogenous fertilisers —
cyanamide and nitrate of lime. As in previous years, nitrate of soda
has proved the most effective source of nitrogen for mangolds on the
Rothamsted soil, and the newer fertilisers did not give the results
which might have been expected.

At the Laboratory the pot experiments on the continuous
growth of plants in the same soil have been continued for another
season without as yet any conclusive results, and the same statement
might be applied to the experiments upon clover sickness. The
vegetation house was very largely given up to a new series of
experiments on the treatment of "sick" greenhouse soils, which have
become unfit for the continued growth of crops after two years' use
in the greenhouse, though they are still exceptionally rich in plant
food. Methods of treating the soil by heating to various tempera-
tures and by the use of antiseptics were tested with satisfactory
results, and a method for dealing with soil on a commercial scale has
been worked out, which is being extensively tested. It seems
likely that at a very small cost the growers of tomatoes and
cucumbers under glass may be saved from what has hitherto been
the expensive necessity of frequently renewing their soil. Drs.
Russell and Hutchinson, with Mr. Petherbridge, have been studying
in detail the chemical, physical and biological changes brought about
in the soil by the treatment, and the results are almost ready for
publication. Dr. Russell has also been extending his work upon the
part played by the protozoa in the production of sewage-sick soils
and the effect of partial sterilisation in restoring their activity. This
work has been undertaken in connection with Mr. J. Golding on
sewage farms at Kegworth and Kingston, and a very considerable
measure of success has been attained by the treatment.

The experiments on the toxic and stimulating effects of small

quantities of various mineral substances were continued, and a series
of experiments were begun on the growth of plants in extracts of the
soils from the experimental plots. These latter trials have yielded
some very striking results, which are to be repeated and extended in
the coming year. Another series of experiments dealt with the
growth of plants in nutritive solutions of various concentrations,
either as water cultures or with the nutritive solution added to sand
so as to keep the sand moist but not wet. In all cases growth was
found to be proportional to the concentration of the solution, even
though the solutions were regularly renewed and always provided
the plant with an excess of nutrients. It was also found that
the soluble nutrients could dififuse with perfect freedom along the
thin water films coating the grains of sand, and that there was no
retardation of growth even when the nutrients were enclosed in
porous pots inside the sand, so that they were forced to travel by
diffusion before they could reach the plant's roots. Further
experiments on this subject are projected for the coming year.

Dr. Brenchley resumed her study of the weeds of arable land,
taking this time a district on the borders of North West Wiltshire
and Somerset, which gave her a range of formations including some
of those that were dealt with in her work of 1911 on the soils of
South Bedfordshire. It is interesting to find that the association of
particular weeds with particular soils which prevailed in South
Bedfordshire did not always hold for the same formations and weeds
in the new district. Dr. Brenchley's second paper dealing with her
1912 work is now going through the press.

During the year the Board of Agriculture has published the
Report on the Agriculture and Soils of Kent, Surrey and Sussex carried
out by Dr. Russell and myself. The Report forms a book of 206
pages with 56 maps and plates, and gives the analyses, mechanical
and chemical, of 124 soils with their subsoils, derived from 14
formations. The report contains an account with some historical
notes of the agriculture and rural industries of the district, illustrated
by a series of maps showing the distribution of crops. The
dependence of this distribution upon the character of the soils and
the rainfall is discussed, and recommendations are made as to the
systems of manuring,seed mixtures, etc., appropriate to each formation.

A more elaborate study of the fatting and non-fatting pastures
of Romney Marsh has been brought to a conclusion, and a paper on
the subject is now ready for the press. No very pronounced
difference could be found between either soils or the herbage of the
two pastures. The difference, w^hich is very real in practice, seems
to be due to an accumulation of small causes acting over a long

10

period of time, tlie fatting pastures beinj? slightly higher and drier,
while the only chemical difference in the soils was a greater propor-
tion of phosphoric acid in the soils from the fatting fields. The soils
from the fatting fields were also considerably more active, and
produced ammonia and nitrate at a greater rate, especially in the
earlier part of the season. No light on the greater feeding value of
one herbage over the other was obtained from their analyses; it is
evident that the ordinary methods of analysis of feeding stuffs are
not sufficiently refined to deal witli a question of this kind.

The following papers have been published during the year.

H. B. Hutchinson and N. H. J. Miller. " The Direct As-
similation of Ifwrgatiic and Orgafiic Forms of Nitrogen
by Higher Plantsr Centr. Bakt. I\ar. 1911. ii, 30, 513.

In these experiments barley and peas were grown in water
cultures under perfectly sterile conditions, and the nitrogen required
for nutrition was supplied in various forms of combination other
than the nitrates upon which plants are generally considered to be
dependent. The technical difficulties of growing plants under sterile
conditions are considerable, but they were successfully overcome, and
in all the cases dealt with the culture medium was found to have
remained sterile at the end of the experiment. It was found possible
to get plants to grow when supplied with a large number of
compounds of nitrogen, which must have been taken up directly
because of the absence of organisms to convert them into simpler
forms of combination. Of the compounds tested ammonia gave
satisfactory growth, the plants being characterised by a high pro-
portion of nitrogen in their dry matter. The greatest growth how-
ever was obtained witli urea. Barbituric acid, acetamide, alloxan,
soluble humus, and peptone were also satisfactory sources of nitro-
gen, while formamide, glycine, alanine, guanidine hydrochloride,
cyanuric acid and oxamide gave rise to a distinct though more
limited amount of growth. Ilydroxylamine hydrochloride, ethyl
nitrate, propionitrile, methyl carbamate, gave negative results,
as also probably did trimethylamine, para-uxdizme, and hexam-
ethylenetetramine. Tetranitrometliane proved to be toxic. Plants
are thus shown to be capable of utilising directly many of the
compounds of nitrogen which may occur in the soil as products of
bacterial decay, as well as the ammonia and nitrates wliich are the
final terms of such changes.

T. CiOODEY. ' A coutrihution to our knowledge of the Protozoa
of the Soil r Proc. Roy. Soc. 1911. B. 84,165.

In this paper Mr. Goodey gives a detailed description with
figures of the various species of protozoa which he has been able to

11

isolate from soils. Mr. Goodey also devised a method for driving
the protozoa rapidly out of the soils, and so of enumerating them
directly. The method depends essentially upon the fact that when
an electric current is applied to a medium containing living protozoa
they travel with the current to the cathode. It was not found
possible to obtain ciliated protozoa in an active condition until
after the cultures had been incubated for from two to four hours. When
first observed they also had the appearance of organisms that had
just emerged from the encysted state, and contained no trace of food.
As two to four hours is also the time required for these ciliated
protozoa to emerge from their cysts, Goodey concludes that in any
normal soil the protozoa are not active but encysted, and therefore
cannot be effective in limiting the number of bacteria, as has been
suggested by Russell and Hutchinson. The investigation deals only
with the ciliated protozoa, and the amoeba in the soil may still have
the effect tliat Russell and Hutchinson attribute to them. Moreover,
under certain conditions of free moisture supply and temperature the
protozoa must become active, and these are also the conditions
whicli would make for the development of bacteria.

A. L). Hall and N. H. J. Miller. ''The Absorption of
Atnmoiiia /roni the Atmosphere.'' Jour. Agric. Sci.
1911. 4, 5(>.

This paper deals with a series of experiments on the rate of
absorption of annnonia from the atmosphere, when shallow dishes
containing dilute sul[)lmric acid were exposed close to the surface of
the ground and at 4 feet above it, in the Laboratory grounds, above
Broadbalk field and the grass field. The dishes were protected from
rain, and were also covered by line gauze screens to keep out the
flies and dust, which were found in the earlier experiments to
interfere seriously with the results. Determinations of the ammonia
absorbed were made every month, and the trials were continued for
two years. The amount of annnonia absorbed proved to be very
much less tlian had been obtained by previous investigators working
with similar methods, and there is evidence that this was due to the
exclusion of dust, etc., and perhaps to the diminished circulation of
the air over the absorbing liquid which was brought about by the
gauze screens. The dishes on the high level generally absorbed
more ammonia than those near the ground; this also is probably due
to the greater circulation of the air. The dishes in the Laboratory
grounds gave the highest returns, probably because of the proximity
of chimneys. The metliod however did not lead to any conclusions
as to whether the soil acts normally as an absorbent of annnonia
from the atmosphere, or whether it yields ammonia to the atmosphere.

12

However, for scmie weeks after ammcynium salts had been supplied
as manure to the Broadbalk Field, there was an enormous increase in
the amount of ammonia absorbed from the air, and the lower dishes
during this pericid absorbed much more than the upper one. This
may be taken as evidence that there will be some loss of nitrogen
to the soil as free ammonia, whenever ammonium salts are supplied
as a fertiliser to soils containing calcium carbonate,

W, E, BKliNCHLEY. ** The Weeds of Arable Land m relation
io the Soils on which they grow.'* Annals of Botany.
1911, 25,155,

This paper contains a description of the distribution of weeds
of arable land upon the following formations in Hertfordshire and
South Bedfordshire : — Clay-with-flints, Alluvium, Chalk, Gault,
Lower Greensand and Oxford Clay, A distinct association was
found to exist between some of the species and the soils upon which
they grew, but the determining factor proved to be the texture of the
soil, except in the one case of the calcareous soils derived from the
chalk. For example, Bartsia Odontites and Mentha arvensis were
confined to clay, Chrysanthemum segetum^ Unmex acetosella and
Spergula arvensis were confined to s^'ind, and are probably charac-
teristic of an acid soil condition, while the Bladder Campion, Silene
CucubaluSf Geranium pusillum and a few others were confined to
Chalk, A certain number of weeds, like Shepherd's Purse, Chick-
weed, Horsetail, Coltsfoot, etc, appeared to occur indifferently
on all soils. It is impossible to say how far some of the associations
are valid until the work has been extended to a number of similar
soils in different localities,

W, B, Mercek and A. 1), Haij.. ' The Experimental Error
of Field Trials.' jour. Agric. Sci. 1911. 4, 107.

This pillar contains a discussion of the results obtained in 1910,
when an acre of mangolds apparently uniform was harvested in 200
equal plots, and an acre of wheat was similarly divided into 300 plots,
from each of which the grain and straw were harvested separately.
The results are set out and discussed by various statistical methods.
They show that the probable error attaching to a field trial consisting'
of two 'plots alone is in the neighbourhood of plus or minus 5 per
cent., and this error, though it diminishes with tlie size of the plots, is
not greatly reduced when the plots are made larger than g^ of an
acre. By repeating the plots receiving any particular treatment and
scattering them about the experimental area, a considerable reduction
(an be effected in the experimental error, though an increase of the
number of plots above 5 is not attended by any great further
reiluction of error. The authors consider that the most satisfactory

13

unit for field trials consists of five plots, each 5^0 of an acre in extent,
regularly distributed about the experimental area, and each harvested
separately. This would yield results true within 1 to 2 per cent, for
the particular season. Effects of climate can only be eliminated by
continuing the experiments over a term of years.

A. D. Hall and E. J. Russell. ''Report on the Agriculture
and Soils of Kent, Surrey and Sussex.'' Published for the
Board of Agriculture by H.M. Stationery Office. 1911. 2/6.

This Report has been already described.

A. D. Hall and E. J. Russell. " Soil Surveys and Soil
Analyses.'' Jour. Agric. Sci. 1911. 4, 182.

In this paper the results of the analyses contained in the above
Report are discussed from a scientific standpoint. The paper deals
with the methods of taking a sample, and the degree of accuracy
which may be expected to attach to the processes both of analysis
and sampling. The fractions of the soil, consisting of particles of
a specified size, were also subjected to analysis, and the paper further
discusses the interpretation of the results obtained by analysis and
certain correlations which are shown to exist between the chemical
and mechanical analyses. This paper is of technical interest only,
being addressed to chemists who have the conduct of the soil
analyses rather than to the general agriculturist.

E. J. Russell and J. Goldinci. " Sewage Sickness in Soil and
Its Amelioration by Partial Sterilisation." Jour. Soc.
Chem. Ind. 1911. 30.
This paper deals with an investigation of the state into which
the soil of sewage farms arrives after the continued application of
sewage, whereby it is so far injured both in its physical and bio-
logical conditions that it will no longer either let the sewage
percolate or purify what passes through. Sewage-sick soil was
found to possess a very limited bacterial activity and to be excep-
tionally rich in those protozoan organisms which Russell and Hutch-
inson have regarded as the limiting factor in the development of
bacteria in soils. Partial sterilisation of the soil, either by treatment
with antiseptics or by heating, was followed by a very large increase
in the number of bacteria ; in one case they rose from about 40
million to over 400 million per gram of the soil. Accompanying
this increase in bacterial activity there was a renewal of the
purifying effect of the soil upon the sewage, and it was found
possible to restore the sewage-sick soil and make it become an even
more effective filter than before, either by heating the soil sufficiently
to char it slightly or by treating it with the vapour of toluene.

14

CROPS GROWN IN ROTATION. AGDELL FIELD.

PRODUCE PER ACRE.

Year.

CROP.

O.

Unmanured.

M.

Mineral
Manure.

C.

Complete

Mineral and

Nitrogenous

Manure.

5.
Fallow.

6.
Beans

or
Clover.

3.
Fallow.

4.
Beans

or
Clover.

1.

Fallow.

2.
Beans

or
Clover.

FIFTEENTH COURSE

1904-7.

1904

Roots (Swedes) Cwt.

16-8

64

1512

1714

3186

203 -2

1905 1

Barley Grain ... Bus.
Barley Straw ... Cwt.

15-5
lOT)

73
80

160
10-5

152
11 3

23-1
135

31 4
201

1906

Clo\er Hay ... Cwt.

—

41

—

410

—

9-5*

1907 •'

Wheat Grain ... Bus.
Wheat Straw ... Cwt.

163
214

214
271

19- 1
286

36-8
49 6

25- 1
353

29 3
35 1

LAST COMPLETE COURSE

16th), 1903-1

1.

1908

Roots (Swedes) Cwt.

216

64

1790

2358

395 4

3140

1909 •

Bai-Jey Grain ... Bus.
Barley Straw ... Cwt.

11-4
101

100

ir3

174
127

221
169

26 8
18-7

334
238

1910

Clover ( 1st crop Cwt.
Hay ( 2nd crop Cwt.

—

IT)
158

—

241
400

—

32-2
445

1911 J

Wheat Grain ... Bus.
Wheat Straw ... Cwt.

239
204

245
214

3 19
286

378
335

353

293

380
32-5

The plant almost entirely failed on this plot, and new seed was
sown broadcast on May 1st, 1906.

15

METEOROLOGICAL RECORDS, 1911

{See " Guide;' page 16, Table IX.)

Rain.

No. of

Drainage througli
soil.

Temperature.

Total Fall.

Rainv

Bright

Days.

Sun-
shine.

20 ins.

40 ins.

60 ins.

Max.

Min.

5-inch

ttsVtt

ToW

Funnel

Acre

Acre

deep.

deep.

deep.

Gauge.

Gauge.

Gauge.

Inches.

Inches.

No.

Inches.

Inches.

Inches.

Hours.

"F.

°F.

Jan.

1-269

1-375

15

1163

1277

1266

64-7

41-9

322

Feb. ...

1-782

1878

15

0776

0717

0741

76-4

45-9

33 1

March ...

2 09C

2-267

20

1 245

1-3.56

1-370

85 -2

471

34-8

April

1501

1-594

11

0533

0-586

1091

163-8

53-5

377

May ...

3 -688

3 -788

10

2 020

1856

1878

211-6

651

446

June

2 601

2-736

12

0854

0837

0 792

201-8

67-4

491

Julv ...

0-636

0-654

5

0 007

0040

0045

315-6

76-3

535

August ...

0 950

1048

10

—

0 004

0 004

2273

759

550

Sept. ..

1366

1517

9

—

—

—

222'9

688

472

Oct. ...

3 301

3474

17

1 947

1828

1-723

98-8

561

420

Nov. ...

3 -266

3444

21

2 -847

2719

2-672

68-2

48-3

370

Dec. ...

6110

6-255

26

6- 164

5-971

5-822

49 3

480

370

Total or
Mean

28-560

30030

171

17556

17191

17-404

17856

579

419

MANGOLDS,

{See " Guide,

BARN FIELD, 1911.

" page 11, Table VI.)

Strip.

Strip
Manures.

Cross Dressings.

O.

N.

A.

A.C.

C.

None.

Nitrate of
Soda.

Ammonium
Salts.

Rape Cake &

Ammonium

Salts.

Rape Cake.

1

Dung only ...

Tons.
(R 13 41

IL. 2 24

Tons.
14-87

532

Tons.
9 14

412

Tons.
1453

3-60

Tons.
1577

355

2

Dung, Super,
Potash

IR 14 94

iL. 240

1229

512

1245 2030

534 4 73

21 19

3 97

4

Complete
Minerals

(R. 2 14

(l. 1-28

( 6 41 •
t 4 89 1

( 469 I
1 4 02 j

6 14 1341

427 j 612

1179

397

5

Superphosphate
only

(R. 0 90

(L. 120

564

4 -45

115 1 095

1-71 ; 1-32

086

104

6

Super and
Potash

(R. 136

( L. 099

5 18

382

453 823

3-45 524

8 13

402

7

Super, Sulph.
Mag. & Chloride
Sodium

(R. 148

\L. 112

516

413

575

3-79

888

5-72

834

413

8

None

(R. 0 80

"l L. 099

230

2-55

109

1-43

114

1-47

051

093

16
HAY. THE PARK GRASS PLOTS, 1911.

{See ''Guided page 19, Table XI.)

Quick Lime (ground) at the rate of 2000 lb. per acre, applied to the South half of
plots 1 to 4-2, 7 to 11-2, 13 and 16, in January, 1907.

(1) Received Farmyard Dung, 8 years, 1856—63. (3) Nitrate of Soda alone
previously.

(2) Ammonium Salts alone previous to 1869.

Yield of Hay per acre.

Plot.

Manuring.

1st Crop.

2nd Crop.

Total.

Cwt.

Cwt.

31

f 17-3

173

121

Unmanured

( 190

190

2

Unmanured (1)

213

213

1

Ammonium Salts alone (1)

211

211

4-1

Superphosphate of Lime

204

204

8

Mineral Manure without Potash ...

23-6

236

7

Complete Mineral Manure

319

319

6

As 7, lS69and since (2)

288

cu

288

15

As 7, 1876 and since (3)

333

O

33-3

5

Superpliosphate and Potash, 1898

;-;

and since

16' 7

^

167

17

Nitrate of Soda alone

303

Q

303

4-2

Superphosphate and Amm. Salts ...

265

3

265

10

Mineral Manure (without Potash)

and Amm. Salts

.311

w

311

9

Complete Mineral Manure and Amm.

m

Salts

45-5

O

455

13

Dung and Fish Guano, once in 4 years

39 1

A

391

11-1

Complete Mineral Manure and extra

Amm. Salts

465

46 5

11-2

As 11-1, and Silicate Soda

529

52 9

16

Compleie Mineral Manure and Nit.

Soda = 43 1b. N

39 9

39 9

14

Complete Mineral Manure and Nit.

Soda=86lb. N

444

44-4

BOTANICAL COMPOSITION, PER CENT.

First Crop, 1911.
(See " Guided page 20, Table XII.)

Plot.

Manuring.

Gramineae.
I'er cent.

Leguminosae.

Other Orders.

Per cent.

Per cent.

3

Unmanured

45-7

45

498

4-1

Superphosphate of Lime

45 2

100

448

8

Mineral Manure without Potash

515

90

395

7

Complete Mineral Manure

653

10 4

24 3

6

As 7. 1869 and since (2)

58-3

121

29 6

15

As 7, 1876 and since (3)

618

4-8

33'\

17
WHEAT. BROADBALK FIELD, 1911.

{See " Guide:' page 26, Table XIV.)

Plot.

Manuring.

Dressed Grain.

Straw.

Yield.

Weight
per Bushel.

2

3

5

6

7

8

9
10
11
12
13
14
15

16

17 (

18 (
19

20(1)

Farmyard Manure

Unmanured

Complete Mineral Manure

As 5, and single Amm. Salts
As 5, and double Amm. Salts
As 5. and treble Amm. Salts
As 5, and single Nitrate Soda

Double Amm. Salts alone

As 10, and Superphosphate

As 10, and Super and Sulph. Soda
As 10. and Super and Sulph. Potash
As 10, and Super and Sulph. Mag.
Double Amm. Salts in Autumn, and

Minerals

Double Nitrate and Minerals
Minerals alone, or double Amm. Salts

alone, in alternate years ...

Rape Cake alone

As 7, but e.xcluding Superphosphate

Bushels.
35-2
125
14-8
172
25 6
36 4
29 -9
228
201
270
297
241

24 1

404
t *13S
) t27-3

28-6

21-6

lbs.
667
64 4
651
653
660
666
65-6
65- 1
632

64 8
66 0
644

65-8

66 8

*64-9

t66- 1

65 8
657

Cwt.
36-9
98
12-8
179
276
357
290
172
152
20 6

27-4 !
189

22 3

424
*117
t24'6

247

180

'roduce by Minerals. f Produce by Ammonium Saltt

(1) Commenced in 1906.

BARLEY. HOOS FIELD, 1911.

(See " Guide:' page 33, Table XVI.)

Dressed Grain.

Plot.

Manuring.

Straw.

Yield.

Weight
per Bushel.

1 O

2 O

3 O

4 O

Unmanured

Superphosphate only

Alkali Salts onlv

Complete Minerals

Bushels.

4-9

119

43

5 9

lbs.
544
558
54-9
56- 1

Cwt.
55
91
5-3

7-8

1 A

2 A

3 A

4 A

Amm. Salts only

Superphos. and Amm. Salts
Alkali Salts and Amm. Salts
Complete Minerals and Amm. Salts

13 8
103
11-8
28-5

5^9
53-5
556
563

125
11-6
141

22-9

1 N
2N
3N

4 N

Nitrate of Soda alone
Superphos. and Nitrate Soda
Alkali Salts and Nitrate Soda
Complete Minerals and Nitrate Soda

16-2
26- 1
125
289

53-8
554
543
55S

17-8
247
145
237

1 C
2C
3 C

4C

Rape Cake alone

Superphos. and Rape Cake

Alkali Salts and Rape Cake

Complete Minerals and Rape Cake

27-4
282
21-6
257

56-8
57 1
56 0
56 6

207
208
186
201

7-1
7-2

Unmanured (after Dung, 185271) ...
Farmyard Dung

95
230

564
562

10 5
240

BARLEY. HOOS FIELD, 19U.

(Previous Cropping : Potatoes, 1876-1901; Barley, 1902 and 1903;
Oats, 1904; Barley, 1905 and since.)

{See ''Guide:' page 40, Table XIX.)

Plot.

1

2

3
4

Manures applied

to the Potatoes,

1876-1901.

Unmanured since.

Dressed Grain.

Straw.

Total
Produce.

1

Yield.

Weight per
Bushel.

Unmanured ...

Unmanured 1882 to 1901.
previously Dung only

Dung 1883 to 1901

Dung 1883 to 1901

Bushels.
(36 lbs.)
. 4 0

108
13-6

lbs.

541

563
570

Cwt.
12
50

114
135

1
lbs. 1

175

797

1919
2337

WHEAT AFTER FALLOW (without manure 1851 and since).

HOOS FIELD, 1911.

{See " Guider page 41, Table XX.)

Dressed Cirain

Straw

Total produce

Yield— 17 0 Bushels.
Weight per Bushel — 642 lbs.
13 7 cwt.
2687 lbs.

19

COMPARATIVE TEST OF NITROGENOUS
FERTILISERS.

MANGOLDS (after Wheat in 1910, and Barley in 1909).

LITTLE HOOS FIELD, 1911.

Produce per acre.

Plot.

Manuring in 1911.

Roots.

Leaves.

Total.

Tons.

Tons.

Tons.

n

6/

3 cwt. Superphosphate, and 200 lb.
Sulphate of Potash

( 9-7
( 9-8

22
24

11-9
12-2

21
7/

As 1 and 6, and Nitrate of Soda^
50 1b. N

( 17-6
t 131

31
2-7

207
158

3)
8)

As 1 and 6, and Nitrate of Lime =
50 1b. N

( 140

■( 114

36
33

17-6
147

4)
9/

As 1 and 6. and Sulphate of Ammonia
-50 1b. N

( 14 0
( 95

11
2-4

162
119

51
10)

As 1 and 6, and Cyanamide=^50lb. N.

/ 126
( 9-5

23
24

14-9
11 9

0)
11)

As 1 and 6, and equal parts Nitrate of
Lime and Cyanamide = 50 lb. N.

1 96
i 99

31
24

127
123

go)

12 j

As 1 and 6. and a mixture of 1 part
Nitrate of Lime and 2 parts Cyan-
amide- 50 lb. N.

J 99

3-1 !

20

130
104

20

LITTLE HOOS FIELD, 1904-1911.

RESIDUAL VALUE OF VARIOUS MANURES.

{See " Guide," pages 41 and 42.)
TOTAL PRODUCE— Grain and Straw, or Roots and Leaves, per acre.

Series
and

Manuring.

Swedes

Barley

Man-
golds

Spring
Wheat

Swedes

Barley

Wheat

Man-
golds

Plot. 1

1904.

1905.

1906.

1907.

1908.

1909.

1910.

1911.

'

Tons.

lbs.

Tons.

lbs.

Tons.

lbs.

lbs.

Tons.

A 1

Inmanurecl

103

2323

171

3650

140

3792

2270

116

Dung (ordinarv). 1*>U4 aiul l'K38

13 1

4649

18- 2

4673

19 1

5128

2572

139

.•i

1905 and 1909

88 i

3501

17-5 i

5695

14-5

5544

2681

141

\

1906 and 1910

88

2269

182

5471

15 5

4057

2406

125 1

5

1907 and 1911

98

2402

14-9

6903

17-3

4581

2358

158

141

B 1

Dung (cake fed), 1904 and 1908

157

4177

19 4

4319

224

5362

2386

2

Unmannred

100

2417

16 2

4025

143

3862

2261

12 0

3 !

Dung (cake fed). 1905 and 1909

95

5530

18-5

5497

142

6641

2921

14 2 I

4 '

1906 and 1910

114

2772

256

6489

169

4400

3502

14 4

5

1907 and 1911

94

2649

144

9407

190

4298

2369

171

C 1

Shoddv. 1904 and 1908

147

3656

21 0

4667

197

3969

2295

114

2

1905 and 1909

111

4363

23 6

4550

16' 3

4558

2387

11 6

1 ^

Unmanured

106

2588

177

4334

151

3850

2561

117

1 4

Shoddy. 1906 and 1910

107

2512

242

6231

191

4466

3461

140

! 5

1

1907 and 1911

103

2615

169

7495

22'2

5448

2560

147

Idi

Guano, 1904 and 1908

146

2550

20 1

4056

209

3608

1742

10-5

2

1905 and 1909

HO

5176

197

4165

153

6834

2114

11-5

3

1906 and 1910

109

2857

25 6

4846

159

4053

3392

11 1

4

Unmanured

10 6

2985

187

4618

17 4

4510

2739

irs

5

Guano, 1907 and 1911

106

2680

174

7375

157

4014

2374

142

E 1

Rape Cake, 1904 and 1908 ...

14 1

2674

17-8

3887

197

3750

2180

107

2

1905 and 1909 ...

112

4185

179

4326

151

5203

2242

117

3

1906 and 1910 ...

9-5

2645

227

4584

145

3866

3486

115 ;

4

1907 and 1911 ...

105

2734

194

6619

152

4661

2516

14 5 1

5

Unmannred

108

2769

195

4527

147

4155

2784

127

F 1

Unmanured

11-7

3132

22 9

4749

141

4814

3166

87

2

Superphosphate, 1904 and 1908

122

3025

23 2

5064

169

1 4726

3223

10-9

3

1905 and 1909

102

3949

23 6

4956

146

! 4973

K) ^?

, 117

4

1906 and 1910

97

3913

24 1

5419

160

5280

2682

12-8

5

1907 and 1911

97

4221

23 6

5698

164

! 5641

3190

142

G 1

Hone Meal. 1904 and 1908 ...

129

3176

231

5203

167

14445

' 3345

^ 9-9

2

1905 and 1909 ...

10 1

! 3636

22- 1

5821

143

4922

3657

9-9

3

Unmanured

10 2

i 3495

20 -6

5491

127

4247

3701

9-2

4

Bone Meal, 1906 and 1910 ...

99

3450

226

r)043

142

4711

3263

10 5 i

5

' ,, 1907 and I'M 1

9 2

3525

221

6276

19 9

5285

3512

126

115 1

HI

Basic Slag, 1904 and 1908 ...

11 8

4400

20-5

1 6285

138

4182

1 3564

2

1905 and 1909 ...

10 4

1 4002

21-3

' 5930

13-6

4530

3596

120 1

3

1906 and 1910 ...

'r4

1 3()62

214

5860

13 6

4431

3943

125

4

1907 and 1911

Tl

3624

170

5816

14 4

1 38(.0

3804

12 0 j

5

I'nMianiM'ed

S f)

1 3293

174

5933

114

1 45 1 1

4003

1(» 5

Tlip yiH*!^ «>n

ti uhicli the inaiiun!

in; printed in heavier lyiie.

ipplied

n any M'ven year

21

Subscribers and Donors

to the Rothamsted Experimental Station,

1904 and since.

The Goldsmiths' Company (endowment for Soil Investigation).

J. F. Mason, Esq., M.P. (The "James Mason" Laboratory).

The Permanent Nitrate Committee.

The Fertiliser Manufacturers' Association.

The Potash Syndicate.

The Sulphate of Ammonia Committee.

The Clothworkfrs' Company.

A. D. Acland, Esq.

The Right Hon. Lord Averury, F.R.S.

Messrs. F. W. Berk & Co.

The Right Hon. Lord Blyth.

A. Brassey, Eso.

The Right Hon. Sir J. T. Brunner, Bart., P.C.

Sir E. Hildred Carlile, M.P.

W. T. Coles, Esq.

Sir R. P. Cooper, Bart.

H. Shepherd Cross, Eso.

His Grace the Duke of Devonshire, P.C.

Messrs. Ellis and Everard.

Sir John Evans, K.C.B., F.R.S.

Sir Walter Gilbey, Bart.

Sir Eustace Gurney.

List of Subscribers and Donors contd.

SiH A. Hkndhhson, Bart.
H. Tylston Hodgson, Esg.
A. H. HorJNSWOHTfi, 1'"^.

A. Howard Esq.

Ti!r. r?iGHT Hon. Lord Ivkagh.

W. i:. KBEN, Es^.

SiK ('harles Lawes-Wittkwronge, Bart.

R. Mond, Esg.

Capt. I \ Morrison, M.P.

W. Morrison, Esq.

Dr. Hugo Mullkr, F.R.S.

Hknry S. Nunn, Esg.

Marlborough R. Pryok, i <».

William Ransom k, Esg.

The Right Hon. Lord Roms* im i..

B. S. Rowntree, Esq.
Frederick Seebohm, Esq.
B. Stanier, Esq., M.P.

< .. Stkphrnson, Esg.

Dr. J. Augustus Vohlckkk, m.a.

Philip F. Walker, Esg.

The Rkjht Hon. Lord Walsin(.ham, F.R.S.

Sir J. Wkrnher, Bart.

J. Martin White, Esq.

W. R. WooLRYCH, Esq.

23

The Incorporated Society for
Extendinfi the Rothamsted Experiments.

MEMHhlRS OF COUNCIL.

His Grace thk Dukk of Dkvonshirk, P.C. (Chairman)

H. E. Armstrong, ICsy., l.l. D. I ic*.

y<. H. hiFFKN, Esq., M.a

H. T. HkowN, Esq., LL.I)., i-.K.b.

The Right F^on. Sir J. T. Brunnrr, Bart , \rr

Thk Hk;ht Hon. Earl CAURiNr/roN, K,G.

j. li. Parmf.r, Esg., M.A., VM.S.

A. h. Ham, Esg., M.A., I .1:.,. {Hon, Secretary).

]. V. Mason, Esg., U.V. {Vice-Chairman).

Robert Mond, Esg.

Caft. J. A. Morrison, M.P.

Hugo Mullkr, Esg., FJ..!)., F.R.S. iTreanurer).

Sir W. S. Pridkaux.

A. B. Rkndlr, Esg.. M.A h l R S.

Sir ]. H. Thorold, FUki

|. A. Voelcker, Esg., M.A., PFi.D.

Sir Julius Wkrnher, Bart,

J. Martin White, Esg.