The Waste Products of Agriculture

8/12/2019 The Waste Products of Agriculture

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The Waste Products of

AgricultureTheir Utilization as Humusby

Sir Albert Howard, C.I.., !.A.

"irector of the Institute of Plant Industr#, Indore,and Agricultural Ad$iser to States in Central India and %a&'utana

and

(eshwant ". Wad, !. Sc.

Chief Assistant in Chemistr#, Institute of Plant Industr#, Indore

Hum'hre# !ilford)*ford Uni$ersit# Press

+ondon ew (or- Toronto !elbourneomba# Calcutta !adras

/01/

To

Sir %eginald 2lanc#

3.C.I.., C.S.I., C.I.., I.C.S.

!ember of the Council of India

4ormerl# Agent to the 2o$ernor52eneral in Central India

4irst President of the oard of 2o$ernors of the Institute of Plant Industr#, Indore

6/0785/0709


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Preface

)ne of the main features of cro' 'roduction at the 'resent da# is waste. *ce't in the

4ar ast, where the large indigenous 'o'ulation has to be fed from the 'roduce of thecountr#5side, little is being done to utilize com'letel# the b#5'roducts of the farm in

maintaining the fertilit# of the soil. The e$er5growing su''lies of agricultural 'roduce,

needed b# industr# and trade, ha$e been 'ro$ided either b# ta-ing u' new land or b#

the 'urchase of artificial manures. oth these methods are uneconomic. The

e*'loitation of $irgin soil is a form of 'lunder. An# e*'enditure on fertilizers which

can be a$oided raises the cost of 'roduction, and therefore reduces the margin of

'rofit. It needs no argument to urge that, in maintaining the fertilit# of the soil, the

most careful attention should be 'aid to the utilization of the waste 'roducts of

agriculture itself before an# demands are made on ca'ital 55 natural or ac:uired.

4or the last twent#5si* #ears, the senior author has been engaged in the stud# of cro''roduction in India and in de$ising means b# which the 'roduce of the soil could be

increased b# methods within the resources of the small holder. These in$estigations

fell into two di$isions; 6/9 the im'ro$ement of the $ariet#< and 679 the intensi$e

culti$ation of the new t#'es. In the wor- of re'lacing the indigenous cro's of India b#

higher #ielding $arieties, it was soon realized that the full 'ossibilities in 'lant

breeding could onl# be achie$ed when the soil in which the im'ro$ed t#'es are grown

is 'ro$ided with an ade:uate su''l# of organic matter in the right condition. Im'ro$ed

$arieties b# themsel$es could be relied on to gi$e an increased #ield in the

neighbourhood of ten 'er cent. Im'ro$ed $arieties 'lus better soil conditions were

found to 'roduce an increment u' to a hundred 'er cent or e$en more.

Ste's were therefore ta-en; 6/9 to stud# the con$ersion of all forms of $egetable and

animal wastes into organic matter 6humus9 suitable for the needs of the growing cro'@ in

2erman#, /7@ in 4rance, /@ in ngland and Wales, >@ in Scotland but onl# 8/ in the

United States. In Canada, according to %iddell, the /0// figures show that e$er#

/,@@@ acres called for onl# 7> wor-ers. This obser$er states that in the three 'rairie

'ro$inces BAlberta, !anitoba, Sas-atchewan the figures are e$en more stri-ing; the

area under field cro's was /D,>DD,@0/ acres, and the numbers engaged in agriculture

was 7E1,8D7, so that each 'erson so em'lo#ed was res'onsible for >7 acres. $er#

/,@@@ acres re:uired onl# /> wor-ers. Since these data were 'ublished, further

statements ha$e a''eared from which it would seem that the size of the wor-ing

'o'ulation in agriculture in orth America has shrun- still further.9 This state of

things has arisen from the dearness and scarcit# of labour, which has naturall# led tothe stud# of labour5sa$ing de$ices including the use of machiner#. Whene$er a


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machine can be in$ented which sa$es human labour its s'read is ra'id. ngines of

$arious -inds are the rule e$er#where. The ine$itable march of the combine5har$ester,

in all the wheat5'roducing areas of the world, is the latest e*am'le of the

mechanization of the agriculture of the west.

Another feature of this e*tensi$e s#stem of large5scale agriculture is the de$elo'mentof food 'reser$ation 'rocesses, of trans'ort and of mar-eting, b# which the 'roducts

of agriculture are chea'l# and ra'idl# mo$ed from the field to the centres of

distribution and consum'tion. There is no great dearth of ca'ital at an# stage. !one#

can alwa#s be found for an# new machine and for an# new de$elo'ment which is

li-el# to return a di$idend. +and and ca'ital are abundant< efficient trans'ort and good

mar-ets abound. The com'arati$el# small su''l# of suitable labour and its high cost

'ro$ide the chief agricultural 'roblems of the west.

This s#stem of agriculture is essentiall# modern and has de$elo'ed largel# as one of

the conse:uences of the disco$er# of the steam engine and the ra'id e*'loitation of

the su''lies of coal, oil and water5'ower. It has onl# been made 'ossible b# thee*istence of $ast areas of $irgin land in 'arts of the earthFs surface on which the white

races can li$e and wor-. As alread# mentioned the wea- 'oint in this method of cro'

'roduction is that it is new and lac-s the bac-ing which onl# a long 'eriod of 'ractical

e*'erience can su''l#. !other arth is 'ro$ided with an abundant store of reser$e

fertilit# which can alwa#s be e*'loited for a time. $er# reall# successful s#stem of

agriculture howe$er must be based on the long $iew, otherwise the da# of rec-oning

is certain.

Side b# side with this method of utilizing the land there has been a great de$elo'ment

of science. fforts ha$e been made to enlist the hel' of a number of se'arate sciences

in stud#ing the 'roblems of agriculture and in increasing the 'roduction of the soil.

This has entailed the foundation of numerous e*'eriment stations, which e$er# #ear

'our out a large $olume of 'rinted results and ad$ice to the farmer. At first the

scientific wor-ers naturall# de$oted themsel$es to sol$ing local 'roblems and to

furnishing scientific e*'lanations of $arious agricultural 'ractices. This 'hase is now

'assing. A new note is beginning to a''ear in the 'ublications of the e*'eriment

stations, namel# that of direction and ad$ice which can onl# be ad$anced b# men

whose education and training combine the ideas of science with the aims of the

statesman. The feeling is not onl# growing but is being e*'ressed that it is no longer

the business of science merel# to sol$e the 'roblems of the moment. Something more

is needed. The chief function of science in the agriculture of the future is to 'ro$ideintelligent direction in general 'olic# and to 'oint the wa#.

The Agricultural Systems of the Orient

Peasant Holdings

The chief feature of the agricultural s#stems of the east is the small size of the

holding. The relation between man5'ower and culti$ated area in India is gi$en in

Table I. In this table, based on the Census Reportof /07/, the number of wor-ers and

the acreage culti$ated ha$e been calculated for the chief 'ro$inces of ritish India.

Incidentall# these figures illustrate how intense is the struggle for e*istence in this'ortion of the tro'ics.


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Table I.

The elation bet!een "an-#o!er and

$ulti%ated Area in India

Provinces

Number of acres cultivated

by 100 ordinary cultivators

Bombay 1,215

North-West

Frontier Province1,122

Punjab 1!

"entral Provinces !#!

Burma 5$5

%adras #1

Ben&al '12

Bihar and (rissa '0

)ssam 2$

*nited Provinces 251

These minute holdings are fre:uentl# culti$ated b# e*tensi$e methods 6those suitable

for large areas9 which neither utilize the full energies of man and beast nor the

'otential fertilit# of the soil. Such a s#stem of agriculture can onl# result in 'o$ert#.

The ob$ious line of ad$ance is the gradual introduction of more intensi$e methods,

for which the su''l# of suitable manure, within the means of the a$erage culti$ator, is

bound to 'ro$e an im'ortant factor.

If we turn to the 4ar ast, to China and Ga'an, a similar s#stem of small holdings is

accom'anied b# an e$en more intense 'ressure of 'o'ulation both human and bo$ine.In the introduction toFarmers of Forty Centuries, 3ing states that the three main

islands of Ga'an had in /0@D a 'o'ulation of 8>,0DD,@@1, maintained on 7@,@@@ s:uare

miles of culti$ated fields. This is at the rate of 7,180 to the s:uare mile or more than

three 'eo'le to each acre. 6These figures agree $er# closel# with those :uoted in the

Japan Year Bookof /01/ in which the number of 'ersons 'er s:uare -ilometre is

gi$en as 0>0; e:ui$alent to 7,811 to the s:uare mile.9 In addition Ga'an fed on each

s:uare mile of culti$ation a $er# large animal 'o'ulation 55 >0 horses and > cattle,

nearl# all em'lo#ed in labour< E7 'oultr#< /1 swine, goats and shee'. Although no

accurate statistics are a$ailable in China, the e*am'les :uoted b# 3ing re$eal a

condition of affairs not unli-e Ga'an. In the Shantung Pro$ince, a farmer with a famil#

of twel$e -e't one don-e#, one cow and two 'igs on 7. acres of culti$ated land 55 adensit# of 'o'ulation at the rate of 1,@D7 'eo'le, 7> don-e#s, 7> cattle and /7 'igs


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'er s:uare mile. The a$erage of se$en Chinese holdings $isited ga$e a maintenance

ca'acit# of /,DE1 'eo'le, 7/7 cattle or don-e#s and 100 'igs 55 nearl# 7,@@@

consumers and 8@@ rough food transformers 'er s:uare mile of farm land. In

com'arison with these remar-able figures, the corres'onding statistics for /0@@ in the

case of the United States 'er s:uare mile were; 'o'ulation >/, horses and mules 1@.

The 'roblems of tro'ical agriculture for the most 'art relate to small holdings. The

main 'ur'ose of this 'easant agriculture is cro' 'roduction< animal husbandr# is much

less im'ortant. In India the cro's grown fall into two classes 55 6/9 food and fodder

cro's and 679 mone# cro's. The former includes, in order of area; rice, millets, wheat,

'ulses and fodder cro's, barle# and maize and sugar5cane. The mone# cro's are more

$aried< cotton and oil seeds are the most im'ortant, followed b# &ute and other fibres,

tobacco, tea, o'ium, indigo and coffee. It will be seen that food and fodder cro's

com'rise E7 'er cent of the total area under cro's and that mone# cro's, as far as

e*tent is concerned, are relati$el# unim'ortant.

Table II.Agricultural Statistics of &ritish India'

()*+-*,

)rea, in acres, under food and fodder cro+s

ice !,502,000

%illets '!,$,000

Wheat 2#,1!1,000

.ram 1#,$$#,000

Pulses and other &ood &rains 2,15#,000

Fodder cro+s !,#0,000

"ondiments, s+ices, fruits,

ve&etables, and misc/ food

cro+s

,5',000

Barley $,'!,000

%aie 5,555,000

u&ar ',0#1,000

otal, food and fodder cro+s21$,',00

0

)rea, in acres, under money cro+s

"otton 15,$!,000


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(il seeds, chie3y ra+e and

mustard, sesamum,

&roundnuts and linseed

1#,,000

4ute and other bres #,#11,000

6yes, tannin& materials, dru&s,

narcotics and miscellaneous

cro+s

1,2,000

obacco 1,055,000

ea '!,000

(+ium 5,000

7ndi&o 10#,000

"o8ee 1,000

otal, money cro+s '!,!',000

The 'rimar# function of Indian agriculture is to su''l# the culti$ator and his cattle

with food. Com'ared with this dut# all other matters are subsidiar#. The houses are

built of mud, thatched with grass and are almost de$oid of furniture. *'enditure on

clothing and warmth is, on account of the customs of the countr# and the nature of theclimate, much smaller than in uro'ean countries. e$ertheless, the culti$ators

re:uire a little mone# with which to 'a# the land re$enue and to 'urchase a few

necessaries in the $illage mar-ets. Hence the growth of mone# cro's to the e*tent of

about one5fifth the total culti$ated area. 6See Table III below.9 The 'roduce, after

con$ersion into cash, is afterwards either wor-ed u' in the local mills or e*'orted. To

some e*tent food cro's are also mone# cro's. The 'o'ulation of the towns and cities

is largel# fed from the 'roduce of the soil, while in addition a small 'ercentage of the

total food grains 'roduced is e*'orted to foreign countries. In some cro's li-e sugar5

cane, the total out5turn is insufficient for the towns and large :uantities of sugar are

im'orted from Ga$a, !auritius and the continent of uro'e.

Table III.

ield of the "ore Im#ortant $ro#s of

India' ()*+-*,

Food cro+s

ice 2,$'$,000 tons

Wheat !,#1,000

%illets ,!0$,000


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.ram ',,000

Barley 2,550,000

u&ar ',2'#,000

%aie 1,1,000

%oney cro+s

4ute12,1'2,000 bales 9each

#00 lb/:

"otton #,$0,000 9each #00 lb/:

.roundnuts 2,0'5,000 tons/

a+e and

mustard!$,000 tons/

;inseed #0,000 tons/

esamum/ #11,000 tons/

"astor seed 12!,000 tons/

ea '2,1,!00 lb/

"o8ee '#,2!$,!0$ lb/

ubber 2',002,00 lb/

7ndi&o 1!,100 c


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s#stem of terraces combined with surface5drainage. The ad$antage is not all

on the side of the State. The manuring of tea soils in Ga$a is far less necessar#

than in Ce#lon and India, while one im'ortant conse:uence of the retention of

the $aluable soil made b# the forest is health# growth, which suffers

remar-abl# little damage from insect and fungoid 'ests.

Unde%elo#ed Areas

=er# large stretches of the )rient are still under forest and at 'resent carr# a $er#

small 'o'ulation, su''orted b# hunting, fishing and b# the small culti$ated areas

surrounding the $illages. These unde$elo'ed forest areas occur e$er#where,

'articularl# in the !ala# Archi'elago, the 4ederated !ala# States, urma and the low

countr# of Ce#lon. In the search for the ideal method of manuring in the tro'ics, the

greatest care will ha$e to be ta-en to 'reser$e the $aluable surface soil whene$er the

forest cano'# has to be remo$ed for the creation of new culti$ated land. Some at an#

rate of these 'otentiall# rich tracts are almost certain to be ta-en u' during the 'resent

centur#. The# will therefore 'ro$ide am'le o''ortunities of a''l#ing an# lessons insoil management, which science can e*tract from e*'eriment and from e*'erience.

The serious mista-es of the 'ast must not be re'eated when the time comes for

de$elo'ing the $ast areas of tro'ical forest still untouched.

It will be e$ident that the s#stems of agriculture of the west and of the east are $er#

different and that the two ha$e little or nothing in common. In a sense these two

methods of managing land remind one of the two sides of a coin. The one

su''lements the other; each can be regarded as a 'art of one great whole. Clearl#

when attem'ting to e$ol$e the ideal s#stem of manuring and soil management of the

future, both of these widel# different methods of agriculture must be studied. This hasbeen done b# the senior author for the last twent#5si* #ears in $arious 'arts of India 55

on the allu$ium of the Indo52angetic 'lain at Pusa in ihar, on the loess soils of the

uetta =alle# on the Western 4rontier and on the blac- cotton soils of 'eninsular India

at Indore. The chief climatic factors at Indore are re'resented in Plate II. The climate

of uetta resembles generall# that of Persia, where the rainfall is recei$ed mainl#

during the winter months, often in the form of snow. At these three centres a method

of utilizing all the $egetable and animal wastes of the holding has graduall# been

e$ol$ed. The latest scientific wor- of the )ccident and 'articularl# that recentl#

accom'lished at the e*'eriment station of ew Gerse#, together with the 'ractices in

$ogue in India and the 4ar ast, ha$e been welded together and s#nthesized into a

s#stem for the continuous manufacture of manure throughout the #ear so that it formsan integral 'art of the industr# of agriculture.


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Plate I. Rainfall, temperature,

humidity and drainage, Pusa,

1922.

Full-size image

Plate II. Rainfall, ground-water level, temperature and

humidity, Indore, entral India, 192!.

Full-size image

6In considering all this information 55 the $arious agricultural s#stems in use at the

'resent time, as well as the large $olume of scientific 'a'ers dealing with manurial

:uestions, which ha$e been 'oured out b# the e*'eriment stations during the last fift#

#ears, we ha$e been im'ressed b# the e$ils inse'arable from the 'resent

fragmentation of an# large agricultural 'roblem and its attac- b# wa# of the se'arate

science. All this seems to follow from the e*cessi$e s'ecialization which is now

ta-ing 'lace, both in the teaching and in the a''lication of science. In the training

gi$en to the students and in much of the 'ublished wor-, the tendenc# of -nowingmore and more about less and less is e$er# #ear becoming more mar-ed. 4or this
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reason an# re$iew of the 'roblem of increasing soil fertilit# is rendered 'eculiarl#

difficult, not onl# b# the $ast mass of 'ublished 'a'ers but also b# their fragmentar#

and 'iecemeal nature.9

o e*tra labour is re:uired in our manure factor#. o im'orted chemicals such as

Adco are needed in this 'rocess. o ca'ital is re:uired at an# stage of themanufacture. The methods now in use at Indore form the main sub&ect of this boo-,

which also attem'ts to deal with a number of related matters such as 55 the role of

organic matter in the soil, the methods of re'lenishing the su''l# of organic matter

now in use and the recent in$estigations which ha$e been carried out on the

conditions necessar# for con$erting raw organic residues into humus which can be

immediatel# nitrified in the soil and so made use of b# the 'lant. The Indore 'rocess

can easil# be carried out, not onl# in the tro'ics but also on the small holdings of the

tem'erate regions and on the allotments 6'ro$ided s'ace is made a$ailable9 in the

neighbourhood of urban areas, where it is now the 'ractice to burn most of the

$egetable waste. How ra'idl# the s#stem can be introduced into the farming s#stems

of the )ccident is a :uestion to which no answer can be gi$en until the ideas in thisboo- ha$e been full# tried out in western agriculture. It is not im'ossible that the#

ma# founder for a time on the 'resent high cost of labour. The method howe$er is in

full accord with the well5mar-ed tendenc# in western agriculture towards a more

intensi$e 'roduction. The ine$itable change o$er from e*tensi$e to intensi$e methods

has alread# begun. 4or 'roduction to be more economical, the acre #ield must be

increased. Alread# in the United States the suggestion has been made that the line of

ad$ance in cro' 'roduction lies in restricting the area culti$ated. A 'ortion of the

im'o$erished 'rairie lands should go bac- to grass. The cro's needed should be raised

from a smaller area. These ideas will become 'racticable the moment the farmer

learns how to utilize the waste 'roducts of his fields in increasing the fertilit# of the

soil. This is the greatest need of agriculture at the 'resent da#.

Chapter 2

Oranic !atter and "oil #ertility

The ancients and the moderns are in the com'letest agreement as to the im'ortance of

organic matter in maintaining the fertilit# of the soil. This is e$ident when the

methods of cro' 'roduction in the time of the %omans are com'ared with the $iewsnow held b# man# of the leading e*'eriment station wor-ers in the United States and

other 'arts of the world. In %oman times, the management of the manure hea' had

alread# reached an ad$anced stage. In 8@ .C. =arro drew attention to the great

im'ortance of the com'lete deca# of manure before it was a''lied to the land. To

bring this about, the manure hea', during the 'eriod of storage, had to be -e't moist.

In A.". 0@ Columella em'hasized the im'ortance of constructing the 'its 6in which

farm#ard manure was stored9 in such a manner that dr#ing out was im'ossible. He

mentions the need of turning this material in summer to facilitate deca#, and

suggested that ri'ened manure should alwa#s be used for corn, while the fresh

material could be a''lied with safet# to grass land. The %omans therefore not onl#

understood the im'ortance of organic matter in cro' 'roduction but had gone a longwa# towards mastering the 'rinci'le that, to obtain the best results, it is necessar# to


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arrange for the deca# of farm#ard manure before it is a''lied to arable land. It is

interesting to turn from the writings of the ancients to the account of the s#m'osium

on FSoil )rganic !atter and 2reen5manuringF arranged b# the American Societ# of

Agronom# at Washington ".C. on 77 o$ember /07E, the main results of which

a''eared in theJournal of the American Society of Aronomyof )ctober /070.

Without e*ce'tion, the in$estigators who too- 'art in this conference laid the greatestem'hasis on the im'ortance of -ee'ing u' the su''l# of organic matter in the soil, and

on disco$ering the most effecti$e and the most economical method of doing this

under the $arious conditions, as regards moisture, which the soils of the United States

'resent.

"uring the 7,@@@ #ears which ha$e ela'sed since =arro wrote in 8@ .C. and the

American in$estigators met in /07E, there has occurred onl# one brief 'eriod during

which the role of organic matter was to some e*tent forgotten. This too- 'lace after

+iebigFs Chemistry in its Application to Ariculture and Physioloyfirst a''eared in

/E8@. +iebig em'hasized the fact that 'lants deri$e their carbon from the carbon

dio*ide of the atmos'here and ad$anced the $iew that, in order that a soil ma# remainfertile, all that is necessar# is to return to it, in the form of manure, the mineral

constituents and the nitrogen that ha$e been ta-en awa# in the cro'. The disco$er# of

the true origin of the carbon of 'lants not unnaturall# suggested that the organic

matter in the soil was of little conse:uence. itrogen and minerals onl# remained, the

latter being found in the 'lant ashes. When therefore anal#ses of the cro's had been

made, it would be 'ossible to draw u' tables showing the farmer what he must add in

the wa# of nitrogen and minerals in an# 'articular case. These $iews and the

contro$ersies to which the# ga$e rise, combined with the results of the %othamsted

e*'eriments 6started b# +awes and 2ilbert in /E819 led to the ado'tion of artificial

manures b# man# of the farmers of uro'e. The %othamsted e*'eriments

undoubtedl# 'ro$ed that if the 'ro'er :uantities of combined nitrogen, 'hos'hates and

'otash are added to the soil, satisfactor# cro's for man# #ears can be obtained without

the addition of organic matter be#ond that afforded b# the roots of the cro's grown.

4urther, the results of hundreds of trials, in the course of ordinar# farming 'ractice,

confirmed the fact that the &udicious addition of nitrogenous artificial fertilizers can,

in the great ma&orit# of cases, be relied on to increase the #ield. It was onl# natural

that results of this -ind, combined with the im'ortant fact that the a''lication of

artificials often 'a#s in 'ractice, 'roduced a mar-ed effect on current o'inion and also

on teaching. 4or nearl# a centur# after +iebigFs ideas first a''eared, the ma&orit# of

agricultural chemists held that all that mattered in obtaining ma*imum #ields was the

addition of so man# 'ounds of nitrogen, 'hos'horus and 'otassium to the acre.e#ond this the onl# other factor of im'ortance was the liming of acid soils. The great

de$elo'ment of the artificial manure industr# followed as a matter of course.

The 'lace of organic matter in the soil econom# was forgotten. The old methods of

maintaining soil fertilit# naturall# fell into the bac-ground.

4or a time all seemed to go well. It is onl# in com'arati$el# recent #ears that

e*'eriment station wor-ers ha$e begun to understand the 'art 'la#ed in cro'

'roduction b# the micro5organisms of the soil and to realize that the su''l# of

artificials is not the whole stor#. Something more is needed. The need for the

maintenance of the su''l# of organic matter soon became a''arent. The $iew nowbeginning to be held is that, onl# after the su''l# of organic matter has been


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ade:uatel# 'ro$ided for, will the full benefit of artificials be realized. There a''ears to

be a great field for future e*'eriment in the &udicious use of artificials to land alread#

in a fair state of fertilit#.

In all this howe$er there was one im'ortant e*ce'tion. In the )rient, the artificial

manure 'hase had 'racticall# no influence on indigenous 'ractice and 'assedunheeded. The +iebig tradition failed to influence the farmers of fort# centuries. o

demand for these 'roducts of the west e*ists in China. At the 'resent da# it would be

difficult to 'urchase such a substance as sul'hate of ammonia in the bazaars of rural

India.

Soil Humus' its Origin and ature

What is the origin and nature of the organic matter or soil FhumusF and what 'art does

it 'la# in soil fertilit#J These matters form the sub&ect of the 'resent cha'ter.

In the 'resentation which follows, the fullest use has been made of 6/9 one of the'a'ers of Wa-sman 6Pa'er o. 7D> of the Gournal Series, ew Gerse# Agricultural

*'eriment Station, "e'artment of Soil Chemistr# and acteriolog#, afterwards

'ublished in Soil Science, 77, /07>, '. /719 and 679 of the s#m'osium on soil organic

matter and green5manuring which a''eared in the issue of theJournal of the

American Society of Aronomyof )ctober /070. These im'ortant contributions to the

sub&ect ha$e made it eas# briefl# to s-etch the necessar# scientific bac-ground for the

'resentation of the Indore 'rocess.

The organic matter found in the soil consists of two $er# different classes of material;

6/9 the constituents of 'lants and animals which ha$e been introduced into the soil andare undergoing decom'osition< $arious unstable intermediate 'roducts which ha$e

been formed under certain en$ironmental conditions< substances li-e lignified

cellulose which are more resistant to decom'osition and which ma# 'ersist in the soil

for some time< and 679 number of $aluable materials which ha$e been synthesi!edb#

the numerous grou's of micro5organisms which form the soil 'o'ulation. The soil

organic matter is thus a heterogeneous mass of substances which is constantl#

undergoing changes in com'osition. When its com'osition reaches a certain stage of

e:uilibrium, it becomes more or less homogeneous and is then incor'orated into the

soil as FhumusF. This definition of soil organic matter, which is due to Wa-sman, is of

great im'ortance. Soil organic matter or FhumusF is not merel# the residue left when

$egetable and animal residues deca#. It contains in addition the $aluable materialss#nthesized and left behind b# the fungi and bacteria of the soil 'o'ulation. !oreo$er

it is a 'roduct of the general soil conditions which obtain in an# 'articular localit#,

and therefore $aries in com'osition and character from one soil t#'e to another. It is

not the same all o$er the world. The soil humus for e*am'le of the blac- cotton soils

of India is not identical with that of the allu$ium of the Indo52angetic 'lain.

The $arious ste's in the formation of soil organic matter are somewhat as follows.

When the fresh remains of 'lants or animals are added to the soil, a 'ortion of this

organic matter is at once attac-ed b# a large number of the micro5organisms 'resent.

%a'id and intense decom'osition ensues. The nature of these organisms de'ends on

the soil conditions 6mechanical and chemical com'osition and 'h#sical condition9 andon the soil en$ironment 6moisture content, reaction and aeration, and the 'resence of


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The /ormation of Humus as a esult of the Synthesizing Acti%ities

of "icro-organisms

Although the im'ortant 'art 'la#ed b# microorganisms in the formation of soil humus

has onl# $er# recentl# been full# understood, ne$ertheless the older literature contains

a number of useful contributions to the sub&ect. !ost of these earl# 'a'ers a''earedtowards the end of the last centur#< man# of them related to other branches of

-nowledge and were not written from the 'oint of $iew of agriculture. The# ha$e

been summed u' b# Wa-sman, from whose 'a'er the following account has been

're'ared. Post5%amann and !uller considered that the FhumusF bodies obtained from

soil often consist of the chitinous remains of insects and animal e*crete. Wettstein and

Winterstein showed that chitin is characteristic of $arious fungi and not of bacteria.

Schmoo- ad$anced the $iew that the 'rotein nitrogen in the soil was mostl# 'resent in

the bodies of bacteria and 'rotozoa. Trusso$ showed that the 'roto'lasm of fungi is a

source of humus in the soil. Schreiner and Store# suggested that $arious characteristic

constituents of the soil are 'robabl# s#nthesized b# micro5organisms.

The earlier wor- on this sub&ect has been considerabl# de$elo'ed, first b# 4alc- and

more recentl# b# Wa-sman. 4alc- showed that organic matter in forest soils can be

transformed into different t#'es of humus in at least three wa#s; 6/9 The #earl#

additions of raw organic matter are com'letel# decom'osed b# fungi 6microcriny9

accom'anied b# the s#nthesis of fungus 'roto'lasm, which ser$es as an e*cellent

fertilizer for the forest trees. In this 'rocess the celluloses are decom'osed com'letel#,

whereas the lignins are more resistant. 679 The decom'osition of the organic matter is

begun b# fungi and then carried on b# lower in$ertebrates and bacteria 6anthracriny9.

The fungus m#celium as well as the original organic matter are de$oured b# $arious

lar$ae 'roducing a dar- FhumusF mass which, in the 'resence of bases, is o*idized b#bacteria with the ultimate liberation of carbon dio*ide and the formation of nitrate. 619

The formation of 'eat 6anthroeny9, which 4alc- e*'lains as resulting from the

absence of an abundant fungus de$elo'ment. Wa-sman carried the sub&ect still further

and called attention to the similarit# between the carbon5nitrogen ratio of the soil

organic matter and that of the 'roto'lasm of the soil fungi and other micro5organisms,

and suggested that these 'robabl# ma-e u' a large 'art of the soil FhumusF. He further

'ointed out that when cellulose is added to the soil, it decom'oses onl# in 'ro'ortion

to the a$ailable combined nitrogen 'resent. This is because the decom'osition is

brought about b# fungi and bacteria, both of which re:uire combined nitrogen. The

ratio between the amount of cellulose decom'osed and the nitrogen re:uired is about

1@;/, so that, for e$er# thirt# 'arts of cellulose decom'osed b# the fungi and bacteria,one 'art of inorganic nitrogen 6ammonium salt or nitrate9 will be built u' into

microbial 'roto'lasm. In the 'resence of sufficient combined nitrogen and under

aerobic conditions, the decom'osition of cellulose is $er# ra'id. The same is true of

$egetable wastes li-e straw, maize stal-s, wood 'roducts and other materials rich in

celluloses, 'entosans and lower carboh#drates but 'oor in nitrogen. These facts

e*'lain the in&urious effects on cro' growth which follow the addition of straw and

green5manure to the soil. The decom'osition of these materials remo$es large

:uantities of combined nitrogen from the soil solution. This nitrogen is then

tem'oraril# stored in the form of microbial 'roto'lasm, when for a time it is 'laced

be#ond the reach of the growing cro'.

Since Wa-smanFs 'a'er a''eared in /07>, an im'ortant contribution to this sub&ect


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/ ?.reen-%anurin& and 7ts )++lication to )&ricultural Practices/? )/ 4/Pieters and oland %cee/

In dealing with the :uestion of organic matter in humid soils, +#on first 'resented a

critical sur$e# of the literature dealing with the losses of nitrogen in soils and

concluded that;

1/ he loss of &aseous nitro&en may, under some conditions, cause a&reater removal of nitro&en from a soil than occurs throu&habsor+tion by cro+ +lants/

2/ he conditions ind areC 9a: tilla&eor stirrin& the soil in any


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22/104

a''ears to be s'reading can onl# be e*'lained b# the great need of these de'leted

soils for fresh su''lies of organic matter.

Chapter $

%he "ources of Oranic !atter

A number of sources of soil organic matter e*ist, namel#; 6/9 the roots of cro's left

behind at har$est, including the weeds turned under in the course of culti$ation< 679the algae met with in large :uantities in rice fields, on the surface of the soils of

tro'ical countries during the rain# season and to some e*tent in all soils< 619 green5

manure< 689 farm#ard manure< 69 artificial farm#ard manure. In addition to these

su''lies, certain b#5'roducts of industries, such as oil5ca-es and wool5waste, are also

em'lo#ed as sources of organic matter. These, howe$er, are small in total amount and

need not be considered. *ce't in China and Ga'an and to a limited e*tent in India,

little or no use is made of night soil in cro' 'roduction.

The oot-Systems of $ro#s

It is not alwa#s realized that about half of e$er# cro' 55 the root5s#stem 55 remains inthe ground at har$est time and thus 'ro$ides automaticall# a continuous return of

organic matter to the soil. The weeds and their roots turned in during the ordinar#

course of culti$ation add to this su''l#. When these residues, su''lemented b# the

fi*ation of nitrogen from the atmos'here, are accom'anied b# s-ilful soil

management, cro' 'roduction can be maintained at a moderate le$el without the

addition of an# manure whatsoe$er. A good e*am'le of such a s#stem of farming

without manure is to be found on the allu$ial soils of the United Pro$inces, where the

field records of ten centuries 'ro$e that the land 'roduces fair cro's #ear after #ear

without an# falling off in fertilit#. A 'erfect balance has been reached between the

manurial re:uirements of the cro's har$ested and the natural 'rocesses which

recu'erate fertilit#. A similar, although not so stri-ing a result, is afforded b# the'ermanent wheat 'lot at %othamsted, where this cro' has been grown e$er# #ear on

the same land without manure since /E88. This 'lot, which has been without manure

of an# -ind since /E10, showed a slow decline in 'roduction for the first eighteen

#ears after which the #ield has been 'racticall# constant. S#stems of soil management

such as these 'ro$ide, as it were, the base line for the would5be im'ro$er. othing

e*ists in the worldFs agriculture below this le$el. At the worst, therefore, the organic

matter of a soil, constantl# cro''ed without manure, does not disa''ear altogether.

The wheel of life slows down. It does not sto'.


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24/104

in adding to the store of organic matter and combined nitrogen in the soil. At the end

of the last centur# it seemed so eas#, b# merel# turning in a leguminous cro', to settle

at one stro-e and in a $er# economical fashion the great 'roblem of maintaining soil

fertilit#. At the e*'enditure of a $er# little trouble, the soil might be made to manure

itself. A su''l# of combined nitrogen, as well as a fair :uantit# of organic matter,

might be 'ro$ided without an# serious interference with ordinar# cro''ing. Thesee*'ectations ha$e led to innumerable green5manuring e*'eriments all o$er the world

with 'racticall# e$er# s'ecies of leguminous cro'. The results howe$er ha$e left

much to be desired. In a few cases, 'articularl# on o'en soils and where the rainfall,

after the 'loughing in of the green cro', is well distributed, the results ha$e been

satisfactor#. )n rice lands, where abundance of water ensures the maintenance of

swam' conditions, somewhat similar results ha$e been obtained. In the $ast ma&orit#

of cases, howe$er. green5manuring has been disa''ointing. As a general method of

soil im'ro$ement, the game is hardl# worth the candle. )n the monsoon fed areas of

India the rainfall is often so uncertain, after the green cro' is 'loughed in, that for

long 'eriods deca# is arrested. Sowing time arri$es at a stage when the soil contains a

mass of half5rotted material, with insufficient nitrogen and moisture for the growth ofa cro'. 4ailure results. The cro's raised after green5manure are worse than those

obtained on similar land left fallow. 4or this reason green5manuring has not been

ta-en u' b# the 'eo'le in India, in s'ite of the e*'eriments and 'ro'aganda of the

Agricultural "e'artment.

It soon became e$ident, during the earl# #ears of the 'resent centur# in India, that no

matter what the rainfall and the soil conditions ma# be, a definite time factor is in

o'eration in green5manuring. A 'eriod of not less than eight wee-s must ela'se,

between the 'loughing in of the green cro' and the 'lanting of the ne*t, if satisfactor#

results are to be obtained. This was well brought out in the green5manuring

e*'eriments on tobacco, carried out at Pusa between /0/7 and /0/. Some #ears later,

the e*'lanation of this factor, as well as the general conditions necessar# for the deca#

of a green5manure cro' were furnished b# the wor- done at the ew Gerse#

e*'eriment station b# Wa-sman and his co5wor-ers. The deca# and incor'oration of

green5manure in the soil has been shown to be a $er# com'le* 'rocess, de'ending on;

6/9 the chemical com'osition of the 'lants which ma-e u' the green5manure, which in

turn largel# de'ends on the age of the cro' when 'loughed in< 679 the nature of the

decom'osition of the $arious grou's of organic com'le*es in the 'lant b# the different

t#'es of soil organisms, which in turn is influenced b# such factors as moisture,

aeration, and the su''l# of a$ailable nitrogen and 'hos'hates needed b# these

organisms, and 619 the metabolism of the microorganisms ta-ing 'art in the deca# ofthe green cro'.

The 'rocess of incor'oration ta-es 'lace on the following lines. When the green5

manure cro' is 'loughed in, the first stages of deca# are brought about b# fungi,

which re:uire for their acti$ities am'le su''lies of air, moisture and combined

nitrogen, as well as the soluble and easil# decom'osable carboh#drates su''lied b#

the green cro'. If the su''l# of nitrogen 'ro$ided b# the green5manure is insufficient,

the stores of soluble nitrates in the soil solution are utilized b# the fungi. "eca# is

ra'id 'ro$ided all these essential factors are simultaneousl# arranged for. The result is

that the whole energies of the soil at this 'eriod are gi$en u' to the needs of the fungi

of deca#, which s#nthesize large :uantities of 'roto'lasm from the materials su''liedb# the green cro' and the soil solution. "uring this 'hase, most of the nitrogen 'resent


25/104

is built u' into m#celial tissue, and is therefore not immediatel# a$ailable for the

growth of cro's. The ne*t stage is the deca# of the remainder of the green5manure,

including the m#celial tissue itself, b# $arious grou's of bacteria, followed b# the

incor'oration of the whole mass into the soil organic matter. This must first be

nitrified before the soil solution and the cro' can obtain an# benefit from this form of

manuring. Clearl# all this ta-es time, and needs abundance of o*#gen as well as acontinuous su''l# of soil moisture. If an# of the limiting factors 55 nitrogen su''l#, air

or moisture 55 are in defect, it is ob$ious that the final stage of nitrifiable organic

matter will not be :uic-l# reached. The soil will not onl# contain a mass of undigested

material, but will be 'oor in a$ailable nitrogen and 'erha's low in moisture as well.

Seeds sown in such a soil can onl# result in a 'oor cro'. The in$estigations of the

ew Gerse# e*'eriment station e*'lain the im'ortance of the time5factor in green5

manuring, and incidentall# show that the ordinar# green5manuring e*'eriments in

India cannot 'ossibl# succeed. The sooner the# are discontinued the better. othing is

to be gained b# attem'ting the ho'eless tas- of manufacturing soil organic matter

under conditions which cannot be controlled.

The :uestion at once arises as to whether the green5manuring 'rocess can be regulated

in such a manner that the results can be relied u'onJ A number of attem'ts ha$e been

made in this direction in India, of which that carried out b# Clar-e at Shah&ahan'ur is

the most 'romising. 2reen cro's of sann hem' 6Crotalaria juncea+.9 ha$e been

successfull# utilized for the growth of sugar5cane. The secret of the Shah&ahan'ur

'rocess is to 'ro$ide am'le moisture, b# means of irrigation, for the first stages of the

deca# of the green5manure. The rainfall, after the hem' cro' is 'loughed in, is

carefull# watched. If it is less than fi$e inches during the first fortnight of Se'tember,

the fields are irrigated. This enables the first 'hase of the deca# of the green cro' b#

the soil fungi to be com'leted. Practicall# all the nitrogen is then in the form of easil#

decom'osable m#celial tissue. "uring the autumn, nitrification is 're$ented b# dr#ing

out the surface soil. The nitrogen is, as it were, -e't in the ban- till the sugar5cane is

'lanted under irrigation in !arch. itrification then sets in and the a$ailable su''lies

of combined nitrogen are made use of b# the sugar5cane. In this wa# cro's of o$er

thirt# tons of cane to the acre ha$e been grown without the addition of an# manure

be#ond the hem', grown on the same land the 're$ious rains and treated in the

manner indicated abo$e. These results do not a''ear to ha$e been obtained with an#

other cro' than sugar5cane 'lanted in !arch. It would be interesting to ha$e figures

for wheat, sown in )ctober, i.e. about si* wee-s after the hem' was 'loughed under.

It is 'robable that e$en with irrigation, this inter$al is insufficient for the 'ro'er

incor'oration of the green cro' into the bod# of the soil organic matter and itssubse:uent nitrification. In this case, the Shah&ahan'ur method, $aluable and

interesting as it is, can onl# ha$e a limited a''lication.

Is it 'ossible to de$ise a method of green5manuring, b# means of the leguminous cro',

which a$oids all ris-s, is certain, and also ma-es the fullest use of this s#stemJ There

are two 'ossible wa#s in which the growing of a leguminous green5manure cro' ma#

benefit the soil. These are; 6/9 the well5-nown ad$antages of such cro's in the rotation

in increasing the nitrogen su''l# and in stimulating the micro5organisms in the soil,

and 679 the effects of incor'orating the green cro' into the store of soil organic matter.

+ohnis, howe$er, showed, in man# green5manuring e*'eriments with leguminous

cro's, that the same results were obtained when the cro' was remo$ed as when it was'loughed under 55 a conclusion which is in full accord with Wa-smanFs wor-. It


26/104

follows from this that the double ad$antage of a leguminous green5manure cro' can

onl# be achie$edpro"ided full use of the crop itself can be found outside the field#

either as fodder for animals# for makin silae or as material for the manufacture of

compost. This latter method has been successfull# wor-ed out at Indore, and will be

described in the ne*t cha'ter. The real 'lace of the leguminous cro' in green5

manuring seems to be in 'ro$iding material for the manufacture of organic matter in acom'ost factor#, s'eciall# designed for the 'ur'ose.

The e*act 'eriod in the life histor# of the green cro', when it should be rea'ed for

com'osting, is an im'ortant matter. If the cro' is cut before the grand 'eriod of

growth is com'leted, the ma*imum amount of $egetable waste will not be obtained.

)n the other hand, an earl# har$est will #ield a 'roduct rich in nitrogen and suitable

for ra'id deca# 6A''endi* C9. +ate har$esting is also attended with disad$antages. If

rea'ed after flowering begins, the green cro' will ha$e used u' a good deal of the rich

nodule tissue which will then be tem'oraril# remo$ed from the soil and will not

benefit the ne*t cro'. 4urther, the older the cro', the more unfa$ourable the carbon5

nitrogen ratio becomes. The best stage for remo$al will be &ust before floweringbegins. At this 'oint, most of the nitrates in the soil solution ha$e been absorbed b#

the cro' and ha$e been ban-ed, either in the form of an easil# decom'osable root5

s#stem or as com'ost material, the chemical com'osition of which is e*actl# what is

needed to im'ro$e the carbon5nitrogen ratio of the other $egetable wastes of the farm.

When the green cro' is rea'ed at this stage the following ad$antages are obtained; 6/9

The nitrates of the soil solution are safel# ban-ed. 679 The ne*t cro' deri$es the

ma*imum benefit from an easil# decom'osable and uniforml# distributed root5

s#stem, rich in combined nitrogen, the deca# and incor'oration of which is well

within the 'owers of the soil. 619 The store of $egetable waste for com'osting is

increased in amount and im'ro$ed in chemical com'osition b# the uniform

distribution of the combined nitrogen throughout the tissues of the green cro'.

/armyard "anure

4rom the beginning of agriculture, the utilization of farm wastes, rotted b# means of

the urine and dung of animals, has been the 'rinci'al means of re'lenishing soil

losses. $en at the 'resent da#, in s'ite of the establishment of numerous e*'eriment

stations and the em'lo#ment of an arm# of in$estigators, the methods in $ogue in the

're'aration and storage of this 'roduct lea$e much to be desired. $en under the

co$ered5#ard s#stem, when the dung and litter are left under the animals until a la#er

se$eral feet thic- is 'roduced, and the 'roduct is 'rotected from the weather, as muchas fifteen 'er cent of the $aluable nitrogen is lost. When the dung is carted out into a

hea' to ri'en, as is the usual 'ractice, the losses of nitrogen are e$en greater. %ussell

and %ichards, who some #ears ago carried out an elaborate in$estigation on the

storage of farm#ard manure at %othamsted, concluded that; 6/9 the s#stem of lea$ing

the manure under the beasts till it is re:uired for the fields, as in the bo* or co$ered5

#ard s#stem, is the best whene$er this is 'racticable< 679 the ideal method of storage is

under anaerobic conditions at a tem'erature of 7> degrees C.< 619 the manure hea',

howe$er well made and 'rotected, in$ol$es losses of nitrogen< and 689 the best ho'e

of im'ro$ement lies in storing the manure in watertight tan-s or 'its, so made that

the# can be com'letel# closed and thereb# allow the attainment of 'erfect anaerobic

conditions. These in$estigations, 'ublished in /0/D, clearl# indicate that one of thereasons for the 'resent im'erfect management of farm#ard manure lies in the fact that


27/104

the conditions are sometimes aerobic, at others anaerobic, whereas the# should be one

or the other throughout. In other words, there is no 'ro'er management of the air

su''l#. !oisture is not usuall# in defect, e*ce't in hot countries li-e India where there

is abundant air but often little moisture. Ta-ing 2reat ritain and India as e*treme

cases of the management of farm#ard manure, we find one or other of the following

conditions in o'eration. In 2reat ritain, the irregular air su''l# of the manure hea'leads to serious losses of nitrogen.

The final 'roduct is not a fine 'owder but a 'artiall# rotted material, which cannot be

incor'orated into the 'ore5s'aces of the soil until further deca# has ta-en 'lace. The

soil therefore has to do a good deal of wor- before the farm#ard manure, a''lied on

the surface in lum's, can be uniforml# distributed through and incor'orated into the

soil mass. In India, the storage of farm#ard manure leads to the loss of so much

moisture, that often insufficient deca# ta-es 'lace before it finds its wa# into the soil.

+osses of nitrogen ma# be 're$ented in this wa# but the wor- thrown u'on the soil is

e$en greater than in tem'erate regions. )nl# in China and Ga'an is an# real attem't

made to 're'are the manure for the use of the cro', and to relie$e the soil fromunnecessar# wor-. What is needed throughout the world is a continuous s#stem of

're'aring farm#ard manure in which 6/9 all losses of nitrogen are a$oided, and, 679

the $arious ste's from the raw material to the finished 'roduct follow a definite 'lan,

based on the orderl# brea-ing down of the materials, and the 're'aration of a finished

'roduct, read# for immediate nitrification, which can easil# be incor'orated into the

soil. At the same time, an attem't should be made to gain as much nitrogen as

'ossible b# fi*ation from the atmos'here. )nl# when all this is done will the

're'aration of farm#ard manure be based on correct scientific 'rinci'les.

Arti1cial /armyard "anure

"uring the last ten #ears, an additional source of soil organic matter has been utilized,

namel#, artificial or s#nthetic farm#ard manure. In /07/, the results of e*'eriments,

carried out b# Hutchinson and %ichards at %othamsted on the con$ersion of straw into

manure without the inter$ention of li$e stoc-, were 'ublished. In this 'ioneering

wor-, which constitutes an im'ortant milestone in the de$elo'ment of cro'

'roduction, a method was de$ised b# which straw could be con$erted into a substance

ha$ing man# of the 'ro'erties of stable manure. In the 'reliminar# e*'eriments, the

most 'romising results were obtained when the straw was sub&ected to the action of a

culture of an aerobic cellulose decom'osing organism 6Spirochoeta cytophaa9,

whose acti$ities were found to de'end on the mineral substances 'resent in the culturefluid. The essential factors in the 'roduction of well5rotted farm#ard manure from

straw were found to be; air su''l#< a suitable tem'erature, and a small amount of

soluble combined nitrogen. The fermentation was aerobic< the brea-down of the straw

was most ra'id in a neutral or slightl# al-aline medium in the 'resence of sufficient

a$ailable nitrogen. Urine, urea, ammonium carbonate and 'e'tone 6within certain

concentrations9 were all useful forms of combined nitrogen. Sul'hate of ammonia b#

itself was not suitable, as the medium soon became mar-edl# acid. The concentration

of the combined nitrogen added was found to be im'ortant. When this was in e*cess,

nitrogen was lost from the mass before deca# could 'roceed< when it was in defect, a

mar-ed tendenc# to fi* nitrogen was obser$ed. The 'ublication of this 'a'er soon led

to a number of further in$estigations, and to numberless attem'ts all o$er the world to're'are artificial farm#ard manure from e$er# -ind of $egetable waste. The 'rinci'les


28/104

underl#ing the con$ersion are now well understood, and ha$e recentl# been summed

u' b# Wa-sman and his co5wor-ers in theJournal of the American Society of

Aronomy67/, /070, '. 119 in a 'a'er which should be carefull# studied b# all

interested in this im'ortant sub&ect. The 'rinci'les underl#ing the con$ersion are so

well 'ut b# these in$estigators that the# are best gi$en in the authorsF own words;

FThe 'roblems in$ol$ed in the stud# of the 'rinci'les underl#ing the

decom'osition of mature straw and other 'lant residues in com'osts, leading

to the formation of so5called artificial manure, in$ol$e a -nowledge of; 6a9 the

com'osition of the 'lant material< 6b9 the mechanism of the decom'osition

'rocesses which are brought about b# the micro5organisms< and 6c9 a

-nowledge of the metabolism of these organisms.

FStraw and other farm residues, which are commonl# used for the 'ur'ose of

com'osting, consist 'redominantl# 6>@ 'er cent or more9 of celluloses and

hemi5celluloses, which undergo ra'id decom'osition in the 'resence of

aufficient nitrogen and other minerals, of lignins 6/ to 7@ 'er cent9 which aremore resistant to decom'osition and which graduall# accumulate, of water5

soluble substances 6 to /7 'er cent9 which decom'ose $er# ra'idl#, of

'roteins which are usuall# 'resent in $er# small amounts 67.7 to 1@ 'er cent9

but which graduall# increase in concentration with the ad$ance of

decom'osition, and of the mineral 'ortion or ash.

FThe 'rocesses of decom'osition in$ol$ed in the com'osting consist largel# in

the disa''earance of the celluloses and hemi5celluloses, which ma-e u' more

than E@ 'er cent of the organic matter which is undergoing decom'osition in

the 'rocess of formation of artificial manures. These 'ol#5saccharides cannot

be used as direct sources of energ# b# nitrogen5fi*ing bacteria and their

decom'osition de'ends entirel# u'on the action of $arious fungi and aerobic

bacteria. In the 'rocess of decom'osition of the celluloses and hemi5

celluloses, the micro5organisms bring about the s#nthesis of microbial cell

substance. This ma# be :uite considerable, fre:uentl# e:ui$alent to a fifth or

e$en more of the actual organic matter decom'osed. To s#nthesize these large

:uantities of organic matter, the micro5organisms re:uire large :uantities of

a$ailable nitrogen and 'hos'horus and a fa$ourable reaction. The nitrogen and

'hos'horus are used for the building u' of the 'roteins and nucleins in the

microbial cells. Since there is a direct relation between the celluloses

decom'osed and the organic matter s#nthesized, it should be e*'ected alsothat there would be a direct relation between the cellulose decom'osed and the

amount of nitrogen re:uired. As a matter of fact, for e$er# fort# or fift# 'arts

of cellulose and hemi5cellulose decom'osed, one unit of a$ailable nitrogen has

to be added to the com'ost.

FAs the 'lant residues used in the 're'aration of artificial manure are 'oor in

nitrogen, a$ailable inorganic nitrogen must be introduced for the 'ur'ose of

bringing about acti$e decom'osition. This e*'lains the increase in the 'rotein

content of the com'ost accom'an#ing the gradual decrease of the celluloses

and hemi5celluloses.


29/104

FIn general, artificial com'osts can be 're'ared from 'lant residues of an#

chemical com'osition so long as the nature of these residues and of the

'rocesses in$ol$ed in their decom'osition are -nown. # regulating the

tem'erature and moisture content and b# introducing the re:uired amounts of

nitrogen, 'hos'horus, 'otassium and calcium carbonate, the s'eed of

decom'osition and the nature of the 'roduct formed can be controlled.F

It is not 'ossible in the s'ace a$ailable to summarize all the $arious e*'eriments

which ha$e been made in 2reat ritain, the United States, India and other 'arts of the

world on the actual con$ersion of $egetable residues into artificial farm#ard manure.

It will be sufficient to refer to t#'ical e*am'les of what has been done. The

%othamsted in$estigations ha$e been continued and ha$e led to a 'atented 'rocess,

-nown as Adco, b# which the re:uisite nitrogenous and 'hos'hatic food for the

micro5organisms, as well as a base for the neutralization of acidit#, are added to the

$egetable wastes in the form of 'owders. 4ull details and numerous illustrations are to

be found in the $arious Adco 'am'hlets. The ob&ect of 'atenting the 'rocess is not

'rofit for the in$entors but the raising of funds for further research. All users of Adcotherefore are not onl# 'ro$ided with a useful mi*ture but also ma-e a small

contribution to the cost of fundamental research wor-. In India, the $arious

e*'eriments on the 'roduction of artificial farm#ard manure from a large number of

materials, such as 'ric-l# 'ear, fallen lea$es, town refuse, mahua6Bassia latifolia+.9

flowers, weeds, banana waste, leguminous 'lants such as sann hem', green 'ea stal-s

and $arious weeds ha$e recentl# been summed u' b# 4owler, whose 'a'er 6see

ibliogra'h# below9 should be consulted for details. The materials em'lo#ed for

adding the necessar# nitrogen and other materials for the micro5organisms were night5

soil, cow5dung, cattle urine, acti$ated sludge or chemicals li-e sul'hate of ammonia

and calcium c#anamide. A large number of e*'eriments are described from which it is

clear that $er# useful manures, containing from / to 8 'er cent of nitrogen, were

obtained, which in field trials with rice and maize ga$e results e:ual to or better than

an# other nitrogenous manure in common use. Attem'ts were made in the course of

this wor- to determine the amount of nitrogen fi*ation from the air which occurs

during the con$ersion of the $egetable waste. It was found, when 'ro'er care was

ta-en to su''l# the necessar# organisms, that a considerable amount of free nitrogen

was actuall# absorbed. These results, which agree with others on the same 'oint, are

of considerable interest. If in the con$ersion of $egetable wastes into artificial

farm#ard manure additional nitrogen can be gained, ob$iousl# the ideal conditions

ha$e been disco$ered. )nce such 'rinci'les ha$e been correctl# ascertained and 'ut

into 'ractice, it might then be 'ossible to deal not onl# with the manure hea' itself butalso with green5manuring, so that actual fi*ation can be substituted for the losses of

nitrogen which now occur.

As is to be e*'ected in such a matter as this, the 're'aration of artificial farm#ard

manure has been in actual o'eration centuries before Hutchinson and %ichards began

their wor- at %othamsted. 3ing, inFarmers of Forty Centuries, describes the

con$ersion b# the Chinese 'easants of clo$er 6Astraalus sinicus9 into manure b#

mi*ing the green cro' with rich canal mud To all intents and 'ur'oses, this s#stem

closel# resembles the Adco 'rocess. )nce more the em'irical methods, disco$ered

during centuries of 'ractice, ha$e 'receded the results obtained b# the a''lication of

'ure science. e$ertheless, although in a sense the %othamsted wor-ers ha$e beenantici'ated, it is :uite safe to sa# that but for their wor-, the utilization of green clo$er


30/104

in China, although described in the literature of the sub&ect, would ha$e 'assed

unheeded. It was the no$elt# of the %othamsted in$estigations which has 'ro$ed so

useful and so stimulating.

) critical e=amination of the literature on the +rinci+les underlyin& the

conversion into humus of the chief &rou+s of crude or&anic matter --

&reen-manure, farmyard manure and ve&etable


31/104

conditions just outlined/ his includes, in a sin&le +rocess, the various

fra&ments of the subject, such as the care of the manure hea+, &reen-

manurin&, the utiliation of all ve&etable


32/104


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Plate III. attle-shed.

The com'ost factor# 6Plates I=9 itself is a $er# sim'le arrangement. It consists of

thirt#5three 'its, each 1@ ft. b# /8 ft. and 7 ft. dee' with slo'ing sides, arranged in

three rows with aufficient s'ace between the lines of 'its for the eas# 'assage of

loaded carts. The 'its themsel$es are in 'airs, with a s'ace /7 ft. wide between each

'air. This arrangement enables carts to be brought u' to an# 'articular 'it. Am'le

access from the com'ost factor# to the main roads is also necessar#, so that during the

carting of the com'ost to the fields, loaded and em't# carts can easil# 'ass one

another, and also lea$e room for the standing carts which are being filled. 4or a large

factor# it is an ad$antage to ha$e water laid on, so that the 'eriodical moistening of

the com'ost can be done b# means of a hose 'i'e. At Indore, water is 'um'ed through

a 1 in. 'i'e into a 'ressed steel tan-, E ft. b# E ft. b# E ft., holding 1,7@@ gallons,

which is carried on walls, 8 ft. abo$e the ground, to 'ro$ide the necessar# head. This

su''l# lasts about a wee-. Water is led b# /5/K7 in. 'i'es from the tan- to eight ta's,

to which the armoured hose can be screwed. ach ta' ser$es about si* 'its. Thegeneral arrangement will be clear from Plate I=.


34/104

Plate I". Plan of #ompost fa#tory at Indore.

The total cost of the water tan-, including arrangements for distribution, was %s. />@

6e:ui$alent to about /7@ 'ounds sterling9. This was made u' as follows; tan-, %s.

D@< 'i'e s#stem, %s. 8>>< girders for tan-, %s. 1/< armoured hose, %s. 7E; railwa#

freight, %s. EE< masonr# wor-, %s. /8E< labour, including fitting u', %s. /70.

The s'ace under the tan-, which is walled in on three sides and is o'en on the leeward

side, is used for storing wood ashes, and for -ee'ing the tubs and im'lements needed

for the ma-ing of com'ost.

4or a smaller factor# or for the small holder, such a water s#stem is not necessar#. All

that is needed is that the com'ost 'its should be arranged near a well.

$ollection and Storage of the a! "aterial

Plant Residues

All $egetable wastes from the culti$ated area 55 such as weeds, cotton and other

stal-s, green5manure, cane5trash, fallen lea$es and so forth, and all inedible cro'

residues from the threshing floor 55 are carefull# collected. All wood# materials li-ecotton and 'igeon5'ea 6Cajanus IndicusS'reng.9 stal-s are crushed b# 'lacing on the

farm roads to be tram'led and reduced b# the traffic to a condition resembling bro-en

u' wheat straw 6Plate =9. All green materials 55 such as weeds and green5manures 55

are withered for at least two da#s before use or storage. All these $arious residues are

stac-ed near the cattleshed as recei$ed, la#er b# la#er 55 if 'ossible under co$er during

the rains 55 so that these materials ma# become thoroughl# mi*ed. ach la#er must

not be more than one foot thic-, otherwise difficulties arise in ma-ing a suitable

mi*ture. Care must also be ta-en to remo$e the stac-ed material in $ertical slices so

as to ensure e$en mi*ture. =er# hard and wood# materials 55 such as sugarcane and

millet stum's, wood sha$ings, sawdust and waste 'a'er 55 should be dum'ed

se'aratel# in one of the em't# com'ost 'its with a little earth and -e't moist. Afterthis 'reliminar# treatment, these hard and resistant materials can be readil#


35/104

com'osted. Stee'ing such materials in water for two da#s, before addition to the

bedding under the wor- cattle, ser$es the same 'ur'ose.

Plate ". rushing #otton sal$s %y road traffi#.

$rine %arth and &ood Ashes

All the earth remo$ed from the silage 'its, all earth# swee'ings from the threshing

floors and all silt from drains are stored in a con$enient 'lace near the cattle5shed.

This 'ro$ides an ade:uate su''l# of suitable earth for absorbing the urine of the wor-

cattle, and acting as a base in the ma-ing of com'ost. This earth is s'read e$enl# on

the cattle5shed floor to a de'th of si* inches and renewed e$er# three or four months.

Half the urine earth when remo$ed from the floor should be crushed 6Plate =I9 in a

mortar mill6See PlateFs = and =I9. to brea- u' the large lum's, and should be storedunder co$er as dr# 'owdered urine earth. The other half of the urine earth should be

a''lied direct to the fields as manure. All a$ailable wood ashes should be stored under

co$er, as in the case of the 'owdered urine earth. These materials 6urine earth and

wood ashes9 are as essential in the manufacture of com'ost as the 'lant residues

themsel$es.

Plate "I. Powdering urine earth in a mortar mill.

&ater and Air


36/104

oth water and air are needed for the com'ost 'rocess, which therefore must be

carried out near a well or other source of fresh water.

Arrangement and 2is#osal of the &edding under the Wor3 $attle

6All :uantities in the following refer to one 'air of o*en. The figures should bemulti'lied, when necessar#, b# the number of 'airs of o*en -e't.9

All the uneaten food and an# damaged silage are thrown on the wet 'ortions of the

cattle5shed floor. )ne and a halfpals64ig. /9 of

stac-ed $egetable refuse, together with not more than

one5twentieth of this amount of hard resistant

material 6such as wood sha$ings, sawdust or waste

'a'er9 from the soa-ing 'it are s'read on the floor. 6A

palis a stretcher made of a 'iece of gunn# sheet, 8 ft.

b# 1 ft., nailed to two bamboos each D ft. > in. long.9

The cattle slee' on this bedding during the night. In

this wa# the bedding gets crushed and bro-en still

further and also im'regnated with urine. e*t morning one5fourth of a taari64ig. 79

of fresh dung is remo$ed to the com'ost 'it< the rest of the cattle dung being scattered

on the bedding in lum's not bigger than a small orange< or this e*cess dung can be

made into cow5dung ca-es 6kundas9 for fuel.

6A taariis a bowl made of sheet iron, ca'acit# fi$e5

se$enths of a cubic foot. In Table I= the metal bowls

are con$erted into 'ounds or double handfulls of the

materials used.'undas, thin flat cow5dung ca-es,about twel$e inches in diameter and one inch thic-,

are used in the $illages of India as fuel for the

coo-ing of food.9 Two5fifths of a taariof dr# urine

earth is s'rin-led on the used bedding in the same manner as murum6(urumis the

Hindustani name of the 'ermeable la#er of deca#ed basalt which underlies the blac-

cotton soils of India9 is s'read on roads.

The bedding is then transferred b# a s'ade 64ig. 19 on to thepalfrom one end to the

other and remo$ed to the com'ost 'it. In this wa# the raw material used for the

com'ost is made 'erfectl# homogeneous. The earthen floor of the cattle5shed should

then be swe't clean, the swee'ings being remo$ed onapalto the com'ost 'it. All wet 'atches on the floor

are co$ered with new earth, after scra'ing out the

$er# wet 'ortions. In this wa# all smell in the cattle5

shed is a$oided and the breeding of flies in the earth

underneath the animals is entirel# 're$ented. edding

for the ne*t da# can then be laid as described abo$e.

"uring the rains, the bedding should consist of three

la#ers 55 a bottom la#er and a to' la#er of dr#

material s'eciall# reser$ed for the 'ur'ose, an# withered residues being sandwiched

in between. )n $er# wet da#s, all the urine earth ma# be added to the bedding beforeremo$al to the com'ost hea'.

Fig. 1. & stret#her 'pal( for

removing %edding.

Fig. 2. & sheet-iron %owl 'tagari(.

Fig. ). & spade 'phawra( used in

#ompost ma$ing.


37/104

The $olume and weight of the $arious materials which are mo$ed to and fro in the

sheet5iron bowls 6taaries9 are gi$en in Table I=.

Table I4

4olume 5In 2ouble Handfulls6 and Weight 5In7b.6 of the $ontents of a Tagari

Golume in

double

handfulls

Wei&ht in

lb/

Fresh dun& $/5 '/5

Po


38/104

added, as the# arri$e, from one edge of the 'it b# sim'l# allowing the bamboo 'ole of

thepalne*t the 'it to fall into it 6Plate =II9.

The other 'ole is then lifted so that the rest of the

bedding dro's easil# into the 'it. The material is then

s'read b# means of the ra-e in a la#er, not e*ceedingtwo inches thic- o$er the com'ost 'it. All tram'ling

of the charged 'it must be a$oided as this interferes

with aeration. Some dr# urine earth and then the

stirred slurr# are first s'rin-led thinl# on each charge of bedding, which should a''ear

e$enl# wetted. The soa-ed residues from the tub are then scattered on each la#er of

bedding.

This inoculates the mass with acti$e fungus throughout. The 'olished surfaces of the

bedding are also co$ered with an acti$e adherent coating. This leads to ra'id and e$en

crumbling. The $olume of the slurr# is made u' with more dung, fungus starter and

water as re:uired. The 'it is charged with the bedding, la#erb# la#er, until all the bedding is used u'. The swee'ings from

the cattle5shed floor, which are rich in urine, are s'rin-led on

the to' of each da#Fs charge with a taari, followed b# one5

third of a tin of fresh water. This distributes the urine e$enl#

throughout the dail# charge and also 're$ents e*cess dr#ing.

Another watering in the e$ening, with two5thirds of a tin, and

a third watering the ne*t morning with one5third of a tin

com'letes the charge. The 'it or a suitable 'ortion of it

should be filled u' to the brim in si* da#s or less, the

remaining 'art being filled subse:uentl#. 6The 'eriod of

charging must not e*ceed si* da#s, whether or no the 'it is com'letel# filled b# then.

ach si* da#sF charge should be regarded as one unit in the manufacture of com'ost,

no matter whether the 'it is filled com'letel# or not.9 $er#thing is now read# for the

de$elo'ment of an acti$e fungus growth 6the first stage in the manufacture of

com'ost9. When 'ro'erl# managed, a $ertical section of the fermenting mass should

a''ear :uite uniform and should not show an# alternate la#ers.

Fig. *. +ooden ra$e for #harging

pits.

Fig. . +ater tin.


39/104

Plate "II. harging the ompost pits '1( harging the ompost pits '2( &pplying the

slurry

As the 'its are fre:uentl# full of water during the greater 'art of the rains, the com'ost

must be made in hea's 6Plate =III9 from the middle of Gune to / )ctober. The

dimensions of the hea's should not e*ceed D ft. b# D ft. at the to', E ft. b# E ft. at the

bottom and 7 ft. in height. The dimensions of these monsoon hea's 6an# one of which

is not necessaril# com'leted b# the amount of $egetable waste which can be

accumulated in si* da#s9 must not be e*ceeded, otherwise aeration difficulties are

certain to be encountered. The decom'osition in hea's during the rains does not ta-e

'lace so e$enl# as in the 'its.

Plate "III. ompost manufa#ture in the rainy season


40/104

"uring the earl# rains, all the material in the 'its must be transferred to hea's on the

surface. This is most con$enientl# done at the time of the first, second or third turn.

The subse:uent waterings are most im'ortant, otherwise deca# will sto'. The first

watering is done twel$e da#s 6da#s should be counted from the date on which thefilling of the 'it begins9 after charging, when /.7 tins are added e$enl# o$er the

whole surface. 4urther water is added at the time of the first, second and third turning

and afterwards as needed. "uring the rains, the :uantit# of water as gi$en abo$e must

be added at the time of charging< the subse:uent waterings during the rains ma# be

reduced or com'letel# omitted according to the weather. Stagnant rain5water from the

'its should ne$er be used. When watering is done b# a hose 'i'e from a tan- as at

Indore, the amount added can easil# be ad&usted if the rate of flow is -nown.

Turning the $om#ost

To ensure uniform mi*ture and deca#, and to 'ro$ide the necessar# amount of waterand air as well as a su''l# of suitable bacteria, it is necessar# to turn the material three

times. The onl# difficult# which is li-el# to arise in the 'rocess is the establishment of

anaerobic conditions between the 'eriod of charging and the first turn. This can be

caused b# o$erwatering or b# want of attention to the mi*ing. It is at once indicated

b# the smell and b# the a''earance of flies attem'ting to breed in the mass. When this

occurs, the hea' should be turned at once with the addition of dung slurr# and wood

ashes.

First turn.

Si*teen da#s after charge 6Plate IL9. Sufficient fresh water should be read# 55 aboutfour tins according to the season. Three5fifths of a taariof com'ost is ta-en from

another 'it thirt# da#s old 6&ust after the second turn9 and scattered on the surface of

the material. This is necessar# for inoculating the mass with the 'ro'er bacteria. The

to' la#er of the com'ost is then loosened and mi*ed, a 'ortion at a time, with a ra-e

and well moistened with water. Half the hea' is sliced with a s'ade a few inches

breadthwise and $erticall# from to' to bottom to fill one taariat a time. )aariafter

taariis 'oured in rows on the other undisturbed half to ma-e a la#er which is then

s'rin-led with water. This is re'eated until one5half of the contents of the 'it is

doubled lengthwise o$er the other. The hea' is then watered, suflicient being added at

this first turn to 're$ent the wasteful use of water afterwards. After turning, the hea'

should not rise more than twel$e inches abo$e ground le$el. The second watering, /.tins, is gi$en twent#5four da#s after charge. At the first turn, the materials should be

arranged on the windward side of the 'it to a$oid the cooling of the mass and also

e*cessi$e dr#ing. "uring the rains, when hea's are made, it is not 'ossible to double

one5half of the hea' o$er the other. The material should then be com'letel# turned and

the hea' re5made. The hea's should be made as near as 'ossible to each other.

Chapter (

%he Chief #actors in the Indore Process


41/104

The Indore 'rocess enables the Indian culti$ator to transform his mi*ed $egetable

wastes into humus< in other words to become a chemical manufacturer. The reactions

in$ol$ed are those which ta-e 'lace under aerobic conditions during the natural deca#

of organic residues in the soil. The ob&ect of the 'rocess is to bring these changes

under strict control and then to intensif# them. A -nowledge of the chemical 'rocesses

in$ol$ed and of their relati$e im'ortance is therefore essential in a''l#ing the 'rocessto other conditions. These matters form the sub&ect of the 'resent cha'ter.

The $ontinuous Su##ly of "i8ed 4egetable Wastes

A continuous su''l# of mi*ed $egetable wastes throughout the #ear, in a 'ro'er state

of di$ision, is the chief factor in the 'rocess. The ideal chemical com'osition of these

materials should be such that, after the bedding stage, the carbon5nitrogen ratio is in

the neighbourhood of 11;/. The material should also be in such a 'h#sical condition

that the fungi and bacteria can obtain read# access to, and brea- down the tissues

without dela#. The bar-, which is the natural 'rotection of the celluloses and lignins

against the inroads of fungi and bacteria, must first be destro#ed. This is the reasonwh# all wood# materials 55 such as cotton5stal-s, 'igeon5'ea stal-s and sann hem'

6Crotalaria juncea+.9 55 are laid on the roads and crushed b# the traffic into a fine

state of di$ision before com'osting. Still more refractor# residues li-e the stum's of

sugar5cane and millets, sha$ings, sawdust, waste 'a'er and 'ac-ing materials, old

gunn# bags and similar substances, must either be stee'ed in water for fort#5eight

hours or mi*ed with moist earth in a 'it for a few da#s before 'assing, in small

:uantities dail#, into the bedding.

The $egetable wastes which ha$e been utilized at Indore for the last si* #ears are the

following;

Residues a"ailable in lare *uantities+Cotton stal-s, sann hem' 55 either as green

'lants rea'ed before the flowering stage or as dried stems of the cro' -e't for seed,

'igeon5'ea stal-s, sugar5cane trash, weeds, fallen lea$es.

Residues a"ailable in moderate *uantities+!i*ed dried grass, gram stal-s, wheat

straw, uneaten and deca#ed silage, millet stal-s damaged b# rain, residues of the

safflower cro', ground5nut hus-s, ground5nut stal-s and lea$es damaged b# rain,

sugar5cane and millet stum's.

Residues a"ailable in small *uantities+Waste 'a'er and 'ac-ing materials, sha$ings,sawdust, worn out gunn# bags, old can$as, worn out uniforms, old leather belting.

The chemical com'osition of the abo$e or of similar materials is gi$en in Table =I.

Table 4I

$om#osition of the a! "aterials

%aterial(r&anic

matter)sh

Protein

sFats Fibre

oluble

carbo-

hydrate

s

Nitro&en


42/104

%alvi cotton-stal>s

9


43/104

residues

.round-nut hus>s !5/!0 1#/20 /5 2/!0 55/'5 1'/' 1/21

It will be seen that the raw materials a$ailable at Indore differ greatl# in chemical

com'osition and 'articularl# in the 'ercentage of nitrogen. !an# of these wastes,

such as cotton5stal-s, the stems of sann hem' and of the 'igeon5'ea, and cane trash

are too low in nitrogen for ra'id com'osting. )thers 55 such as green hem', rea'ed

&ust before flowering, ground5nut residues and leguminous and other weeds 55 contain

higher 'ercentages of nitrogen, a 'ortion of which is certain to be lost during the

'rocess if these materials are com'osted singl#. A 'ro'er mi*ture of the $arious

materials a$ailable, so that the nitrogen content of the mass throughout the #ear is

-e't uniform and sufficientl# high, is the first condition of success. 4or this reason it

is necessar# to collect and stac- the $arious residues in such a manner that a regular

su''l# of dr#, mi*ed, $egetable wastes 6as alread# stated with a carbon5nitrogen ratioin the neighbourhood of 11;/ after the material has been used as bedding9 is a$ailable

right through the #ear. This could onl# be accom'lished at Indore; 6/9 b# cutting the

cotton5stal-s soon after 'ic-ing is o$er so as to secure the ma*imum number of

lea$es< 679 b# growing a large area of sann hem', which contains when withered as

much as 7.1 'er cent of nitrogen< and 619 b# securing as much green weeds, groundnut

residues and fallen lea$es as 'ossible for the mi*ture. All these materials are rich in

nitrogen, and hel' to bring the carbon5nitrogen ratio near the re:uired standard. #

stac-ing the $arious constituents in la#ers, not more than one foot thic-, and b# a

&udicious admi*ture with the residues richest in nitrogen, it is 'ossible to 'ro$ide a

continuous su''l# of dr# mi*ed material of the correct chemical com'osition. "uring

the rains, a good deal of the raw material is in the form of fresh green weeds, rich in

nitrogen and soluble carbo5h#drates. These must be s'read, in thin la#ers, on the grass

borders of the fields alongside the roads and withered, before being carried to the

stac- or used as one of the constituents of the bedding. )nl# in this wa# can the most

be made of this $aluable material. Collecting weeds in tem'orar# hea's on the borders

of fields leads to serious waste of the soluble carbo5h#drates and also of the nitrogen.

$om#osting Single "aterials

A number of e*'eriments ha$e been carried out at Indore during the last four #ears

with the following single materials 55 cotton5stal-s, 'igeon'ea stal-s, cane trash,weeds 6green and withered9, sann hem' 6green and withered9. When necessar# these

residues were either 'assed through a chaff cutter or crushed with a disc harrow

before com'osting direct in hea's, eighteen inches high, or in 'its filled to the same

de'th. In some cases Adco was em'lo#ed as the source of nitrogen and base, in others

cattle5dung and urine earth were used. Sufficient water was alwa#s added to maintain

a high moisture content 6Table =II9.

Table 4II

"oisture $ontent of $otton-stal3 Hea#s

No/ of Nitro&en su++ly Percenta&e of moisture


44/104

hea+ and baseon

'/'/'0

on 15-'-

'0on '-#-'0

1"attle-dun& and

urine earth$2 5$ $2

2 H $ $ #

' H 5 $ $2

# H $2 $2 5$

5 H 5 2 '!

$ )dco $ $ $$

Although the cotton residues, fermented direct with urine earth and cattle5dung,

contained />. 'er cent of green lea$es 6high in nitrogen9 and e$er# care was ta-en to

maintain the correct relation between air and water, the results were not com'letel#

satisfactor#. 4ermentation was ra'id at the beginning, due to the 'resence of the

lea$es, but slowed down afterwards. It too- I@ da#s to obtain a usable 'roduct, as

com'ared with the ninet# da#s re:uired for mi*ed wastes.

In the case of cotton5stal-s, bro-en down b# the use of Adco, the results were still

more unsatisfactor#. Se$eral interesting facts howe$er came to light. The fermentation

tended to be une$en< the tem'erature of the hea's was alwa#s irregular< the mass didnot retain moisture well< a $er# large :uantit# of water was needed. The final 'roduct,

although high in nitrogen, tended to be somewhat coarse and to contain a good deal of

'artiall# decom'osed material Plate LI9. The ma*imum tem'eratures in the Adco

hea's during the first /@@ da#s fell from 1. degrees C. to 70. degrees C. 6In the

standard Indore 'rocess, the range of tem'erature during ninet# da#s was > degrees

C. to 11 degrees C.9 The final 'roduct was fairl# satisfactor# as regards fineness 6E@.

'er cent 'assed through a sie$e of si* meshes to the linear inch9 and high in total and

a$ailable nitrogen 6total 7.@, a$ailable @.87 'er cent9. The corres'onding figures for

the 'roduct made from cotton5stal-s with cattle5dung and urine earth were 55 fineness

E8.7 'er cent and total nitrogen /.>/, of which @./1 'er cent was a$ailable. In s'ite of

the higher nitrogen content obtained in the Adco 'roduct, no increase in growth wasobtained when e:ual :uantities of both -inds of cotton5stal- com'ost were used in 'ot

cultures of millet 64ig. D9. This result 'robabl# follows from the fact that the use of

Adco often 'roduces com'ost with a carbon5nitrogen ratio narrower than /@;/, the

ideal which should be aimed at in the manufacture of humus. The e*tra nitrogen in

such cases is alwa#s liable to be lost before the cro' can ma-e use of it.


45/104

Fig. /. 0he effe#t of Indore and &d#o #omposts on millet

The results obtained in the direct com'osting of other single materials, li-e 'igeon5

'ea stal-s and cane trash, were still more unsatisfactor#. When used alone, either withcow5dung and urine earth or with Adco, little change too- 'lace in a month in s'ite of

co'ious watering and occasional stirring. When, howe$er, these materials were 'assed

through the cattle5shed and used as bedding, the results were distinctl# better but not

reall# satisfactor#. At the end of si* months, the hea's were onl# about half

decom'osed.

"ifficulties also arise when weeds 6fresh or withered9 or sann hem' 6fresh or

withered9 are com'osted b# themsel$es or when a mi*ture of the two is em'lo#ed. In

the first 'lace, the nitrogen content of this material is too high and serious losses of

this element ta-e 'lace. In the second 'lace, these residues, 'articularl# when fresh,

tend to 'ac- closel# in the hea's and to 're$ent aufficient aeration 6Table =III9. 4orthis reason, withered weeds or withered sann must ne$er form more than about 1@ 'er

cent of the $olume of the bedding, the rest being made u' of mi*ed residues li-e

cotton and 'igeon5'ea stal-s with a much lower nitrogen content.

Table 4III

7osses of itrogen esulting from the $lose

Te8ture o

Documents

The Waste Products of Agriculture