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Title: The Waste Products of Agriculture
Author: Albert Howard
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THE WASTE PRODUCTS OF AGRICULTURE (1931)
Their Utilization as Humus

BY ALBERT HOWARD, C.I.E., M.A.
Director of the Institute Of Plant Industry, Indore,
and Agricultural Adviser to States in Central India and Rajputana

AND

YESHWANT D. WAD, M. Sc.

Chief Assistant in Chemistry, Institute of Plant Industry, Indore



To

SIR REGINALD GLANCY
K.C.I.E., C.S.I., C.I.E., I.C.S.
Member of the Council of India
Formerly Agent to the Governor-General in Central India
First President of the Board of Governors of the Institute of Plant
Industry, Indore (1924-1929)




PREFACE



One of the main features of crop production at the present day is waste.
Except in the Far East, where the large indigenous population has to be
fed from the produce of the country-side, little is being done to
utilize completely the by-products of the farm in maintaining the
fertility of the soil. The ever-growing supplies of agricultural
produce, needed by industry and trade, have been provided either by
taking up new land or by the purchase of artificial manures. Both these
methods are uneconomic. The exploitation of virgin soil is a form of
plunder. Any expenditure on fertilizers which can be avoided raises the
cost of production, and therefore reduces the margin of profit. It needs
no argument to urge that, in maintaining the fertility of the soil, the
most careful attention should be paid to the utilization of the waste
products of agriculture itself before any demands are made on
capital--natural or acquired.

For the last twenty-six years, the senior author has been engaged in the
study of crop production in India and in devising means by which the
produce of the soil could be increased by methods within the resources
of the small holder. These investigations fell into two divisions: (1)
the improvement of the variety; and (2) the intensive cultivation of the
new types. In the work of replacing the indigenous crops of India by
higher yielding varieties, it was soon realized that the full
possibilities in plant breeding could only be achieved when the soil in
which the improved types are grown is provided with an adequate supply
of organic matter in the right condition. Improved varieties by
themselves could be relied on to give an increased yield in the
neighbourhood of ten per cent. Improved varieties plus better soil
conditions were found to produce an increment up to a hundred per cent
or even more.

Steps were therefore taken: (1) to study the conversion of all forms of
vegetable and animal wastes into organic matter (humus) suitable for the
needs of the growing crop; and (2) to work out a simple process by which
the Indian cultivator could prepare an adequate supply of this material
from the by-products of his holding. In other words he has been shown
how to become a chemical manufacturer. This task involved a careful
study of the various systems of agriculture which so far have been
evolved and particularly of the methods by which they replenish the soil
organic matter. The line of advance in raising crop production in India
to a much higher level then became clear. Very marked progress could be
made by welding the various fragments of this subject--the care of the
manure heap, green-manuring and the preparation of artificial farmyard
manure--into a single process, which could be worked continuously
throughout the year and which could be relied upon to yield a supply of
humus, uniform in chemical composition and ready for incorporation into
the soil. This has been accomplished at the Institute of Plant Industry
at Indore. The work is now being taken up in Sind and at various centres
in Central India and Rajputana.

The Indore process for the manufacture of humus is described in detail
in the following pages. It can be adopted as it stands throughout the
tropics and sub-tropics, and also on the small holdings and allotments
of the temperate zone. How rapidly the method can be incorporated into
the large-scale agriculture of the west is a question which experience
alone can answer. It will in all probability depend on how far the
process can be mechanized.

In the field of rural hygiene there is great scope for the new method.
It can be applied to the utilization of all human, animal and vegetable
wastes in such a manner that the breeding of flies is prevented, the
water and the food-supply of the people safeguarded and the general
health of the locality improved. Cleaner and healthier villages will
then go hand in hand with heavier crops.


A.H.
Y.D.W.
Indore
6 April, 1931





CONTENTS




I INTRODUCTION

II ORGANIC MATTER AND SOIL FERTILITY

III THE SOURCES OF ORGANIC MATTER

IV THE MANUFACTURE OF COMPOST BY THE INDORE METHOD

V THE CHIEF FACTORS IN THE INDORE PROCESS

VI APPLICATION TO OTHER AREAS

APPENDIXES:--

A The Manurial Problem in India

B Some Aspects of Soil Improvement in Relation to Crop Production

C Nitrogen Transformation in the Decomposition of Natural Organic
Materials at Different Stages of Growth

D An Experiment in the Management of Indian Labour



Of composts shall the Muse disdain to sing?
Nor soil her heavenly plumes? The sacred Muse
Nought sordid deems, but what is base nought fair,
Unless true Virtue stamp it with her seal.
Then, planter, wouldst thou double thine estate,
Never, ah! never, be asham'd to tread
Thy dung-heaps. (From Grainger's The Sugar Cane.)




INTRODUCTION



The maintenance of the fertility of the soil is the first condition of
any permanent system of agriculture. In the ordinary processes of crop
production, fertility is steadily lost; its continuous restoration by
means of manuring and soil management is therefore imperative.

In considering how the ideal method of manuring and of soil management
can be devised, the first step is to bring under review the various
systems of agriculture which so far have been evolved. These fall for
the most part into two main groups: (1) the methods of the Occident to
which a large amount of scientific attention has been devoted during the
last fifty years; and (2) the practices of the Orient which have been
almost unaffected by western science.

The systems of agriculture of the Occident and of the Orient will now be
briefly considered with a view of extracting from each ideas and results
which can be utilized in the evolution of the ideal method of
maintaining and increasing the fertility of the soil.

NOTE: In the general organization of agriculture, Europe stands mid-way
between the east and the west and provides, as it were, the connecting
link between these two methods of farming.


THE AGRICULTURAL SYSTEMS OF THE OCCIDENT

The most striking characteristic of the agriculture of the west is the
comparatively large size of the holding. Large farms are the rule; small
holdings are the exception.

NOTE: The growth of allotments for the production of vegetables in the
neighbourhood of urban areas is a comparatively recent phenomenon and
only affects a small area.

The large farms of the west are for the most part engaged in the
production of food and a few raw materials like wool for the urban
populations of the world, which are mainly concerned with manufacture
and trade. To produce these vast supplies, and at the same time to place
them on the markets at low rates, practically all the unoccupied
temperate regions of the world, which are suitable for the white races,
have already been utilized. The best areas of North America, of the
Argentine, of South Africa and large tracts of Australia and practically
the whole of New Zealand have during the last hundred years been
exploited to produce the endless procession of cargoes of food and raw
materials required by the great markets of the world.

The weakness of this system of agriculture lies in the fact that it is
new and has not yet received the support which centuries of successful
experience alone can provide. At first it was based on the exploitation
of the stores of organic matter accumulated by virgin land, which at the
best could not last for more than a limited number of years. Even now
there is practically no attempt to utilize the large quantities of wheat
straw and other vegetable wastes for keeping up the store of organic
matter in the soil. The new areas of North America for example soon
showed signs of exhaustion. Manuring has become necessary as in the case
of the older fields of Europe. To supply the large quantities of
combined nitrogen needed, all possible sources except the right one--the
systematic conversion of the waste products of agriculture into
humus--have one after the other been utilized: guano from the islands
off the Peruvian coast, nitrate of soda from Chile, sulphate of ammonia
from coal and more recently synthetic nitrogen compounds obtained from
the atmosphere. These substances are supplemented by another class of
nitrogenous organic manures such as artificial guanos, dried blood and
slaughter-house residues, oil cakes and wool waste--the by-products of
agriculture--and by another group of artificials--the various phosphatic
and potassic fertilizers. These supplies of concentrated manures have
enabled agricultural production to be kept at a high level. The fact of
their existence for a time tended to distract attention from the fullest
utilization of the by-products of the farm. Recently, however, a change
has taken place and a large amount of scientific effort has been devoted
to the problems which centre round the waste products, both animal and
vegetable, of agriculture itself. The need of keeping up the supply of
organic matter in the soil is now widely recognized.

After the large size of the holding and the necessity of manuring, the
high cost of labour is another leading characteristic of western
farming. The number of men per square mile of agricultural land who
actually work is low.

NOTE: The comparative figures of crop production per worker for the
five-year period preceding the War, prepared by the United States
Department of Agriculture, are instructive. The number of workers
employed per 1,000 acres of crop land was approximately 235 in Italy,
160 in Germany, 120 in France, 105 in England and Wales, 60 in Scotland
but only 41 in the United States. In Canada, according to Riddell, the
1911 figures show that every 1,000 acres called for only 26 workers.
This observer states that in the three prairie provinces (Alberta,
Manitoba, Saskatchewan) the figures are even more striking: the area
under field crops was 17,677,091 acres, and the numbers engaged in
agriculture was 283,472, so that each person so employed was responsible
for 62 acres. Every 1,000 acres required only 16 workers. Since these
data were published, further statements have appeared from which it
would seem that the size of the working population in agriculture in
North America has shrunk still further.

This state of things has arisen from the dearness and scarcity of
labour, which has naturally led to the study of labour-saving devices
including the use of machinery. Whenever a machine can be invented which
saves human labour its spread is rapid. Engines of various kinds are the
rule everywhere. The inevitable march of the combine-harvester, in all
the wheat-producing areas of the world, is the latest example of the
mechanization of the agriculture of the west. Another feature of this
extensive system of large-scale agriculture is the development of food
preservation processes, of transport and of marketing, by which the
products of agriculture are cheaply and rapidly moved from the field to
the centres of distribution and consumption. There is no great dearth of
capital at any stage. Money can always be found for any new machine and
for any new development which is likely to return a dividend. Land and
capital are abundant; efficient transport and good markets abound. The
comparatively small supply of suitable labour and its high cost provide
the chief agricultural problems of the west.

This system of agriculture is essentially modern and has developed
largely as one of the consequences of the discovery of the steam engine
and the rapid exploitation of the supplies of coal, oil and water-power.
It has only been made possible by the existence of vast areas of virgin
land in parts of the earth's surface on which the white races can live
and work. As already mentioned the weak point in this method of crop
production is that it is new and lacks the backing which only a long
period of practical experience can supply. Mother Earth is provided with
an abundant store of reserve fertility which can always be exploited for
a time. Every really successful system of agriculture however must be
based on the long view, otherwise the day of reckoning is certain.

Side by side with this method of utilizing the land there has been a
great development of science. Efforts have been made to enlist the help
of a number of separate sciences in studying the problems of agriculture
and in increasing the production of the soil. This has entailed the
foundation of numerous experiment stations, which every year pour out a
large volume of printed results and advice to the farmer. At first the
scientific workers naturally devoted themselves to solving local
problems and to furnishing scientific explanations of various
agricultural practices. This phase is now passing. A new note is
beginning to appear in the publications of the experiment stations,
namely that of direction and advice which can only be advanced by men
whose education and training combine the ideas of science with the aims
of the statesman. The feeling is not only growing but is being expressed
that it is no longer the business of science merely to solve the
problems of the moment. Something more is needed. The chief function of
science in the agriculture of the future is to provide intelligent
direction in general policy and to point the way.



THE AGRICULTURAL SYSTEMS OF THE ORIENT

Peasant Holdings

The chief feature of the agricultural systems of the east is the small
size of the holding. The relation between man-power and cultivated area
in India is given in Table I. In this table, based on the Census Report
of 1921, the number of workers and the acreage cultivated have been
calculated for the chief provinces of British India. Incidentally these
figures illustrate how intense is the struggle for existence in this
portion of the tropics.


TABLE I.--THE RELATION BETWEEN MAN-POWER AND CULTIVATED AREA IN INDIA

Provinces        Number of acres cultivated by 100 ordinary cultivators

Bombay                                   1,215
North-West Frontier Province             1,122
Punjab                                     918
Central Provinces                          848
Burma                                      565
Madras                                     491
Bengal                                     312
Bihar and Orissa                           309
Assam                                      296
United Provinces                           251


These minute holdings are frequently cultivated by extensive methods
(those suitable for large areas) which neither utilize the full energies
of man and beast nor the potential fertility of the soil. Such a system
of agriculture can only result in poverty. The obvious line of advance
is the gradual introduction of more intensive methods, for which the
supply of suitable manure, within the means of the average cultivator,
is bound to prove an important factor.

If we turn to the Far East, to China and Japan, a similar system of
small holdings is accompanied by an even more intense pressure of
population both human and bovine. In the introduction to Farmers of
Forty Centuries, King states that the three main islands of Japan had in
1907 a population of 46,977,003, maintained on 20,000 square miles of
cultivated fields. This is at the rate of 2,349 to the square mile or
more than three people to each acre. Note that these figures agree very
closely with those quoted in the Japan Year Book of 1931 in which the
number of persons per square kilometre is given as 969: equivalent to
2,433 to the square mile.

In addition Japan fed on each square mile of cultivation a very large
animal population--69 horses and 56 cattle, nearly all employed in
labour; 825 poultry; 13 swine, goats and sheep. Although no accurate
statistics are available in China, the examples quoted by King reveal a
condition of affairs not unlike Japan. In the Shantung Province, a
farmer with a family of twelve kept one donkey, one cow and two pigs on
2.5 acres of cultivated land--a density of population at the rate of
3,072 people, 256 donkeys, 256 cattle and 512 pigs per square mile. The
average of seven Chinese holdings visited gave a maintenance capacity of
1,783 people, 212 cattle or donkeys and 399 pigs--nearly 2,000 consumers
and 400 rough food transformers per square mile of farm land. In
comparison with these remarkable figures, the corresponding statistics
for 1900 in the case of the United States per square mile were:
population 61, horses and mules 30.

The problems of tropical agriculture for the most part relate to small
holdings. The main purpose of this peasant agriculture is crop
production; animal husbandry is much less important. In India the crops
grown fall into two classes--(1) food and fodder crops and (2) money
crops. The former includes, in order of area: rice, millets, wheat,
pulses and fodder crops, barley and maize and sugar-cane. The money
crops are more varied; cotton and oil seeds are the most important,
followed by jute and other fibres, tobacco, tea, opium, indigo and
coffee. It will be seen that food and fodder crops comprise 82 per cent
of the total area under crops and that money crops, as far as extent is
concerned, are relatively unimportant.


TABLE II.--AGRICULTURAL STATISTICS OF BRITISH INDIA, 1926-27

Area, in acres, under food and fodder crops

Rice                               78,502,000
Millets                            38,776,000
Wheat                              24,181,000
Gram                               14,664,000
Pulses and other good grains       29,154,000
Fodder crops                        8,940,000
Condiments, spices, fruits,
vegetables, and misc. food crops    7,537,000
Barley                              6,387,000
Maize                               5,555,000
Sugar                               3,041,000

TOTAL, FOOD AND FODDER CROPS      216,737,000


Area, in acres, under money crops

Cotton                             15,687,000
Oil seeds, chiefly rape and
mustard, sesamum, groundnuts
and linseed                        14,999,000
Jute and other fibres               4,411,000
Dyes, tanning materials, drugs,
narcotics and miscellaneous crops   1,729,000
Tobacco                             1,055,000
Tea                                   738,000
Opium                                  59,000
Indigo                                104,000
Coffee                                 91,000

TOTAL, MONEY CROPS                 38,873,000


The primary function of Indian agriculture is to supply the cultivator
and his cattle with food. Compared with this duty all other matters are
subsidiary. The houses are built of mud, thatched with grass and are
almost devoid of furniture. Expenditure on clothing and warmth is, on
account of the customs of the country and the nature of the climate,
much smaller than in European countries. Nevertheless, the cultivators
require a little money with which to pay the land revenue and to
purchase a few necessaries in the village markets. Hence the growth of
money crops to the extent of about one-fifth the total cultivated area.
The produce, after conversion into cash, is afterwards either worked up
in the local mills or exported. To some extent food crops are also money
crops. The population of the towns and cities is largely fed from the
produce of the soil, while in addition a small percentage of the total
food grains produced is exported to foreign countries. In some crops
like sugar-cane, the total out-turn is insufficient for the towns and
large quantities of sugar are imported from Java, Mauritius and the
continent of Europe.

When we come to the details of soil management, a further striking
difference between the methods in vogue in the west and on the peasant
holdings of the east is at once manifest. In China, fertility has for
centuries been maintained at a high level without the importation of
artificial manures. Although it was not till 1888, after a protracted
controversy lasting thirty years, that western science finally accepted
as proved the important part played by pulse crops in enriching the
soil, nevertheless centuries of experience had taught the peasants of
the east the same lesson. The leguminous crop in the rotation is
everywhere one of their old fixed practices. Moreover, on the alluvium
of the Indo-Gangetic Plain, the deep, spreading root-system of the
pigeon pea (Cajanus indicus Spreng.) is utilized by the peasantry as an
efficient substitute for the periodical subsoil ploughing which these
closely-packed, silt-like soils require. In the case of the best
cultivators, the general soil management and particularly the
conservation and utilization of combined nitrogen has already reached a
high level. This has been described, in the case of the United Provinces
of India, by Clarke in a recent paper which has been reproduced as
Appendix B. In China and Japan not only the method of soil management
but also the great attention that is paid to the systematic preparation,
outside the field, of food materials for the crop from all kinds of
vegetable and animal wastes compelled the admiration of one of the most
brilliant of the agricultural investigators of the last generation. The
results are set out by King in his unfinished work--Farmers of Forty
Centuries--which should be prescribed as a textbook in every
agricultural school and college in the world.

Another feature of this agriculture is the cultivation of rice wherever
the soil and water-supply permit. In the scientific consideration of the
methods of soil management under which the rice crop of the Orient is
produced, practical experience at first seems to contradict one of the
great principles of the agricultural science of the Occident, namely the
dependence of cereals on nitrogenous manures. Large crops of rice are
produced in many parts of India on the same land year after year without
the addition of any manure whatever. The rice fields of the country
export paddy in large quantities to the centres of population or abroad,
but there is no corresponding import of combined nitrogen.

Taking Burma as an example of an area exporting rice beyond seas, during
the twenty years ending 1924, about 25,000,000 tons of paddy have been
exported from a tract roughly 10,000,000 acres in area. As unhusked rice
contains about 1.2 per cent of nitrogen the amount of this element,
shipped overseas during twenty years or destroyed in the burning of the
husk, is in the neighbourhood of 300,000 tons. As this constant drain of
nitrogen is not made up for by the import of manure, we should expect to
find a gradual loss of fertility. Nevertheless this does not take place
either in Burma or in Bengal, where rice has been grown on the same land
year after year for centuries. Nearly the soil must obtain fresh
supplies of nitrogen from somewhere, otherwise the crop would cease to
grow. The only likely source is fixation from the atmosphere, probably
in the submerged algal film on the surface of the mud. This is one of
the problems of tropical agriculture which calls for early
investigation.

Another important difference between the east and the west concerns the
supply of labour. In the Orient it is everywhere adequate, as would
naturally follow from the great density of the rural population. Indeed
in India it is so abundant that if the time wasted by the cultivators
and their cattle for a single year could be calculated as money, at the
local rates of labour, a perfectly colossal figure would be obtained.
One of the problems underlying the development of agriculture in India
is the discovery of the best means of utilizing this constant drain, in
the shape of wasted hours, for increasing crop production. There is
therefore no lack of human labour in developing the agriculture of the
east. Another favourable factor is the existence of excellent breeds of
work-cattle and of the buffalo.

NOTE: The buffalo is the milch cow of the Orient and is capable not only
of useful labour in the cultivation of rice, but also of living and
producing large quantities of rich milk on a diet on which the best
dairy cows of Europe and America would starve. The digestive processes
of the buffalo is a subject which appears to have escaped the attention
of the investigators of animal nutrition.

The last characteristic of this ancient system of agriculture is lack of
money. Again there is a great contrast between the east and the west.
There is little or no spare capital for the improvement of the holding.
Over large tracts of India at any rate, the cultivators are in the hands
of the moneylender and indebtedness is the rule. For many years one of
the pre-occupations of Government has been the discovery of safeguards
by which the cultivator can be saved from the worst consequences of his
own folly--reckless borrowing for unproductive purposes--and maintained
on the land. The recent development of co-operation and the rapid
increase in the number of primary credit societies has only been
possible because of this volume of indebtedness.


PLANTATIONS

While small holdings, accompanied by a dense population, are an
important feature of eastern agriculture, nevertheless there are
exceptions. Throughout this portion of the tropics European enterprise
has removed the original forest and established in its place extensive
plantations of such crops as sugar-cane, tea, rubber and coffee. The
labour for these estates is obtained from indigenous sources; the
capital and management are contributed by Europeans. Plantations of this
kind are common all over the east and are an important feature of the
agriculture of Java, Ceylon, the Federated Malay States, Assam and the
uplands of Southern India. One of the features of this agriculture is
the attention paid to manurial problems. Comparatively large sums of
money are expended every year in the purchase of artificial manures,
mainly for keeping up the supply of combined nitrogen. During a tour in
Ceylon in 1908, when visits were paid by the senior author to a number
of tea estates, the managers invariably produced their manurial
programme on which suggestions were always invited. Ceylon at that time
offered a tragic example of the damage which results from uncontrolled
tropical rainfall on sloping land, from which the forest canopy had been
removed without providing a proper system of terracing combined with
surface-drainage. Over large areas of hilly country, formerly forest and
now exclusively under tea, practically the whole of the valuable surface
soil rich in humus had been lost by denudation. The tea plant was
producing crops from the relatively poor subsoil, supplemented by the
constant application of expensive manures.

In a recent review of this question in Crop Production in India
published in 1924, the damage which has resulted from erosion on the
plantations of the Orient was referred to (pp. 14-5) as follows:--


It is in the planting areas of the east, however, that the most
striking examples of soil denudation are to be found. Instances
of damage to the natural capital of the country are to be seen on
the tea estates near Darjeeling, on the hill-sides in Sikkim on the
upper terraces in the vale of Kashmir, in the Kumaon Hilis, on
the tea estates in Ceylon and Assam, and in the planting districts
of Southern India and the Federated Malay States. In most of
these areas forest land was so abundant that the need for the
preservation of the soil was not at first recognized. Thanks to the
efforts of Hope, a former scientific officer employed by the tea
industry in Assam the control of the drainage and the checking
of erosion are now widely recognized and are being dealt with by
the planters in many parts of India. A great impetus to this
work was given by the publication in India of a detailed account of
the methods in use by the Dutch planters in Java, where the
terracing and drainage of sloping land, under tea and other crops
has been carried to a high stage of perfection. In this island
the area of land available for planting is strictly limited, while
the feeding of the large indigenous population is always a
serious problem. As a consequence the development of the island is
very strictly controlled by the Government, and one of the
conditions of planting new forest lands is the provision of a
suitable system of terraces combined with surface-drainage.
The advantage is not all on the side of the State. The manuring of
tea soils in Java is far less necessary than in Ceylon and
India, while one important consequence of the retention of the
valuable soil made by the forest is healthy growth, which
suffers remarkably little damage from insect and fungoid pests.


UNDEVELOPED AREAS

Very large stretches of the Orient are still under forest and at present
carry a very small population, supported by hunting, fishing and by the
small cultivated areas surrounding the villages. These undeveloped
forest areas occur everywhere, particularly in the Malay Archipelago,
the Federated Malay States, Burma and the low country of Ceylon. In the
search for the ideal method of manuring in the tropics, the greatest
care will have to be taken to preserve the valuable surface soil
whenever the forest canopy has to be removed for the creation of new
cultivated land. Some at any rate of these potentially rich tracts are
almost certain to be taken up during the present century. They will
therefore provide ample opportunities of applying any lessons in soil
management, which science can extract from experiment and from
experience. The serious mistakes of the past must not be repeated when
the time comes for developing the vast areas of tropical forest still
untouched.

It will be evident that the systems of agriculture of the west and of
the east are very different and that the two have 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 supplements the other: each can be regarded
as a part of one great whole. Clearly when attempting to evolve the
ideal system of manuring and soil management of the future, both of
these widely different methods of agriculture must be studied. This has
been done by the senior author for the last twenty-six years in various
parts of India--on the alluvium of the Indo-Gangetic plain at Pusa in
Bihar, on the loess soils of the Quetta Valley on the Western Frontier
and on the black cotton soils of peninsular India at Indore. The chief
climatic factors at Indore are represented in Plate II. The climate of
Quetta resembles generally that of Persia, where the rainfall is
received mainly during the winter months, often in the form of snow. At
these three centres a method of utilizing all the vegetable and animal
wastes of the holding has gradually been evolved. The latest scientific
work of the Occident and particularly that recently accomplished at the
experiment station of New Jersey, together with the practices in vogue
in India and the Far East, have been welded together and synthesized
into a system for the continuous manufacture of manure throughout the
year so that it forms an integral part of the industry of agriculture.

In considering all this information--the various agricultural systems in
use at the present time, as well as the large volume of scientific
papers dealing with manurial questions, which have been poured out by
the experiment stations during the last fifty years, we have been
impressed by the evils inseparable from the present fragmentation of any
large agricultural problem and its attack by way of the separate
science. All this seems to follow from the excessive specialization
which is now taking place, both in the teaching and in the application
of science. In the training given to the students and in much of the
published work, the tendency of knowing more and more about less and
less is every year becoming more marked. For this reason any review of
the problem of increasing soil fertility is rendered peculiarly
difficult, not only by the vast mass of published papers but also by
their fragmentary and piecemeal nature.

No extra labour is required in our manure factory. No imported chemicals
such as Adco are needed in this process. No capital is required at any
stage of the manufacture. The methods now in use at Indore form the main
subject of this book, which also attempts to deal with a number of
related matters such as--the role of organic matter in the soil, the
methods of replenishing the supply of organic matter now in use and the
recent investigations which have been carried out on the conditions
necessary for converting raw organic residues into humus which can be
immediately nitrified in the soil and so made use of by the plant. The
Indore process can easily be carried out, not only in the tropics but
also on the small holdings of the temperate regions and on the
allotments (provided space is made available) in the neighbourhood of
urban areas, where it is now the practice to burn most of the vegetable
waste. How rapidly the system can be introduced into the farming systems
of the Occident is a question to which no answer can be given until the
ideas in this book have been fully tried out in western agriculture. It
is not impossible that they may founder for a time on the present high
cost of labour. The method however is in full accord with the
well-marked tendency in western agriculture towards a more intensive
production. The inevitable change over from extensive to intensive
methods has already begun. For production to be more economical, the
acre yield must be increased. Already in the United States the
suggestion has been made that the line of advance in crop production
lies in restricting the area cultivated. A portion of the impoverished
prairie lands should go back to grass. The crops needed should be raised
from a smaller area. These ideas will become practicable the moment the
farmer learns how to utilize the waste products of his fields in
increasing the fertility of the soil. This is the greatest need of
agriculture at the present day.


BIBLIOGRAPHY

CLARKE, G.--'Some Aspects of Soil Improvement in Relation to Crop
Production,' Proc. of the Seventeenth Indian Science Congress, Asiatic
Society of Bengal, Calcutta,1930, p. 23.

DUCKER, H. C.--'Soil Erosion Problems of the Makwapala and Port Herold
Experiment Stations, Nyasaland,' Empire Cotton Growing Review, 8, 1931,
p. 10.

FELSINGER, E. O.--'Memorandum on a System of Drainage Calculated to
Control the Flow of Water on Up-country Estates, with a view to
reducing Soil Erosion to a Minimum,' Tropical Agriculturist, 71, 1928,
p. 221; 74, 1930, p. 68.

HOWARD, A.--Crop Production in India, a Critical Survey of its Problems,
Oxford University Press, 1924.

HOWARD, A. and HOWARD, G. L. C.--The Development of Indian Agriculture,
Oxford University Press, 1929.

KING, F. H.--Farmers of Forty Centuries or Permanent Agriculture in
China, Korea and Japan, London, 1926.

LIPMAN, J. G.--'Soils and Men,' Proc. of the Inter. Congress on Soil
Science, Washington, D.C., 1928, p. 18.

MATTHAEI, L. E.--'More Mechanization in Farming, International Labour
Review, Geneva, 23, 1931, p.324.

PERCY, LORD EUSTACE--Education' at the Cross Roads, London, 1930.

Report of the Royal Commission on Agriculture in India Calcutta, 1928.

RIDDELL, W. A.--'The Influence of Machinery on Agricultural Conditions
in North America,' International Labour Review, Geneva, 13, 1926, p.
309.

WAGNER, W.--Die Chinesische Landwirtschaft, Berlin, 1926, p 222.




Chpater II



ORGANIC MATTER AND SOIL FERTILITY


The ancients and the moderns are in the completest agreement as to the
importance of organic matter in maintaining the fertility of the soil.
This is evident when the methods of crop production in the time of the
Romans are compared with the views now held by many of the leading
experiment station workers in the United States and other parts of the
world. In Roman times, the management of the manure heap had already
reached an advanced stage. In 40 B.C. Varro drew attention to the great
importance of the complete decay of manure before it was applied to the
land. To bring this about, the manure heap, during the period of
storage, had to be kept moist. In A.D. 90 Columella emphasized the
importance of constructing the pits (in which farmyard manure was
stored) in such a manner that drying out was impossible. He mentions the
need of turning this material in summer to facilitate decay, and
suggested that ripened manure should always be used for corn, while the
fresh material could be applied with safety to grass land. The Romans
therefore not only understood the importance of organic matter in crop
production but had gone a long way towards mastering the principle that,
to obtain the best results, it is necessary to arrange for the decay of
farmyard manure before it is applied to arable land. It is interesting
to turn from the writings of the ancients to the account of the
symposium on 'Soil Organic Matter and Green-manuring' arranged by the
American Society of Agronomy at Washington D.C. on 22 November 1928, the
main results of which appeared in the Journal of the American Society of
Agronomy of October 1929. Without exception, the investigators who took
part in this conference laid the greatest emphasis on the importance of
keeping up the supply of organic matter in the soil, and on discovering
the most effective and the most economical method of doing this under
the various conditions, as regards moisture, which the soils of the
United States present.

During the 2,000 years which have elapsed since Varro wrote in 40 B.C.
and the American investigators met in 1928, there has occurred only one
brief period during which the role of organic matter was to some extent
forgotten. This took place after Liebig's Chemistry in its Application
to Agriculture and Physiology first appeared in 1840. Liebig emphasized
the fact that plants derive their carbon from the carbon dioxide of the
atmosphere and advanced the view that, in order that a soil may remain
fertile, all that is necessary is to return to it, in the form of
manure, the mineral constituents and the nitrogen that have been taken
away in the crop. The discovery of the true origin of the carbon of
plants not unnaturally suggested that the organic matter in the soil was
of little consequence. Nitrogen and minerals only remained, the latter
being found in the plant ashes. When therefore analyses of the crops had
been made, it would be possible to draw up tables showing the farmer
what he must add in the way of nitrogen and minerals in any particular
case. These views and the controversies to which they gave rise,
combined with the results of the Rothamsted experiments (started by
Lawes and Gilbert in 1843) led to the adoption of artificial manures by
many of the farmers of Europe. The Rothamsted experiments undoubtedly
proved that if the proper quantities of combined nitrogen, phosphates
and potash are added to the soil, satisfactory crops for many years can
be obtained without the addition of organic matter beyond that afforded
by the roots of the crops grown. Further, the results of hundreds of
trials, in the course of ordinary farming practice, confirmed the fact
that the judicious addition of nitrogenous artificial fertilizers can,
in the great majority of cases, be relied on to increase the yield. It
was only natural that results of this kind, combined with the important
fact that the application of artificials often pays in practice,
produced a marked effect on current opinion and also on teaching. For
nearly a century after Liebig's ideas first appeared, the majority of
agricultural chemists held that all that mattered in obtaining maximum
yields was the addition of so many pounds of nitrogen, phosphorus and
potassium to the acre. Beyond this the only other factor of importance
was the liming of acid soils. The great development of the artificial
manure industry followed as a matter of course.

The place of organic matter in the soil economy was forgotten. The old
methods of maintaining soil fertility naturally fell into the
background.

For a time all seemed to go well. It is only in comparatively recent
years that experiment station workers have begun to understand the part
played in crop production by the micro-organisms of the soil and to
realize that the supply of artificials is not the whole story. Something
more is needed. The need for the maintenance of the supply of organic
matter soon became apparent. The view now beginning to be held is that,
only after the supply of organic matter has been adequately provided
for, will the full benefit of artificials be realized. There appears to
be a great field for future experiment in the judicious use of
artificials to land already in a fair state of fertility.

In all this however there was one important exception. In the Orient,
the artificial manure phase had practically no influence on indigenous
practice and passed unheeded. The Liebig tradition failed to influence
the farmers of forty centuries. No demand for these products of the west
exists in China. At the present day it would be difficult to purchase
such a substance as sulphate of ammonia in the bazaars of rural India.


SOIL HUMUS, ITS ORIGIN AND NATURE

What is the origin and nature of the organic matter or soil 'humus' and
what part does it play in soil fertility? These matters form the subject
of the present chapter.

NOTE: In the presentation which follows, the fullest use has been made
of (1) one of the papers of Waksman (Paper No. 276 of the Journal
Series, New Jersey Agricultural Experiment Station, Department of Soil
Chemistry and Bacteriology, afterwards published in Soil Science, 22,
1926, p. 123) and (2) of the symposium on soil organic matter and
green-manuring which appeared in the issue of the Journal of the
American Society of Agronomy of October 1929. These important
contributions to the subject have made it easy briefly to sketch the
necessary scientific background for the presentation of the Indore
process.

The organic matter found in the soil consists of two very different
classes of material: (1) the constituents of plants and animals which
have been introduced into the soil and are undergoing decomposition;
various unstable intermediate products which have been formed under
certain environmental conditions; substances like lignified cellulose
which are more resistant to decomposition and which may persist in the
soil for some time; and (2) number of valuable materials which have been
synthesized by the numerous groups of micro-organisms which form the
soil population. The soil organic matter is thus a heterogeneous mass of
substances which is constantly undergoing changes in composition. When
its composition reaches a certain stage of equilibrium, it becomes more
or less homogeneous and is then incorporated into the soil as 'humus'.
This definition of soil organic matter, which is due to Waksman, is of
great importance. Soil organic matter or 'humus' is not merely the
residue left when vegetable and animal residues decay. It contains in
addition the valuable materials synthesized and left behind by the fungi
and bacteria of the soil population. Moreover it is a product of the
general soil conditions which obtain in any particular locality, and
therefore varies in composition and character from one soil type to
another. It is not the same all over the world. The soil humus for
example of the black cotton soils of India is not identical with that of
the alluvium of the Indo-Gangetic plain.

The various steps in the formation of soil organic matter are somewhat
as follows. When the fresh remains of plants or animals are added to the
soil, a portion of this organic matter is at once attacked by a large
number of the micro-organisms present. Rapid and intense decomposition
ensues. The nature of these organisms depends on the soil conditions
(mechanical and chemical composition and physical condition) and on the
soil environment (moisture content, reaction and aeration, and the
presence of available minerals). The decomposition processes can best be
followed by measuring one of the end-products of the reaction--carbon
dioxide. The rate of evolution of this gas depends on the nature of the
organic matter, on the organisms which take part in the process and on
the soil environmental conditions. As soon as the readily decomposable
constituents of the plant and animal remains (sugars, starches, pectins,
celluloses, proteins, amino-acids) have disappeared, the speed of
decomposition diminishes and a condition of equilibrium tends to become
established. At this stage only those constituents of the original
organic matter, such as the lignins which are acted upon slowly, are
left. These and the substances synthesized by the micro-organisms
together form the soil humus and then undergo only a slow transformation
during which a moderate but constant stream of carbon dioxide is
liberated. At the same time the nitrogen of this soil humus is similarly
converted into ammonia which, under favourable conditions, is then
transformed into nitrate. It will be clear therefore that the soil
organic matter or humus is a manufactured product and that its
composition is not everywhere the same, but will vary with the soil
conditions under which it is produced. Like all manufactured articles,
it must be properly made if it is to be really effective. Too much
attention therefore cannot be paid to its preparation.

After the production of humus and its incorporation into the soil mass,
the next step is its utilization by the crop. This can only take place
when this organic matter is decomposed by the micro-organisms of the
soil. This process is very slow, as can be seen by placing a quantity of
soil under favourable environmental conditions and measuring the rate of
decomposition, either by the evolution of carbon dioxide or by the
accumulation of ammonia and nitrate nitrogen. Since the ratio between
the carbon and nitrogen content of the humus in normal cultivated soils
is more or less constant, approaching 10:1, the evolution of carbon
dioxide will be accompanied by the liberation of available nitrogen.
This oxidation of the carbon and of the nitrogen is comparatively very
slow, as only slow-growing groups of microorganisms are capable of
attacking it. These organisms are aerobic and moreover can only work
effectively when the general soil reaction is favourable. Their
activities are therefore hastened in non-acid peat soils by draining, in
acid peat soils by draining and liming, and in acid soils by liming.

It will be clear that the utilization of vegetable and animal wastes in
crop production involves two definite steps: (1) the formation of humus
and its incorporation into the soil and (2) the slow oxidation of this
product accompanied by the production of available nitrogen. Both of
these stages are brought about by micro-organisms for which suitable
environmental conditions are essential. The requirements of the first
phase--the preparation of humus and its incorporation into the soil
mass--are so intense that if the process takes place in the soil itself,
it is certain to interfere with the development of the crop. The needs
of the second phase--the utilization of humus--are much less intense and
can proceed in the soil without harm to the growing plant. From the
point of view of crop production therefore, it will be a distinct
advantage to separate these two stages and to prepare the humus outside
the field. In this matter the Chinese have anticipated the teachings of
western science. The cultivators of the Orient were the first to grasp
and act upon the master idea that the growth of a crop involves two
separate processes, the preparation of food-materials from vegetable and
animal wastes which must be done outside the field, and the actual
growing of the crop. Only in this way can the soil be protected from
overwork


THE FORMATION OF HUMUS AS A RESULT OF THE SYNTHESIZING ACTIVITIES OF
MICRO-ORGANISMS

Although the important part played by microorganisms in the formation of
soil humus has only very recently been fully understood, nevertheless
the older literature contains a number of useful contributions
to the subject. Most of these early papers appeared towards
the end of the last century; many of them related to other branches
of knowledge and were not written from the point of view of agriculture.
They have been summed up by Waksman, from whose paper the
following account has been prepared. Post-Ramann and Muller considered
that the 'humus' bodies obtained from soil often consist of the
chitinous remains of insects and animal excrete. Wettstein and
Winterstein showed that chitin is characteristic of various fungi and
not of bacteria. Schmook advanced the view that the protein nitrogen in
the soil was mostly present in the bodies of bacteria and protozoa.
Trussov showed that the protoplasm of fungi is a source of humus in the
soil. Schreiner and Storey suggested that various characteristic
constituents of the soil are probably synthesized by micro-organisms.

The earlier work on this subject has been considerably developed, first
by Falck and more recently by Waksman. Falck showed that organic matter
in forest soils can be transformed into different types of humus in at
least three ways: (1) The yearly additions of raw organic matter are
completely decomposed by fungi (microcriny) accompanied by the synthesis
of fungus protoplasm, which serves as an excellent fertilizer for the
forest trees. In this process the celluloses are decomposed completely,
whereas the lignins are more resistant. (2) The decomposition of the
organic matter is begun by fungi and then carried on by lower
invertebrates and bacteria (anthracriny). The fungus mycelium as well as
the original organic matter are devoured by various larvae producing a
dark 'humus' mass which, in the presence of bases, is oxidized by
bacteria with the ultimate liberation of carbon dioxide and the
formation of nitrate. (3) The formation of peat (anthrogeny), which
Falck explains as resulting from the absence of an abundant fungus
development. Waksman carried the subject still further and called
attention to the similarity between the carbon-nitrogen ratio of the
soil organic matter and that of the protoplasm of the soil fungi and
other micro-organisms, and suggested that these probably make up a large
part of the soil 'humus'. He further pointed out that when cellulose is
added to the soil, it decomposes only in proportion to the available
combined nitrogen present. This is because the decomposition is brought
about by fungi and bacteria, both of which require combined nitrogen.
The ratio between the amount of cellulose decomposed and the nitrogen
required is about 30:1, so that, for every thirty parts of cellulose
decomposed by the fungi and bacteria, one part of inorganic nitrogen
(ammonium salt or nitrate) will be built up into microbial protoplasm.
In the presence of sufficient combined nitrogen and under aerobic
conditions, the decomposition of cellulose is very rapid. The same is
true of vegetable wastes like straw, maize stalks, wood products and
other materials rich in celluloses, pentosans and lower carbohydrates
but poor in nitrogen. These facts explain the injurious effects on crop
growth which follow the addition of straw and green-manure to the soil.
The decomposition of these materials removes large quantities of
combined nitrogen from the soil solution. This nitrogen is then
temporarily stored in the form of microbial protoplasm, when for a time
it is placed beyond the reach of the growing crop.

Since Waksman's paper appeared in 1926, an important contribution to
this subject has recently been made by Phillips, Weite and Smith. The
results of these investigators (which agree with our experience at
Indore) has removed the impression that lignin is comparatively
resistant to the action of micro-organisms. Under suitable conditions,
soil organisms are capable of decomposing lignin as found in lignified
plant materials (cornstalks, oat hulls, corn cobs and wheat straw), the
rate of decomposition being as great as that of cellulose and pentosans.


THE ROLE OF HUMUS IN THE SOIL

From the immediately practical point of view, the actual role of humus
in the soil is of even greater interest than its formation, nature and
decomposition. This material influences soil fertility in the following
ways:--

1. The physical properties of humus exert a favourable influence on the
tilth, moisture-retaining capacity and temperature of the soil as well
as on the nature of the soil solution.

2. The chemical properties of humus enable it to combine with the soil
bases, and to interact with various salts. It thereby influences the
general soil reaction, either acting directly as a weak organic acid or
by combining with bases liberating the more highly dissociating organic
acids.

3. The biological properties of humus offer not only a habitat but also
a source of energy, nitrogen and minerals for various micro-organisms.

These properties--physical, chemical and biological--confer upon humus a
place apart in the general work of the soil including crop production.
It is not too much to say that this material provides the very basis of
successful soil management and of agricultural practice.


THE WASHINGTON SYMPOSIUM ON SOIL ORGANIC MATTER

Once the origin and nature of the soil organic matter is understood and
the importance of this material in soil fertility is appreciated, the
next step is to consider how best to make use of this information and to
weld it into farming practice. With this object in view a symposium on
soil organic matter and green-manuring was arranged at Washington D.C.
on 22 November 1928, when the following papers were read and
discussed:--

I. 'The Relation of Soil Type to Organic Matter.' C. F. Marbut.

2. 'Organic Matter Problems in Humid Soils.' T. Lyttleton Lyon.

3. 'Organic Matter Problems Under Dry-Farming Conditions.' J. C. Russell

4. 'Organic Matter Problems in Irrigated Soils.' P. S. Burgess.

5. 'Chemical and Microbiological Principles Underlying the Use of
Green-Manures.' S. A. Waksman (by title only).

6. 'Influence of Organic Manures on the Chemical and Biological
Properties of Arid Soils.' J. E. Greaves.

7. 'Green-Manuring and Its Application to Agricultural.' A. J. Pieters
and Roland McKee.

In dealing with the question of organic matter in humid soils, Lyon
first presented a critical survey of the literature dealing with the
losses of nitrogen in soils and concluded that:--

1. The loss of gaseous nitrogen may, under some conditions, cause a
greater removal of nitrogen from a soil than occurs through absorption
by crop plants.

2. The conditions which favour a large loss of this kind are: (a)
tillage or stirring the soil in any way, (b) absence of plant growth,
(c) high nitrogen content of a soil, (d) application of large quantities
of nitrogenous manures, and (e) possibly the application of lime to some
soils.

3. The loss of gaseous nitrogen does not take into account the amount
fixed by soil organisms and therefore the calculated losses are less
than actually occurred.

These losses of gaseous nitrogen from the soil may arise in five
possible ways:--

1. There may be an escape of part of the ammonia during the process of
ammonification.

2. There may be a reduction of nitrates to form nitrogen as a result of
alternating oxidation and reduction.

3. There may be a loss of gaseous nitrogen in the oxidation of ammonia
to nitrous acid since nitrogen is possibly an intermediate product in
this process.

4. A loss of nitrogen may result from the interaction of nitrous acid
with the NH2 group of the amino-acids.

5. A loss of gaseous nitrogen may occur as a result of the decomposition
of ammonium nitrite in the process of nitrification.

In connexion with these losses of nitrogen it was pointed out in the
discussion that the following two facts must be considered: (1) The
ratio of carbon to nitrogen in the soils of the humid regions tends to
maintain itself in the region of 10:1. If the organic residues left in
the soil or applied to it afterwards have a higher carbon-nitrogen ratio
than 10:1, an adjustment is soon effected, the extra carbon disappearing
into the atmosphere as carbon dioxide. If the carbon-nitrogen ratio is
less than 10:1, there is likely to be a loss of nitrogen before the
ratio is adjusted. (2) The nitrogen content of any given soil tends to
come to an equilibrium at a point which depends upon the nature of the
soil, the effective climate and the cropping system. When therefore the
nitrogen supply is increased in any way, the excess is soon dissipated
when the soil comes under cultivation.

The information placed before the meeting by Russel (Nebraska) on the
role of organic matter under dry-farming conditions was most
instructive, and throws a flood of light on the consequences which are
certain to follow the continuous cropping of virgin land without manure.
A rapid and continuous fall in the total organic matter content,
accompanied by loss of nitrogen, occurs together with a corresponding
falling off in cropping power. Side by side, the water-holding capacity
of these soils decreases, while the structure and tilth exhibit marked
degeneration. All this has naturally led to attempts being made to
restore the original content of organic matter. The results obtained,
however, have been most disappointing, for the reason that most of these
efforts have been directed towards the direct incorporation of
green-manures and raw organic matter like straw into the soil under
conditions of low rainfall. In many cases more harm than good has
resulted. Russel concludes that the problem of the restoration of
organic matter under dry-land conditions is extremely complicated and
difficult and leans to the view that the solution of the problem might
after all be found in the direction of nitrogenous fertilizers.
Experience at Indore, however, suggests that all these difficulties
could at once be avoided if the available supplies of green-manure,
straw and other raw organic matter could first be composted outside the
field before being applied to the land. The American farmers are
obviously trying to overwork the soil and Mother Earth naturally
objects.

The application of organic matter to the soil is followed by a number of
important indirect results. These were dealt with by Greaves in a most
interesting communication, in which the results obtained over a number
of years on two different types of Utah soils were discussed. The first
(Nephi) was typical dry-farm soil, the second was under irrigation
(Greenville). In both the results were similar. The application of
organic matter increased the ammonifying, nitrifying and nitrogen fixing
processes of the soil. The gains in nitrogen, due to non-symbiotic
nitrogen fixers, occurring under greenhouse conditions, varied from 0 to
304 lb. per acre foot of soil. The greatest gains occurred when legumes
were used in the manure. The gain occurring in the soil under field
conditions, and attributed to non-symbiotic nitrogen fixation, was 44
lb. per acre annually. Approximately 3,000 lb. of applied organic
material were decomposed every year.

The last paper of the symposium dealt with the practice of
green-manuring throughout the United States, with the various crops
which are turned under, and with the great need for further exact
experimentation on this question. Pieters and McKee state: 'In reviewing
the experimental work that has been done with green-manures in the
United States and the practices that are now followed it is evident that
much work remains to be done before many questions can be settled or
answered. Some of these fall clearly in the field of chemistry, others
in physiology, and still others in bacteriology or other specialized
fields of biology. Some, however, are strictly agronomic problems or so
directly involved with crop production that their solution can perhaps
best be undertaken by the agronomist or carried on with his active
co-operation. It takes but a hasty survey to indicate the wide scope
this work must cover in order to answer the specific questions for the
many soil types, various climatic conditions, and for each of the large
number of agronomic and horticultural crops involved.' In no case is
there any reference in this paper to the growing of green-manures for
the express purpose of providing material for composting, possibly
because the need for this material has not yet been fully realized and
because of the labour involved. Green-manuring in the United States, as
in India and other parts of the world, is still in the empirical stage.
Green crops are grown merely to provide a supply of organic matter for
turning into the soil. What happens afterwards is a matter of chance. If
the results are favourable, so much the better; if anything untoward
occurs, one must hope for better things next time. That such an
uncertain practice persists at all in the United States and that it
appears to be spreading can only be explained by the great need of these
depleted soils for fresh supplies of organic matter.



BIBLIOGRAPHY

LIEBIG, J.--Chemistry in its Application to Agriculture and Physiology,
1840.

PHILLIPS, M., WETTE, H. D., and SMITH, N. R.--The Decomposition of
Lignified Materials by Soil Microorganisms,' Soil Science, 30, 1930, p.
383.

RUSSELL, E. J.--Soil Conditions and Plant Growth, London, 1927.

RUSSELL, E. J. and RICHARDS, E. H.--'The Changes taking place during the
Storage of Farmyard Manure,' Journ. Of Agric. Science, 8, 1917, p. 495.

'Symposium on Soil Organic Matter and Green-Manuring,' Journ. of the
American Society of Agronomy, 21, 1929, p. 943

WAKSMAN, S. A.--'The Origin and Nature of the Soil Organic Matter or
Soil "Humus": 1--Introductory and Historical,' Soil Science, 22, 1926,
p. 123.




Chapter III



THE SOURCES OF ORGANIC MATTER


A number of sources of soil organic matter exist, namely: (1) the roots
of crops left behind at harvest, including the weeds turned under in the
course of cultivation; (2) the algae met with in large quantities in
rice fields, on the surface of the soils of tropical countries during
the rainy season and to some extent in all soils; (3) green-manure; (4)
farmyard manure; (5) artificial farmyard manure. In addition to these
supplies, certain by-products of industries, such as oil-cakes and
wool-waste, are also employed as sources of organic matter. These,
however, are small in total amount and need not be considered. Except in
China and Japan and to a limited extent in India, little or no use is
made of night soil in crop production.


THE ROOT-SYSTEMS OF CROPS

It is not always realized that about half of every crop--the
root-system--remains in the ground at harvest time and thus provides
automatically a continuous return of organic matter to the soil. The
weeds and their roots turned in during the ordinary course of
cultivation add to this supply. When these residues, supplemented by the
fixation of nitrogen from the atmosphere, are accompanied by skilful
soil management, crop production can be maintained at a moderate level
without the addition of any manure whatsoever. A good example of such a
system of farming without manure is to be found on the alluvial soils of
the United Provinces, where the field records of ten centuries prove
that the land produces fair crops year after year without any falling
off in fertility. A perfect balance has been reached between the
manurial requirements of the crops harvested and the natural processes
which recuperate fertility. A similar, although not so striking a
result, is afforded by the permanent wheat plot at Rothamsted, where
this crop has been grown every year on the same land without manure
since 1844. This plot, which has been without manure of any kind since
1839, showed a slow decline in production for the first eighteen years
after which the yield has been practically constant. Systems of soil
management such as these provide, as it were, the base line for the
would-be improver. Nothing exists in the world's agriculture below this
level. At the worst, therefore, the organic matter of a soil, constantly
cropped without manure, does not disappear altogether. The wheel of life
slows down. It does not stop.


SOIL ALGAE

One source of readily decomposable organic matter, which is available in
India just at the moment when the cold season crops need it, is to be
found in the shape of a thick algal film on the surface of cultivated
soils during the second half of the rains. This film has also been
observed in Africa, Ceylon and Java, and is probably universal during
the rainy season in all parts of the tropics. As is well known, there
are two periods in India when the crop is in greatest need of combined
nitrogen: (1) at the break of the monsoon in June and July, and (2) when
the cold season crops are sown in October after the rains. These latter
are planted at a time when the available nitrogen in the surface soil is
likely to be in great defect. The land has been exposed to heavy rain
for long periods; the surface soil is often waterlogged. Nitrates under
such conditions are easily lost by leaching and also by
de-nitrification. The conditions are therefore altogether unfavourable
for any approach towards an ample supply of nitrate when sowing time
comes round in early October. How do the cold weather crops obtain a
sufficient supply of this essential food material? It is more than
probable that the deficiency is made up for, in part at least, by the
rapid decay of the algal film (which also appears to be one of the
factors in nitrogen fixation) during the last cultivations preceding the
sowing of the cold weather crop in October. It is possible that some
changes may have to be made in soil management with a view to
stimulating the growth of this algal film. One of the beneficial effects
of growing a green-manure crop like sann hemp for composting, during the
early rains, may prove to be due to the favourable environment provided
for the rapid establishment of the algal film. On monsoon fallow land it
will probably be found best to suspend surface cultivation during the
second half of the rains when the film is most active. There is already
among the cultivators of India a tendency to stop stirring the surface,
from the middle to the end of the rains, even when this involves the
growth of weeds. This coincides with the period when the algal film is
most noticeable. The indigenous practices may therefore prove to be
based on sound scientific principles. Here are ready to hand several
interesting subjects which urgently call for study under actual tropical
conditions. When this is undertaken, the investigation should include:
(1) the conditions most favourable for the establishment of the algal
film; (2) the part played by algae and associated bacteria in nitrogen
fixation; (3) the role of algae in banking easily destroyed combined
nitrogen during the rains; and (4) the supply of easily decomposable and
easily nitrifiable organic matter for the use of the cold weather crops.
In the rice fields of the tropics, the algal carpet is even more evident
than on ordinary cultivated soils. The total weight of organic matter
added every year to each acre of rice land in the shape of algal remains
must be considerable and must serve as a useful addition to the store of
organic matter. Apart from the fixation of nitrogen from the air, it may
help to explain why such heavy crops of paddy can be obtained in India,
year after year on the same land, without manure.


GREEN-MANURES

Since the investigations of Schulz-Lupitz first showed how open sandy
soils in Germany can be rapidly improved in texture by the incorporation
of green-manures, the future possibilities of this method of enriching
the land became apparent to the investigators of the Occident. After the
role of the nodules (found on the roots of leguminous plants) in the
fixation of atmospheric nitrogen was proved, the problems of
green-manuring have naturally centred round the utilization of the
leguminous crop in adding to the store of organic matter and combined
nitrogen in the soil. At the end of the last century it seemed so easy,
by merely turning in a leguminous crop, to settle at one stroke and in a
very economical fashion the great problem of maintaining soil fertility.
At the expenditure of a very little trouble, the soil might be made to
manure itself. A supply of combined nitrogen, as well as a fair quantity
of organic matter, might be provided without any serious interference
with ordinary cropping. These expectations have led to innumerable
green-manuring experiments all over the world with practically every
species of leguminous crop. The results however have left much to be
desired. In a few cases, particularly on open soils and where the
rainfall, after the ploughing in of the green crop, is well distributed,
the results have been satisfactory. On rice lands, where abundance of
water ensures the maintenance of swamp conditions, somewhat similar
results have been obtained. In the vast majority of cases, however.
green-manuring has been disappointing. As a general method of soil
improvement, the game is hardly worth the candle. On the monsoon fed
areas of India the rainfall is often so uncertain, after the green crop
is ploughed in, that for long periods decay is arrested. Sowing time
arrives at a stage when the soil contains a mass of half-rotted
material, with insufficient nitrogen and moisture for the growth of a
crop. Failure results. The crops raised after green-manure are worse
than those obtained on similar land left fallow. For this reason
green-manuring has not been taken up by the people in India, in spite of
the experiments and propaganda of the Agricultural Department.

It soon became evident, during the early years of the present century in
India, that no matter what the rainfall and the soil conditions may be,
a definite time factor is in operation in green-manuring. A period of
not less than eight weeks must elapse, between the ploughing in of the
green crop and the planting of the next, if satisfactory results are to
be obtained. This was well brought out in the green-manuring experiments
on tobacco, carried out at Pusa between 1912 and 1915. Some years later,
the explanation of this factor, as well as the general conditions
necessary for the decay of a green-manure crop were furnished by the
work done at the New Jersey experiment station by Waksman and his
co-workers. The decay and incorporation of green-manure in the soil has
been shown to be a very complex process, depending on: (1) the chemical
composition of the plants which make up the green-manure, which in turn
largely depends on the age of the crop when ploughed in; (2) the nature
of the decomposition of the various groups of organic complexes in the
plant by the different types of soil organisms, which in turn is
influenced by such factors as moisture, aeration, and the supply of
available nitrogen and phosphates needed by these organisms, and (3) the
metabolism of the microorganisms taking part in the decay of the green
crop.

The process of incorporation takes place on the following lines. When
the green-manure crop is ploughed in, the first stages of decay are
brought about by fungi, which require for their activities ample
supplies of air, moisture and combined nitrogen, as well as the soluble
and easily decomposable carbohydrates supplied by the green crop. If the
supply of nitrogen provided by the green-manure is insufficient, the
stores of soluble nitrates in the soil solution are utilized by the
fungi. Decay is rapid provided all these essential factors are
simultaneously arranged for. The result is that the whole energies of
the soil at this period are given up to the needs of the fungi of decay,
which synthesize large quantities of protoplasm from the materials
supplied by the green crop and the soil solution. During this phase,
most of the nitrogen present is built up into mycelial tissue, and is
therefore not immediately available for the growth of crops. The next
stage is the decay of the remainder of the green-manure, including the
mycelial tissue itself, by various groups of bacteria, followed by the
incorporation of the whole mass into the soil organic matter. This must
first be nitrified before the soil solution and the crop can obtain any
benefit from this form of manuring. Clearly all this takes time, and
needs abundance of oxygen as well as a continuous supply of soil
moisture. If any of the limiting factors--nitrogen supply, air or
moisture--are in defect, it is obvious that the final stage of
nitrifiable organic matter will not be quickly reached. The soil will
not only contain a mass of undigested material, but will be poor in
available nitrogen and perhaps low in moisture as well. Seeds sown in
such a soil can only result in a poor crop. The investigations of the
New Jersey experiment station explain the importance of the time-factor
in green-manuring, and incidentally show that the ordinary
green-manuring experiments in India cannot possibly succeed. The sooner
they are discontinued the better. Nothing is to be gained by attempting
the hopeless task of manufacturing soil organic matter under conditions
which cannot be controlled.

The question at once arises as to whether the green-manuring process
can be regulated in such a manner that the results can be relied upon? A
number of attempts have been made in this direction in India, of which
that carried out by Clarke at Shahjahanpur is the most promising. Green
crops of sann hemp (Crotalaria juncea L.) have been successfully
utilized for the growth of sugar-cane. The secret of the Shahjahanpur
process is to provide ample moisture, by means of irrigation, for the
first stages of the decay of the green-manure. The rainfall, after the
hemp crop is ploughed in, is carefully watched. If it is less than five
inches during the first fortnight of September, the fields are
irrigated. This enables the first phase of the decay of the green crop
by the soil fungi to be completed. Practically all the nitrogen is then
in the form of easily decomposable mycelial tissue. During the autumn,
nitrification is prevented by drying out the surface soil. The nitrogen
is, as it were, kept in the bank till the sugar-cane is planted under
irrigation in March. Nitrification then sets in and the available
supplies of combined nitrogen are made use of by the sugar-cane. In this
way crops of over thirty tons of cane to the acre have been grown
without the addition of any manure beyond the hemp, grown on the same
land the previous rains and treated in the manner indicated above. These
results do not appear to have been obtained with any other crop than
sugar-cane planted in March. It would be interesting to have figures for
wheat, sown in October, i.e. about six weeks after the hemp was ploughed
under. It is probable that even with irrigation, this interval is
insufficient for the proper incorporation of the green crop into the
body of the soil organic matter and its subsequent nitrification. In
this case, the Shahjahanpur method, valuable and interesting as it is,
can only have a limited application.

Is it possible to devise a method of green-manuring, by means of the
leguminous crop, which avoids all risks, is certain, and also makes the
fullest use of this system? There are two possible ways in which the
growing of a leguminous green-manure crop may benefit the soil. These
are: (1) the well-known advantages of such crops in the rotation in
increasing the nitrogen supply and in stimulating the micro-organisms in
the soil, and (2) the effects of incorporating the green crop into the
store of soil organic matter. Lohnis, however, showed, in many
green-manuring experiments with leguminous crops, that the same results
were obtained when the crop was removed as when it was ploughed under--a
conclusion which is in full accord with Waksman's work. It follows from
this that the double advantage of a leguminous green-manure crop can
only be achieved provided fall use of the crop itself can be found
outside the field, either as fodder for animals, for making silage or as
material for the manufacture of compost. This latter method has been
successfully worked out at Indore, and will be described in the next
chapter. The real place of the leguminous crop in green-manuring seems
to be in providing material for the manufacture of organic matter in a
compost factory, specially designed for the purpose.

The exact period in the life history of the green crop, when it should
be reaped for composting, is an important matter. If the crop is cut
before the grand period of growth is completed, the maximum amount of
vegetable waste will not be obtained. On the other hand, an early
harvest will yield a product rich in nitrogen and suitable for rapid
decay (Appendix C). Late harvesting is also attended with disadvantages.
If reaped after flowering begins, the green crop will have used up a
good deal of the rich nodule tissue which will then be temporarily
removed from the soil and will not benefit the next crop. Further, the
older the crop, the more unfavourable the carbon-nitrogen ratio becomes.
The best stage for removal will be just before flowering begins. At this
point, most of the nitrates in the soil solution have been absorbed by
the crop and have been banked, either in the form of an easily
decomposable root-system or as compost material, the chemical
composition of which is exactly what is needed to improve the
carbon-nitrogen ratio of the other vegetable wastes of the farm. When
the green crop is reaped at this stage the following advantages are
obtained: (1) The nitrates of the soil solution are safely banked. (2)
The next crop derives the maximum benefit from an easily decomposable
and uniformly distributed root-system, rich in combined nitrogen, the
decay and incorporation of which is well within the powers of the soil.
(3) The store of vegetable waste for composting is increased in amount
and improved in chemical composition by the uniform distribution of the
combined nitrogen throughout the tissues of the green crop.


FARMYARD MANURE

From the beginning of agriculture, the utilization of farm wastes,
rotted by means of the urine and dung of animals, has been the principal
means of replenishing soil losses. Even at the present day, in spite of
the establishment of numerous experiment stations and the employment of
an army of investigators, the methods in vogue in the preparation and
storage of this product leave much to be desired. Even under the
covered-yard system, when the dung and litter are left under the animals
until a layer several feet thick is produced, and the product is
protected from the weather, as much as fifteen per cent of the valuable
nitrogen is lost. When the dung is carted out into a heap to ripen, as
is the usual practice, the losses of nitrogen are even greater. Russell
and Richards, who some years ago carried out an elaborate investigation
on the storage of farmyard manure at Rothamsted, concluded that: (1) the
system of leaving the manure under the beasts till it is required for
the fields, as in the box or covered-yard system, is the best whenever
this is practicable; (2) the ideal method of storage is under anaerobic
conditions at a temperature of 26 degrees C.; (3) the manure heap, however
well made and protected, involves losses of nitrogen; and (4) the best
hope of improvement lies in storing the manure in watertight tanks or
pits, so made that they can be completely closed and thereby allow the
attainment of perfect anaerobic conditions. These investigations,
published in 1917, clearly indicate that one of the reasons for the
present imperfect management of farmyard manure lies in the fact that
the conditions are sometimes aerobic, at others anaerobic, whereas they
should be one or the other throughout. In other words, there is no
proper management of the air supply. Moisture is not usually in defect,
except in hot countries like India where there is abundant air but often
little moisture. Taking Great Britain and India as extreme cases of the
management of farmyard manure, we find one or other of the following
conditions in operation. In Great Britain, the irregular air supply of
the manure heap leads to serious losses of nitrogen.

The final product is not a fine powder but a partially rotted material,
which cannot be incorporated into the pore-spaces of the soil until
further decay has taken place. The soil therefore has to do a good deal
of work before the farmyard manure, applied on the surface in lumps, can
be uniformly distributed through and incorporated into the soil mass. In
India, the storage of farmyard manure leads to the loss of so much
moisture, that often insufficient decay takes place before it finds its
way into the soil. Losses of nitrogen may be prevented in this way but
the work thrown upon the soil is even greater than in temperate regions.
Only in China and Japan is any real attempt made to prepare the manure
for the use of the crop, and to relieve the soil from unnecessary work.
What is needed throughout the world is a continuous system of preparing
farmyard manure in which (1) all losses of nitrogen are avoided, and,
(2) the various steps from the raw material to the finished product
follow a definite plan, based on the orderly breaking down of the
materials, and the preparation of a finished product, ready for
immediate nitrification, which can easily be incorporated into the soil.
At the same time, an attempt should be made to gain as much nitrogen as
possible by fixation from the atmosphere. Only when all this is done
will the preparation of farmyard manure be based on correct scientific
principles.


ARTIFICIAL FARMYARD MANURE

During the last ten years, an additional source of soil organic matter
has been utilized, namely, artificial or synthetic farmyard manure. In
1921, the results of experiments, carried out by Hutchinson and Richards
at Rothamsted on the conversion of straw into manure without the
intervention of live stock, were published. In this pioneering work,
which constitutes an important milestone in the development of crop
production, a method was devised by which straw could be converted into
a substance having many of the properties of stable manure. In the
preliminary experiments, the most promising results were obtained when
the straw was subjected to the action of a culture of an aerobic
cellulose decomposing organism (Spirochoeta cytophaga), whose activities
were found to depend on the mineral substances present in the culture
fluid. The essential factors in the production of well-rotted farmyard
manure from straw were found to be: air supply; a suitable temperature,
and a small amount of soluble combined nitrogen. The fermentation was
aerobic; the breakdown of the straw was most rapid in a neutral or
slightly alkaline medium in the presence of sufficient available
nitrogen. Urine, urea, ammonium carbonate and peptone (within certain
concentrations) were all useful forms of combined nitrogen. Sulphate of
ammonia by itself was not suitable, as the medium soon became markedly
acid. The concentration of the combined nitrogen added was found to be
important. When this was in excess, nitrogen was lost from the mass
before decay could proceed; when it was in defect, a marked tendency to
fix nitrogen was observed. The publication of this paper soon led to a
number of further investigations, and to numberless attempts all over
the world to prepare artificial farmyard manure from every kind of
vegetable waste. The principles underlying the conversion are now well
understood, and have recently been summed up by Waksman and his
co-workers in the Journal of the American Society of Agronomy (21, 1929,
p. 533) in a paper which should be carefully studied by all interested
in this important subject. The principles underlying the conversion are
so well put by these investigators that they are best given in the
authors' own words:--

'The problems involved in the study of the principles underlying
the decomposition of mature straw and other plant residues in
composts, leading to the formation of so-called artificial manure,
involve a knowledge of: (a) the composition of the plant
material; (b) the mechanism of the decomposition processes which
are brought about by the micro-organisms; and (c) a knowledge
of the metabolism of these organisms.

'Straw and other farm residues, which are commonly used for the
purpose of composting, consist predominantly (60 per cent or
more) of celluloses and hemi-celluloses, which undergo rapid
decomposition in the presence of aufficient nitrogen and other
minerals, of lignins (15 to 20 per cent) which are more resistant to
 decomposition and which gradually accumulate, of water-soluble
substances (5 to 12 per cent) which decompose very rapidly, of
proteins which are usually present in very small amounts (2.2 to 30
per cent) but which gradually increase in concentration with the
advance of decomposition, and of the mineral portion or ash.


'The processes of decomposition involved in the composting consist
largely in the disappearance of the celluloses and hemi-celluloses,
which make up more than 80 per cent of the organic matter which
is undergoing decomposition in the process of formation of artificial
manures. These poly-saccharides cannot be used as direct sources
of energy by nitrogen-fixing bacteria and their decomposition
depends entirely upon the action of various fungi and aerobic
bacteria. In the process of decomposition of the celluloses
and hemi-celluloses, the micro-organisms bring about the synthesis
of microbial cell substance. This may be quite considerable, frequently
equivalent to a fifth or even more of the actual organic matter
decomposed. To synthesize these large quantities of organic matter,
the micro-organisms require large quantities of available nitrogen
and phosphorus and a favourable reaction. The nitrogen and phosphorus
are used for the building up of the proteins and nucleins in the
microbial cells. Since there is a direct relation between the
celluloses decomposed and the organic matter synthesized, it
should be expected also that there would be a direct relation between
the cellulose decomposed and the amount of nitrogen required.
As a matter of fact, for every forty or fifty parts of cellulose
and hemi-cellulose decomposed, one unit of available nitrogen has
to be added to the compost.


'As the plant residues used in the preparation of "artificial
manure" are poor in nitrogen, available inorganic nitrogen must
be introduced for the purpose of bringing about active decomposition.
This explains the increase in the protein content of the compost
accompanying the gradual decrease of the celluloses and hemi-celluloses.


'In general, artificial composts can be prepared from plant residues
of any chemical composition so long as the nature of these
residues and of the processes involved in their decomposition are
known. By regulating the temperature and moisture content and
by introducing the required amounts of nitrogen, phosphorus,
potassium and calcium carbonate, the speed of decomposition and
the nature of the product formed can be controlled.'


It is not possible in the space available to summarize all the various
experiments which have been made in Great Britain, the United States,
India and other parts of the world on the actual conversion of vegetable
residues into artificial farmyard manure. It will be sufficient to refer
to typical examples of what has been done. The Rothamsted investigations
have been continued and have led to a patented process, known as Adco,
by which the requisite nitrogenous and phosphatic food for the
micro-organisms, as well as a base for the neutralization of acidity,
are added to the vegetable wastes in the form of powders. Full details
and numerous illustrations are to be found in the various Adco
pamphlets. The object of patenting the process is not profit for the
inventors but the raising of funds for further research. All users of
Adco therefore are not only provided with a useful mixture but also make
a small contribution to the cost of fundamental research work. In India,
the various experiments on the production of artificial farmyard manure
from a large number of materials, such as prickly pear, fallen leaves,
town refuse, mahua (Bassia latifolia L.) flowers, weeds, banana waste,
leguminous plants such as sann hemp, green pea stalks and various weeds
have recently been summed up by Fowler, whose paper (see Bibliography
below) should be consulted for details. The materials employed for
adding the necessary nitrogen and other materials for the
micro-organisms were night-soil, cow-dung, cattle urine, activated
sludge or chemicals like sulphate of ammonia and calcium cyanamide. A
large number of experiments are described from which it is clear that
very useful manures, containing from 1 to 4 per cent of nitrogen, were
obtained, which in field trials with rice and maize gave results equal
to or better than any other nitrogenous manure in common use. Attempts
were made in the course of this work to determine the amount of nitrogen
fixation from the air which occurs during the conversion of the
vegetable waste. It was found, when proper care was taken to supply the
necessary organisms, that a considerable amount of free nitrogen was
actually absorbed. These results, which agree with others on the same
point, are of considerable interest. If in the conversion of vegetable
wastes into artificial farmyard manure additional nitrogen can be
gained, obviously the ideal conditions have been discovered. Once such
principles have been correctly ascertained and put into practice, it
might then be possible to deal not only with the manure heap itself but
also with green-manuring, so that actual fixation can be substituted for
the losses of nitrogen which now occur.

As is to be expected in such a matter as this, the preparation of
artificial farmyard manure has been in actual operation centuries before
Hutchinson and Richards began their work at Rothamsted. King, in Farmers
of Forty Centuries, describes the conversion by the Chinese peasants of
clover (Astragalus sinicus) into manure by mixing the green crop with
rich canal mud To all intents and purposes, this system closely
resembles the Adco process. Once more the empirical methods, discovered
during centuries of practice, have preceded the results obtained by the
application of pure science. Nevertheless, although in a sense the
Rothamsted workers have been anticipated, it is quite safe to say that
but for their work, the utilization of green clover in China, although
described in the literature of the subject, would have passed unheeded.
It was the novelty of the Rothamsted investigations which has proved so
useful and so stimulating.

A critical examination of the literature on the principles underlying
the conversion into humus of the chief groups of crude organic
matter--green-manure, farmyard manure and vegetable wastes--reveals one
fundamental weakness, namely, the fragmentation, into a number of
loosely related sections, of what is essentially one subject. Farmyard
manure, green-manure and the preparation of synthetic farmyard manure
are always dealt with as if they were separate things and not parts of
one great project. Even Waksman (whose contributions to the principles
underlying the conversion of vegetable wastes into humus cannot fail to
compel the admiration of all investigators), when the time came to write
up his work for the agronomists of the United States, contributed three
separate papers to the Journal of the American Society of Agronomy--one
on farmyard manure, one on green-manure and the third on artificial
farmyard manure--instead of synthesizing all these related subjects into
one single contribution. When we come to the practical side of the
question, a similar fragmentation is apparent. Green-manuring is always
a separate process. The manure heap and its utilization from the time of
the Romans to the present day, forms a special section of the work of
the farm. The manufacture of artificial farmyard manure is again split
off as an isolated operation. This particularism, in the most recent
papers, is reflected in the separate conversion of each kind of
vegetable waste, although it follows, from considerations of chemical
composition, that a mixture of residues is much more likely to possess a
suitable carbon-nitrogen ratio than any single material. As will be
evident from a study of Waksman's three papers referred to above, the
principles underlying the decay of farmyard manure, of green-manure and
the preparation of artificial farmyard manure are essentially the same,
namely, the synthesis of humus, by means of fungi and bacteria, from
crude vegetable matter, various nutrients, air, water and bases. This
humus increases the supply of soil organic matter and is capable of
rapid nitrification. What is needed is the welding of all the separate
fragments of the subject into a well ordered system. One process is
required, not several. The agriculturist of the future must be shown how
to become a chemical manufacturer. Further, the method finally adopted
must be so elastic that it can be introduced into almost any system of
agriculture. Again, it must be simple, safe and must yield a continuous
and uniform product, capable of being instantly utilized by the crop. No
waste of valuable nitrogen should occur at any stage. If possible,
matters should be so arranged that the fixation of atmospheric nitrogen
takes place at all stages of the process--in the compost factory and
afterwards in the soil. In the next chapter, a continuous process of
making humus is described which furfils the conditions just outlined.
This includes, in a single process, the various fragments of the
subject, such as the care of the manure heap, green-manuring, the
utilization of all vegetable wastes as well as the urine earth from the
cattle shed and the wood ashes from the labourers' quarters. By its
means, the waste products of 300 acres of land are converted every year
into about 1,OOO cart-loads of valuable humus, of uniform chemical
composition and of uniform fineness. When this material is added to the
soil there is a rapid increase in fertility. The practical results
obtained at Indore prove that all that is needed to raise crop
production to a much higher level throughout the world is the orderly
utilization of the waste products of agriculture itself.



BIBLIOGRAPHY

BRISTOL, B. M.--'On the Alga-flora of some dessicated English Soils:
an Important Factor in Soil Biology,' Annals of Botany, 34, 1920, P.35.

BRISTOL, M. B. and PAGE, H. J.--'A Critical Enquiry into the Alleged
Fixation of Nitrogen by Green Alga,' Annals of Applied Biology, 10,
1923, p. 378.

BRISTor-ROACH, B. M.--'The Present Position of our Knowledge of the
Distribution and Functions of Alga, in the Soil,' Proc. of the Inter.
Congress of Soil Science, Washington, D.C., 1928, p. 30.

CARBERY, M. and FINLOW, R. S.--'Artificial Farmyard Manure,' Agric.
Jonrn. of India, 23, 1928, p. 80.

CLARKE, G., BANERJEE, S. C., NAIB HUSAIN, M., and QAYUM, A.--'Nitrate
Fluctuation in the Gangetic Alluvium and Some Aspects of the Nitrogen
Problem in India,' Agric. Journ. of India, 17, 1922, p. 463.

CLARKE, G.--'Some Aspects of Soil Improvement in relation to Crop
Production,' Proc. of the Seventeenth Indian Science Congress, Asiatic
Society of Bengal, Calcutta, 1930, p. 23.

DOBBS, A. C-' Green-Manuring in India,' Bull. 56, Agric. Research
Institute, Pusa, 1916.

FOWLER, G. J.--'Recent Experiments on the Preparation of Organic
Matter,' Agric. Journ. of India, 25, 1930, p 363.

HALL, A. D.--The Book of the Rothamsted Experiments, London, 1905.

HOWARD, A. and HOWARD, G. L. C.--'The Improvement of Tobacco Cultivation
in Bihar,' Bull. 50, Agric. Research Institute, Pusa, 1915.

HOWARD, A.--Crop Production in India, a Critical Survey of its Problems,
Oxford University Press, 1924.

HOWARD, A. and HOWARD, G. L. C.--The Application of Science to Crop
Production, an Experiment carried out at the Institute of Plant
Industry, Indore, Oxford University Press, 1929.

HUTCHINSON, H. B. and RICHARDS, E. H.--'Artificial Farmyard Manure,'
Journ. of the Min. of Agric. (London), 28, 1921, p. 398.

KING, F. H.--Farmers of Forty Centuries, or Permanent Agriculture in
China, Korea and Japan, London, 1926.

LOHNIS, F.--'Nitrogen Availability of Green Manures,' Soil Science, 22,
1926, p. 253.

LOHNIS, F.--'Effect of Growing Legumes upon succeeding Crops,' Soil
Science, 22, 1926, p. 355.

RUSSELL, E. J.--Soil Conditions and Plant Growth, London, 1927.

RUSSELL, E. J.--'The Present Status of Soil Microbiology,' Proc. of the
Inter. Congress on Soil Science, Washington, D.C., 1928, p. 36.

RUSSELL, E. J. and RICHARDS, E. H.--'The Changes taking place during the
Storage of Farmyard Manure,' Journ. of Agric. Science, 8, 1927, p. 495.

RUSSELL, E. J. and others.--The Micro-organisms in the Soil, London,
1923.

WAKSMAN, S. A.--'Chemical and Microbiological Principles underlying the
Decomposition of Green-Manures in the Soil,' Journ. of the Amer. Soc.
of Agronomy, 21, 1929, p. 1.

WAKSMAN, S. A., TENNEY, F. G. and DIEHM, R. A.--'Chemical and
Microbiological Principles underlying the Transformation of Organic
Matter in the Preparation of Artificial Manures,' Journ. of the Amer.
Soc. of Agronomy, 21, 1929, p.533.

WAKSMAN, S. A. and DIEHM, R. A.--Chemical and Microbiological
Principles underlying the Transformation of Organic Matter in Stable
Manure in the Soil,' Journ. Of the Amer. Soc. of Agronomy, 21, 1929,
p.795.




Chapter IV



THE MANUFACTURE OF COMPOST BY THE INDORE METHOD


The aim of the Indore method of manufacturing compost is by means of a
simple process to unite the advantages of three very different things:
(1) the results of scientific research on the transformation of plant
residues; (2) the agricultural experience of the past, and (3) the ideal
line of advance in the soil management of the future--in such a manner
that all the by-products of agriculture can be systematically converted
into humus. An essential feature of this synthesis is the avoidance of
anything in the nature of fragmentation of the factors. All available
vegetable matter, including the soiled bedding from the cattle-shed, all
unconsumed crop residues, fallen leaves and other forest wastes,
farmyard manure, green-manures and weeds pass systematically through
the compost factory, which also utilizes the urine earth from the floor
of the cattle-shed together with the available supply of wood ashes from
the blacksmith's shop and the workmen's quarters. The only other
materials employed are air and water. This manufacture is continuous
right through the year, including the rainy season, when a slight
modification has to be made to ensure sufficient aeration. The product
is a finely divided leaf-mould, of high nitrifying power, ready for
immediate use. The fine state of division enables the compost to be
rapidly incorporated and to exert its maximum influence on a very large
area of the internal surface of the soil.

The Indore process thus utilizes all the by-products of agriculture and
produces an essential manure. Besides doing this any successful system
of manufacturing compost must also fulfil the following conditions:--

1. The labour required must be reduced to a minimum. The process must
fit in with the care of the work cattle and with the ordinary working of
the farm.

2. A suitable and also a regular carbon-nitrogen ratio must be produced
by well mixing the vegetable residues before going into the compost
pits. Unless this is arranged for, decay is always retarded. The mixing
of these residues, combined with the proper breaking up of all
refractory materials is essential for rapid and vigorous fermentation
and for uniformity throughout the process.

3. The process must be rapid. To achieve this it must be aerobic
throughout, and must include arrangements for an adequate supply of
water and for inoculation, at the right moment, with the proper fungi
and bacteria. The general reaction of the mass must be maintained,
within the optimum range, by means of earth and wood ashes. The
maintenance of the proper relationship between air and water, so that no
delay takes place in the manufacture, proved to be the greatest
practical difficulty when evolving the process.

4. There should be no losses of nitrogen at any stage; if possible,
matters should be so arranged that fixation takes place in the compost
factory itself and afterwards in the field. To conserve the nitrogen,
the manufacture must stop as soon as the compost reaches the
nitrification stage, when it must either be used or banked. It can best
be used as a top dressing for irrigated crops; it can be preserved, as
money is kept in a bank, by applying it to the fields when dilution with
the large volume of soil arrests further changes till the next rains.

5. There must be no serious competition between the last stages of the
decay of the compost and the work of the soil in growing a crop. This is
accomplished by carrying the manufacture of humus up to the point when
nitrification is about to begin. In this way the Chinese principle of
dividing the growing of a crop into two separate processes--(1) the
preparation of the food materials outside the field, and (2) the actual
growing of the crop--can be introduced into general agricultural
practice.

6. The compost should not only add to the store of organic matter and
provide combined nitrogen for the soil solution but should also
stimulate the micro-organisms.

7. The manufacture must be a cleanly and a sanitary process from the
point of view both of man and also of his crops. There must be no smell
at any stage, flies must not breed in the compost pits or in the earth
under the work cattle. The seeds of weeds, the spores of harmful fungi,
the eggs of noxious insects must first be destroyed and then utilized as
raw material for more compost. All this is achieved by the combination,
in the compost pits during long periods, of high temperature and high
humidity with adequate aeration.


THE COMPOST FACTORY

The compost factory at Indore adjoins the cattle shed. This latter has
been constructed for forty oxen and is provided with a cubicle, in which
a supply of powdered urine earth can conveniently be stored. The cattle
stand on earth. A paved floor is undesirable as the animals rest better,
are more comfortable and are warmer on an earthen floor. The earth on
which the cattle stand absorbs the urine, and is replaced by new earth
to a depth of six inches every three or four months. The compost factory
(Plates III and IV show the cattle shed and compost factory) itself is a
very simple arrangement. It consists of thirty-three pits, each 30 ft.
by 14 ft. and 2 ft. deep with sloping sides, arranged in three rows with
aufficient space between the lines of pits for the easy passage of
loaded carts. The pits themselves are in pairs, with a space 12 ft. wide
between each pair. This arrangement enables carts to be brought up to
any particular pit. Ample access from the compost factory to the main
roads is also necessary, so that during the carting of the compost to
the fields, loaded and empty carts can easily pass one another, and also
leave room for the standing carts which are being filled. For a large
factory it is an advantage to have water laid on, so that the periodical
moistening of the compost can be done by means of a hose pipe. At
Indore, water is pumped through a 3 in. pipe into a pressed steel tank,
8 ft. by 8 ft. by 8 ft., holding 3,200 gallons, which is carried on walls,
4 ft. above the ground, to provide the necessary head. This supply lasts
about a week. Water is led by 1-1/2 in. pipes from the tank to eight taps,
to which the armoured hose can be screwed. Each tap serves about six pits.
The general arrangement will be clear from Plate IV.

The total cost of the water tank, including arrangements for
distribution, was Rs. 1650 (equivalent to about 120 pounds sterling). This
was made up as follows: tank, Rs. 750; pipe system, Rs. 466; girders for
tank, Rs. 31; armoured hose, Rs. 28: railway freight, Rs. 88; masonry
work, Rs. 148; labour, including fitting up, Rs. 129.

The space under the tank, which is walled in on three sides and is open
on the leeward side, is used for storing wood ashes, and for keeping the
tubs and implements needed for the making of compost.

For a smaller factory or for the small holder, such a water system is
not necessary. All that is needed is that the compost pits should be
arranged near a well.


COLLECTION AND STORAGE OF THE RAW MATERIAL

Plant Residues.--All vegetable wastes from the cultivated area--such as
weeds, cotton and other stalks, green-manure, cane-trash, fallen leaves
and so forth, and all inedible crop residues from the threshing
floor--are carefully collected. All woody materials like cotton and
pigeon-pea (Cajanus Indicus Spreng.) stalks are crushed by placing on
the farm roads to be trampled and reduced by the traffic to a condition
resembling broken up wheat straw (Plate V). All green materials--such as
weeds and green-manures--are withered for at least two days before use
or storage. All these various residues are stacked near the cattleshed
as received, layer by layer--if possible under cover during the
rains--so that these materials may become thoroughly mixed. Each layer
must not be more than one foot thick, otherwise difficulties arise in
making a suitable mixture. Care must also be taken to remove the stacked
material in vertical slices so as to ensure even mixture. Very hard and
woody materials--such as sugarcane and millet stumps, wood shavings,
sawdust and waste paper--should be dumped separately in one of the empty
compost pits with a little earth and kept moist. After this preliminary
treatment, these hard and resistant materials can be readily composted.
Steeping such materials in water for two days, before addition to the
bedding under the work cattle, serves the same purpose.

Urine Earth and Wood Ashes.--All the earth removed from the silage pits,
all earthy sweepings from the threshing floors and all silt from drains
are stored in a convenient place near the cattle-shed. This provides an
adequate supply of suitable earth for absorbing the urine of the work
cattle, and acting as a base in the making of compost. This earth is
spread evenly on the cattle-shed floor to a depth of six inches and
renewed every three or four months. Half the urine earth when removed
from the floor should be crushed (Plate VI) in a mortar mill(See Plate's
V and VI). to break up the large lumps, and should be stored under cover
as dry powdered urine earth. The other half of the urine earth should be
applied direct to the fields as manure. All available wood ashes should
be stored under cover, as in the case of the powdered urine earth. These
materials (urine earth and wood ashes) are as essential in the
manufacture of compost as the plant residues themselves.

Water and-Air. Both water and air are needed for the compost process,
which therefore must be carried out near a well or other source of fresh
water.


ARRANGEMENT AND DISPOSAL OF THE BEDDING UNDER THE WORK CATTLE

(All quantities in the following refer to one pair of oxen. The figures
should be multiplied, when necessary, by the number of pairs of oxen
kept.)

All the uneaten food and any damaged silage are thrown on the wet
portions of the cattle-shed floor. One and a half pals of stacked
vegetable refuse, together with not more than one-twentieth of this
amount of hard resistant material (such as wood shavings, sawdust or
waste paper) from the soaking pit are spread on the floor.
(A pal is a stretcher made of a piece of gunny sheet (4 ft. by 3 ft.)
nailed to two bamboos each 7 ft. 6 in. long.) The cattle sleep on
this bedding during the night. In this way the bedding gets crushed and
broken still further and also impregnated with urine. Next morning
one-fourthof a tagari of fresh dung is removed to the compost
pit; the rest of the cattle dung being scattered on the bedding
in lumps not bigger than a small orange; or this excess dung can
be made into cow-dung cakes (kundas) for fuel. (A tagari is a bowl made
of sheet iron, capacity five-sevenths of a cubic foot. In Table IV the
metal bowls are converted into pounds or double handfulls of the
materials used. Kundas, thin flat cow-dung cakes, about twelve inches in
diameter and one inch thick, are used in the villages of India as fuel
for the cooking of food.) Two-fifths of a tagari of dry urine earth is
sprinkled on the used bedding in the same manner as murum (Murum is the
Hindustani name of the permeable layer of decayed basalt which underlies
the black cotton soils of India) is spread on roads. The bedding is then
transferred by a spade on to the pal from one end to the other and
removed to the compost pit. In this way the raw material used for the
compost is made perfectly homogeneous. The earthen floor of the
cattle-shed should then be swept clean, the sweepings being removed on a
pal to the compost pit. All wet patches on the floor are covered with
new earth, after scraping out the very wet portions. In this way all
smell in the cattle-shed is avoided and the breeding of flies in the
earth underneath the animals is entirely prevented. Bedding for the next
day can then be laid as described above.

During the rains, the bedding should consist of three layers--a bottom
layer and a top layer of dry material specially reserved for the
purpose, any withered residues being sandwiched in between. On very wet
days, all the urine earth may be added to the bedding before removal to
the compost heap.

The volume and weight of the various materials which are moved to and
fro in the sheet-iron bowls (tagaries) are given in Table IV.


TABLE IV

VOLUME (IN DOUBLE HANDFULLS) AND WEIGHT (IN LB.)
OF THE CONTENTS OF A TAGARI

                           Volume in double handfulls     Weight in lb.

Fresh dung                              6.5                    39.5
Powdered urine earth                   20.5                    22.5
Wood ashes                             15                      20
Fungus innoculant                       6                      20
Bacterial innoculant                    6                      20
Refractory vegetable residues                                   9
Mixed vegetable residues                                        9
Impregnated bedding                                            16.5
Sweepings from the cattles-shed floor                          19



CHARGING THE COMPOST PITS


A convenient size for a compost pit is 30 ft. by I4 ft. and 2 ft. deep
with sloping sides. The depth of the compost pit is most important on
account of the aeration factor. It should never exceed 24 in. A wooden
tub, a rake, a bowl (tagari), and a few empty kerosine tins (each
holding four gallons) with handles are all that are needed besides the
pal.

The following materials are placed alongside each compost pit--powdered
urine earth, two fifths tagari, fresh dung, one-quarter tagari; fungus
material, three tenths tagari, taken from a compost pit ten to fifteen
days old; wood ashes, one twentieth tagari; water, one kerosine tin. The
wood ashes and one twentieth of a tagari of urine earth are mixed with
some dung and fungus material in a portion of the water to make a thin
slurry. The pals of bedding should be added, as they arrive, from one
edge of the pit by simply allowing the bamboo pole of the pal next the
pit to fall into it (Plate VII). The other pole is then lifted so that
the rest of the bedding drops easily into the pit. The material is then
spread by means of the rake in a layer, not exceeding two inches thick
over the compost pit. All trampling of the charged pit must be avoided
as this interferes with aeration. Some dry urine earth and then the
stirred slurry are first sprinkled thinly on each charge of bedding,
which should appear evenly wetted. The soaked residues from the tub are
then scattered on each layer of bedding. This inoculates the mass with
active fungus throughout. The polished surfaces of the bedding are also
covered with an active adherent coating. This leads to rapid and even
crumbling. The volume of the slurry is made up with more dung, fungus
starter and water as required. The pit is charged with the bedding,
layer by layer, until all the bedding is used up. The sweepings from the
cattle-shed floor, which are rich in urine, are sprinkled on the top of
each day's charge with a tagari, followed by one-third of a tin of fresh
water. This distributes the urine evenly throughout the daily charge and
also prevents excess drying. Another watering in the evening, with
two-thirds of a tin, and a third watering the next morning with
one-third of a tin completes the charge. The pit or a suitable portion
of it should be filled up to the brim in six days or less, the remaining
part being filled subsequently.

The period of charging must not exceed six days, whether or no the pit
is completely filled by then. Each six days' charge should be regarded
as one unit in the manufacture of compost, no matter whether the pit is
filled completely or not.

Everything is now ready for the development of an active fungus growth
(the first stage in the manufacture of compost). When properly managed,
a vertical section of the fermenting mass should appear quite uniform
and should not show any alternate layers.

As the pits are frequently full of water during the greater part of the
rains, the compost must be made in heaps from the middle of June to I
October. The dimensions of the heaps should not exceed 7 ft. by 7 ft. at
the top, 8 ft. by 8 ft. at the bottom and 2 ft. in height. The
dimensions of these monsoon heaps (any one of which is not necessarily
completed by the amount of vegetable waste which can be accumulated in
six days) must not be exceeded, otherwise aeration difficulties are
certain to be encountered. The decomposition in heaps during the rains
does not take place so evenly as in the pits.

During the early rains, all the material in the pits must be transferred
to heaps on the surface. This is most conveniently done at the time of
the first, second or third turn.

The subsequent waterings are most important, otherwise decay will stop.
The first watering is done twelve days (counted from the date on which
the filling of the pit begins) after charging, when 1.25 tins are added
evenly over the whole surface. Further water is added at the time of the
first, second and third turning and afterwards as needed. During the
rains, the quantity of water as given above must be added at the time of
charging; the subsequent waterings during the rains may be reduced or
completely omitted according to the weather. Stagnant rain-water from
the pits should never be used. When watering is done by a hose pipe from
a tank as at Indore, the amount added can easily be adjusted if the rate
of flow is known.


TURNING THE COMPOST

To ensure uniform mixture and decay, and to provide the necessary amount
of water and air as well as a supply of suitable bacteria, it is
necessary to turn the material three times. The only difficulty which is
likely to arise in the process is the establishment of anaerobic
conditions between the period of charging and the first turn. This can
be caused by overwatering or by want of attention to the mixing. It is
at once indicated by the smell and by the appearance of flies attempting
to breed in the mass. When this occurs, the heap should be turned at
once with the addition of dung slurry and wood ashes.

First turn. Sixteen days after charge (Plate IX). Sufficient fresh water
should be ready--about four tins according to the season. Three-fifths
of a tagari of compost is taken from another pit thirty days old (just
after the second turn) and scattered on the surface of the material.
This is necessary for inoculating the mass with the proper bacteria. The
top layer of the compost is then loosened and mixed, a portion at a
time, with a rake and well moistened with water. Half the heap is sliced
with a spade a few inches breadthwise and vertically from top to bottom
to fill one tagari at a time. Tagari after tagari is poured in rows on
the other undisturbed half to make a layer which is then sprinkled with
water. This is repeated until one-half of the contents of the pit is
doubled lengthwise over the other. The heap is then watered, suflicient
being added at this first turn to prevent the wasteful use of water
afterwards. After turning, the heap should not rise more than twelve
inches above ground level. The second watering, 1.5 tins, is given
twenty-four days after charge. At the first turn, the materials should
be arranged on the windward side of the pit to avoid the cooling of the
mass and also excessive drying. During the rains, when heaps are made,
it is not possible to double one-half of the heap over the other. The
material should then be completely turned and the heap re-made. The
heaps should be made as near as possible to each other.

Second turn. One month after charge (Plate IX). The water required is
about three tins. The material is cut vertically in two inch slices and
piled up with watering as before along the empty half of the pit. The
material should fall loosely, under each stroke of the spade and not in
lumps, so as to ensure copious aeration. The third and fourth waterings,
1.5 tins each, are given five and six weeks after charge.

Third turn. Two months after charge. About two tins of water are
necessary. A rectangular heap is made on the ground alongside the pit or
in the field not more than 10 ft. broad at the base, 9 ft. wide at the
top and 3.5 ft. high, the material being spaded and piled with watering
as before. When the heap is made in the field, all the water needed
should be added at the time of carting. The contents of several pits may
now be placed side by side to save space, to economize water and to
facilitate removal. The fifth and sixth waterings, 1.25 tins each, are
given nine and ten weeks after charge. For the first time during the
process, extra labour, namely three men and four women for six hours, is
required for each pit at the third turn. As the heap can be made either
in the factory or in the field, this additional labour can be debited to
the application of the humus to the land.

Three months after charge the manure is ready, when it should be applied
to the land. If kept in heaps longer than three months after charge,
nitrogen is certain to be lost. There is no great harm in putting the
manure on the land after two months if urgently required, especially
when the process has run for some time and everything is in full working
order.


TIME-TABLE OF OPERATIONS

The complete time-table of the manufacture of compost, which takes
ninety days, is given in Table V.


TABLE V

THE COMPLETE TIME-TABLE FOR ONE COMPOST PIT

Day                     Event

1      Charging begins.
6      Charging ends.
10     Fungus growth established.
12     First watering.
16/17  First turning, compost inoculated with bacteria from another pit
           thirty-days old.
24     Second watering.
30/32  Second turning.
38     Third watering.
45     Fourth watering.
60     Third turning.
67     Fifth watering
75     Sixth watering
90     Removal to field.



OUTPUT

Fifty cart-loads of ripe compost per pair of oxen per annum can be made
from the plant residues available on any holding. The quantity can be
more than doubled when all the dung and urine earth are used, provided
of course sufficient vegetable refuse can be secured. Fifty to
seventy-five tins (200 to 300 gallons) of water, according to the
season, are sufficient to make one cart-load of finished compost. No
extra labour is required other than that usually employed in the
cattle-shed, namely two men and three women. These are sufficient for
the work connected with forty oxen and the preparation of 1,000 carts of
compost per annum.

The labour needed for the annual manufacture of 1000 cart-loads of
compost has been reduced to a minimum by: (1) the provision of a water
supply; (2) the general design of the cattle-shed and compost factory
and (3) the detailed training of the labour force to carry out the work
quickly and without unnecessary fatigue. This aspect of the manufacture
of humus has been greatly assisted by the system of managing labour
adopted at the Institute (Appendix D).

During the year 1930, when 840 cart-loads of compost were prepared, a
careful record of the actual time spent on compost making by the labour
employed to look after the work cattle, was made. It was found that one
half of the time of this labour was spent on the care of the cattle and
one half on the making of compost. The The total wages debited to actual
compost making came to Rs 441.5, i.e. to 8.5 annas, or ninepence
halfpenny, per cart-load of finished material. During the present year,
1931, the output has increased and is expected to reach 1,000 cart-
loads. It is best to spread the compost on the land directly it becomes
ready, so as to facilitate the distribution of farm work throughout the
year.


MANURIAL VALUE OF INDORE COMPOST

One-cart load of Indore compost is equivalent, as regards nitrogen
content, to two cart-loads of ordinary farmyard manure. Properly made
compost has another great advantage over ordinary manure, namely its
fine powdery character which enables it to be uniformly incorporated
with the soil and to be rapidly converted into food materials for the
crop. Taking everything into consideration, Indore compost has about
three times the value of ordinary manure.




Chapter V



THE CHIEF FACTORS IN THE INDORE


PROCESS

The Indore process enables the Indian cultivator to transform his mixed
vegetable wastes into humus; in other words to become a chemical
manufacturer. The reactions involved are those which take place under
aerobic conditions during the natural decay of organic residues in the
soil. The object of the process is to bring these changes under strict
control and then to intensify them. A knowledge of the chemical
processes involved and of their relative importance is therefore
essential in applying the process to other conditions. These matters
form the subject of the present chapter.


THE CONTINUOUS SUPPLY OF MIXED VEGETABLE WASTES

A continuous supply of mixed vegetable wastes throughout the year, in a
proper state of division, is the chief factor in the process. The ideal
chemical composition of these materials should be such that, after the
bedding stage, the carbon-nitrogen ratio is in the neighbourhood of
33:1. The material should also be in such a physical condition that the
fungi and bacteria can obtain ready access to, and break down the
tissues without delay. The bark, which is the natural protection of the
celluloses and lignins against the inroads of fungi and bacteria, must
first be destroyed. This is the reason why all woody materials--such as
cotton-stalks, pigeon-pea stalks and sann hemp (Crotalaria juncea
L.)--are laid on the roads and crushed by the traffic into a fine state
of division before composting. Still more refractory residues like the
stumps of sugar-cane and millets, shavings, sawdust, waste paper and
packing materials, old gunny bags and similar substances, must either be
steeped in water for forty-eight hours or mixed with moist earth in a
pit for a few days before passing, in small quantities daily, into the
bedding.

The vegetable wastes which have been utilized at Indore for the last six
years are the following:--

Residues available in large quantities: Cotton stalks, sann hemp--either
as green plants reaped before the flowering stage or as dried stems of
the crop kept for seed, pigeon-pea stalks, sugar-cane trash, weeds,
fallen leaves.

Residues available in moderate quantities: Mixed dried grass, gram
stalks, wheat straw, uneaten and decayed silage, millet stalks damaged
by rain, residues of the safflower crop, ground-nut husks, ground-nut
stalks and leaves damaged by rain, sugar-cane and millet stumps.

Residues available in small quantities: Waste paper and packing
materials, shavings, sawdust, worn out gunny bags, old canvas, worn out
uniforms, old leather belting.

. . . . The raw materials available at Indore differ greatly in chemical
composition and particularly in the percentage of nitrogen. Many of
these wastes, such as cotton-stalks, the stems of sann hemp and of the
pigeon-pea, and cane trash are too low in nitrogen for rapid
composting. Others--such as green hemp, reaped just before flowering,
ground-nut residues and leguminous and other weeds--contain higher
percentages of nitrogen, a portion of which is certain to be lost during
the process if these materials are composted singly. A proper mixture of
the various materials available, so that the nitrogen content of the
mass throughout the year is kept uniform and sufficiently high, is the
first condition of success. For this reason it is necessary to collect
and stack the various residues in such a manner that a regular supply of
dry, mixed, vegetable wastes (as already stated with a carbon-nitrogen
ratio in the neighbourhood of 33:1 after the material has been used as
bedding) is available right through the year. This could only be
accomplished at Indore: (1) by cutting the cotton-stalks soon after
picking is over so as to secure the maximum number of leaves; (2) by
growing a large area of sann hemp, which contains when withered as much
as 2.3 per cent of nitrogen; and (3) by securing as much green weeds,
groundnut residues and fallen leaves as possible for the mixture. All
these materials are rich in nitrogen, and help to bring the
carbon-nitrogen ratio near the required standard. By stacking the
various constituents in layers, not more than one foot thick, and by a
judicious admixture with the residues richest in nitrogen, it is
possible to provide a continuous supply of dry mixed material of the
correct chemical composition. During the rains, a good deal of the raw
material is in the form of fresh green weeds, rich in nitrogen and
soluble carbo-hydrates. These must be spread, in thin layers, on the
grass borders of the fields alongside the roads and withered, before
being carried to the stack or used as one of the constituents of the
bedding. Only in this way can the most be made of this valuable
material. Collecting weeds in temporary heaps on the borders of fields
leads to serious waste of the soluble carbo-hydrates and also of the
nitrogen.


COMPOSTING SINGLE MATERIALS

A number of experiments have been carried out at Indore during the last
four years with the following single materials--cotton-stalks, pigeonpea
stalks, cane trash, weeds (green and withered), sann hemp (green and
withered). When necessary these residues were either passed through a
chaff cutter or crushed with a disc harrow before composting direct in
heaps, eighteen inches high, or in pits filled to the same depth. In
some cases Adco was employed as the source of nitrogen and base, in
others cattle-dung and urine earth were used. Sufficient water was
always added to maintain a high moisture content.

Although the cotton residues, fermented direct with urine earth and
cattle-dung, contained 16.5 per cent of green leaves (high in nitrogen)
and every care was taken to maintain the correct relation between air
and water, the results were not completely satisfactory. Fermentation
was rapid at the beginning, due to the presence of the leaves, but
slowed down afterwards. It took I50 days to obtain a usable product, as
compared with the ninety days required for mixed wastes.

In the case of cotton-stalks, broken down by the use of Adco, the
results were still more unsatisfactory. Several interesting facts
however came to light. The fermentation tended to be uneven; the
temperature of the heaps was always irregular; the mass did not retain
moisture well; a very large quantity of water was needed. The final
product, although high in nitrogen, tended to be somewhat coarse and to
contain a good deal of partially decomposed material. The maximum
temperatures in the Adco heaps during the first 100 days fell from
53.5 degrees C. to 29.5 degrees C. (In the standard Indore process, the
range of temperature during ninety days was 65 degrees C. to
33 degrees C.) The final product was fairly satisfactory as regards
fineness (80.5 per cent passed through a sieve of six meshes to the linear
inch) and high in total and available nitrogen (total 2.50, available
0.42 per cent). The corresponding figures for the product made from
cotton-stalks with cattle-dung and urine earth were--fineness 84.2 per
cent and total nitrogen 1.61, of which 0.I3 per cent was available.
In spite of the higher nitrogen content obtained in the Adco product,
no increase in growth was obtained when equal quantities of both kinds of
cotton-stalk compost were used in pot cultures of millet. This result
probably follows from the fact that the use of Adco often produces compost
with a carbon-nitrogen ratio narrower than 10:1, the ideal which should
be aimed at in the manufacture of humus. The extra nitrogen in such cases
is always liable to be lost before the crop can make use of it.

The results obtained in the direct composting of other single materials,
like pigeon-pea stalks and cane trash, were still more unsatisfactory.
When used alone, either with cow-dung and urine earth or with Adco,
little change took place in a month in spite of copious watering and
occasional stirring. When, however, these materials were passed through
the cattle-shed and used as bedding, the results were distinctly better
but not really satisfactory. At the end of six months, the heaps were
only about half decomposed.

Difficulties also arise when weeds (fresh or withered) or sann hemp
(fresh or withered) are composted by themselves or when a mixture of the
two is employed. In the first place, the nitrogen content of this
material is too high and serious losses of this element take place. In
the second place, these residues, particularly when fresh, tend to pack
closely in the heaps and to prevent aufficient aeration (Table VIII).
For this reason, withered weeds or withered sann must never form more
than about 30 per cent of the volume of the bedding, the rest being made
up of mixed residues like cotton and pigeon-pea stalks with a much lower
nitrogen content.


TABLE VIII

LOSSES OF NITROGEN RESULTING FROM THE CLOSE TEXTURE OF THE MASS

No. of pit  Withered    Total      Total nitrogen   Loss or    Percentage
            materials   nitrogen   (lb.) in the     gain of    loss
            used        (lb.) at   finished         nitorgen   or gain
                        beginning  product          (lb.)

34          Weeds         44.2      25.7           -18.5      -41.8
38          Half sann,
            half weeds    42.8      28.4           -14.5      -33.8
40            "do."       49.7      29.2           -20.5      -41.3
41          Mixed
            residues      28.3      29.5             +1.3        +4.4


When one food material at a time is provided for the fungi and bacteria,
loss of nitrogen or aeration difficulties or both always occur. When a
mixed diet is employed, everything goes smoothly, provided of course all
other important details receive attention.


NITROGEN REQUIREMENTS

The total amount of combined nitrogen which must be added to the mixed
residues for the use of the micro-organisms is less than was at first
expected. The vegetable wastes from the 300 acres of land at the
disposal of the Institute can be converted into humus by means of half
the urine earth and one quarter of the cattle-dung of the forty oxen
maintained for the work of the station. A satisfactory product, with a
suitable carbon-nitrogen ratio, can be obtained with this reduced supply
of dung (Table IX). At first all the urine earth was employed in
composting, but it was soon found that better aeration resulted with
only half the quantity. Although in many cases the compost made with
full dung contains about 0.15 per cent more nitrogen than that made with
reduced dung, the results obtained in the field were always the same.
The surplus urine earth is used for manuring the land, the extra
cattle-dung can either be used up in composting or can be sold for the
manufacture of cow-dung cakes (kundas). This means: (1) that the present
high output of compost could be doubled if sufficient vegetable wastes
could be obtained; and (2) that even after this increased output is
reached, half the dung would still be in excess.


TABLE IX

RESULTS WITH REDUCED (ONE-FOURTH) AND FULL DUNG

No.     Amount of  Total N  Total N  Percent Percent  Percent Carbon Fine-
of pit  dung used  (lb.)    (lb.)    gain    of N at  of N    nitro-ness
                   at        at      of N    begin    at end  gen
                   begin     end                              ratio

14     Reduced     29.12    32.36    11.1    0.67      0.84   11.6:1  88.5
15     Full        32.70    34.87     6.6    0.70      0.72   12.6:1  82.5


The fact that the cultivator really requires only a fraction of his
cow-dung for converting all his vegetable wastes into humus, disposes
once and for all of the view that the salvation of Indian agriculture
lies in substituting some other fuel for cow-dung cakes. This material
is essential for the slow cooking needed for a vegetarian diet As no
other suitable fuel. exists in many of the villages of India, cow-dung
must be utilized. Fortunately, when all the available vegetable wastes
have been converted into humus, a large supply of cow-dung for fuel will
still be available, and there is no reason why it should not be burnt.
The ashes, however, should be carefully collected and employed as a base
in the compost process.

In all the comparative trials which have been made at Indore, with Adco
on the one hand and with urine earth and cow-dung on the other hand, far
more satisfactory results have been obtained with the indigenous
materials. The weak point of Adco is that it does nothing to overcome one
of the great difficulties in composting, namely the absorption of moisture
in the early stages. In the hot weather in India, the Adco pits lose
moisture so rapidly that the fermentation stops, the temperature becomes
uneven and then falls. When, however, urine earth and cow-dung are used,
the residues become covered with a thin colloidal film, which not only
retains moisture but contains the combined nitrogen and minerals required
by the fungi. This film enables the moisture to penetrate the mass
and helps the fungi to establish themselves. Another disadvantage
of Adco is that when this material is used according to the directions,
the carbon-nitrogen ratio of the final product is narrower than the
ideal 10:1. Nitrogen is almost certain to be lost before the crop can
make use of it, particularly when Adco compost is added to the land
some weeks before sowing takes place.


THE AMOUNT OF WATER NEEDED

It is an easy matter to waste large quantities of water in the process.
As a result of repeated trials, the maximum economy of water is obtained
when I68 gallons (for every 400 tagaries of used bedding) are added at
the time of charging and during the next twenty-four hours. After this,
the watering should proceed as laid down in Chapter IV. Any departure,
in either direction, leads to a waste of water. . . The standard water
requirements as now adopted, per cart-load of finished compost, varies
from 200 to 300 gallons according to the season. The Malwa Plateau, on
which Indore is situated, is a windswept area in which the humidity is
low for at least eight months in the year. It is unlikely, therefore,
that these quantities will be greatly exceeded, except in very dry areas
like the Punjab and Sind.

At the beginning of the process, care should be taken to add just
sufficient moisture to keep the average water content below 50 per cent
of complete saturation, so as to help the fungi to establish themselves
rapidly and strongly. This matter is important, as the vegetable wastes
take up water very slowly at the beginning. If too much is added at this
stage, free water tends to accumulate in the air spaces and to hinder
aeration. This checks the growth of the fungi, which thrive best if the
total moisture is below 50 per cent. The moment the crumbling of the
material sets in, water is absorbed more rapidly. After the first turn
and till the compost is ready to cart to the fields, the total moisture
content should vary between 50 and 60 per cent. After the final turn,
when no more water is added, the percentage again drops to what it was
at the beginning, namely under 50 per cent. During the rains, the water
content of the heaps naturally tends to run a little higher than in the
dry season. The depressing effect on the fermentation of very heavy
monsoon downpours was well brought out during a wet period of seven days
(10-16 September 1930), when 12.86 inches occurred, 11.65 inches of
which were received in one continuous fall, lasting seventy-two hours.
At the end of this spell, there was a temporary fall in the temperature
of the heaps. Three or four days after the downpour stopped,
fermentation again became vigorous as is seen by the rapid rise in the
temperature (Table XII).


TABLE XII

THE EFFECT OF HEAVY RAINFALL (12.86 INCHES)
ON THE TEMPERATURE OF FERMENTING HEAPS

(temperature in degrees C)

Age of Heap   Before the rain   After the rain   Three days after the rain
                                                               stopped
First week            61                  44                      53
First week            59                  37                      50
After the first turn  55                  38                      52
Afterthe first turn   54                  39                      53
After the second turn 51                  30                      48
After the second turn 48                  32                      48
After the third turn  41                  29                      38
After the third turn  40                  30                      38



THE SUPPLY OF AIR

The control of the aeration factor is perhaps the most difficult part of
the process, and requires careful attention. The first condition of
success in obtaining a sufficient supply of oxygen and nitrogen for the
micro-organisms, is the use of mixed bedding which maintains an open
texture through out the process. As already explained, single materials
always tend to pack too closely and to cut off the air supply. The
second condition of success is attention to detail at the time of
charging. The bedding must be carefully spread, the urine earth, the
cow-dung slurry and the wood ashes must be evenly scattered. Water must
be properly distributed over the whole mass, and there must be no
trampling. At the time of the first and second turns, the spading or
forking must be carried out so that the material falls lightly, when
thorough mixing takes place with the maximum amount of aeration. The
third condition of success concerns the depth of the pit or heap, which
must never exceed twenty-four inches. This is the maximum distance to
which air can penetrate the fermenting mass in sufficient volume. If
this depth is exceeded, two things happen: (1) the decay of the layers
below twenty-four inches is retarded; (2) is always a loss of nitrogen
through denitrification (Table XIII).


TABLE XIII  COMPOST MAKING IN DEEP AND SHALLOW PITS

                                      Pits 4 ft. deep      Pits 2 ft. deep
Amount of material (lb.) in charge        4500                  4514
Total nitrogen (lb.) at the beginning    31.25                  29.12
Total nitrogen (lb.) at the end          29.49                  32.36
Loss or gain of nitrogen (lb.)          -1.76                  +3.24
Percentage loss or gain of nitrogen     -6.1                  +11.1


The air supply can also be permanently interfered with if too much earth
and cow-dung are used at the time of the first charge. These materials
make the whole mass too solid and pack it too closely. Anaerobic
conditions are then established. This is indicated by the smell and by
the appearance of flies, which then find suitable breeding conditions.
The remedy is at once to turn the material, with the addition of
cow-dung slurry and wood ashes. Temporary interruptions in aeration also
follow overwatering or the soaking due to heavy rain. These troubles,
however, pass in two or three days as the heap dries and the surplus
moisture is gradually taken up by the mass (Table XII).


THE MAINTENANCE OF THE GENERAL REACTION


In order to maintain the general reaction of the mass within the optimum
range, a suitable base is necessary for neutralizing excessive acidity,
and for the temporary absorption of any ammonia that may be given off
during the process. The urine earth and wood ashes provide this in the
most economical manner. Black cotton soil (Table XIV) contains an ample
reserve of weak bases. The buffering effect of these maintains


TABLE XIV  MECHANICAL AND CHEMICAL ANALYSES OF BLACK SOIL

Mechanical

Fraction                          I                II                  III
Clay                            42.5              45.6                38.3
Fine Silt                       19.6              21.8                17.7
Silt                            12.5              10.8                11.3
Fine Sand                        7.4               4.2                 6.7
Coarse Sand                     10.2               6.0                 3.0
Moisture                         3.3               6.4                 3.0
Loss on Ignition                 3.0               5.7                 2.7
Calcium Carbonate                1.6               6.1                 1.4

Chemical
Constituent

Insolubles                      56.1              73.8                68.7
FE203                            9.8               9.1                11.2
MNO2                            --               0.1                 0.3
CaO                              6.6               0.9                 1.0
MgO                              2.5               1.5                 1.8
K2O                              0.4               0.2                 0.4
Na2O                             0.2
P205                             0.08              0.17               0.06
CO2                              0.8               0.1                0.4
N                                0.03              0.05               0.05
Organic combined water           9.4               7.4                5.83


the general reaction constant throughout (Table XV). Further, black soil
contains a high percentage of clay, the colloids of which are most
useful in two ways. In the first place, these substances are capable of
temporarily absorbing, till required for oxidation, any ammonia given
off in the process. In the second place, the colloids, when mixed with
the urine and cow-dung, cover the vegetable wastes with a thin,
nutrient, moisture-retaining film


TABLE XV  REACTION AND TEMPERATURE IN THE INDORE PROCESS

Stage                         pH value           Temperature in degrees C.

One day after charge             7.2                       63
After first turn (19 days old)   7.4                       49
After second turn (34 days old)  7.5                       45
After third turn (60 days old)   7.6                       41
Ripe manure (90 days old)        7.7                       35


which is of the utmost value, not only in the gradual absorption of
water but also in providing the fungi with a favourable nidus for the
steady breaking down of the vegetable wastes. The result is the rapid
establishment of a vigorous mycelial growth, and the early crumbling of
the whole mass. When a colloidal film is not employed, as in the Adco
process, it is most difficult to get the material to absorb and retain
sufficient moisture. Consequently, an even and vigorous mycelial growth
is never quickly obtained. The colloids in soil are essential, both for
coaxing water into the material and also for enabling the fungi to
establish themselves rapidly and vigorously. The fungi are the storm
troops of the composting process, and must be furnished with all the
armament they need.

In a recent paper, received just as this chapter was completed, Jensen
has shown that cellulose decomposing bacteria multiply most strongly at
pH 7.0-8.0.


THE FERMENTATION PROCESSES

In addition to providing suitable conditions for the rapid development
of the micro-organisms, it is necessary to inoculate the mass at the
proper moment, so that there is no delay in the conversion. This is
arranged for at the time of charging, when the pits are uniformly
infected with actively growing fungus mycelium, taken from a compost pit
ten to fifteen days old. At the same time, the bacteria present in
cow-dung are introduced in large numbers. A further inoculation is
carried out at the time of the first turn, when compost from a pit
thirty days old is introduced into the mass. This provides a supply of
the organisms required for the second half of the process.

The activity of the various micro-organisms can most easily be followed
from the temperature records. A very high temperature, about
65 degrees C., is established at the outset, which continues for a long
time with only a moderate downward gradient (Table XVI). This range fits
in very well with the optimum temperature conditions required for the
micro-organisms which break down cellulose. The aerobic thermophylic
bacteria thrive best between 43 degrees and 63 degrees C.; the fungi
between 40 degrees and 55 degrees C.


TABLE XVI  TEMPERATURE RANGE IN A NORMAL PIT

Moisture 45 to 55 per cent

Age in days                        Temperature in  degrees C
     3                                          63
     4                                          60
     6                                          58
    11                                          55
    12                                          53
    13                                          49
    14                                          49
                                           First Turn
    18                                          49
    20                                          51
    22                                          48
    24                                          47
    29                                          46
                                          Second Turn
    37                                          49
    38                                          45
    40                                          40
    43                                          39
    57                                          39
                                            Third Turn
    61                                          41
    66                                          39
    76                                          38
    82                                          36
    90                                          33

Period in days for each fall of 5  degrees C

Temperature Range    No. of Days
(degrees C.)
65-60                    4
60-55                    7
55-50                    1
50-45                   25
45-40                    2
40-35                   44
35-30                   14
Total                   97 days


The temperatures throughout the fermenting mass are extraordinarily
uniform in the pits; in the heaps the range is somewhat greater. An
analysis of the figures shows that, before each turn, a definite slowing
down in the fermentation takes place. As soon as the mass is remade,
when more thorough admixture with copious aeration occurs, there is a
renewal of activity during which the undecomposed portion of the
vegetable matter from the outside of the pit or heap is attacked. At
least three types of fermentation appear to be involved, which succeed
one another with great rapidity. Two of these--those which occur between
50 degrees to 45 degrees C. and 40 degrees  to 35 degrees C.--are long
continued. It is during these latter stages of the process that the
transformation of the vegetable wastes into humus occurs, accompanied by
the rapid crumbling and shrinkage of the mass. A detailed analysis of the
phases of micro-biological activity and the determination of the organisms
concerned has not yet been carried out. The results, when obtained,
cannot fail to throw considerable light on the real origin of humus and
should also help to clear up a large field of rather obscure organic
chemistry. This subject can naturally be more effectively studied in the
mass under factory conditions than on a small scale in pot cultures or
in the laboratory.

Wind is always a source of trouble and does most harm during the early
stages of fermentation--between charging and the first turn--by lowering
the temperature. The effect is most marked in the heaps which helps to
explain why the process is not quite so efficient in the rains as it is
in pits during the rest of the year.

The wind factor can be minimized during the rains by arranging the heaps
so that they shelter each other. The pits must always be orientated so
that the length is at right angles to the direction of the prevailing
wind. This gives each pit a windward and a leeward side. The first turn
must always be made towards the windward side, so that the earth wall of
the pit protects the mass. Temporary spells of cold weather of short
duration, such as occur in India, have no injurious effect. The
fermentation is so vigorous that these sudden changes of temperature are
not able to check the process. Hence in the tropics, compost houses are
unnecessary. The disintegrating power of the process is so intense that
unbroken stems of grass and weeds, several feet in length, are reduced
in ninety days to partially decayed fragments only a few inches in
length. The long continued moist heat of the fermentation also leads to
other useful results besides helping to soften and break down the mass.
The high temperatures make the process sanitary, and prevent all
objectionable smell. Flies and other insects cannot breed in the hot mass.
The seeds of weeds are killed in the process, as is shown by the fact that
no weeds grow on the heaps of ripe compost. To confirm this point, Is. of
grass seeds were mixed with the bedding of two pits. Germination tests
of the ripe manure gave negative results in each case.


GAINS AND LOSSES OF NITROGEN

A simple means of testing the efficiency of the process is to determine
the amount of nitrogen lost. When vegetable wastes, with a
carbon-nitrogen ratio in the neighbourhood of 33:1, are composted under
strict aerobic conditions in the presence of suitable bases, there
should be no loss of nitrogen whatsoever. If any loss of this element
occurs, the process itself must be at fault. A careful nitrogen balance
sheet has therefore been kept for a number of pits and heaps, which
shows that under normal conditions no loss of nitrogen takes place
(Table XX). On the contrary, nitrogen is gained, apparently by fixation
from the atmosphere.


TABLE XX  NITROGEN BALANCE SHEETS IN NORMAL PITS AND HEAPS

No.    Description    Total N (lb.)  Total N (lb.)  Total gain  Percentage
                      at the         in the         in          gain
                      beginning      finished       nitrogen    of
                                     product                    nitrogen

Pit
14 Standard (1/4 dung) 29.12          32.36           3.24        11.1
15 Full dung           32.70          34.87           2.17         6.6
16 Dry dung            30.41          32.33           1.92         6.3
18 Full dung (residues
     low in nitrogen)  29.10          36.77           7.67        26.3
19 Dry dung            29.55          30.70           1.15         3.9
20 Standard (1/4 dung) 24.73          25.80           1.07         4.3
21 Full dung (half
   period in monsoon)  32.35          33.40           0.15         0.45
Heap
42 Monsoon             22.28          29.52           1.24         4.4



In one case, No. 18, in which residues poor in nitrogen were composted
with the full supply of dung, a very large amount of fixation took
place. It will be interesting to investigate cases such as these in
greater detail, and to determine the exact conditions under which such a
large volume of free nitrogen can be fixed.

While losses of nitrogen do not take place in normal pits or heaps,
waterlogging of the pits during the early rains, even for a short
period, is at once followed by denitrification (Table XXI).


TABLE XXI  NITROGEN BALANCE SHEET OF TEMPORARILY WATERLOGGED PITS

No.   Description    Total N (lb.)  Total N (lb.)  Total gain Percentage
                     at the         in the        in          gain of
                     beginning      finished      nitrogren   nitrogen
                                    product

Pit
24 Full dung          31.80          29.66          2.14       6.7
25 Full dung          29.55          27.10          2.15       8.1



Nitrogen is always lost in the first stage of the process--between
charging and the first turn--whenever the nitrogen content of the mass
is too high at the beginning (Table XXII).


TABLE XXII  CHANGES IN NITROGEN CONTENT DURING THE
FIRST STAGES OF THE PROCESS

No. Description             Percentage Nitrogen   Percentage Nitrogen
                            at the beginning    after the first turn

                            Residues poor in nitrogen

Pit 14  Standard--dry season      0.68                 0.84
Pit 25  Standard--dry season      0.63                 0.60
Heap 41 Standard--monsoon         0.64                 0.64

                            Residues rich in nitrogen

Pit 5   Full dung--dry season     1.04                 0.70
Pit 6   Full dung--dry season     0.86                 0.73
Pit 40  Full dung--monsoon        1.30                 1.03


Another loss of nitrogen which has to be guarded against takes place
when the final product is kept too long in heaps. An appreciable loss of
nitrogen takes place even when the compost is kept for an extra month in
the heap (Table XXIII). After ninety days the process is complete, when
the humus should be used as a top dressing for growing crops or else
banked by applying it to the land, when it becomes diluted with such large
volumes of dry earth that all further changes are checked.


TABLE XXIII  NITROGEN LOSSES DURING STORAGE IN HEAPS

No. of Pit  Percentage of total nitrogen     Percentage of total nitrogen
            on dry basis after three months  on dry basis after four months
7                            0.90                      0.88
8                            1.00                      0.93
14                           0.84                      0.81
15                           0.72                      0.68



THE CHARACTER OF THE FINAL PRODUCT

The ripe compost consists of a brownish-black, finely divided powder, of
which about 80 per cent will pass through a sieve of six meshes to the
linear inch. The state of division of an organic manure is an important
factor, second only to its chemical composition. This property enables
the Indore compost to be rapidly and easily incorporated, and to exert
its maximum effect on the internal surface of the soil. The
carbon-nitrogen ratio is not far from the ideal figure of 10:1. The
nitrogen is therefore in a stable form, which does not permit of
liberation beyond the absorption capacity of the crop. The percentage of
total nitrogen is also satisfactory, varying from 0.8 to 1.0 per cent
(Table XXIV).


TABLE XXIV  COMPOSITION OF THE FINAL PRODUCT

No. of   Mater-     Org- Total  Sili-   Nitro- P205  K2O  C/N  Sol- Fine-
pit      ials        anic  ash    cates    gen                    uble   ness
or heap  used        Matter       and sand                        humus

Heap    Cotton-stalks
        with reduced
        (1/4) dung  33.92 66.09   34.97    1.61  0.48  3.38 16.5:1 11.56 68.15
Pit 7   Dry mixed
        residues    20.14 79.87   46.91    0.0   0.41  1.95 11.2:1  5.56 72.3
Pit 14  Dry mixed
        residues    19.66 80.34   46.32    0.84  0.68  2.35 11.6:1  6.27 88.5
Pit 8   Dry mixed
        with full
        dung        20.19 79.82   46.27   1.004  0.51  3.05 10.8:1  4.83 81.3
Pit 15  Dry mixed
        with full
        dung        18.39 81.62   51.33   0.725  --  2.43 12.6:1  3.86 82.5
Pit 5   Dry mixed
        with full
        dung        19.76 80.24   50.11   0.841  0.403 2.23 11.7:1  5.29 84.0

Results obtained in the monsoon

Heap 6  Mixed withered
        weeds       21.25 78.75   47.55   0.862  0.43  2.33 12.3:1  4.01 76.3
Heap 10 Mixed withered
        weeds       22.05 77.95   47.77   0.808  0.49  4.99 13.6:1  4.07 78.4
Heap 22 Mixed withered
        weeds       22.09 77.91   48.45   0.914  0.51  3.59 12:1    4.31 75.7
Heap 34 Mixed withered
        weeds       19.38 80.63   48.7    0.625  0.59  5.31 15.5:1  4.27 79.4
Heap 40 Half withered
        weeds, half
        sann        21.05 79.95   47.61   0.825  0.55  2.85 12.75:1 5.96 78.6
Heap 42 Dry mixed
        residues    21.69 78.32   46.41   0.806  0.62  3.65 13.5:1  5.36 84.0


The nitrifying power of the compost, particularly that made from mixed
residues, is very satisfactory. Laboratory tests, carried out under
conditions resembling those of the field during the early monsoon
rains . . . bring out clearly the superiority of the product made from
mixed residues.

Besides its value as a source of readily available nitrogen, the Indore
compost acts as an indirect manure. The permeability of the black cotton
soil is markedly improved, particularly by the product from mixed
residues. The loss of permeability which takes place in these soils
after the early rains, is perhaps the greatest obstacle to high yields
of cotton. A manure, therefore, which will help to remove this factor,
is exactly what the cultivator needs. This property will prove of the
greatest value in keeping alkali in check, when the process is applied
to the close alluvial soils of the Punjab and Sind.

It will be clear from the results set out in this chapter that a
solution of the problem of utilizing the waste products of agriculture
itself has been solved, by methods which are well within the means of
any industrious cultivator. All the recent work on the problems of
manuring points clearly to the supreme importance of organic matter of
the right type. This must possess a carbon-nitrogen ratio in the
neighbourhood of 10:1, and must be synthesized from crop residues by
means of fungi and bacteria, working under aerobic conditions. Clearly
the thing to do is to manufacture such a product in a compost factory
under strict control, and then to add the organic matter to the soil.
This has been accomplished at Indore.

NOTE: After this chapter was written, a paper by Waksman and Gerretsen
appeared in the issue of Ecology of January 1931, which confirms the
results set out above in a very remarkable way, The New Jersey
experiments deal with the influence of temperature and moisture on the
decomposition of plant residues as a whole. The higher the temperature,
the more rapid is the decomposition of the material including the
lignins. At the highest temperature, 37 degrees C., the carbon-nitrogen
ratio was reduced from about 100 to 11.3:1, to almost the ratio of the
organic matter in normal soil. When decomposition was most favourable and
most rapid, the final carbon-nitrogen ratio was practically the same as
that in soil humus. This is exactly what happens in the Indore process.
The American results, which were obtained under laboratory conditions,
fully confirm our factory experience of the last four years in India and
can be applied, practically as they stand, to the Indore process.



BIBLIOGRAPHY

BRAYNE, F. L.--The Remaking of Village India, Oxford University Press,
1929.

DUBOS, R. J.--'Influence of Environmental Conditions on the Activities
of Cellulose Decomposing Organisms in the Soil,' Ecology, 9, 1928, p. 12.

HOWARD, A. and HOWARD, G. L. C.--The Application of Science to Crop
Production, an Experiment carried out at the Institute of Plant
Industry, Indore, Oxford University Press, 1929.

HUTCHINSON, H. B.--'The Influence of Plant Residues on Nitrogen Fixation
and on losses of Nitrates in the Soil,' Journ. of Agric. Science, 9,
1918, p. 92.

JENSEN, H. L.--'The Microbiology of Farmyard Manure in Soil. 1--Changes
in the Micro-flora and their Relation to Nitrification,' Journ. of
Agric. Science, 21, 1931, p. 38.

RUSSELL, E. J. and RICHARDS, E. H.--'The Changes taking Place during the
Storage of Farmyard Manure,' Journ. Of Agric. Science, 8, 1917, p. 95.

VILJOEN, J. A., FRED, E. B. and PETERSON, W. H.--'The Fermentation of
Cellulose by Thermophilic Bacteria,' Journ. of Agric. Science, 16, 1926,
p. 1.

VOELCKER, J. A.--Report on the Improvement of Indian Agriculture,
London, 1893.

WAKSMAN, S. A--'The Influence of Micro-organisms upon the
Carbon-Nitrogen Ratio in the Soil,' Journ. of Agric. Science, 14, 1924,
p. 535.

WAKSMAN, S. A. and TENNEY, F. Q.--'Composition of Natural Organic
Materials and their Decomposition in Soil. IV--The Nature and Rapidity
of the various Organic Complexes in different Plant Materials under
Aerobic Conditions,' Soil Science, 28, 1929, p. 55.

WAKSMAN, S. A. and DIEHM, R. A.--'Chemical and Microbiological
Principles underlying the Transformation of Organic Matter in Stable
Manure in the Soil,' Journ. of the American Soc. of Agronomy, 21, 1929,
p. 795.

WAKSMAN, S. A. and GERRETSEN, F. C.--'Influence of Temperature and
Moisture upon the Nature and Extent of Decomposition of Plant Residues
by Micro-organisms,' Ecology, 12, 1931, p. 33.

WHITING, A. L. and SCHOONOVER, W. R.--The Comparative Rate of
Decomposition of green and cured Clover Tops in Soil, Soil Science, 9,
1920, p.137.




Chapter VI




APPLICATION TO OTHER AREAS


In the present chapter, the various adaptations that will be needed, and
the further investigations that must be undertaken before the Indore
process can be widely adopted, will briefly be considered.


ADAPTATIONS

As far as the tropics and sub-tropics are concerned, the process can be
adopted as it stands. No particular difficulties are likely to be
encountered at any stage. After the collection, storage and admixture of
the raw materials, including dung and urine earth, the two chief factors
on which success depends are: (1) the maintenance of a high temperature
in the pits or heaps; and (2) adequate aeration throughout the
manufacture. With ordinary care, temperature difficulties are unlikely
to occur, as the daily mean in these regions is always high, and the
occasional cold spells are of short duration. All that is needed is the
proper orientation of the pits or heaps to prevent overdue cooling by
high winds, particularly during the interval between charging and the
first turn. The maintenance of the correct degree of aeration requires
more care. The chief difficulty likely to arise is the flooding of the
pits after heavy rain or by the rise of the ground water. The material
then becomes thoroughly soaked, and adequate aeration is impossible.
If this overwatering cannot be prevented by catch drains, pits will
have to be given up and the manufacture conducted in heaps on the
surface. Direct wetting through heavy falls does little or no
permanent harm. This was clearly established at Indore during
the monsoon of 1930, when the total rainfall was forty-five
inches, most of which was received between I5 June and 15 September.
This included five falls of over two inches and two of over five inches
in twenty-four hours. In spite of these heavy downpours, the conversion
proceeded evenly and without difficulty; there was little or no loss of
soluble nitrogen by leaching; the amount of moisture absorbed from the
rainfall did not interfere with the oxygen supply. For these reasons it
is not necessary in warm countries to carry on the manufacture under
cover. The erection and maintenance of sheds therefore need not be
considered.

In the damper areas of the tropics like parts of Africa and the West
Indies, which do not possess a cattle force at all comparable with that
of India, a difficulty in maintaining the correct carbon-nitrogen ratio
of the mixture may occur. There may be insufficient dung and urine earth
for converting the large quantities of vegetable wastes which are
available. The shortage can be made up by the use of nitrate of soda or
by the Adco powders. If such artificials are employed, it will be a
great advantage to make use of soil as the principal base for keeping
the general reaction uniform and within the optimum range. Soil is the
best base for neutralizing acidity and for absorbing ammonia and is far
more effective than lime or wood ashes. This material possesses two
other important advantages in the making of compost. In the first place,
the soil colloids are very retentive of moisture and so help to keep the
water content of the mass steady. In the second place, the colloids
cover the vegetable matter with a thin adherent film which can retain in
situ all the materials--combined nitrogen and minerals, soluble
carbohydrates, water and oxygen essential for the rapid development of
the micro-organisms. The result is that there is no delay in the
breaking down of the vegetable wastes and in the synthesis of microbial
tissue. When earth is omitted from the mixture, two difficulties at once
arise. The supply of moisture for the microorganisms is intermittent;
the general reaction becomes inconsistant. Delays ensue. For these
reasons, the Adco process could easily be improved by the judicious use
of earth. If lime were omitted from the Adco mixture, the freight on
this item could be saved and the usefulness of the rest of the powder
increased.

In those areas of the temperate regions where winter occurs, one
important modification of the process may be needed. As will be evident
from a study of the results set out in Chapter V, one of the
difficulties against which provision has to be made is the lowering of
the temperature of the fermenting mass by cold and wind. For the
micro-organisms to complete the conversion in ninety days, the heaps
must be kept at a high temperature throughout. No difficulties are
likely to arise during the summer. Trouble however is likely during the
colder months--November to April. During this period the fermentation
may have to be carried out in sheds or in compost houses on the Japanese
principle. Many existing farm buildings could be adapted for the
purpose; the ideal structure however would have to be designed--a task
which will be lightened after a careful study of the methods in use in
those areas of Japan where compost houses are the rule.

The difficulty of adopting the system in countries like Canada, the
United States and Great Britain, where labour is dear and scarce, will
be solved by the mechanization of the process. The first step would be
for one or two of the experiment stations to transform all their
vegetable wastes into compost by hand labour regardless of expense, and
then to determine the value of the product in maintaining crop
production at a high level. The full possibilities of humus will only
appear when the dressings of compost are supplemented by the addition of
suitable artificials. The combination of the two, applied at the right
moment and in proper proportions, will open the door to the intensive
crop production of the future. Humus and artificials will supplement one
another. Further, the artificials must not be confined to those which
merely supply nitrogen, phosphates and potash. Substances like lime and
sulphur, which flocculate the soil colloids and so improve the filth,
must be included.

In other words, the manuring of the future wild have to be both direct
and indirect.


FURTHER INVESTIGATIONS

In the tropics and sub-tropics, an important aspect of the process is
its application to the future sanitation of the village. The fact that
forty oxen are kept at the Institute of Plant Industry, Indore, and that
compost is manufactured throughout the year, without the slightest smell
and without the breeding of flies, indicates clearly the line of advance
in dealing with village sanitation. All that appears to be needed is to
adapt the Indore process (which employs cow-dung and urine earth) to the
use of night soil, and to utilize the present sanitary services in
showing the people how to transform the village wastes (including all
forms of litter of vegetable origin) into compost. No difficulties are
likely to be experienced in the actual conversion of the waste products
of the rural population into humus. The process will be more rapid than
when cow-dung is used: a factor which is all to the good. Besides the
valuable compost that will be obtained, a number of other advantages
will follow. Rural hygiene will enter on a new phase. The fly nuisance
will disappear. Practically all the infection, which is now carried by
these insects from filth to the food and water supply of the population,
will be automatically destroyed by the combination of high temperature,
high humidity and copious aeration of the compost heaps. In the tropics
parasites like hookworm will tend to decrease in numbers. A rapid
improvement in the general health and the amenities of the village will
ensue. What is needed to bring about these results is the working out of
a simple process on the lines of the one described in this book. It will
not prove a difficult. It will be easy to-design a series of screened
pits and screened areas in the neighbourhood of an Indian village, and
to teach the sweepers how to carry on the manufacture of compost without
smell and without the breeding of flies. The conditions which render
these two nuisances impossible will at the same time destroy practically
all the harmful parasites and germs which now infect the population.
Provided the work is carried out by the village scavengers, no caste
difficulties are likely to arise. The process can easily be welded into
the existing village system. A beginning has been made in the direction
indicated by Mr. F. L. Brayne, I.C.S., Deputy Commissioner of Jhelum
(formerly Deputy Commissioner of Gurgaon). Mr. Brayne has designed a
latrine pit, which without much difficulty could be perfected for use
throughout the tropics and sub-tropics. The method will have to be
adapted both to dry weather and to monsoon conditions, and will have to
be worked for a year or two under strict microbiological and chemical
control before being brought to the notice of the people. Work on these
lines has already been started in the model village belonging to the
Institute of Plant Industry at Indore. If, as seems certain, a
practicable method can be devised, steps will at once be taken to get it
taken up in the villages of the Central India and Rajputana States. Its
spread to the rest of India, and all over the tropics and subtropics,
will be a matter of a very few years.

The moment a suitable method of dealing with the sanitation of the
village has been designed and the influence of the process on the
general health of the people and on the fertility of the fields becomes
manifest, the results can be carried further. The public health of the
military cantonments and of the smaller towns can then be considered as
one subject. In place of the present expensive division of those aspects
of the general problem of sanitation, which deal with solid wastes, into
a number of imperfectly related items, such as--the disposal of night
soil, the use of disinfectants, the collection and destruction by
burning of vegetable wastes including fallen leaves, the prevention of
the fly nuisance, the purlfication and safeguarding of the water supply
and the inoculation of the population against such diseases as enteric
fever and cholera--it will be possible to transform these waste products
of the population into valuable humus in a scientific way, and so avoid
most if not all the existing difficulties. Such results, as far as urban
areas are concerned, will naturally be the work of years. In the
villages, however, progress should be rapid. The first important step on
the road has already been taken in the form of the Indore process. It
will not be a difficult matter to expand the opening which has been
made. Little increase in public expenditure will be called for. The
funds and staff, now devoted to rural hygiene, can at once be deflected
to the manufacture of compost and to increasing the produce of the soil.



BIBLIOGRAPHY

BRAYNE, F. L.--The Remaking of Village India, Oxford University Press,
1929.

HALL, A. D.--' Some Secondary Actions of Manures upon the Soil,' Journ.
of the Royal Agric. Soc. of England, 70, 1909, p. 12.

HOWARD, A. and HOWARD, G. L. C.--The Application of Science to Crop
Production, an Experiment carried out at the Institute of Plant
Industry, Indore, Oxford University Press, Bombay, 19Z9.

KING, F. H.--Farmers of Forty Centuries or Permanent Agriculture in
China, Korea and Japan, London, 1926.




APPENDIX A



THE MANURIAL PROBLEM IN INDIA


The manurial problems of India were considered in detail by the recent
Royal Commission on Agriculture in India which, after an extensive study
of the subject lasting more than two years, reported in 1928. That
section of the report which deals with fertilizers is reprinted in full
below. A study of this account will bring home to the investigator and
to the general reader the evils which invariably result from the
fragmentation of any large agricultural problem.

(Extract from the Report of the Royal Commission on Agriculture in
India, Bombay, 1928, pp. 80-93.)


FERTILIZERS

80. 'Of the principal plant-food materials in which the soils of India
are deficient by far the most important (except in parts of the
crystalline tracts where the deficiency of phosphates may be more
serious) is nitrogen, and the manurial problem in India is, in the main,
one of nitrogen deficiency. India, as is well known, depends almost
exclusively on the recuperative effects of natural processes in the soil
to restore the combined nitrogen annually removed in the crops, for but
little of this is returned to the soil in any other way. Much of the
farmyard manure available is burnt as fuel whilst a large quantity of
combined nitrogen is exported in the form of oil seeds, food and other
grains, and animal products such as hides and bones. This loss is in no
way compensated by the importation of nitrogenous fertilizers, for
1925-26 was the first year which the imports of sulphate of ammonia into
this country, which amounted only to 4,724 tons, exceeded the exports
and was also the first year in which the greater part of the production
of this fertilizer by the Tata Iron and Steel Company at Jamshedpur and
in the coalfields of Bengal and Bihar and Orissa was consumed in India.
In these circumstances, it is fortunate that the recuperative processes
in the soil are more pronounced in tropical and sub-tropical than in
temperate regions. Although it has been stated in evidence before us
that it has not been established that improved and higher yielding
varieties of crops, more especially of wheat and sugar-cane, take more
from the soil than the varieties they replace, and that their
cultivation on present lines will not, therefore, be followed by any
loss of permanent fertility, we are of opinion that there is
justification for the view that improved crops generally require, for
their fullest development, more liberal manurial treatment than those
ordinarily grown. The subject is one which requires careful study by the
agricultural departments in India and should form an essential part of
the investigations discussed in the following paragraph.


MANURIAL EXPERIMENTS

81. An acceleration of the recuperative processes in the soil can be
effected by improved agricultural methods, by adequate soil aeration,
judicious rotations and the cultivation of green-manure crops. The loss
of combined nitrogen can also be partially made up by the application of
natural and artificial manures. With certain definite exceptions,
however, such as, for instance, sugar-cane and the more valuable garden
crops, it has yet to be determined for what conditions and for what
crops artificial manures can be profitably used to stimulate crop
production in India. In this connexion, we have been impressed by the
importance of research into the fundamental problems connected with
losses in nitrogen and with nitrogen recuperation. We saw something of
the work in this field which was being carried on at Pusa by Dr.
Harrison and at Nagpur by Dr. Annett. Although, ever since the
reorganization of the agricultural departments in 1905, manurial
experiments have engaged a large part of their time and energies and
have been carried out on every agricultural station in India, it cannot
be said that the agricultural experts are even yet in a position to give
satisfactory advice to the cultivator in regard to the use of manures. A
large amount of data has been collected but it has not been studied
systematically or reduced to a form which would enable clear and
definite conclusions to be drawn. The problem requires to be studied in
three aspects: in relation, in the first instance, to the crops which
are dependent solely on rainfall, in the second, to crops which are
grown on irrigated land, and lastly, to the planters' crops and
intensive cultivation such as that of sugar-cane and garden crops. It is
hardly necessary to point out that the use of nitrogenous or other
artificial fertilizers is not profitable in all conditions. Where crop
production is limited by a small rainfall, the annual additions of
combined nitrogen to the soil as the result of natural processes may be
sufficient to meet the needs of a crop the out-turn of which is limited
by the moisture available. It has, for example, been found in the
Central Provinces that the application of fertilizers benefits dry
crops, including unirrigated cotton, only in years when the rainfall is
adequate and that, in particular, it does not benefit wheat which, in
that province, is grown on rainfall only. The planting community, which
has its own specialist officers, needs no advice from the agricultural
departments in regard to the economic use of manures. We would, however,
take this opportunity of stressing the value of close touch between the
community and the departments in regard to this and other agricultural
matters It is essential that the departments should be in a position to
give the ordinary cultivator, both of irrigated and unirrigated crops,
definite guidance on the point. The first step is the careful study of
the existing material and the correlation of the results hitherto
obtained. The second step is the formulation of a programme of
experiment with the object of ascertaining, with all possible accuracy,
the extent to which fertilizers can be used with profit. This programme
should include the laying out of a short series of permanent manurial
plots, on lines appropriate to conditions in India, on provincial
experimental farms. Only by conducting manurial experiments over a
number of years will it be possible to compile such records as would
make a substantial contribution to the knowledge of the problems of
manures and manuring under tropical and sub-tropical conditions about
which little is yet known. The scientific value of continuous
experiments depends on accurate methods of collection of all relevant
data with a view to their subsequent correlation. All such schemes for
manurial trials would ordinarily be drawn up by the Director of
Agriculture in close consultation with the agricultural chemist and the
deputy directors of agriculture under whose immediate supervision the
experiments would be conducted. We wish especially to emphasize the
importance of manurial experiments on unirrigated land as the cultivator
of such land, who runs, with his very limited financial resources, the
risk of losing his crop in an unfavourable season, stands most in need
of guidance in this matter. The study of the available data and the
formulation of an ordered programme to replace the present somewhat
haphazard methods of dealing with the problem would, we think, provide
sufficient work to justify an officer of the Agricultural Department
being placed on special duty for a limited period, but we prefer to make
no definite recommendations on this point and to leave it to the
consideration of the local governments. Local conditions vary so greatly
between province and province, especially in regard to unirrigated land,
that it does not appear necessary to attach an officer to Pusa specially
to assist the provinces in this investigation. The Council of
Agricultural Research should be in a position to advise as to the manner
in which the experiments can best be conducted so as to secure
uniformity of method as far as possible and to render the results
obtained in one province of some value to other provinces.


INTERNAL SOURCES OF SUPPLY AND THEIR DEVELOPMENT

(a) FARMYARD MANURE

82. The first question which arises, in considering the internal
supplies of nitrogen available in India and the methods by which these
can best be developed, is that of the use of farmyard manure as fuel.
The view is generally held that it is the absence of a sufficient supply
of firewood which, over large parts of India, compels the burning of
cow-dung as fuel. But it must be recognized that there is often a
definite preference for this form of fuel, as its slow burning character
is regarded as making it specially suitable to the needs of the Indian
housewife. Thus we are informed that, in Burma, immigrant labourers from
India persist in using cow-dung as fuel although an abundant supply of
firewood is readily available. Our evidence does not suggest any
alternative fuel for domestic purposes in districts where wood and coal
are dear. In some tracts, cotton-stalks, the dry stubble and stalks of
tur (Cajanus indicus), the pith of jute and sann hemp and the bagass of
sugar-cane, where the use of the McGlashan furnace leaves a surplus
which is not required for boiling the juice, could be utilized for fuel
to a far greater extent than they are at present. Fuel plantations, more
especially irrigated plantations, the formation of which we discuss in
Chapters VIII and X, can assist only in a very limited area. In our
view, the agricultural departments have a difficult task to perform in
attempting to promote the utilization of farmyard manure for its proper
purpose. Propaganda in this direction can only prove effective if an
alternative fuel is suggested and if the cultivator can be sufficiently
imbued with a sense of thrift to induce him to burn that which will
probably seem to him a less satisfactory substance. There has been
little advance in regard to the preservation of manure since Dr.
Voelcker wrote his report on Indian agriculture in 1893. The practice of
providing litter for cattle is rarely, if ever, adopted except on
government farms. No efforts are made by the cultivator to preserve
cattle urine. Manure pits are still seldom found in Indian villages.
Where they do exist, no attempts are made to preserve the manurial value
of the contents or to safeguard the public health by covering the
material with earth.


(b) COMPOSTS

83. While the task is difficult, there is no doubt that something can be
done to promote the better preservation of such farmyard manure as is
not diverted to consumption as fuel, by using it as a compost with
village sweepings, leaves, and other decomposed vegetable matter. In
this connexion, we are impressed by the results achieved in the Gurgaon
district of the Punjab, where many villages have, as a direct
consequence of propaganda, adopted the practice of depositing in pits
all village sweepings and refuse, along with a proportion of cow dung.
The effects on crops to which such manure has been applied, and on the
sanitation and general amenities of the villages, were most marked.
There is no reason why efforts on similar lines should not be made in
other parts of the country. The Indian cultivator has much to learn from
the Chinese and the Japanese cultivator in regard to the manufacture of
composts. Artificial fertilizers are used as little in China as they are
in India; but there is no organic refuse of any kind in that country
which does not find its way back to the fields as a fertilizer. Not only
is all human waste carefully collected and utilized, but enormous
quantities of compost are manufactured from the waste of cattle, horses,
swine and poultry, combined with herbage straw, and other similar waste.
Garbage and sewage are both used as manure. The agricultural departments
in India are fully alive to the necessity for instructing the cultivator
in the better preservation of manure and the use of composts, but there
is great scope for an extension of their activities in this respect. For
example, the possibilities of manufacturing synthetic farmyard manure
from waste organic material on the lines worked out at Rothamsted
deserve to be fully investigated. At Rothamsted, research was at first
directed towards discovering artificial means whereby the decomposition
of straw might be effected. Straw contains three essentials to plant
growth, viz. nitrogen, phosphate and potash. The work proved successful
and a method was devised for treating large quantities of straw for the
preparation of manure. Reagents were subsequently discovered which were
capable of bringing about the rapid rotting, not only of straw but also
of other plant residues, and thus of producing a valuable organic manure
at a moderate cost. Synthetic farmyard manure is being prepared by the
departments of agriculture in Madras and the Central Provinces. The
agricultural department in Bengal, following the valuable lead given by
Rothamsted, has attempted the manufacture of artificial farmyard manure
on a considerable scale. Cattle urine and washings from cattle-sheds,
mixed with bone meal, have been used with immediate success. Weeds,
various grasses, sugar-cane trash, refuse, straw, prickly-pear, etc.,
have all proved capable of breaking down into excellent material
approximating more or less closely in appearance and in composition to
that of cow-dung. Experiments have also been made in Burma but have not
so far proved successful. Valuable work on the preparation of composts
from night soil and refuse and from cattle urine, weeds, etc., is being
done by Dr. Fowler at Cawnpore. In Europe, work of this character has
now emerged from the experimental stage and processes devised for
dealing with various classes of materials are already on the market. In
India, however, the departments concerned have still to devise and
introduce a practical method which can be used with profit by the
ordinary cultivator on his own land.

The manurial value of earth obtained from the sites of abandoned
villages is recognized in many parts of India. The quantities available
are, however, negligible in relation to the manurial requirements of the
country.


(c) NIGHT SOIL:

84. Prejudice against the use of night soil has deterred the cultivator
in India from utilizing to the best advantage a valuable source of
combined nitrogen. There is, however, evidence that this prejudice is
weakening and that, where night soil is available in the form of
poudrette, it is tending to disappear. From the point of view of public
health, the use of poudrette is preferable to that of crude night soil
and, given co-operation between agricultural departments and municipal
authorities, there is hope that the manufacture of poudrette should
prove profitable to municipalities and beneficial to the cultivators in
their neighbourhood. The methods of converting night soil into poudrette
adopted at Nasik and elsewhere in the Bombay Presidency have been highly
successful and appear well worth study by other municipalities. The
advantages of this system of dealing with night soil appear to us to
justify a recommendation that the departments of local self-government
in all provinces should bring them to the notice of all municipal
authorities and should also take steps to establish a centre at which
members of the municipal sanitary staffs can receive a suitable training
in this method of disposing of night soil. The agricultural departments
should keep a watchful eye on all experiments in the conversion of night
soil into manure and should themselves conduct such experiments. Where
municipal authorities in any part of the country are in a position to
supply it, the agricultural departments should assist them to find a
market by arranging demonstrations of the value of night soil as manure
on plots in the neighbourhood of the towns.

Another way in which night soil can be converted into a form in which
its use is less obnoxious to the cultivator is by the adoption of the
activated sludge process. This process reduces sewage, by the passage of
air through it, to a product which can either be used as required in the
form of effluent from the sewage tanks or dried and sent where there is
a demand for it. The activated sludge process is suitable only for towns
which have a sewage system. It is much more expensive than conversion
into poudrette but has the advantage of conserving a larger percentage
of nitrogen. Up to the present, this system has been adopted in India on
any considerable scale only at Tatanagar. The possibility of selling the
product at a price that would yield a fair return on the cost of
manufacture must depend upon a careful survey of all the relevant
factors, including the local market for the product. In estimating the
cost of the necessary plant, due regard should be paid to the cost which
would be involved in installing any alternative method of sewage
disposal, and, if it should prove possible to place a valuable
fertilizer at the disposal of the cultivators at a price they can afford
to pay, without risk of imposing any additional net charge upon the
local ratepayers, we think that it is in the public interest that such
schemes should be adopted.


(d) LEGUMINOUS CROPS

85. Another indigenous source of combined nitrogen to which increasing
attention is now being paid by the agricultural departments in India, is
leguminous crops and green-manures. The value of leguminous crops in his
rotation has always been recognized by the cultivator and the work
before the agricultural departments in regard to these crops lies not so
much in popularizing the principle of their cultivation as in
discovering the varieties of leguminous crops best suited to increase
the soil fertility and in recommending such varieties to the
cultivators. Recent research has drawn attention to the fact that such
crops vary greatly in their power of fixing nitrogen in the soil and
should not be regarded as of equal value. Moreover, it is only when the
leguminous crop is grown for green-manure that, in all cases, the soil
gains in nitrogen. Mr. Howard instances gram as a crop which improves
the soil and Java indigo as a crop which seriously depletes the supply
of combined nitrogen.


(e) GREEN-MANURES

86. The agricultural departments in India have devoted much time and
attention to work on green-manure crops with a view to discovering the
crops which can best be used for green-manure, the time at which they
should be grown and the manner in which they should be applied. Their
work has shown that sann hemp on the whole gives the best result and it
would doubtless be more often grown for use as green-manure were it not
that it may exhaust so much of the moisture in the soil that, when it is
ploughed in, there is not sufficient left both to decompose it and to
enable a second crop to grow. Much experimental work is still,
therefore, required to discover the green-manure crops which can best be
included in the cultivators' rotations. The economics of green-manure
crops from the point of view of the small cultivator also require to be
worked out. The small cultivator is naturally hesitant about growing a
crop which only indirectly brings him any financial advantage. With his
slender resources, it is indeed not unreasonable for him to take the
view that he cannot afford to sacrifice even a catch crop in this way
and it is therefore not until the agricultural departments are in a
position to demonstrate to him beyond a shadow of doubt the paying
nature of green-manure crops on small holdings that these departments
will be justified in persuading the small cultivator to adopt them or
that their advocacy of them will stand any chance of success. In the
present state of knowledge, such crops would appear an expedient to be
adopted by the larger landholder and, for the small cultivator, a
leguminous crop in his rotation would seem to hold out better prospects
of benefit.

The possibility of growing such crops as dhaincha and ground-nut, the
leaves of which can be used as green-manure without interfering with the
commercial value of the crop, is worth consideration. The use of
ground-nut in this way for green-manure would furnish an additional
reason for extending the area of this valuable crop. In the case of
crops of a woody nature such as sann hemp, it must, however, be
remembered that their utility as green-manure for the succeeding rabi
crops depends to a large extent on the presence of sufficient moisture
in the soil to rot the dry stems and roots.

In Madras, the Punjab and the Central Provinces, the experiment has been
made of encouraging the cultivation of green-manure crops under
irrigation by the remission of the charge for water from government
sources or irrigation. The fact that the results have so far been
disappointing may be due to a failure to accompany the remission with
sufficient propaganda as to the advantages to be derived from the
growing of these crops. We think that the continuance of the concession
and its extension to other areas should be conditional on its being
accompanied by an active campaign of propaganda, directed particularly
to the larger landholder rather than the small cultivator. All areas
where the concession is made should be kept under regular examination.
If, after a period of five to ten years, it should appear that the
concession given in regard to water charges has failed to achieve its
main purpose, it should be rescinded.


(f) 0IL CAKES

87. The loss to India of a valuable source of combined nitrogen as the
result of the export of so large a proportion of its production of oil
seeds was emphasized by many witnesses before us. The [figures for]
yield and exports of oil seeds during the last fifteen years . . . .
indicate that, of the out-turn of the seed of cotton, ground-nut, rape
and mustard, linseed and sesamum, the exports amount to an average of
eighteen per cent and they suggest the loss which the soil of India
suffers by the export of a valuable by-product on the assumption that
the whole of the nitrogen contained might be returned to the soil. Under
existing practice, indeed, much of this material would probably be fed
to cattle and subsequently dissipated as fuel. But it is not surprising
that the view that an export tax on oil seeds and oil cakes within the
purchasing power of the cultivator has found much favour and even
received the support of the Board of Agriculture in 1919 and of the
majority of the Indian Taxation Enquiry Committee, but not that of the
Indian Fiscal Commission. Some witnesses before us went further and
urged the total prohibition of export. Whilst we fully recognize the
advantages to Indian agriculture which would follow from a greatly
extended use of certain oil cakes as a manure for the more valuable
crops such as sugar-cane, tobacco, cotton and tea, we cannot but feel
that those who suggest the attainment of this object by the restriction
or prohibition of exports have failed to realize the economic
implications of their proposal. In the first place, it must be
remembered that India has no monopoly of the world's supplies of
oil-seeds and is not even the chief supplier of those seeds. The world's
linseed market is controlled by the Argentine crop and the sesamum
market by the Chinese crop. The competition of West Africa in the supply
of edible oils is becoming increasingly serious. In these circumstances,
it is an economic axiom that an export duty will be borne by the
producer and that the cultivator will, therefore, receive a lower price
for the oil seeds exported. The acreage under oil seeds in British India
is still considerably below the pre-war level and the tendency to
replace oil seeds by other crops which may be inferred from this would
undoubtedly be greatly accentuated if any effective restrictions on
export were imposed. The immediate fall in price, which would result
from such restrictions, would tend to a reduction of area and
consequently of out-turn. Even if such a fall in prices were obtained by
the method advocated, the gain to the cultivator qua consumer would be
far more than counterbalanced by the disadvantage to the cultivator qua
grower by the loss of the income he at present derives from his export
market. In the second place, it may be argued that if the Indian
oil-crushing industry were fully developed to deal with the present
out-turn of oil seeds, then the area might remain at its present level
and there would grow up a considerable export of oil, while the cake
would remain to be used as a feeding stuff or manure. The market for oil
in this country is, however, a very limited one and will remain so until
India has reached a more advanced stage of industrial development. The
oil-crushing industry would, therefore, have to depend mainly on the
export market for the sale of its main product. The problem of cheap and
efficient transport to the great industrial centres of the west presents
almost insurmountable difficulties. Oil-crushers in India would find
themselves in competition with a well-established and highly efficient
industry and there is little reason to believe that their costs of
production or the quality of their product would enable them to compete
successfully with that industry. In the third place, even if restriction
on exports succeeded in reducing the price of oil cakes, this would mean
that a section of the agricultural community would be penalized for the
benefit of another and much smaller section, for the growers of oil
seeds would probably not be those who would make the most use of the oil
cakes.

A similar line of reasoning applies to oil cakes, the average exports of
which from India for the five years ending 1925-26 were 165,600 tons,
against a negligible import. The oil cakes exported from India are a far
less important factor in the world's supply than are the oil seeds and,
in these circumstances, the burden of the duty would be entirely borne
by the producer, in this case the crushing industry. There can, in our
view, be little doubt that the effect of a duty on oil cakes, with or
without a duty on oil seeds, would be the curtailment of oil-crushing
activities and a diminution in the available supply of oil cakes, in
other words, it would have effects entirely different from those desired
by its advocates. It is not, therefore, by any restriction on trade that
Indian agriculture is likely to reap greater advantages from the supply
of combined nitrogen available in the large crops of oil seeds she
produces. The only methods by which these advantages can be secured are
by the natural development of the oil-crushing industry coupled with
great changes in cattle management and in the use of fuel. The question
how far the development of the industry can be promoted by Government
assistance in the matter of overcoming difficulties of transport and in
the form of technological advice in regard to improved methods of
manufacture and standardization is one for the departments of industries
rather than the departments of agriculture. An extension of the
oil-crushing industry would undoubtedly tend to promote the welfare of
Indian agriculture and we would commend the investigation of its
possibilities to the earnest consideration of all local governments.


(g) SULPHATE OF AMMONIA

88. The important potential sources of supply of combined nitrogen
discussed in the preceding paragraphs are supplemented to a small though
increasing extent by the sulphate of ammonia recovered as a by-product
from coal at the Tata Iron and Steel Company's works at Jamshedpur and
on the coalfields of Bengal and Bihar and Orissa. There has been a very
marked increase both in the consumption and production of this
fertilizer in India in recent years. Of the 4,436 tons produced in 1919,
all but 472 tons were exported and there were no imports. In 1925, of
the estimated production of 14,771 tons, 6,395 tons were retained in
India. With three exceptions, all the producers of sulphate of ammonia
in India have joined the British Sulphate of Ammonia Federation which,
through its Indian agents, is conducting active propaganda to promote
the use of artificial fertilizers and has established a number of local
agencies in agricultural areas in several provinces. The manner in which
this source of supply is being developed is very satisfactory and it is
still more satisfactory that a market for increasing quantities of the
sulphate of ammonia produced in India is being found in the country. The
importance of the price factor need hardly be stressed, for though the
present average price of Rs. 140 per ton free on rail at Calcutta is
much lower than that which prevailed immediately after the War, it is
sufficiently high to preclude the application of sulphate of ammonia to
any except the most valuable of the cultivators' crops, such as
sugar-cane or garden crops.


(h) ARTIFICIAL NITROGENOUS FERTILIZERS

89. A method of increasing the internal supplies of combined nitrogen in
India, the adoption of which has received powerful support, is the
establishment of synthetic processes for obtaining combined nitrogen
from the air in forms suitable for use as fertilizers. The Indian Sugar
Committee was of opinion that, from the point of view of the development
of the sugar industry alone, the successful introduction of synthetic
processes in India was a matter of the first importance. That Committee
recommended that the possibilities of utilizing the hydro-electric
schemes, which were at that time under investigation in the Punjab and
the United Provinces, for the fixation of nitrogen should be thoroughly
examined and that, if it were found that electric energy could be
obtained at a rate approximating to Rs. 60 per kilowatt year, a unit
plant of sufficient size to afford trustworthy information should be
installed. Of the three processes in use for the fixation of atmospheric
nitrogen, the arc process, the cyanamide process and the manufacture of
ammonia by direct synthesis, the Committee considered the cyanamide
process as the one which offered the best prospects of success in India
but drew attention to the possibilities of the Haber process for
obtaining synthetic sulphate of ammonia.

The position has changed greatly since the report of the Sugar Committee
was written. The full effects of the diversion of the capital,
enterprise and, above all, the research devoted to the manufacture of
munitions to the production of peace time requirements, had not been
felt in 1920. Since then, it has resulted in a fall in the world's price
of nitrogen by fifty per cent, and there are prospects of still lower
prices in the near future. We see no reason to question the view which
was placed before us in the course of the evidence we took in London
that, in present circumstances, only very large units with a minimum
capacity of about 150,000 tons of pure nitrogen per annum can be
expected to pay even under the most favourable conditions in Great
Britain and on the Continent of Europe and that conditions in India make
it much less likely that even a unit of that capacity would prove a
paying proposition. The possibilities of manufacturing nitrogen from the
air in India have already been exhaustively examined by a leading firm
of chemical manufacturers in England, which has decided against
proceeding with the project. It is probable that no factory on a scale
which could be contemplated by any local government, or even by the
Imperial Government, would be in a position to produce synthetic
nitrogenous fertilizers at a price less than that at which they can be
imported. The whole object of establishing such a factory, that of
producing fertilizers at a price which would place them within the reach
of a far greater proportion of the agricultural community than is at
present in a position to use them, would be defeated if a protective
duty were imposed to enable its out-turn to compete against imported
supplies. It is also to be hoped that, should the demand for artificial
fertilizers in India make it worth while, private enterprise will come
forward to erect synthetic nitrogen works in this country. While the
economics of the industry remain as they stand to-day, we are unable to
recommend any further investigation into the subject under government
auspices.


CENTRAL ORGANIZATION FOR RESEARCH ON FERTILIZERS

90. The discussion of the question of nitrogenous fertilizers would not
be complete without mention of the proposal placed before us by the
British Sulphate of Ammonia Federation, Ltd., and Nitram, Ltd., for the
establishment by the Government of India of a central fertilizer
organization on which the Imperial and provincial agricultural
departments as well as the important fertilizer interests would be
represented. The two companies, which are already spending 23,000 pounds
annually on research and propaganda in India, expressed their
willingness to increase this amount to 50,000 pounds, the additional
amount to be handed over to a central organization constituted in the
manner they suggest, provided that an equal sum is contributed by
Government. The companies have made it clear that the research and
propaganda they contemplate would be on the use of fertilizers generally
and would not in any way be confined to that of the products they
manufacture or sell. This offer, though not disinterested is undoubtedly
generous and we have given it our most careful consideration. We regret,
however, that we are unable to see our way to recommend its acceptance.
We cannot but feel that, whatever safeguards were imposed, the work of,
and the advice given by, an organization, at least half the cost of
which was borne by firms closely interested in the subject matter
of the investigation, would be suspect and would thus be deprived
of much of its usefulness, especially since, as we have pointed out,
the agricultural departments in India are not yet in a position
to pronounce authoritatively on the relative advantages of natural
and artificial fertilizers. We, therefore, consider it preferable
that the agricultural departments should remain entirely independent
in this matter but we need hardly say that we would welcome the
establishment by the two firms mentioned, or by any other fertilizer
firms, of their own research stations in India working in the fullest
co-operation with the agricultural departments, the Indian Tea
Association, the Indian Central Cotton Committee and any other
bodies interested in the fertilizer question. So much work remains
to be done on the manurial problems of India that it is desirable that
every possible agency should be employed on it. To the supply by the
fertilizer interests of free samples for trial by the agricultural
departments there can, of course, be no objection, but we do not
consider that any financial assistance beyond what is involved in this
should be accepted. In coming to this conclusion, we have not overlooked
the fact that the Rothamsted Experimental Station accepts grants from
fertilizer interests to meet the cost of experiments with their
products. Rothamsted is not, however, a government institution and,
further, the experiments it carries out are only undertaken on the clear
understanding that the information obtained is not to be used for
purposes of propaganda. The conditions at Rothamsted are thus entirely
different from those under which it is proposed that the central
fertilizer organization in India should function.


BONES AND BONE MEAL

91. Nitrogen deficiency can be remedied to some extent by the
application of bones and bone meal. This form of fertilizer is, however,
of greater value as a means of rectifying the deficiency of phosphates
which, as we have pointed out, is more prominent in peninsular India and
Lower Burma than that of nitrogen. As with other forms of combined
nitrogen, an important quantity of this fertilizer is lost to India by a
failure to apply it to the soil and by export. Except in the War period,
the total export of bones from India has shown little variation in the
last twenty years. The average exports for the five years ending 1914-15
were 90,452 tons, valued at RS.64.20 lakhs. For the five years ending
1924-25 they were 87,881 tons, valued at Rs. 95.94 lakhs. In 1925-26
they were 84,297 tons valued at Rs. 89.16 lakhs and in 1926-27 100,005
tons valued at Rs. 97.76 lakhs. The imports of bone manures are
negligible. Practically the whole of the exports are in the form of the
manufactured product, that is in the form of crushed bones or of bone
meal, the highest figure for the export of uncrushed bones in recent
years being 545 tons in 1924-25. Only a very small proportion of the
bone manure manufactured in India is consumed in the country. During the
War period, when prices were low, freight space difficult to obtain and
export demand weak, it was estimated that not more than ten per cent of
the total production was consumed in India, and this at a time when the
prices of all Indian agricultural produce were exceptionally high.
Enquiries we have made show that there is no reason to believe that the
percentage retained for internal consumption has increased since the
close of the War. Many witnesses before us advocated that the heavy
drain of phosphates involved in the large export of bones from this
country should be ended by the total prohibition of exports and this
proposal received the support of the Board of Agriculture in 1919,
whilst the majority of the Indian Taxation Enquiry Committee recommended
the imposition of an export duty. For much the same reasons as those for
which we have rejected the proposal for an export duty on oil seeds and
oil cakes, we are unable to support this recommendation. As was pointed
out by the Board of Agriculture in 1922, local consumption, even in the
most favourable conditions in recent years, has accounted for such a
small fraction of the total production that the industry could not
continue to exist on that fraction, and the imposition of an export duty
would involve a serious danger of its extinction through the closing
down of its markets. Further, any restrictions on export would deprive
one of the poorest sections of the population of a source of income of
which it stands badly in need.

For slow growing crops such as fruit trees the rough crushing of bones
is sufficient, but for other crops fine grinding is required. The
crushing mills are at present located almost entirely at the ports and,
in order to get bone manures to the cultivator, the establishment of
small bone-crushing factories at up-country centres where sufficient
supplies of bones are available has been advocated. A far more thorough
investigation of the economics of the bone-crushing industry than has
yet been carried out is, we consider, required before the establishment
of such mills can safely be undertaken by private enterprise. The first
essential is to obtain definite data in regard to the price at which,
and the crops for which, the use of bone meal is advantageous to the
cultivator. We suggest that the agricultural departments should take
early steps to collect these data. The department of Government
responsible should also investigate the cost of processing bones with
special reference to those districts in which the development of
hydro-electric schemes gives promise of a supply of cheap power. It
should then be a comparatively easy matter to determine whether the
level of prices is such as to justify any attempts on the part of
Government to interest private, or preferably co-operative, enterprise
in the establishment of bone-crushing mills in suitable centres. In
determining the level of prices, allowance should be made for the
advantage which local mills will enjoy in competition for local custom
with the large units at the ports through the saving to the local
concerns of the two-way transportation charges borne by the product of
the port mills.


FISH MANURES

92. Little need be said about fish manures which are another source of
supply of both phosphates and nitrogen. The export of these from India
for the five years ending 1925-26 averaged 16,774 tons valued at Rs.
19.94 lakhs. In 1926-Z7 only 7,404 tons were exported valued at Rs. 9.21
lakhs. Except for a negligible export from Bombay and Sind, the exports
of fish manures are confined to the west coast of Madras and parts of
Burma.

The arguments against the prohibition of the export of bones or for the
imposition of an export duty apply equally to fish manures. Any
restriction of export would involve most serious hardship on the small
and impoverished fishing communities of the two provinces, and cannot,
therefore, be justified. The only measures which can be undertaken to
lessen the export of fish manures, without damage to the fish-oil
industry or the curtailment of the amount of fish caught, are measures
to establish that such manures can be profitably used for Indian
agriculture at the price obtained for them in the export market.


NATURAL

93. Reference should be made here to the extensive deposits of natural
phosphates which are to be found in the Trichinopoly district of Madras
and in South Bihar. In neither tract do these phosphates exist in a form
in which they can be utilized economically for the manufacture of
superphosphate; and their employment in agriculture has been limited to
applications of the crude material in pulverized form. This source of
supply does not offer any important possibilities.'




APPENDIX B



SOME ASPECTS OF SOIL IMPROVEMENT IN RELATION TO CROP PRODUCTION
By G. CLARKE, C.I.E., F.I.C., M.L.C.
(Proceedings of the Seventeenth Indian Science Congress,
Asiatic Society of Bengal, Calcutta, 1930, p. 23.)


I ASK your permission to direct your attention to some aspects of soil
improvement in relation to crop production. I propose to pass in brief
review some of our problems and then to touch on the work to which my
colleagues, Khan Sahib Sheikh Mohammad Naib Husain, Rai Sahib S. C.
Banerjee, and myself have devoted a number of years at the Shahjahanpur
Research Station. My subject is directly connected with the supply of
the first necessity of life, namely, food. By what methods is the world
going to continue to feed its growing population? It is increasing at
the rate of nearly twenty millions a year, and it cannot be suddenly
checked. Can food be found for all these extra mouths, or will the
pressure on our land resources become unbearable, and end in disaster?
That is the colossal problem facing the world in the next few
generations. It must be met either by a continual expansion of
cultivation, or an intensification of production on land already
cultivated.

How do we stand in India in respect to these questions? I have proceeded
in a somewhat empirical fashion to ascertain the relation between
population and arable land. I have selected, in making my estimate, the
figures used in international statistics, the total area sown and the
current fallows. I have deducted the area required for the production of
exported cotton, food grains, oil seeds, jute, and tea, which account
for about eighty per cent of the value of our exports. This estimate is
admittedly rough and must be regarded as suggestive rather than as an
exact measure, but it is sufficiently near to illustrate my point. I
have taken the year 1922-23, following the census year 1921, and the
year 1925-26. In 1922-23 the total area sown in that part of India for
which agricultural returns are made was 327 million acres, 61 were under
fallow, making a total of 388 million acres. From this may be deducted
as producing exported material for cotton 14, for food grains 9, for oil
seeds 5, for jute 2 for tea 0.6 million acres, or 31 million acres in
round numbers. So that 357 million acres are left to supply the
requirements in home produced food and other essential commodities of
the 292 million people who live in the territory covered by these
figures, viz. 1.2 acres per unit population.

A similar calculation for 1925-26 gives the same result. I have selected
for a summary comparison the United States of America and France, two
countries possessing points of resemblance to India. In both, as in
India, agriculture is of predominant importance. In the United States
356 million acres are in cultivation: 65 million producing exported
material may be deducted from this, leaving 291 million acres of
cultivated land devoted to supplying a population of approximately 112
million, or 2.6 acres per unit of population. The dominant
characteristic of American economic life has hitherto been abundance of
land resources. France, a country which is largely self-supporting, has
36.3 million hectares of cultivated land for a population of 39.3
million, approximately 2.3 acres for each head of the population.

In considering these figures we have to allow for the fact that the
vegetarian diet adopted by our people is more economical of the
resources of the soil than the diet of the people of the United States
and France. Living is cheap in India, but when all has been said that
can be said, we are left with the plain fact before us that we have
one-half the area of cultivated land for a unit of population.

The past experience of the world shows that, as long as new land of the
necessary quality is available, increased food will be obtained less by
increased skill and expenditure on old land than by taking up new land.
Our map has shown for several decades well over a hundred million acres
in the British provinces of India classified as culturable waste. Why is
not new land coming into cultivation? I cannot give a complete answer.
No such process can be observed in steady operation on a scale
sufficient to raise the per capita area of cultivation to a level which
will meet our food requirements. Some recent settlements in this
province show an increase in cultivation of only one to three per cent
in thirty years, while in others the area is stationary. For a number of
reasons the area of culturable waste gives an unreal conception of our
resources. Much of the land thus classified includes areas physically
capable of being employed for crops only when our need is so extreme
that considerations of cost of utilization are relatively secondary.
Fifty per cent we know is situated in Burma and Assam, out of the sphere
of action of our chief agricultural races. A great deal is in tarai
tracts where health reasons prevent extensive settlement. Land is coming
under the plough, to some extent, in the villages of the Sarda Canal
area in these provinces, and will do so elsewhere as irrigation schemes
mature, but in India, as in other parts of the world, new land of the
necessary quality for food crops is no longer easy to find.

This brings me to the first part of my argument--the necessity of
increasing the acre yield of land now under the plough if an ample
supply of food and the home-grown necessaries of life is to be assured
to the Indian worker, and his standard of living raised above
subsistence level. It is a difficult problem but it is not insoluble.

When I considered this matter some months ago, I asked myself three
questions:--

(1) What factors are in our favour, and what are against us, when we
begin to intensify our cultivation?

(2) Will the knowledge and experience of other countries help to
accelerate our progress? What new knowledge do we need?

(3) What is the quantitative measure of the result we may expect?

I propose to give you the answers that suggested themselves to me, based
on conditions in these provinces where my experience has been gained.

We have in our favour two things. In the first place, soil that is easy
to manage and quickly responds to treatment, and, secondly, agricultural
workers attached to their calling and possessing a strongly developed
land sense which, by some curious twist in our make-up, can only be
acquired in childhood. We shall not come up against a shortage of
agricultural workers of the kind that is hindering development in
Australia and Canada. In these countries, a high degree of skill has to
be directed to economy of labour by the use of machinery and
labour-saving devices. In India, our efforts will have to be devoted to
economizing land. We are better placed than most countries as regards
the primary essential for increasing production per unit of land,
namely, man-power. You may ask me, 'What is delaying our progress with
two such assets?' This opens up a wide sociological study. I believe
ignorance and a larger share of ill-health than should fall to the lot
of an average being play a part. The stimulus required seems to be
education of a rural type. I cannot, however, pursue this issue, and
return to my agricultural text.

We have to contend against difficult weather conditions and short
growing seasons requiring early maturing and specialized varieties of
crops. The Howards, in The Development of Indian Agriculture, describe
graphically the effect of the monsoon on the soil and on the people. It
is indeed the dominant factor in rural India.

We shall always at intervals experience years of short rainfall and this
fact gives additional force to my argument for increasing the acre yield
in favourable seasons by improved soil management if we are to avoid
starvation. Much has been done to intensify yields without any
commensurate increase of labour on soil improvement by the introduction
of more heavily cropping varieties. I need only quote as examples wheat
and cotton in the Punjab and wheat and sugar-cane in the United
Provinces, which are adding crores to the cultivators' income. Indian
conditions, however, test the skill of the plant breeder very severely
and further steps in improvement in this direction are not going to be
easily won.

I now pass on to that part of my subject which has greater interest for
a scientific audience than some of the stubborn facts I have placed
before you. I mean the consideration of some aspects of recent work on
soil improvement and the lines on which enquiry may be directed in
India.

Since Boussingault introduced the method of exact field experiment in
1834, research on the soil and the conditions of crop growth has been
continuous in Europe and America. The methods of approach have become
more exact with each advance in pure science. We, therefore, start our
work on soil improvement in India with tools ready made. Investigations
carried out in other countries have given us the principles involved and
often the technique of methods of research. Our work for the moment is
to apply them to conditions where soil processes differ widely both in
intensity and time of occurrence, from those of temperate climates. I
have been impressed by the desirability of applying to our problems a
conception developed in recent years by the Cambridge and Rothamsted
workers, which has given a new and wider significance to the field
experiment. The final yield gives us no indication of what happens
during the plant's life or how it responds to factors operating at
successive stages of growth. The modern method makes quantitative
observations of crops throughout the period of growth and examines the
results by statistical methods This is nothing more than reducing to
exact measurement and scientific treatment the observations which every
practical farmer makes but does not formulate. The advantage is obvious.
Information covering a wider range than the old type of field experiment
can be obtained in a few years, instead of taking generations. You will
remember that Lawes and Gilbert waited twenty years before discussing
the results of their experiments. The field experiment lasting twenty or
more years no longer fulfils our requirements. We want results in a
reasonable time, accompanied by proof of their reliability, which will
tell us not only the final yield but how that yield is obtained.

This leads up to another conception, namely, the critical periods of
crops which will repay closer quantitative study in a country
characterized by singularly short growing periods and rapidly changing
conditions. By critical period, I mean the relatively short interval
during which the plant reaches the maximum sensibility to a given factor
and during which the intensity of that factor will have the greatest
effect on yield. These periods seem to be associated with some phase of
growth in which the plant is undergoing modifications demanding the
rapid formation and movement of food material. Italian workers have
found that the twenty days before the crop comes into ear constitutes an
important critical period for wheat in relation to humidity and soil
moisture. If during this period these factors are in defect of the
minimum needed for the normal development of the plant, the crop will be
small even if there is abundance throughout the rest of the vegetative
period.

Our observations at Shahjahanpur indicate that two periods in the growth
of sugar-cane have special significance: (1) May and early June when the
tillers and root system are developing; and (2) August and September
when the main storage of sugar takes place. A check received at either
of these periods permanently reduces the yield. The acre yield of sugar
is positively and closely correlated with the amount of nitrate nitrogen
in the soil during the first period, and with soil moisture and humidity
in the second period.

Food crops pre-eminently demand combined nitrogen. You will remember how
Sir William Crookes startled the world thirty years ago by the statement
that the wheat-eating races were in deadly peril of starvation owing to
the rapid exhaustion of soil nitrogen. The age in which he lived had
become accustomed to abundant supplies of cheap food from the great
plains of the American Continent. Fertility accumulated since the
glacial period by luxuriant plant growth and bacterial activity suddenly
became available for exploitation, and was plundered at an appalling
rate by rough and ready methods of cultivation. Nitrogen was
disappearing from the soil out of all proportion to the amount recovered
in the crop. The extraordinary fertility of some of these new regions is
shown by the data recorded by Shutt, an acre of soil to a depth of one
foot containing from 20,000 to 25,000 lb. Of nitrogen in an acre foot of
soil in these provinces, which lies between the limits of 1,000 and
3,000 lb. I shall refer to this again shortly.

Crookes was almost the first to realize that there was a limit to cheap
production from new land, but his forecast was too gloomy. He visualized
the exhaustion of the chief granary of the western world within a
generation or two. In some important respects he misapprehended the
problem.

He did not know as we know now that other agencies step in and stop the
plunder of the soil before it has gone too far. It is only under
improper methods of cropping and cultivation that permanent soil
deterioration is a real and dangerous phenomenon. Land properly handled
does not become exhausted. Much of the land of Europe has been
cultivated since the days of the Romans or even earlier. It is, if
anything, more fertile than ever. In India, we have in existence a
method of farming which has maintained for ten centuries at least a
perfect balance between the nitrogen requirements of the crops we
harvest and the processes which recuperate fertility.

When we examine the facts, we must put the Northern Indian cultivator
down as the most economical farmer in the world as far as the
utilization of the potent element of fertility--nitrogen--goes. In this
respect he is more skilful than his Canadian brother. He cannot take a
heavy overdraft of nitrogen from the soil. He has only the small current
account provided by the few pounds annually added by nature, yet he
raises a crop of wheat on irrigated land in the United Provinces that is
not far removed from the Canadian average. He does more with a little
nitrogen than any farmer I ever heard of. We need not concern ourselves
with soil deterioration in these provinces. The present standard of
fertility can be maintained indefinitely. This is not my text.
Production must be raised if we are to live in reasonable security and
comfort.

In one respect Crookes was right. He foresaw that the intensification of
production required more combined nitrogen than the limited supplies
furnished by the distillation of coal and the nitrate deposits, to
counterbalance the colossal wastage which civilization and urban life
bring about. The fixation of atmospheric nitrogen was, as he put it,
vital to the progress of civilized humanity. This problem has been
solved in the last ten years and is one of the remarkable achievements
of applied science. It could have been solved sooner if money had been
forthcoming for long-range research, but it took the War to bring us to
our senses. Thirty years ago, the fixation of 29.4 grams of a mixture of
nitrogen and oxygen at the expenditure of one horse-power was recorded
as a scientific achievement. In 1928-29 the estimated production of
nitrogen compounds by synthetic processes was equivalent to 1.3 million
metric tons of pure nitrogen, or over 6 million long tons of sulphate of
ammonia, which can be sold at prices low in comparison with the prices
of agricultural produce. We are entering on an era of nitrogen plenty
which is bound to react favourably on the world's food production. One
of our problems is to find out how we can make use of this discovery in
India. The probability is that the full benefit of fertilizers will be
realized only on land reasonably supplied with organic matter.

I may be allowed here to sound a note of warning. Great as are the
possibilities offered by synthetic nitrogen compounds there is danger in
adjusting our standards of living to increased production based entirely
on imported fertilizers. They may be cut off suddenly by international
disturbances. The War is too near an experience and the promise of
universal peace too uncertain to ignore this side of the question
altogether. It will be but a wise precaution to establish their
manufacture in India when the correct way of using them has been worked
out their value demonstrated, and a demand created.

Our problem is more complex than the simple addition of nitrogen
compounds to the soil. We have to face under peculiar conditions of
climate the question of controlling moisture, organic matter, and air
supply in the soil, of regulating the supplies of nitrogen so that it
may be available in the right form and quantity when the plant most
needs it, so that none may be wasted, and to make use to the utmost of
those processes by which nature supplies nitrogen free of charge. These
problems centre around the changes which organic material undergoes in
the soil and the nitrogen transformations which accompany them.

We have two methods of soil improvement possessing enormous
potentialities for increasing crop production and so simple in operation
that they can be used by everybody:--

(1) the preparation of quick-acting manures from waste organic material;

(2) the use of green manure crops.

I do not propose to discuss recent work on the first method. The
practical details have been worked out thoroughly by the Howards at
Indore, and by Fowler, Richards, and their co-workers at Cawnpore. A
paper on this subject is going to be placed before you by Dr. Fowler. I
will not anticipate what he is going to say beyond remarking that the
results which he has allowed me to examine place in our hands a method
of the greatest value for increasing the out-turn of rabi crops which
require in this province a quicker acting manure than that provided by
turning in a green crop.

We have been working for some years at Shahjahanpur on the utilization
of green-manure for sugar-cane. We have ploughed in on an average of
three years' observations,218 maunds per acre of sanai (Crotalaria
juncea) which adds 50 maunds of dry organic material and 75 lb. of
nitrogen to each acre. We have succeeded in raising crops to 850 maunds
per acre without the addition of any fertilizing agent other than the
sanai produced by the land itself. . . . The practical result is worth
Rs. 90 per acre. Our problem is to find out the conditions of
cultivation necessary to decompose sanai in such a way that: (1)
well-aerated soil containing sufficient organic matter to prevent rapid
drying out is ready for the crop in March; and (2) the nitrogen
exchanges are such that this element is protected from loss until it is
wanted, and is then present in a form which can be rapidly mineralized
for the use of the young crop.

Our method of soil treatment is to bring about the early stages of
decomposition in the presence of ample moisture. The rainfall after the
sanai is ploughed in is carefully watched. If it is less than five
inches in the first fortnight of September the fields are irrigated. In
this way we secure in most of our soils an abundant fungal growth as the
land slowly dries. We prevent large accumulations of nitrates in the
autumn, which may be lost before the sugar-cane is sown, and concentrate
the nitrogen in easily decomposable organic form in mycelial and
microbial tissue, until it is wanted in mineral form in the spring.

Throughout the experiments we have made estimates of nitrate. . . . The
accumulation of nitrate reaches its maximum in May and June just before
the first heavy rain. At this time the crop is about one-third grown. We
have not observed any subsequent large formation of nitrate up to the
completion of growth in October. The final yields are in proportion to
the mineral nitrogen present in the first period and this suggests at
once the importance of available nitrogen in the early stages of the
growth of sugar-cane. This view is by no means a new one. It has
recently been developed by Gregory at South Kensington and Rothamsted,
who found that barley absorbed 90 per cent of its total nitrogen when it
had made about one-third of its growth. If it is substantiated by
further work and found to apply to all crops it gives a clue to several
improvements in soil management.

In our studies in connexion with the intensification of sugar-cane
cultivation we have been influenced by American investigations and
methods, more specially those of the workers led by Waksman, who have
studied the decomposition of cellulose and dead organic material in the
soil. They have shown that the structure of the carbonaceous energy
material in the soil largely determines the type of decomposition and
the nitrogen transformations. If moisture and temperature conditions are
favourable, the decomposition of cellulosic energy material, the chief
constituent of green-manure, is mainly accomplished by fungous activity
resulting in the formation of large quantities of mycelial tissue and
the removal of nitrogen temporarily from the reach of higher plants. The
synthesized material is later decomposed by other micro-organisms
forming mineral nitrogen and humic material, and a definite period of
time is required to complete these changes. A large volume of work has
been published in the last five years. It explains much that was obscure
regarding the utilization of green-manure in India, particularly the
time factor to which Howard drew attention many years ago.

I now approach the last and most difficult part of my task, to estimate
the increased production we may look for by the application of
scientific methods to our agriculture. What I am going to say will be
more readily understood if I give the production of wheat in a few
countries for the crop sown in 1926, which was, on the whole, a good
year throughout the world. It is as follows:--

United Provinces: Irrigated, 12.2 mds. per acre.

Unirrigated, 8 .2 mds. per acre Canada, 13.2 mds. per acre U.S.A., 10.7
mds. per acre France, 13.0 mds. per acre Germany, 17. 5 mds. per acre
Great Britain, 22.5 mds. per acre Belgium,. 26.3 mds. per acre

A glance at these figures shows what an immense potential increase of
production is open in many countries, especially in America and India.
The physical possibility or perhaps even the limit of production in the
United Provinces is shown by the yield obtained at the Shahjahanpur
Research Station. In 1926 it was 28.8 maunds per acre. In the last
eleven years, including two in which the wheat crop was a partial
failure, 243 acres have yielded 5,945 maunds or 24.4 mounds per acre.
Soil and climate do not impose a serious restriction on production. We
cannot, however, take one striking instance of large yields achieved on
a small acreage under favourable conditions as the basis of an estimate
of the future production of the country as a whole. The actual level in
any country is bound to be behind the ideal, no matter how well
developed educational and propaganda machinery may be.

It is safer, if such a course be possible, to consider average results
obtained in countries which have been compelled to employ intensive
methods, but we have no adequate basis of comparison with our
conditions. There is no example of a tropical or semi-tropical country
in which scientific have been applied over a wide area by independent
and unsupervised workers.

Sugar-cane cultivation in Java is often quoted as an example of what can
be done. It illustrates the combined effect of strictly supervised
labour and scientific methods on about one million acres of land,
carried out with the object of gaining the highest possible interest on
Dutch capital. It does not illustrate what we are aiming at in
India--agricultural improvement initiated and carried through by the
people themselves, as the result of education and uplift, on 300 million
acres.

Let us examine the course of events in Europe and America and learn what
we can from them.

In medieval England the yield of wheat was seven maunds per acre. When
the consolidation of holdings was completed by the enclosures in about
the last quarter of the eighteenth century the yield rose to fourteen
maunds per acre. It remained at this level until 1840 when a further
advance was made possible by the use of better methods and the
introduction of nitrogen fertilizers. By 1870 the yield had risen to
twenty maunds per acre.

In America low yields and a growing industrial population are causing
uneasiness. By studying agricultural conditions in other countries the
conclusion has been reached that forty-seven per cent represents a
possible all-round increase of production on the present cropped area.
Experts do not agree as to the probable increase in the next few
decades. This is placed between the limits of ten and thirty per cent.
These figures are based on considerations of labour. This, as I have
said, scarcely enters into our problem in India. We have more people
employed in agriculture per unit of cultivated land than any other
country, with the possible exception of China and Japan.

The improvement of sugar-cane cultivation extends over 2,810,000 acres
in eighteen districts in the United Provinces and gives some indication
of the possible course of events.

The yield of the unimproved crop in a year of average character is 350
maunds per acre. We pass through four definite stages of improvement:--

(1) Better cultivation of the old varieties, yielding 450 maunds per
acre.

(2) The introduction of heavier cropping varieties accompanied by a
further improvement in cultivation, yielding 600 maunds per acre.

(3) The introduction of some fertilizing agent, such as green-manure,
yielding 800 maunds per acre.

(4) The intensive cultivation of heavy cropping varieties, yielding
1,000 maunds per acre.

The increase over the normal production is 28, 71, 128 and 185 per cent.
The analysis of the returns is helpful in connexion with our problem. In
the more important sugar producing districts seventy per cent of the
sugar-cane area is planted with heavier yielding varieties. In some
thirty per cent, and in a few only two per cent.

2,810,000 acres is almost exactly 33 per cent of the total sugar-cane
area in the 18 districts for which special returns are made; on this
area the yield has been slightly more than doubled so that there is an
all-round increase in production of 33 per cent. This has taken 17 years
to accomplish and brings the cultivator in 311 lakhs of rupees extra a
year. I believe if such simple modifications of practice as the use of
green-manure crops and composts made from waste material, were applied
to all our arable land, production would be more than doubled; but this
means that every cultivator would be conducting his agricultural
operations in a scientific manner--a state of affairs not yet reached in
any country. The point is that it is not to be expected. We must allow
for the inertia which will retard the general adoption of improvements
in so large a country as India. After giving due weight to this and
taking into consideration the abundance of our labour resources and the
extraordinary response of our soil to better treatment, it is reasonable
to believe that within the next two or three decades we may increase the
all-round out-turn of our cropped land by 30 per cent in normal seasons.
But I assume that much more money will be spent on scientific research
and extension work in villages than is now spent.

I hope I have said enough to show that soil improvement in India is
worth an effort. It requires generous expenditure from the national
exchequer, and there is no better investment for it gives, to use the
words of Huxley, an immediate return of those things which the most
sordidly practical man admits to have value. We are working in times
well suited for agricultural development. Indifference is giving way.
There is a stir throughout the countryside. We can call the movement
what we like, but the plain fact is that men are no longer satisfied
with a life which provides only hard work and barely enough to eat. Many
things are being suggested, but they deal more often than not with
preliminaries to social well-being and leave untouched the vital problem
of producing more food. In the end the scientific worker will come to
the rescue, and the solution will be reached through the experiment
station.




APPENDIX C



NITROGEN TRANSFORMATION IN THE DECOMPOSITION OF NATURAL ORGANIC
MATERIALS AT DIFFERENT STAGES OF GROWTH


S. A. WAKSMAN and F. G. TENNEY,
New Jersey Agricultural Experiment Station, U.S.A.
(Proceedings and Papers of the first International Congress
of Soil Science, Washington, D C, 1927, p. 209.)

To be able to understand the reasons for the rapidity of liberation of
nitrogen from the decomposition of plants at different stages of growth,
we must know the composition of the plant at these various stages and
the nature of decomposition of the various plant constituents. Although
the plant continues to assimilate nutrients, including nitrogen, until
maturity, the percentage of nitrogen in the plant reaches a maximum at
an early stage, then gradually diminishes, reaching a minimum at
maturity or a little before maturity. This is true not only of nitrogen
but also of certain other elements.

Plant materials decompose more rapidly and the nitrogen is liberated
more readily (in the form of ammonia) at an early stage of growth and
less so when the plant is matured. Two causes are to be considered here:
(1) the rapidity of decomposition of the various plant constituents; (2)
the relation of the nitrogen to the carbon content of the plant tissues.

At an early stage of growth, the plant is rich in water-soluble
constituents, in protein and is low in lignins. When the plant
approaches maturity, the amount of the first diminishes and of the
second increases. The water-soluble constituents, the proteins and even
the pentosans and celluloses decompose very rapidly provided sufficient
nitrogen and minerals are available for the micro-organisms. The lignins
do not decompose at all in a brief period of time of one or two months.
More so, their presence has even an injurious effect upon the
decomposition of the celluloses with which they are combined chemically
or physically. The larger the lignin content of the plant the slower
does the plant decompose even when there is present aufficient nitrogen
and minerals.

It has been shown repeatedly that the organisms (fungi and bacteria)
decomposing the celluloses and pentosans require a very definite amount
of nitrogen for the synthesis of their protoplasm. Since the cell
substance of living and dead protoplasm always contain a definite,
although varying, amount of nitrogen and since there is a more or less
definite ratio between the amount of cellulose decomposed and cell
substance synthesized, depending of course upon the nature of the
organisms and environmental conditions, the ratio between the cellulose
decomposed and nitrogen required by the organisms is also definite. This
nitrogen is transformed from an inorganic into an organic form. Of
course in normal soil, in the presence of the complex cell population,
the cell substance soon decomposes, a part of the nitrogen is again
liberated as ammonia and a part remains in the soil and is resistant to
rapid decomposition. The amount of nitrogen which becomes available in
the soil is a balance between the nitrogen liberated from the
decomposition of the plant materials and that absorbed by the
micro-organisms which decompose the non-nitrogenous and nitrogenous
constituents. The younger the plant, the higher is its nitrogen content
and the more rapidly does it decompose, therefore the greater is the
amount of nitrogen that becomes available. The lower the nitrogen
content of the plant the less of it is liberated and the more of it is
assimilated by micro-organisms.

These phenomena can be brought out most clearly when the same plant is
examined at different stages of growth. The rye plant was selected for
this purpose. The seeds were planted in the fall. The samples taken on
April 28th (I), May 17th (II), June 2nd (III), and June 30th (IV). In
the third sampling the plants were divided into (a) heads, (b) stems and
leaves. The fourth sample was divided into (a) heads, (b) stems and
leaves, (c) roots. The plants were analysed and the rapidity of their
decomposition determined, using sand or soil as a medium and 2 g. of the
organic matter. In the case of sand some inorganic nitrogen and minerals
were added and a soil suspension used for inoculation. The evolution of
carbon dioxide and accumulation of ammonia and nitrate nitrogen was used
as an index of decomposition. Tables I and II show the composition of
the plant and the amount of nitrogen made available after 26 days of
decomposition.


TABLE I  COMPOSITION OF RYE STRAW AT DIFFERENT STAGES OF GROWTH ON
A DRY BASIS

No.         Moisture    Ash   Nitrogen   Cold water   Pento-  Cellu-Lig-
of sample   content                        soluable   sans     lose   nin
            at time                         fraction
            of harvest

I            80.0      7.3      2.39         32.6      15.9    17.2   9.9
II           78.8      5.7      1.76         22.0      20.5    26.1  13.5
IIIa         57.4      4.9      1.01         18.2      22.7    30.6  19.0
IIIb         60.2      5.9      2.20         20.3      22.7    20.1  16.0
IVa          15.0      3.2      1.22          4.7      11.9     4.6  13.4
IVb          15.0      3.7      0.22          9.5      21.7    34.6  18.8
IVc           ?         ?       0.55          4.7      26.6    37.7  21.0


[ed note: Table II has not been included in this etext]

When a plant material contains about 1.7 per cent nitrogen, as in the
rye of the second sampling, there seems to be sufficient nitrogen for
the growth of micro-organisms which decompose this material more or less
completely. When the plant material contains less than 1.7 per cent of
nitrogen, as in the case of the stems and leaves of the third
preparation, additional nitrogen will be required, before the organic
matter is completely decomposed (speaking, of course, relatively, since
if a long enough period of time is allowed for the decomposition, less
additional nitrogen will be needed). If the organic material contains
more than I.7 per cent nitrogen, as in the case of the plants in the
first planting and the heads of the third sampling, a part of the
nitrogen will be liberated as ammonia, in the decomposition processes. .
. . . The decomposition of 10g. dry portions of the second sampling and
20g. dry portions of the stems and leaves of the fourth sampling was
studied separately in a sand medium containing available nitrogen and
minerals. Only the data for the organic matter portion, insoluble in
ether and water, are reported. The results show that the pentosans and
celluloses are rapidly decomposed, while the lignins are affected only
to a very inconsiderable extent. The nitrogen figures are of direct
interest here. Just about as much insoluble protein was left in the
first as in the second experiment: in the first the protein is
considerably reduced, in the second increased. This tends to explain the
activities of the micro-organisms in the soil. The results show that
since there is a very definite ratio between the energy and nitrogen
consumption of the microorganisms decomposing the organic matter, it is
easy to calculate, given a certain amount of plant material and knowing
its nitrogen content, whether nitrogen will be liberated in an available
form or additional nitrogen will be required within a given period of
time. Calculations can also be made as to how much of this nitrogen is
required for the decomposition of the plant material and how long it may
take before the nitrogen is again made available.




APPENDIX D



AN EXPERIMENT IN THE MANAGEMENT OF INDIAN LABOUR


By ALBERT HOWARD, C.I.E.
(International Labour Review, Geneva, I8, 193I, p. 636.)

One of the outstanding problems of the present phase of colonial
development in Asia and Africa is that of the best and most
scientific methods for the organization of work in large-scale
agricultural undertakings. The author of this short article, who
is a well-known authority on tropical agriculture and has for
thirty years contributed to the scientific improvement of
agriculture in the East as Imperial Economic Botanist at the
Government of India Research Station at Pasa, at Quetta, and
latterly in the State of Indore, describes a small-scale
experiment from which many lessons may perhaps be drawn. The
experiment has been tried in the State of Indore under the
stimulus of having to obtain an adequate labour force to carry on
the work of an agricultural experimental station in competition
with the rival attractions exercised by work in neighbouring
factories. No doubt the conditions are not entirely on all fours
with those of plantations carried on under competitive conditions,
but they are sufficiently similar to give the experiment a living
and practical interest. As the author points out, the financial
basis is provided mainly by the cotton industry in India and by
the Indian States members of the Institute of Plant Industry,
without any call for assistance by the Government of India or by
Provincial Governments. As the article shows, the best results
have been obtained under a scheme which provides for a six to
seven and a half hour working day, paid leave, medical attendance,
good housing, and opportunity for promotion for the labour employed.
[Ed. International Labour Review]


The foundation of the new Institute of Plant Industry at Indore in
Central India in October 1924, provided the opportunity of breaking new
ground in at least four directions, namely:--

(1) The best method of applying science to crop production.

(2) The general organization and finance (including audit) of an
agricultural experiment station.

(3) The most effective way of getting the results taken up by the
people; and

(4) The management of the labour force employed.

The present article deals with the last of these items: with the methods
by which a contented and efficient body of labour can be maintained for
the day to day work of an agricultural experiment station, largely
devoted to the production of raw cotton.


THE INSTITUTE AND ITS ORGANIZATION

The Institute of Plant Industry at Indore is supported by an annual
grant of Rs. 1,15,000 from the Indian Central Cotton Committee and by
subscriptions, amounting at the moment to Rs. 47,550 a year, from twenty
of the States of Central India and Rajputana. (In addition to these
sources, the Institute makes use of the produce of the experimental area
of 300 acres, of the royalties on its publications and of a number of
miscellaneous items of income, including the fees earned for advice to
individuals and bodies outside the Society.) During the financial year
1929-1930, the income from all sources was Rs. 1,79,080, the expenditure
was Rs. 1,75,041. The management of the Institute is vested in a Board
of Governors, seven in number, elected by the subscribers, the Director
of the Institute being Secretary of the Board. It will be seen that the
main source of the funds available for the payment of labour is derived
from the Indian Central Cotton Committee (a statutory body representing
the growers, the cotton trade and the officers engaged in research on
cotton) created for implementing the Indian Cotton Cess Act of 1923: an
Act which provides for the creation of a fund for the improvement and
development of the growing, marketing and manufacture of raw cotton in
India. This cess is now levied at the rate of two annas per standard
bale of 400 lb. on all cotton used in the Indian mills or exported from
the country. The money available for the payment of labour at the Indore
Institute is thus largely drawn from the cotton industry itself. At no
period in the history of the institution has any financial assistance of
any kind been asked for or obtained from the Government of India or from
any of the Provincial Governments.

At the beginning, great difficulties were experienced in obtaining an
efficient labour force. The Institute lies alongside the city of Indore,
an important manufacturing and distributing centre with a population of
127,000. Nine large cotton mills (with 177,430 spindles, 5,224 looms, an
invested capital of Rs. 1,67,97,106, and utilizing 68,000 bales of
cotton a year) find work for 12,000 workers. In addition there are a
number of ginning factories and cotton presses. The Institute therefore
had to meet a good deal of local competition in building up its labour
force. It was dearly useless attempting to recruit workers at rates
below those readily obtained at the mills or in the city. Further, it
soon became apparent that if the Institute was to succeed the Director
would have to pay attention to the labour problem and devise means by
which an efficient and contented body of men, women and children could
be attracted and retained for reasonable periods.

Consideration of this problem led the Director to the conclusion that it
could be solved by providing for the regular and effective payment of
wages, for good housing, reasonable hours of work, with regular and
sufficient periods of rest, and for suitable medical attention.

The application of these principles soon met with success. An adequate
labour force has been built up, partly from men recruited locally and
from the Rajputana States and partly from the wives and children of the
sepoys of the Malwa Bhil Corps, the lines of which adjoin the Institute.
A permanent labour force of about 118 is now employed throughout the
year. In addition, a certain amount of temporary labour is employed for
seasonal work.

The precise manner in which the principles above mentioned have been
carried out in practice may now be described.


CONDITIONS OF LABOUR AT THE INSTITUTE

Payment of Labour

Wage rates for men on the permanent staff range from about Rs. 12 to Rs.
20 a month, while men on the temporary staff are paid 7 annas a day,
women 5 annas, boys 3 to 6 annas, and girls 3 to 5 annas. After the rate
of wages has been settled in each case, care is taken that: (1) the
payment of wages is made at regular intervals; and (2) the wages are
paid into the hands of the workers themselves and there are no illicit
deductions on the part of the men who disburse the money.

Regularity of payment is a matter of very great importance in dealing
with Indian labour. At Indore, workers on daily rates receive their
wages twice a month--on the 18th and the 3rd, in each case at 2:30 p.m.
The permanent labour is paid monthly on the third working day of the
following month. To ensure that all payments are actually made according
to the attendance registers all disbursements are made in the presence
of two responsible members of the staff. Both of these men have to sign
a statutory declaration that the payments have actually been made. The
signed statements come regularly before the Director for signature, and
are in due course placed before the auditors. In making payments the
envelope system is used, the payee making a thumb impression in ink in
the register or signing his or her name. These arrangements have been
found to prevent any illicit deductions on the part of the staff. The
payments are made in public; the rate of everybody's pay is known; the
signing of a proper declaration in the register makes it possible to
institute criminal proceedings at once for any irregularity; the
Director is always available for inquiring into any complaints. That
none have ever been made proves that the labourers actually receive
their pay in full at regular intervals. Payment is made in coin; no
attempt at payment in kind has ever been made; no shops for the sale of
food exist on the estate and nothing whatever is done to influence the
workers as to how they should spend their wages.


Hours of Labour

After the regular payment of wages, the hours of labour come next in
importance. Indeed in India rest and wages are to a certain extent
interchangeable as the workers regard any extra rest as equivalent to an
increase in pay. At first, the Institute observed the ten hours' day so
common in India, but this was soon given up. It was found during the hot
months of April, May and June that both the labour and the cattle
required more protection from the hot sun. An experiment was therefore
made to reduce the hours of labour during the hot months to six daily,
beginning work at sunrise and ending the day at sunset. The actual
working hours of the three hot months were arranged in two shifts--four
hours in the morning and two in the afternoon with a six hours' rest
during the heat of the day, i.e. from I0 a.m. to 4 p.m. At the same time
the work was speeded up and both labour and supervising staff were given
to understand that the six hours' day in the hot months could only be
enjoyed if everybody worked continuously and conscientiously.

The first result observed was a marked improvement in the health and
well-being of the men and animals, probably due to the operation of two
factors: the health-giving properties of the early morning air and
avoidance of excessive sunlight. With the improvement in general health
there was a corresponding reduction in cases requiring medical
assistance. To everyone's surprise, it was found possible to speed up
the work very considerably. The experiment of shortening the hours of
labour was then extended to the rest of the year; working hours were
reduced from ten to seven and a half.

These working periods, six hours in the hot weather and seven and a half
during the rest of the year, refer to the time actually at work; an
extra half hour daily is spent in travelling to and from the place of
work. In no case does the working period exceed seven and a half hours
except for about a week at the sowing time of the monsoon crops. During
this period, both man and beast do not obtain much more than two hours
off duty for food during the hours of daylight. A full ten hours' day at
high pressure is then the rule, as all realize that the sowing of cotton
and other crops is a race against time. As soon, however, as sowing is
over, the workers enjoy an extra day's rest on full pay. The sowing of
the monsoon crops is the only agricultural operation in Central India
for which anything more than a seven and a half hours' day is necessary.

For three years the agricultural operations of the Institute have been
conducted on the short hours system. The result has been successful
beyond all expectation. The miracle of speeding up Indian labour has
been achieved and shorter working hours have led not only to contentment
but also to an increased output of work. This result has only been
achieved, however, by careful and detailed planning of the work to be
done each day. The daily work programme is drawn up by the Assistant in
charge of the farm during the previous afternoon and submitted to the
Director as a matter of routine, so that at daybreak each day the
Assistant knows at once what has to be done and no time is lost in
deciding what tasks have to be performed. The taking of the attendance
and the allocation of labour to the various tasks occupies less than
five minutes. In less than ten minutes after assembly, the various gangs
are at work in the fields. A great point is made of getting down to the
job at once. Punctuality is now the rule, and it is becoming rare to
have to deal with late arrivals.

While it is important to start work with the sun, it is equally
important to allow the labourers to reach their homes by sundown,
particularly during the rains when snakes abound. Indian workers like to
reach home in daylight--a point of great importance in obtaining their
willing co-operation. Finally, it is very interesting to note that the
policy of the square deal on the part of the Institute towards its
labourers as regards hours is now being answered by a natural desire on
the part of the workers to give the Institute a square deal. Less
supervision is becoming necessary; everybody realizes that a reduction
in hours is only possible if real work is done.


Leave and Holidays

The Institute is closed, except for work of extreme urgency, on Sundays
and on twelve important festivals during the year. In addition to these
sixty-four days, the permanent labourers are allowed one day's casual
leave and one day's sick leave every month provided they work
twenty-five full days during the month. In cases of injury while on
duty, they are allowed full pay up to a maximum of seven days. In the
case of temporary labour, all holidays and leave, except the extra day
allowed after the sowing of the monsoon crops, are given without pay.


Housing

As regards living accommodation, the demands of Indian labour are very
modest. A roof which does not leak during the rains, a dry earthen
floor, a room which can be locked up, a partially closed-in verandah
which serves both as a kitchen and a store house for firewood, are all
that is expected. At Indore the one-room cottages are arranged in blocks
of six around an open courtyard in which four trees have been planted to
provide shade. The quarters are fumigated and whitewashed once a year
when any petty repairs to the roofs and brickwork are attended to.

After a storm-proof room, the next essential is a supply of good
drinking water and a separate well for washing. The water used for
drinking is raised by a simple wheel pump; the well is provided with a
masonry coping about two feet high; no drinking vessels are allowed to
be dipped into the water. In this way the risk of cholera is greatly
reduced. Once a simple wheel pump is installed, the labourers and their
wives never attempt to lower a bucket by means of a rope.


Provident Fund

So far no provident fund for the workers has been instituted. The
existing provident fund only applies to the permanent staff of the
Institute drawing Rs. 30 per month or more. Till the completest
confidence between the workers and the management has been achieved, any
suggestion of keeping back the pay of a labourer for a provident fund is
likely to be misunderstood. It was decided to start a provident fund for
the educated staff and gradually to extend its benefits to the labour
force if and when a demand comes from the workers themselves.


Medical Arrangements

The workers and staff employed at the Institute obtain free medical
attendance. In addition, the workers and the staff drawing less than Rs.
30 per month obtain free medicaments. The workers are examined weekly by
the doctor so that any precautionary treatment or any advice can be
given in good time. In cases of childbirth the services of a nurse are
provided free of charge. The personality of the Sub-Assistant Surgeon
dealing with Indian labour is very important. The workers deal with an
unpopular man in a very effective fashion--they never make use of his
services.


Certificates and Promotion

An experimental station, like any employer of labour, needs some system
by which the labour force can automatically renew its youth. The annual
export of trained labour to centres at which improvements are being
taken up is one of the important functions of the Institute. For these
reasons, therefore, a supply of promising recruits must be arranged. To
bring this about some system of promotion for proved efficiency had to
be devised. At first this took the form of an annual promotion
examination for the ploughmen. As they increased in efficiency and could
manage and assemble their implements and also plough a straight furrow,
their pay was increased by Re. I per month. This system is now being
superseded by the certificate plan. All the permanent workers in the
Institute are eligible for special training so that they can earn
efficiency certificates for such operations as: (1) cultivation and
sowing; (2) compost making and the care of the work cattle; (3) improved
irrigation methods, including the cultivation of sugar-cane by the Java
method; (4) the manufacture of sugar (Plate XIV). A certificate of
efficiency (with suitable illustrations) signed by the Director can be
awarded for proficiency in all these items. Each certificate which is
awarded annually will carry with it an increase of Rs. 1 per month on
the basic pay. When a member of the labour force has gained all four
certificates, he will become eligible for transfer to other centres on
higher pay. In this way the Institute holds out hope and places it
within the power of any man to increase his starting pay in four years
by about thirty per cent. It also enables an ambitious labourer to save
enough money in a few years to purchase a holding and to become a
cultivator. This is now taking place. Every year a few of the labourers
return to their villages with their savings to take up a holding on
heir own account. Others are deputed for work in the Contributing
States on increased pay. The vacancies are automatically taken either by
younger members of the same family or by volunteers on the waiting list
of temporary workers.


CONCLUSION

It is possible that the system described in this article is only fully
realizable on a farm working under model conditions. Nevertheless, there
are a certain number of elements in this experiment which the writer
feels are of universal validity in dealing with primitive labour. From
the point of view of the worker it is perhaps most essential that he
should feel that he is receiving a square deal. From the point of view
of the management the best results are obtained by scrupulous attention
to pay, by short hours of intensive work, by proper housing and medical
care, and by interesting the worker in the undertaking through giving
his work an educational value.



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