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(The Soil and Health)
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Chapter 3
Systems of AgricultureWhat is agriculture? It is undoubtedly the oldest of the great arts; its beginnings are lost in the mists of man's earliest days. Moreover, it is the foundation of settled life and therefore of all true civilization, for until man had learnt to add the cultivation of plants to his knowledge of hunting and fishing, he could not emerge from his savage existence. This is no mere surmise: observation of surviving primitive tribes, still in the hunting and fishing stage like the Bushmen and Hottentots of Africa, show them unable to progress because they have not mastered and developed the principle of cultivation of the soil.
Primitive Forms of Agriculture
The earliest forms of agriculture were simple processes of gathering or reaping. Man waited until Nature had perfected the fruits of the earth and then seized them for his own use. It is to be noted that what is intercepted is often some form of Nature's storage of reserves; more especially are most ripe seeds the perfect arsenals of natural reserves. Interception may, however, take other forms. A well-developed example of human existence based on a technique of interception is the nomadic pastoral tribe. Pastoral peoples are found all over the world; they have played some part in the history of the human race and often exhibit an advanced degree of culture in certain limited directions, not only material. Their physical existence is sustained on what their flocks and herds produce. To secure adequate grazing for their animals they wander, sometimes to and fro between recognized summer and winter pastures, sometimes over still greater distances. In this way they intercept the fresh vegetable growths brought to birth season by season out of the living earth; however successful, it is nothing more than a harvesting process.
It is presumed rather than known that at some period man extended his idea of harvesting to the gathering of the heads of certain plants, thus adding a vegetable element to the milk, meat, and fish he had been deriving from his animals and the chase. Wild barley, rice, and wheat are all supposed to have been gathered in this way in different parts of the earth. But real agriculture only began when, observing the phenomenon of the germination of seeds, instead of consuming all that they had gathered, men began to save some part of what they had in store for sowing in the ground. This forced them to settlement, for they had to wait until the plants grew from the seed and matured.
If at first the small store of gathered seed was sown in any bare and handy patch, the convenience of clearing away forest growths so as to extend the space for sowing soon became apparent. The next stage was to prepare the ground thus won. The art of tillage has progressed over the centuries. The use of a pointed stick drawn through the ground is still quite common. The first ploughs were drawn by human labour -- a practice which survived even in such countries as Hungary and Romania into the nineteenth century. But the use of animals, tamed for their muscular strength to replace the human team, became the normal and world-wide practice, until ousted in certain continents first by the still more powerful steam engine and now by the internal combustion engine.
What was the purpose of this tillage, which is still the prime agricultural process? The first effect is, of course, physical. The loosened soil makes room for the seed, which thus can grow in abundance, while to cover the sowing with scattered earth or to press it into the ground protects it from the ravages of birds or insects. Secondly, tillage gives access to the air -- and the process of soil respiration starts up, followed by the nitrification of organic matter and the production of soluble nitrates. The rain, too, can penetrate better. In this way physical, biological, and chemical effects are set in motion and a series of lively physiological changes and transformations result from the partnership between soil and plant. The soil produces food materials: the plants begin to grow: the harvest is assured: the sowing has become a crop.
Yet this is not the way in which Nature is accustomed to work. She does not, as a rule, collect her plants, the same plants, in one spot and practice monoculture, but scatters them: her mechanisms for scattering seed are marvellous and most effective. Man's habit, so convenient, of collecting a specified seed and sowing it in a specified area implies, it must be acknowledged, a definite interference with Nature's habits. Moreover, by consuming the harvest and thus removing it from the place where it had grown he for the time being interrupts the round of natural processes.
In fact, man has laid his hand on the great Wheel and for a moment has stopped or deflected its turning. To put it in another way, he has for his own use withdrawn from the soil the products of its fertility. That man is entitled to put his hand on the Wheel has never been doubted, except by such sects as the Doukhobors who argued themselves into a state of declaring it a sin to wound the earth with spades or tools. But if he is to continue to exist, he must send the Wheel forward again on its revolutions. This is a necessary part of all primitive cultivation practices and perhaps a tenet of all true early religions as soon as they lift themselves from the stages of mere animism or fetish worship; at any rate, all the great agricultural systems which have survived have made it their business never to deplete the earth of its fertility without at the same time beginning the process of restoration. This becomes a veritable preoccupation.Shifting Cultivation
The simplest way of doing this is after a time to leave the cultivated patch and thus stop the process of interference. Nature will overrun it again with scrub or forest: soon the green carpet is re-established: in due course humus will accumulate: it will be as it was -- the earth's fruitfulness will be restored. To pass on, therefore, from one patch to another, and again to another and another, is a common primitive practice found in Africa, India, Ceylon, and many other parts of the world, and is known as shifting cultivation. It even occurred in the American continent some ten years or so ago before the Tennessee Valley Authority was constituted by the late President of the United States of America. In this shifting cultivation the fresh patch is usually cleared by burning the jungle: this leaves the ash in situ, and thus retains some of the mineral contents of the burnt vegetation for the benefit of the coming crop. But it is a wasteful method, for a large aggregate area is required to feed a small group, while a long period has to be reckoned to replace the lost fertility. Indeed, this replacement is seldom consummated. The larger trees suffer, the best part of the forest is virtually destroyed. It will also be observed that after using up the riches of the soil man actually does nothing to restore it -- he merely leaves it. This lazy practice constitutes the least satisfactory of many agricultural systems and, entailing constant small movements of working area on the part of those practicing it, is no foundation for a settled civilization. It does, however, show that primitive tribes not only realized the fact that fertility can be exhausted, but also understood how it could be restored.
The Harnessing of the Nile
A much more satisfactory method of restoring soil fertility was evolved in the great river valley of the Nile which, according to some theorists, was the original home of agriculture proper. It is the peculiarity of this great river that it overflows once a year with great regularity, bearing suspended in its flood an accumulation of fertile silt washed down from its catchment basin; this accumulation, rich in both mineral and organic matter, is gently deposited and is capable of yielding an abundant harvest. The process continued for centuries. Early engineering skill led the silt-laden water to embanked fields by means of inundation canals. The deposit was trapped just where it was needed and the land was at the same time saturated with water. When the embanked fields were dry enough, they were ploughed and sown: no rain fell and no more water was needed for a full crop. The annual additions of rich silt made this method of farming permanent. In this way there grew up settled habitations, a great civilization, an historic people.
This basin system of irrigation in Egypt, which is perhaps the best and most permanent that can be devised, has of recent years been replaced by another -- perennial irrigation -- by which the same field can be watered periodically to allow of cotton being grown. For this purpose the Nile has been impounded and a vast reservoir has been created for feeding the canals. But unless the very greatest care is taken to restore and then to maintain the compound soil particles by means of constant dressings of freshly prepared humus these modern methods are doomed. The too frequent flooding of the close silts of this river valley will lead to the formation of alkali salts and then to the death of the soil. This will be the fate of Egypt if the powers-that-be persist in the present methods of cultivation of cotton and do not realize before it is too late that their ancient system of irrigation is, after all, the best. Will a few years of cotton growing make up for the loss of the soil on which the yew, life of Egypt is based? On the answer to this question the future of the Nile valley will depend.Staircase Cultivation
Few areas on the earth's surface are so fortunate as the Nile Valley. What the great river bestowed on the lucky Egyptians has had to be created in other parts of the world, sometimes in the most unpromising conditions. The so-called staircase cultivation of the ancient Peruvians is regarded as one of the oldest forms of agriculture known to us -- it dates from the Stone Age. Without metal tools this people could not remove the dense forest growths of the humid South American valleys. They were driven to the upland areas under grass, scrub, or stone. Here they constructed terraced fields up the slopes of the mountains, tier upon tier, sometimes as many as fifty tiers rising one above the other. The outer retaining walls of these terraces were made of large stones fitted into each other with such accuracy that even at the present day a knife blade cannot be inserted between them. Inside these walls were laid coarse stones and over these clay, then layers of soil several feet thick, all of which had to be imported from beyond the mountains. Just sufficient slope was given to each tiny field for watering, water also being brought in stone aqueducts from immense distances -- one aqueduct of between 400 and 500 miles has been found traversing the mountain slope many hundreds of feet above the valley. Thus a series of gigantic flower pots were formed and in these were grown the crops to nourish a nation and to establish a civilization.
The results of such incredible labour are still to be seen, but the Inca nation itself has vanished. However, in the Hunzas living in a high mountain valley of the Gilgit Agency on the Indian frontier we have an existing demonstration of what a primitive system of agriculture can do if the basic laws of Nature are faithfully followed. The Hunzas are described as far surpassing in health and strength the inhabitants of most other countries; a Hunza can walk across the mountains to Gilgit sixty miles away, transact his business, and return forthwith without feeling unduly fatigued. In a later chapter we shall point to this as illustrative of the vital connection between a sound agriculture and good health. The Hunzas have no great area from which to feed themselves, but for thousands of years they have evolved a system of farming which is perfect. Like the ancient Peruvians they have built stone terraces, whose construction admits of admirable soil drainage and therefore of admirable soil aeration -- for where water drains away properly air is abundantly drawn in. As in the ancient Peruvian system, irrigation is employed to obtain the water and it is not without interest that this water is glacier water bringing down continual additions of fine silt ground out from the rocks by the great cap of ice. It is probable, though it has not been investigated, that the mineral requirements of the fields are thus replenished to a remarkable degree. To provide the essential humus every kind of waste, vegetable, animal, and human, is mixed and decayed together by the cultivators and incorporated into the soil; the law of return is obeyed, the unseen part of the revolution of the great Wheel is faithfully accomplished.The Agriculture of China
It is this return of all wastes to the soil, including the mud of ponds, canals, and ditches, which is the secret of the successful agriculture of the Chinese. The startling thing to realize about this peasant nation of over four hundred million souls is the immense period of time over which they have continued to cultivate their fields and keep them fertile, at least 4,000 years. This is indeed a contrast to the shifting cultivation of the African and it may be observed here that the greatest misfortune of the African continent has been that it never came into contact with the agricultural peoples of the Far East and never revised its systems of cultivation in the light of the knowledge it might thereby have gained -- the great lesson of the Nile basin was not truly apprehended and has had no influence outside Egypt, whereas over large parts of eastern Asia the central problem of agriculture was solved very early, empirically and not by a process of scientific investigation, yet with outstanding success.
The Chinese peasant has hit on a way of supplying his fields with humus by the device of making compost. Compost is the name given to the result of any system of mixing and decaying natural wastes in a heap or pit so as to obtain a product resembling what the forest makes on its floor: this product is then put on the fields and is rich in humus. The Chinese pay great attention to the making of their compost. Every twig, every dead leaf, every unused stalk is gathered up and every bit of animal excrete and the urine, together with all the wastes of the human population, are incorporated. The device of a compost heap is clever. By treating this part of the revolution of the Wheel as a special process, separated from the details of cultivation, time is gained, for the wastes mixed in a heap and kept to the right degree of moisture decay very quickly, and successive dressings can be put on the soil, which thus is kept fed with just what it needs: there is no pause while the soil itself manufactures from the raw wastes the finished humus. On the contrary, everything being ready and the humus being regularly renewed at frequent intervals, the soil is able to feed an uninterrupted succession of plants, and it is a feature of Chinese cultivation that one crop follows another without a pause, indeed crops usually overlap, the ripe crop being skilfully removed by hand from among the young growing plants of the succeeding planting or sowing. In short, what the Chinese farmer really does is ingeniously to extend his area. He, so to say, rolls up the floor of the forest and arranges it in a heap. The great processes of decay go on throughout that heap, spreading themselves over the whole of the internal surface of the heap, that is, over the whole of the surfaces implied in the juxtaposition of every piece of waste against every other. He also overcomes the smallness of the superficial area of his holding by increasing the internal surface of the pore spaces of his soil. This is what matters from the point of view of the crop -- the maximum possible area on which the root hairs can collect water and food materials for the green leaf. To establish and to maintain this maximum pore space there must be abundant humus, as well as a large and active soil population.
Thus is created the most intensive agriculture which the world has so far seen. Each Chinese family lives on the produce of a very tiny piece of ground, an area which would mean downright starvation in most other countries. In spite of great calamities which repeat themselves, principally floods, the causes of which will be mentioned hereafter, the Chinese peasant may be said to be, on the whole, well nourished. His resisting power to the many frightful diseases, sufficient to kill off most other populations, has been noted, while the standard of culture which he has reached and has maintained over the long period of his existence rivals the contributions of Western civilization.
He is indeed the classic example of a nation which has conserved the fertility of its soil. Other nations have done the same, but none over so long a period or on so vast an area. Is it legitimate to interpret the history of the nations by the way in which they have made use of the land which chance or their own velour assigned to them? We have considered some instances where attempts have been made to conserve fertility with greater or lesser success. Let us now turn to some different examples.The Agriculture of Greece and Rome
The agricultural history of the ancient Greeks is not altogether clear. But one thing is certain: in common with most other Mediterranean peoples they permitted an extraordinary amount of destruction of forest growths over some of the areas bordering on this great inland sea. Greece is now a land bare of trees and the continued depredations of the goat have done untold harm to any young growths that have attempted to survive. Whether this process began on a large scale very early and whether the result was a severe disturbance of the drainage of a not very fruitful country, extending on the one hand the area of marsh and on the other inviting erosion, is not certain. Such conditions would affect first the crops and then those who fed off them -- subtle forms of undernourishment and disease would appear. The theory has been put forward that the extraordinary and unexplained collapse of the Greek nation in the fourth and third centuries B.C., after a period of the highest vigour and culture, was due to the spread of malaria. It is a theory which is very reasonable and would explain much.
The case of the Romans, another Mediterranean people, is not quite the same. For many centuries they maintained a flourishing agriculture to which they paid great attention. The backbone of the nation throughout its greatest period was the staunch mass of smallholders, each engaged on cultivating his own farm and only breaking off at intervals to pursue political matters with great vigour or to fight short summer campaigns with the utmost zest. In spite of the attractions of the metropolis and of the wonderful educational influence with which city life shaped law, thought, and conduct, the rural background was conserved and valued; religion remained rather rural throughout and never got very much beyond the peasant outlook. It was the necessity for fighting prolonged foreign campaigns which destroyed all this. Then came the fatal attractions of slave labour. The smallholder was tempted or indeed was obliged to desert his holding for years. Such holdings began to be bought up, for wealth accumulated from the spoils of the East. Slaves were drafted in to work these agglomerations of great estates: the evil latifundium, which means the plantation in its worst form, spread everywhere. The final phase was reached when tillage was given up for the cheaper pastoral industry: where there had been countless flourishing homesteads now ranged great herds of cattle tended by a few nomadic shepherd slaves.
This disastrous change, which was deeply deplored by such writers as Cicero, lasted and, except in northern Italy, was not made good. A few years ago it was possible to see on a mere day's excursion away from Rome a wild shepherd tending his sheep over a ruined countryside which might have been carved out of the most ancient of wildernesses, so entirely was it denuded of all traces of tillage or of the care of man. There must have been some profound upsetting of the balanced processes of Nature to reduce so fertile a country as Italy to such a state and Nature in revenge has preferred to continue her revolution of the Wheel on the lowest gear, spreading her marsh, her scrub, and her desert, where once there were fields and meadows.
Having largely destroyed the food-bearing capacity of the Italian peninsula, the Romans were forced to feed their swollen cities from elsewhere. For the dispossessed rural population drifted to the towns, which became further congested with a great influx of foreigners and foreign slaves: all had to be fed, and Alexandria and Antioch were problems no less great than Rome. First Sicily and then North Africa, at that time great wheat-growing countries, were exhausted. We cannot trace the process and do not know how much to attribute to a false economy, how much to the ravages of centuries of war, as wave after wave of conquerors disputed possession. When these countries reappear after such cataclysms, Sicily is a wild pastoral country, North Africa, except for a few coastal tracts and, of course, always Egypt, a desert.Farming in the Middle Ages
The rest of the continent of Europe was more fortunate. Out of the lingering shadows of the Roman Empire there finally emerged into medieval times a system of agriculture which held its own well into the nineteenth century. Such a long history is an honourable one and we may agree that this system, that of mixed husbandry, was in many essentials excellent. Except where a frozen legal system ground down the cultivator -- "trembling peasants gathering piteous harvests" -- both the large farm and the smallholding, the landlord and the tenant, survived in good health and considerable comfort. Food was abundant and nourishing, and above all the soil remained in good heart.
The system depended on certain principles. In the first place, animal husbandry was practiced alongside of the production of vegetable crops: there was thus a supply of manure. The manure was not made on the most perfect system. The European manure heap, normally regarded as the inevitable method of collecting and storing animal wastes, is nevertheless most inefficient, as will be pointed out in a later chapter (Chapter 12, The Reform of the Manure Heap). But it has played a prime role in maintaining the fertility of our continent, although it is wasteful and extravagant, unhealthy, and unnatural: with the help of the manure heap the return of much of the wastes of farming was assured to the land.
The use of the cesspit was even less successful and it is not surprising that water-borne sewage, when once invented, rapidly replaced it: unfortunately this permitted the final escape of valuable wastes to the sea. To this came to be added, also in the course of the nineteenth century, the further loss of all dustbin refuse which, again on the dictates of the new sanitary science, was destroyed by burning or was buried in unused tips. Nevertheless, until these modern sewage disposal methods were developed, it is significant that all material wastes went back to the soil in however imperfect a way.
A third principle in conserving fertility was the fallow. Arable land was rested by allowing it to remain idle for a year or for a longer period by the establishment of a temporary carpet of grass and weeds. A part at least of the advantage of the bare fallow was the benefit conferred by the weeds. When laid down to grass for sheep, the green carpet rapidly deposited a mass of vegetable wastes under the turf which, with the turf and the animal wastes deposited thereon, provided all the raw materials for sheet-composting when the land came under the plough. Both these methods have been employed in European farming for many centuries and did much to conserve the fertility of the soil.
As long as all these principles governed European farming it could roughly hold its own, although a slow running down of soil fertility remained at all times a possibility, as will be seen in the next chapter. It began to break down seriously with the advent of the Industrial Revolution. But before dealing with the changes thus brought about in European agriculture it will be illuminating to examine in greater detail the story of one people, our own, in terms of the use made by the community of soil fertility. We shall see that, in spite of the great and advantageous practices to which we have alluded, soil fertility was subtly and gradually used up. This has determined much in our national affairs.
Next: 4. The Maintenance of Soil Fertility in Great Britain
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