3. Systems of Agriculture
In lieu of an abstract, here is a brief excerpt of the content:

3 SYSTEMS OF AGRICULTURE WHAT 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, 33 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 dearing 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 practise monoculture, but scatters them: her mechanisms for scattering seed are marvellous and most effective. Man's...