To Plow or Not to Plow 3. Burning Over Land 4. If I were asked to sum up in a few words the basis of this movement and the general results that are being obtained, I should reply that a fertile soil is the foundation of healthy crops, healthy live stock, and last but not least healthy human beings. By a fertile soil is meant one to which Nature's law of return has been faithfully applied, so that it contains an adequate amount of freshly prepared humus made in the form of compost from both vegetable and animal wastes. They are the gifts of Providence which all the resources of Science cannot copy, still less improve.
Mankind can only assist the food factory in two directions.
He can also by selecting crops by plant breeding methods make the most of the energy of sunlight and of the improved soil conditions. But the plant breeder must avoid one obvious blunder. He must not be content with improving the variety only, otherwise his labours will soon lead to the exhaustion of the soil. The improved variety will take more out of the ground and will soon become a boomerang. The plant breeder, therefore, must always be careful not to confine his attention to the variety, but must increase the fertility of the soil at the same time.