Since the Industrial Revolution the processes of growth have been speeded up to produce the food and raw materials needed by the population and the factory. Nothing effective has been done to replace the loss of fertility involved in this vast increase in crop and animal production. The consequences have been disastrous. Agriculture has become unbalance: the land is in revolt: diseases of all kinds are on the increase: in many parts of the world Nature is removing the worn-out soil by means of erosion. The purpose of this book is to draw attention to the destruction of the earth’s capital — the soil; to indicate some of the consequences of this; and to suggest methods by which the lost fertility can be restored and maintained. It is the continuation of an earlier book, The Waste Products of Agriculture, in which the Indore method for maintaining soil fertility by the manufacture of humus from vegetable and animal wastes was described.