In Lieu of Preface.-This book is not a technical treatise and is designed only to point out the plain, every-day facts in the natural scheme of making and keeping soils productive. It is concerned with the crops, methods, and fertilizers that favor the soil. The viewpoint, all the time, is that of the practical man who wants cash compensation for the intelligent care he gives to his land. The farming that leads into debt, and not in the opposite direction, is poor farming, no matter how well the soil may prosper under such treatment. The maintenance and increase of soil fertility go hand in hand with permanent income for the owner when the science that relates to farming is rightly used. Experiment stations and practical farmers have developed a dependable science within recent years, and there is no jarring of observed facts when we get hold of the simple philosophy of it all. Natural Strength of Land.-Nearly all profitable farming in this country is based upon the fundamental fact that our lands are storehouses of fertility, and that this reserve of power is essential to a successful agriculture. Most soils, no matter how unproductive their condition to-day, have natural strength that we take into account, either consciously or unconsciously. Some good farm methods came into use thousands of years ago. Experience led to their acceptance. They were adequate only because there was natural strength in the land.