Synopsis The aim of this book is to summarize accompany intensified use of the soil. It is intended to assist all those concerned with agricultural development and the environment to recognize the problems of soil degradation, and the compatibilities and incompatibilities of increased agricultural production with protection of the environment. This book also describes how, under lower demographic pressure in the past, soil management practices have evolved to provide sustainable soil management systems, adapting both to the environment and to existing social and economic circumstances. An understanding of the factors that determine the sustainability of these systems--and of their breakdown under increasing demographic pressure--has made it possible to establish sound principles of sustainable soil management. A book like this one cannot give exact answers to problems on specific farms. There are just too many differences from one field to another, and one farm to another, to warrant blanket recommendations. To make specific suggestions, it is necessary to know the details of the soil, crop, climate, machinery, human considerations, and other variable factors. Good soil management is better achieved through education and understanding than with blanket recommendations.