This book deals with the soil fertility aspects of the most important humanitarian problem of the next few decades - feeding all the people due to arrive. It is an outgrowth of a course in advanced soil fertility taught previously by the author to graduate students at Iowa State University.

Presents information for practical applications of scientific work on soil fertility. This book emphasizes the use of response curves as the basic biological standard for both evaluation and control, and discusses soil testing and plant analysis as secondary standards.