The period in the development of the humn race during which man began the cultivation of plants marks the dawn of agriculture.

Introduction: Now more than ever the importance of an adequate supply of plant nutrients toensure efficient crop production is being recognized.

Preface: The purpose of the third edition of Soil Fertility and Fertilizers is the same as that of the first two: to present the fundamental principles of soil fertility and fertilizer manufacture and use in a manner suitable for students of agricultue at the junior and senior levels in college.