Agronomy deals with the principles and practices of crop production and soil management. In its broader sense, it includes crop ecology, crop production, crop nutrition, soil fertility, water management, weed control, seed technology etc. To be a good agronomist, one needs to have a sound knowledge of all these agronomic aspects as also some related aspects from other sciences. The task of selecting the terms to be included in any branch of science offers many difficulties particularly in Agronomy, which draws upon from several diverse fields of agriculture. How far, it is advisable to include terms from those over lapping science which lie on the borderland is a question on which no two people might think alike. A compilation of available information has been a felt need of students, teachers, research workers and administrators in Agronomy. This book makes an attempt to present the available information on Agronomy in an easily understandable manner. It would be useful not only to graduate and post graduate students and those appearing in the competitive examinations, but also to the teachers and researchers of the Agricultural Universities / research organizations.