3.1   Soils

. Soils Soil is the uppermost layer of the land surface, usually composed of minerals, organic matter, living organisms, air and water. Grains in the soil are of three categories namely, clay, silt, and sand. Soils are generally formed by the weathering of rocks under different conditions. Some soils are formed by the deposition of agents of denudation. Soils can vary greatly from one region to the other. Types of Soils The Indian Council of Agriculture Research (ICAR) setup in , divides the soils of India into the following eight major groups. They are, . Alluvial soil . Black soils . Red soils . Laterite soils . Forest and mountain soils . Arid and desert soils . Saline and alkaline soils . Peaty and marshy soils