Soil is one of the most important national resources of any country for it not only grows a variety of food and fodder crops but also produces raw materials for various agro-industries.

A complex body showing great many variations in depth, colour, composition and behaviour, soil consists of hard materials called mineral matter, soft and spongy organic matter, water, air and living organisms in varying proportions. Soil has three dimensions namely, length, breadth and depth. Soils have primarily developed from different types of rocks. Rocks can be classified into three main types:igneous, sedimentary and metamorphic.

Soils are classified by characteristics such as the kind and number of horizons or layers that have developed in them. Horizons are distinguished by texture, kind of minerals present, and the presence of salts and alkalis.