
Soil is another natural resource, which is rather most precious of all resources, as it is essential for our survival as well as all other life forms. It is the top surface layer of the Earth’s crust. Rock particles make a large part of the soil.
It provides:
Soil is formed from parent rock material over millions of years by a process called weathering.
Weathering occurs by.
Physical means, such as temperature, rain, wind, frost
Biological means, through the action of plants, animals and micro-organisms.
The other constituents which make up the soil are:
Mineral matter = 45%
Organic matter = 5%
Water = 25%
Air = 25%
Living organisms
Soils are derived from rocks by weathering. Percolating water is especially important in the formation of soils Young soils are stabilised when they become colonised by plants and animals. Eventually dead organic matter builds up and a mature soil as formed. Although the underlying parent rock influences the type of soil formed, the climate and vegetation are just as important.
The soil is classified on the basis of its nature and composition. The six major types of soil in our country are:
