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SOIL

Soil is the loose material found on the surface of the earth. It is made of organic and inorganic particles. The organic particles are derived from dead remains of plants and animals. In the course of time, these particles get decomposed and change into a dark coloured material called humus. The humus present in the soil contributes to the fertility of the land. This is rapidly formed in humid areas due to heavy growth of plants and rich animal life. However, humus is low in desert soil.

The inorganic particles are derived from rocks. They include loose disintegrated particles of different sizes. The large sized particles are called gravel, while the smaller ones are called sand, silt and clay. A mixture of these particles gives rise to different types of soil as per their proportion. These are called sandy, loamy and clayey soils.

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