L-2 The Earth and the changes on it (Part-2) Class 7th D.A.V
39This video is about the formation of soil and the types of soil
Soil is made up up of organic and inorganic particles. The organic particles are derived from dead remains of plants and animals. THese particles gets decomposed and change into a dark colored material called humus. The humus present in the soil contributes the fertility of soil.
The inorganic particles are derived from rocks. The large sized particles called gravel while the smaller ones are called sand, silt and clay. These are called sandy, loamy and clayey soils.
Formation of soil:- It is very slow process takes thousands of years to form a thin layer of soil. The weathering process breaks the rocks into small particles. These are then carried away by water, wind etc and later get deposited at a nree place. Such soil is called a transported soil. But when the soil is formed by the weathering of the parent rock and remains present on the same site, it is called residual soil. The soil forming process continues over long span of time. They start developing in layers one over the other. These layers are called horizons. From bottom to top the lowest horizon is called Bed rock, then comes the horizons weathered rock and it is followed by sub soil and top soil. The topmost horizon is rich in Humus.
Distribution of major soil types:-
Alluvial soil:- It is found in Northern and coastel plains. This type of soil is very fertile and used for agriculture.
Black soil:- It is found in Deccan Plateau and some parts of Gujarat, maharashtra and Karnatka. It is largely used for growing cotton. So it also called as cotton soil.
Red Soil:- It is red due to the presence of Iron particles. It is found to the Peninsular India and some parts of North-East part of India.
Laterite soil:- It is found over the hill slopes of Peninsular Plateau. It is formed by the leaching process.
Apart of these four types there are desert and mountain soils.
Removal of top ;ayer of soil is known as soil erosion. Soil erosion needs to checked through appropriate major of soil conservation such as plantation of trees, crop rotation, muliple cropping method, developing and management of pasture land. We need mass awareness and adoption of these practices at local level.