Soil is one of the most important natural resources. Soil supports the growth of plants. Soil is the natural home of many living organism, such as ants, rats, snakes, and many insects.
Formation of Soil: It takes thousands of years to form even 1 cm of soil. Soil is formed by the weathering process of the rocks. Various natural forces, such as temperature, running water, wind, etc. along with many physical and chemical changes are equally important in the formation of soil formation.
Types of Soil:
Following types of soil are found in India.
Availability: Alluvial soil is found near the river or plains formed by rivers. Alluvial soil is found in the plains of major rivers such as Ganga, Yamuna and Brahmaputra. It is also found in the eastern coastal plains near the rivers Mahanadi, Krishna Godavari and Cauveri.
Nature: Alluvial soil is young in age, i.e. of recent origin. Alluvial soil is very fertile. Alluvial soil is the mixture of various proportions of silt, sand and clay. The older alluvial soil is called Bangar and newer one is called Khadar. Bangar has plenty of fine particles while Khadar has more amount of coarse grains. Alluvial soil is rich in potash, phosphoric acid and lime. Because of presence of these chemicals alluvial soil is good for the growth of sugarcane, paddy, wheat, maize, and pulses.
Map Taken From NCERT Text Book Class 10 Geography
Availability: Black soil is found in the plateau of Maharashtra, Surashtra, Malwa, Madhya Pradesh and Chhattisgarh.
Nature: Black soil has high concentration of fine particles. Due to this, it can hold moisture for long time. It contains calcium, potassium, magnesium and lime. Black soil is suitable for the growth of cotton.
Red and Yellow Soil
The soil looks red due to presence of iron in crystalline or metamorphic rocks. But it looks yellow when it occurs in dehydrated form. Red soil is present in the eastern and southern parts of the Deccan Plateau. Red soil is also found in Orissa, Chhattisgarh, on the southern part of the Gangetic plains and along the piedomont zone of the Western Ghats.
Laterite soil is formed in regions which get high rainfall with high temperature. High rainfall along with high temperature results in leaching of the soil. Microorganisms are killed during the process of leaching. So, humus is either absent or in negligible amount in laterite soil. This soil is mainly found in Kerala, Karnataka, Tamil Nadu, Madhya Pradesh and in hilly areas of Orissa and Assam. Heavy dose of manure can help in making this soil cultivable.
Arid soil is found in those areas which receive scanty rainfall. The soil has a high content of salt. Arid soil can be made cultivable with proper treatment. Arid soil is present in Rajasthan and Gujarat.
The forest soil is found in hilly areas. The soil in upper parts is highly acidic because of denudation. The soil in the lower part is highly fertile.
Soil Erosion and Soil Conservation
Removal of top soil is called soil erosion. Intense farming, grazing, construction activities and other human activities; along with deforestation have led to soil erosion. Soil erosion can even lead to desertification.
Soil conservation is important to prevent soil erosion. Soil conservation can be done by many methods, e.g. afforestation, terrace farming, shelter belt planting, etc.