Why black soil is suitable for the cultivation of cotton ?
Because of their clayey nature, black soil is much required for growing cotton. Cotton cultivation requires high moisture retention. Black soils are very fine grained and dark, contain a high proportion of calcium and magnesium carbonates and highly argillaceous. When wet, they are very tenacious of moisture and exceedingly sticky. They have a high abundance of iron and fairly high quantities of lime, magnesia and alumina. Black soils are poor in nitrogen, phosphorus and organic matter. The soils are generally rich in the montmorillonitic and beidellitic group of clay minerals. It is most suitable for the growth of cotton. It is also known or cotton soil as a reason. It is found in the lava plateaus and the Deccan trap that includes plateaus of Maharashtra, Saurashtra, Malwa, Madhya Pradesh and Chattishgarh and extend in the South-East direction along the Godavari and Krishna valleys. This is because it is deep and clayey and it swells when it is wet and contracts when dry. Therefore it develops wide cracks during the summer.
Black soils are typical pedogenic features over volcanic rocks. In India black soils are found in an irregularly triangular shaped region covering Deccan. 70 million years ago there were huge volcanic eruptions taking place in the North-Western part of Indian plateau and lava spread North-West to South-East direction covering a huge area. Over these region, the rocks are gradually degraded and black soil formed. The soil is famous for its cotton growing capacity. Conducive conditions for such cultivation is its moisture retaining capacity and extensive fertile layers along its profile. The soil is clayey in nature and rich in soil nutrients like calcium, carbonate, magnesium, potash and lime. It is mainly known as black cotton soil because this soil is most suitable for the cotton crop. Along with cotton, the soil is suitable for the cultivation of crops like groundnut, wheat, tobacco, chillies, and jowar.