Tag: soil and crops

Laterite is a soil layer, that is rich in iron oxide and derived from a wide variety of rocks weathering under strongly oxidizing and leaching conditions. It forms in tropical and subtropical regions, where the climate is humid. When the velocity of running water decreases the heaviest particles are deposited on a riverbed. The finest particles (gravel, silt, sand, and clay) are deposited at the mouth of the river, forming a delta made of alluvial soil. 

Alluvial soils are most extensive soil. It is formed due to deposition of the rivers brought down from the upper course of the river. It is found on the combined plain land of the Indus and the Ganga-Brahmaputra rivers which includes Punjab, Haryana, U.P., Bihar and West Bengal. The deltaic alluvium is found in deltas of the Ganga-Brahmaputra, Godavari, Mahanadhi and Kaveri rivers. The coastal alluvium is found in coastal sides of Peninsular India - called riverine soils it is originally found in river basins.

Dead plants and animals are degraded in soil by decomposing bacteria and fungi. The material formed after this decomposition activity is called humus. Humus is very rich in nutrients and black in color. Hence topsoil is the darkest. Greater the amount of humus more is the soil productivity. Thus the correct answer is option A.

Deep black soil has a high proportion of clay and humus and high retentivity of moisture and thus are very productive for cultivation of important crops like cotton, wheat, jowar, linseed, castor, sunflower, millets, rice and sugarcane.

Black soil is the fertile soil present in India. It is abundantly found in Haryana, Maharashtra and Uttar Pradesh. The black colour of the soil is due to the presence of iron, aluminium and humus. This type of soil is most suitable for the cultivation of grains, vegetables and cotton.

Red soil is a mixture of loamy and yellow soils. Its red colour is due to the presence of abundant iron oxide. About two-thirds of Tamil Nadu has Red soil.It is suitable for the cultivation of tobacco, vegetables and paddy. Black soil is the fertile soil present in India. It is abundantly found in Haryana, Maharashtra and Uttar Pradesh. The black colour of the soil is due to the presence of iron, aluminium and humus. This type of soil is most suitable for the cultivation of grains, vegetables and cotton

Laterites are formed by leaching of parent sedimentary rocks. They  are rich in Al and Fe and are found in wet and hot tropical areas. The color of the soil is rusty red due to high Fe content.