GROWING cotton. It is ALSO known as regur soils.Alluvial soilsIt a fine-grained FERTILE soil deposited by water flowing over flood plains or in river beds.Nitrogen is generally low, but POTASH, phosphoric acid, and alkalis are adequate.Black soilsThe black soil in India is rich in metals such as Iron, Magnesium, and Aluminium.It is deficient in Nitrogen, Potassium, Phosphorous, and Humus.Black soil is of red color mainly due to its iron oxide content.Laterite soilsLaterite is a soil and rock type rich in iron and aluminum and is commonly CONSIDERED to have formed in hot and wet tropical areas.Nearly all laterites are of rusty-red coloration, because of high iron oxide content.Laterite soils are rich in iron and aluminum but deficient in nitrogen and potassium.