Details of soil types
Basically, the classification of soils is done on the basis of the colour, clay content and the sandy particles present in them.
Red soils, occupying about 65 percent of our land area, are formed from granites, gneisses and Dharwars as a result of variations in the mineralogical composition, relief and topography. Red soils are not so fertile but are present in almost all districts of our state. The two major crops grown in this soil are groundnuts and horsegram. There are six sub-groups, namely red sandy soils (8 per cent), red earths with loamy sub-soils (30 per cent), red earths with clay subsoil (3 per cent), red loamy soils (9 per cent), deep red loamy soils (3 per cent) and red soils with clay base (12 per cent).
Black soils, which account for 25 per cent of the land area, are also formed from granites, gneisses and Dharwars. These are moderately deep to very deep, calcareous as well as non-calcareous, fine and heavy in texture, neutral to strongly alkaline, generally poorly drained, and poor in nitrogen and phosphorous contents. Cotton is the main crop grown in these soils. Tobacco, turmeric and other cash crops are also grown.
The alluvial soils are marine and riverine deposits occupying five per cent of our state area. These are very deep, medium to fine textured, neutral to alkaline and highly fertile soils. Actually, alluvial soils are formed where river deposition has taken place. These soils are found in the Krishna and Godavari delta areas where rice, sugarcane and fruit gardens are grown.
Coastal sands are formed from sandstones and quartzites and are deep, coarse (sandy) textures, neutral and have low fertility.
Laterite and lateritic soils which occupy one per cent of our state area,
are deep to very deep, medium to fine textured, acidic, well drained but
poor in fertility. Laterite soils are formed where there is a great amount
of heat and humidity. Coconuts, beetlenuts, fruits and pulses are grown
in these soils. Problem soils namely saline, saline alkali and alkali
soils constitute about one per cent, occuring mainly along the sea coast
vagus and are interspersed with black, red and alluvial soils.
To sum up, Coastal sandy, Deltaic alluvial, Black-cotton, Red clayey, loamy, sandy soils cover the coastal districts. Red soils with clay base predominate in Srikakulam, Visakhapatnam and Godavari districts. Black cotton soils are the common type in Krishna and Guntur districts. Red earth with loamy sub-soils and red sandy and loamy soils cover Prakasam and Nellore districts. Lateritic soils are present in Medak, Srikakulam, East Godavari, Chittoor and Nellore districts. Red earths with loamy sub-soils cover about 60 per cent of the Telangana region and occupy the whole of Nalgonda District, major part of Mahaboobnagar, Warangal, Karimnagar and Nizamabad districts. Red sandy soils characterise the Hyderabad, Ranga Reddy, Medak and Mahaboobnagar districts. Black cotton soils are common in Adilabad and Nizamabad districts. They are also present along the western fringes of Telangana regions.
In Rayalaseema region, black cotton soils occur in Cuddapah, Kurnool and Anantapur districts. Red loamy soils occupy Chittoor and Cuddapah districts. The predominant soil type is red earth in Anantapur district. Red earth and sandy soils are also present in parts of Kurnool district. The eastern peripheries of the Rayalaseema region are marked by the presence of ferrous soils which also occur in localised patches throughout the region.