List of top eleven types of soil found in India:- 1. Red Soils 2. Laterite and Lateritic Soils 3. Black Soils 4. Alluvial Soils 5. Desert Soils 6. Saline and Alkaline Soils 7. Peaty and Marshy Soils 8. Tarai Soils 9. Brown Hill Soils 10. Sub-Montane Soils 11. Mountain Meadow Soils.
1. Red Soils:
Red colour in red soils is due to the presence of various oxides of iron. They are either formed in situ or from the products of decomposition of rocks washed to lower level. They include soils locally known as red sandy soil and red alluvium. They are mostly formed under sub-humid climate from a number of rock formations like granite, shales etc.
Their main features are light texture, porous structure, absence of lime and low soluble salts. They are generally poor in fertility constituents such as nitrogen, phosphoric acid, potash and lime and are highly deficient in organic matter. They have a low base exchange capacity, and the colloidal complex is base saturated.
They are slightly acidic to neutral in reaction, the pH ranging from 6.0 to 7.5. The characteristic clay mineral is kaolinite. Area of red soils are whole of Madras and Mysore, part of Andhra Pradesh, M.P., Orissa and Jharkhand (Chotanagpur), Birbhum (W. Bengal), SanthalPargana (Jharkhand), Mirzapur, Jhanfei and Hamirpur districts of U.P. and eastern half of Rajasthan. The most of the red soils have been classed in the order Alfisols.
2. Laterite and Lateritic Soils:
They are found mostly in areas of high rainfall. They are light in texture and have an open free-draining structure. There is no retention of water. There is practically no horizon differentiation in the soil profile. They are deficient in lime and are slightly to moderately acid in reaction. The pH varies from 5.0 to 6.0. They are low in base exchange capacity.
Laterite soils formed at high levels have a pale red colour are highly gravely and are poor in all fertility constituents. These formed at low levels have a darker colour probably due to a great accumulation of humus, a slightly finer texture and are quite well-drained. These soils are found all along the west coast of Maharashtra, Mysore and Kerala, on tops of hills in the Deccan, Madhya Pradesh and in Orissa along the Eastern Ghat.
3. Black Soils:
The black soil developed from Basaltic rock under semi-arid conditions. The soils are black or dark brown in colour. They include soils locally known as regur or black cotton soil, deep black soil, medium black soil. The colour varies considerably, alluvium soil of Narbada and Tapti are blackish-brown. Their texture ranges from sandy loam to heavy clay. Some black soils may be porous and others may be compact and impervious.
One of the characteristic features of black soil is that it swells on wetting during the rainy season and shrinks and cracks in summer. The base exchange capacity of deep black soil is quite high (50 to 75 meq per cent). The pH varies from 7.5 to 8.5. The soils are on the whole low in fertility. The soils are deficient in nitrogen and phosphorus. They are rich in potash and lime. The black soils are found in parts of Maharashtra, Gujarat, M.P., Rajasthan, U.P., A.P., Madras and Mysore.
4. Alluvial Soils:
They are characterised by extreme depth and grey or greyish- brown colour. Their texture varies from sandy loam to clay loam. The structure is also variable, loose and free-draining in the case of sandy soils and compact and impervious in clayey soils.
In immature alluvial soils, there is no distinct horizon differentiation. These soils are most fertile, they are deficient in nitrogen, phosphorus and humus but are well-supplied with lime. Their base exchange capacity is comparatively low. The pH varies from 7.0 to 8.0
They are very extensive in area and cover large parts of Rajasthan, Punjab, U.P., Bihar and West Bengal and extend even into west Assam and north Gujarat. The soils developed in the western parts of the Indo-Gangetic plains are, however, markedly different from those in the eastern region.
5. Desert Soils:
They have developed in arid regions mostly under the influence of physical weathering. They are mainly sandy. They contain large amount of soluble salts and varying proportions of lime. They have a high pH and are very poor in fertility constituents.
Desert soils are found in large parts of Rajasthan, south Punjab and in the dry range of Kutch. The temperature regime is very high throughout the year. The rainfall ranges from 50 cm to less than 10 cm.
6. Saline and Alkaline Soils:
These soils are developed in arid and semi-arid regions. Basin shaped topography (poor drainage) is also responsible for their development. They are mainly found in the black soil region in the south and west, in the Indo-Gangetic alluvium in the north and in the deltaic and coastal regions all along the west and east coast.
7. Peaty and Marshy Soils:
They are formed in depression under submerged conditions and have acquired a blue colour due to the presence of ferrous iron. Peaty soils are found scattered in Kerala, north Bihar and north Uttar Pradesh and have developed in humid regions as a result of the accumulation of large quantities of organic matter.
8. Tarai Soils:
Tarai soils have a wet regime and high water table conditions for most part of the year. Tarai soils are foothill soils and extend in strips of varying widths at the foot of the Himalayas in Jammu and Kashmir, U.P., Jharkhand and West Bengal. Soils under the natural conditions are thickly vegetated and swampy.
Several types of grasses and trees from the native vegetation, on removal of which the soils become highly productive. The soils were derived from the materials washed down by the erosion of mountains. The parent materials are of alluvial sediments and consist of hard clay.
9. Brown Hill Soils:
These soils are formed on the hills under forests. They are mainly found in the Himalayas on sandstones and shales. The surface soils are dark brown loam to silty clay in texture, acidic to neutral in reaction. These soils may be classified in order Alfisols.
10. Sub-Montane Soils:
These soils are formed in high rainfall regions of sub- Himalayan under coniferous forests. The soils are acidic in reaction. The organic matter accumulation is high and there is absence of free lime.
11. Mountain Meadow Soils:
These soils occur at high elevation in the Himalayas. The soils are shallow with grass vegetation.
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