What are types of soil in India?
All types of soil in India display a wide diversity because of the variation in the climate, relief and vegetation. Soil is the thin surface layer on the earth composed of mineral and organic matter supporting the growth of plants. Soils in India display wide diversity because of the variation in geology, climate, relief and vegetation. On the basis of genesis, color, composition and location, the Indian council of Agricultural Research (ICAR) has classified the type of soil in India into the following 8 categories:
- Alluvial Soil
- Laterite Soil
- Black Soil
- Red Soil
- Red And Yellow
- Forest / mountain Soil
- Saline And Alkaline Soil
- Peaty / Organic Soil
Alluvial Soil In India
- Alluvial Soil is a major constituent of types of soil in India. This is the most important soil group of India.
- These are the most productive soils and are depositional in nature as they are transported by streams and rivers. They are largely sandy and loamy in texture and are mixed with both silt and clay.
- They are sufficient in Phosphorus and Potasium, but lack nitrogen and organic matter. These alluvial soils are divided into Bangar (old alluviam) and Khadar (new alluviam).
- Most of the alluvial soils are created by the sediments deposited by the rivers of Indo-Gangetic Plains. Some alluvial soils in the coastal areas are formed by the sea waves.
- They are immature soils with weak profiles (AZONAL). Their chemical composition makes this group of soils as one of the most fertile in the world.
Occurrence: From the Great Indo- Gangetic Plain starting from the Punjab in the West to West Bengal and Assam in the East. They also occur in the deltas of Mahanadi. Godavari, Krishna and Cauvery. Some alluvial soils are found in Narmada and Tapi valleys. Parts in north Gujarat also have some cover of alluvial soils.
The alluvial soils are divided geologically into
(i) Bhangar (old alluvium) and Khadar (new alluvium)
(ii) Bhabbar (in the foothills of Shivaliks)
(iii) Tarai (in the foothills of Shivalik)
Their chemical composition makes Highly productive soils devoted to the cultivation of wheat, rice, pulses, sugarcane, jute, oil seeds, fodder, vegetables and orchards.
Black Soil In India
- These are the typical soils developed on the basaltic rocks of the Deccan plateau.
- The region includes Maharashtra, South and East Gujarat, Western M.P., Northern Karnataka, Northern Andhra Pradesh, North East Tamil Nadu, South East Rajasthan etc. It spreads over 5 lakh km2 area, and is known as ‘Rugur’ or ‘Black Soil’.
- Regur Soil varies in colour from black to chestnut brown. This soil is rich in iron, lime and aluminium content , and has high moisture retentive capacity.
- This soil lack nitrogen, phosphorus and organic matter. These are finely grained and become sticky when wet and develop cracks when dry.
- Apart from cotton crops like groundnut tobacco sugarcane, pulses and oil seeds are also grown in this soil. This soil is also suitable for growing these commodities because of its high moisture retentive capacity.
Red Soil In India
- These soils have been formed through the weathering of granite gneiss and shiest rocks.
- The colour is red, due to the presence of iron oxides.
- It is typically found in Tamil Nadu, Karnataka, Andhra Pradesh, Odhisha and Chhotangapur plateau of Jharkhand have large expanses of this soil.
- This soil lacks nitrogen, phosphorus and humus. It is mainly suitable for the cultivation of coarse grains pulses, tobacco, millets, potatoes and fruits and oil seeds.
Laterite Soil In India
- These are typical soils of the tropical regions with heavy seasonal rainfall alternating with dry season.
- Lime and silica are leached away with rains and soils rich in iron oxide and aluminium compounds are left behind. The organic matter nitrogen, phosphate and calcium are low in these soils.
- At some places, phosphate content and humus may be high. They are found in eastern and western Ghats, Rajmahal hills, parts of Kerala and Karnataka, parts of Chhotanagpur, Meghalaya plateau and Assam .
- The soil is generally of low fertility in which only coarse grains, pulses and oil seeds can be cultivated.
- When irrigated, some laterites are suitable for growing plantation crops like tea, coffee, rubber and coconut etc.
- These soils have a unique distinction of providing valuable building material. Laterite means brick color.
Forest Soil / Mountain Soils
- Formed in the forest and hilly areas with sufficient rainfall. This soil is found mainly in the Himalayan region, Western Ghats, Eastern Ghats and hilly regions of Peninsular India.
- They are rich in humus but deficient in potash, phosphorous and lime. If treated with fertilizers, they are especially suitable for plantations of tea, coffee, spices and tropical fruits in Karnataka, Tamil Nadu and Kerala and wheat, maize, barley and temperate fruits in Jammu and Kashmir and Himachal Pradesh.
- The problem of soil erosion is getting acute in regions having this soil due to deforestation and other developmental activities.
- They are mainly found in Rajasthan, southern Punjab and Haryana and northern Gujarat.
- Being sandy, the water retaining capacity of these soils is low.
- These soils are rich in phosphate and poor in humus content. Wherever irrigation is available, they are devoted to cotton and wheat.
- Millets, maize and pulses are the main crops grown in them.
- Due to dry climate, high temperature and accelerated evaporation there is always a paucity water.
- Thus, these soils lack moisture and humus content. Iron and phosphorus content is normal. Being sandy, the water retaining capacity of these soils is low.
- They are found in west Rajasthan, Southern Punjab and Haryana and north Gujarat.
- With irrigation these soils can be better utilized for cultivation.
Saline And Alkaline Soil In India
- Also known as ‘Usara’ soils, they contain a larger proportion of sodium, potassium and magnesium.
- They occur in arid and semiarid regions and water logged and swampy areas. They acquire salts largely because of dry climate and poor drainage. Infertile soils are formed due to capillary action.
- In some places they are also known as reh, kallar, usar, thur, karl, chopan.
- They are found on southern Punjab and Haryana, west Rajasthan, Kerala coast, Sunderban area etc. This is the least found category among all types of soil in India.
Peaty Soil / Organic Soil
- They are found in the area of heavy rainfall where there is a good grown of vegetation, hence rich in humus and organic content.
- This type of soiloccurs in the northern Bihar, southern Uttaranchal ( Almora district) and coastal areas of west Bengal, Orissa, Kottayam and Alapuha districts of Kerela and parts of Tamil Nadu.
- After the rainy season the regions under this soil is put to paddy cultivation.
Soil Survey Of India
Established in 1958 under Ministry of Agriculture, Government of India, All India Soil & Land Use Survey (renamed as Soil & Land Use Survey of India), is a premier institution in the field of soil survey and land resource mapping in the country. Soil and land survey is conducted for testing ground conditions, doing ground investigation and in-situ testing of soils. The information gathered in a soil survey can be used to predict or estimate the potentials and limitations and behaviours of the soils under different circumstances and their potential uses.
Thus soil surveys can be used to plan the development of new lands or to evaluate the conversion of land to new uses. There are 3 primary types of soil surveys namely – (a) Detailed survey (b) Reconnaissance survey, and (c) Detailed-reconnaissance survey. As soil quality cannot be directly measured, some evaluation indicators are used to determine its quality. These indicators provide clues about how well the soil can function. Indicators can be physical, chemical, and biological characteristics. Indicators can be assessed by qualitative or quantitative techniques. On the basis of these indicators soils can be classified into 4 types – sandy, loamy, silt and clay.