Soils in India
For this, a vast country like India, which has a wide variety of land, rock, climate and natural vegetation, presents a large variety of soils. Soils form the uppermost layer of the earth’s crust. They are the loose rock material containing the remains of plants and animals. This organic matter present in the soil is known as humus. Soil serves as a source of food and moisture for plants. The nature and quality of soil largely depend upon a number of factors. Important among them are: (i) rock from which Soil is derived, (ii) relief of the land, (iii) natural vegetation and climatic conditions which are associated with soils.
Classification of Indian Soils
The Indian Agriculture Research Institute has divided the soils of the country into 27 types according to their colour, texture, mineral matter and retentive capacity of moisture.
However, for the convenience of the discussion, the Soils in India are classified here into the following 11 categories:
1. Alluvial Soils:
The alluvial soil is found in the northern plains of India. It covers nearly 45 per cent of the total land of the country.
Nature of the Soil: The soil is fine grained and is formed of sediments brought down by rivers. It contains humus and fine clay; hence, it is very fertile. Relatively new alluvium is found in the flood plains and deltas. It is locally known as Khadar and is most fertile. Soils which are relatively old and coarse are known as bangar. They lie on the upper side of the river valleys. These are relatively less fertile than Khadar soils.
Influence on Agriculture: Alluvial soil is very productive. Abundant of wheat, sugarcane, oilseeds, pulses, rice and jute is grown on this soil.
2. Regur Soils or Black Soils:
They are common in the Deccan Trap region. These soils are mainly found in Maharashtra, and parts of Gujarat, Madhya Pradesh, Andhra Pradesh and Karnataka. As they are most suited for raising cotton crops, they are known as Black-Cotton Soils. Locally, they are known as Regur Soils.
Nature of the soil: They are made up of volcanic rocks or lava flows. These soils are clayey and contain mineral substances. They retain moisture for a long period.
Influence of Agriculture: They are able to retain water. Crops grow without much irrigation. These soils are fertile and suitable for the production of cotton, jowar, sugarcane, wheat and groundnut. Green skinned bananas grow here in abundance.
3. Red Soils:
Very large parts of the peninsular India, particularly in the states of Tamil Nadu, Andhra Pradesh, Karnataka and Orissa are covered with red soils.
Nature of the soil: These soils have a mixture of sand and clay. They are red in colour as they contain a great proportion of iron oxides. They are deficient in nitrogen, phosphoric acid and humus, but are rich in potash and lime.
Influence on Agriculture: They are relatively less fertile, but are capable of growing good crops with the help of irrigation and fertilizers. Rice, wheat, millet, gram, pulses, sugarcane, oilseeds and cotton are cultivated on these Soils.
4. Laterite Soils:
The laterite soils are found in patches here and there. They occupy the slopes of the mountains of peninsula, in the Vindhyas, the Eastern Ghats, the southern portion of Western Ghats and parts of Chotanagpur, Karnataka and Tamil Nadu.
Nature of the Soil: The word ‘laterite’ comes from a Latin word ‘Later’ which means brick; in fact, these soils look like dust of red bricks. They are red in colour and coarse with a high content of iron-oxides. They are rich in iron, but deficient in lime and nitrogen. These soils are infertile as they cannot retain moisture.
Influence on Agriculture: They are unsuitable for agriculture. Some plants like the cashew can thrive on lateritic soils. Root crops like tapioca also do reasonably well on these soils.
5. Coastal Alluvial Soils:
These Coastal Alluvial soils are found along the east and west of India.
Nature of the soil: These soils are sandy than clayey. They are saline in nature due to oceanic influence.
Influence of Agriculture: They are fertile. Rice and coconut are grown abundantly on these soils.
6. Deltaic Soils:
The Deltaic soils are found on the deltas of the Ganga, Mahanadi, Godavari, Krishna and Kaveri of the east coast and in parts of Rann of Kachchh on the west coast.
Nature of the soil: These muddy soils are saline in nature due to influence of ocean water. They are composed of fine grained sand, clay and other sediments.
Influence on Agriculture: Agriculture is not suitable on these soils as they are too much saline. However, in some areas where salinity of the soil is reduced by protecting the land from saline tide water by building up dams, agriculture can successfully carried be on. Rice, maize and other crops are grown on these soils.
7. Desert Soils:
The Desert soils are found in Rajasthan deserts, the southern parts of the Punjab and Rann of Katchch.
Nature of the soil: These soils contain coarse brown sands and are very porous. They have heavy amount of soluble salt and mineral matters. These soils have low nitrogen and humus content. The soils are formed due to scarcity of rainfall.
Influence on Agriculture: These soils are not suitable for agriculture due to scanty rainfall; however, agriculture can be carried on with the help of irrigation. Bajra, wheat, groundnut can be grown on these soils.
8. Tarai Soils:
These soils are found on the foot-hill regions of the Himalayas in India.
Nature of the Soil: These soils are composed of gravels and coarse grained sand. They are popularly known as ‘bhabar’.
Influence on Agriculture: Tarai forest covers this region. Recently the forest has been cleared for cultivation and rice, sugarcane and soybean are produced on this soil.
9. Mountain forest Soils:
These soils are found on the Himalayan mountain. These soils are of various types such as Brown soils, Podzols, etc.
Nature of the Soil: These soils are made of rock boulders and clay. They are rich in humus and are acidic. The remains of the leaves of trees enrich the soil with humus.
Brown soils are very fertile while the Podzol soils are less fertile and acidic in nature. . They are found in forests of Oaks.
Influence on Agriculture: They are fertile and suitable for cultivation of potatoes, rice, wheat, fruits and tea. Oak trees are good for the growth of Oak trees. Potato and barley grows in Podzolic soil.
10. Alpine Grassland Soils:
These soils are found on higher altitudes of the Himalayas where alpine grasses grow.
Nature of the Soil: These soils are acidic and are of medium fertility.
Influence of Agriculture: On these soils barley, maize, potatoes and wheat are grown.
11. Glacial Soils:
The Glacial Soils soils are found on high altitudes of the Himalayas.
Nature of the soil: They are formed by the glacial deposits and contain boulders, gravels and clay. They lack in humus and are infertile. These soils form terraces in high altitudes.
Influence on Agriculture: Generally, no cultivation is done here. In some few patches barley and potatoes are grown.