Indian Soil

Soil is the mixture of rock debris and organic materials which develop on the earth’s surface. The major factors affecting the formation of soil are relief, parent material, climate, vegetation and other life-forms and time. Besides these, human activities also influence it to a large extent.

Components of the soil are mineral particles, humus, water and air. The actual amount of each of these depend upon the type of soil.

Some soils are deficient in one or more of these, while there are some others that have varied combinations.

India has varied relief features, landforms, climatic realms and vegetation types. These have contributed in the development of various types of soils in India.

On the basis of genesis, colour, composition and location, the soils of India have been classified into :

1. Alluvial soils
2. Black soils
3. Red and Yellow soils
4. Laterite soils
5. Arid soils
6. Saline soils
7. Peaty soils
8. Forest soils.

Alluvial Soils

Alluvial soils are widespread in the northern plains and the river valleys.

These soils cover about 40 per cent of the total area of the country.

The alluvial soils vary in nature from sandy loam to clay.

They are generally rich in potash but poor in phosphorous.

In the Upper and Middle Ganga plain, two different types of alluvial soils have developed, viz. Khadar and Bhangar.

Alluvial soils are intensively cultivated.

Black Soils

Black soil covers most of the Deccan Plateau which includes parts of Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh and some parts of Tamil Nadu.

These soils are also known as the ‘Regur Soil’ or the ‘Black Cotton Soil’.

The black soils are generally clayey, deep and impermeable.

They swell and become sticky when wet and shrink when dried. So, during the dry season, these soil develop wide cracks.

Thus, there occurs a kind of ‘self ploughing’.

Red and Yellow Soils

Red soil develops on crystalline igneous rocks in areas of low rainfall in the eastern and southern part of the Deccan Plateau.

Along the piedmont zone of the Western Ghat, long stretch of area is occupied by red loamy soil.

Yellow and red soils are also found in parts of Odisha and Chattisgarh and in the southern parts of the middle Ganga plain.

The soil develops a reddish colour due to a wide diffusion of iron in crystalline and metamorphic rocks. It looks yellow when it occurs in a hydrated form.

Laterite Soils

Laterite has been derived from the Latin word ‘Later’ which means brick.

The laterite soils develop in areas with high temperature and high rainfall. These are the result of intense leaching due to tropical rains.

Arid Soils

Arid soils range from red to brown in colour.

They are generally sandy in structure and saline in nature.

In some areas, the salt content is so high that common salt is obtained by evaporating the saline water.

Due to the dry climate, high temperature and accelerated evaporation, they lack moisture and humus.

Saline Soils

They are also known as Usara soils.

Saline soils contain a larger proportion of sodium, potassium and magnesium, and thus, they are infertile, and do not support any vegetative growth.

They have more salts, largely because of dry climate and poor drainage.

They occur in arid and semi-arid regions, and in waterlogged and swampy areas.

Peaty Soils

They are found in the areas of heavy rainfall and high humidity, where there is a good growth of vegetation.

Thus, large quantity of dead organic matter accumulates in these areas, and this gives a rich humus and organic content to the soil.

Organic matter in these soils may go even up to 40-50 per cent.

These soils are normally heavy and black in colour.

Forest Soils

As the name suggests, forest soils are formed in the forest areas where sufficient rainfall is available.

The soils vary in structure and texture depending on the mountain environment where they are formed.

They are loamy and silty on valley sides and coarse-grained in the upper slopes.

In the snow-bound areas of the Himalayas, they experience denudation, and are acidic with low humus content.

Classification of Indian Soils