Soils of India

Soils of India are not the same everywhere. It was recognized back from earlier times about the characteristics of different types of soils, and modern classification has been made a few centuries back.

What is Soil?

Soil can be simply defined as a mixture of small rock particles/debris and organic materials/ humus which develop on the earth surface and support growth of plants.

In India, the Indian Council of Agricultural Research (ICAR) has analyzed soils and classified them into eight different types.

Major classification of Indian soils

Alluvial Soil
Black Cotton Soil
Red Soil
Laterite Soil
Mountainous or Forest Soils
Arid or Desert Soil
Saline and Alkaline Soil
Peaty, and Marshy Soil/Bog Soil

This classification scheme is based on constitutional characteristics – colour and the resource significance of the soils.

Alluvial Soils

Alluvial soil, which is the most widely spread and important soil, forms the entire northern plains.
The deposition of these soils has been carried out by three important Himalayan river systems – the Indus, the Ganga, and the Brahmaputra.
These soils also extend in Rajasthan and Gujarat through a narrow corridor.
The eastern coastal plains, particularly the deltas of the Mahanadi, the Godavari, the Krishna, and the Kaveri rivers, also host the presence of alluvial soil.
The alluvial soil consists of various proportions of sand, silt and clay.
Alluvial soils as a whole are very fertile.
Intensive cultivation and dense population are characteristics of regions with alluvial soils, primarily due to their high fertility.
Soils in the drier areas are more alkaline and can be productive after proper treatment and irrigation.

Black Soil

These soils are black in colour and are also known as regur soils.
Black soil is ideal for growing cotton and is also known as black cotton soil.
This type of soil typically characterizes the Deccan trap (Basalt) region, which spreads over the northwest Deccan plateau and consists of lava flows.
They cover the plateaus of Maharashtra, Saurashtra, Malwa, Madhya Pradesh and Chhattisgarh and extend in the south east direction along the Godavari and the Krishna valleys.
The black soils are made up of extremely fine i.e. clayey material.
They are well-known for their capacity to hold moisture.
poor in phosphoric contents.

Red and Yellow Soil

Red soil emerges on crystalline igneous rocks in regions of moderate rainfall in the easterly and southerly sections of the Deccan Plateau.
Some sectors of Odisha and Chattisgarh, as well as the southern parts of the central Ganga plain, also observe the presence of yellow and red soils.
They are generally inadequate in nitrogen, phosphorus, and humus.

Laterite Soil

The laterite soils develop in areas with high temperatures and high rainfall.
Humus content of the soil is remove fast by bacteria that thrive well in high temperatures.
These soils are deficient in organic matter, nitrogen, phosphate, and calcium, while iron oxide and potash are in surplus amounts. Hence, laterites are not proper for cultivation.
Red laterite soils in Tamil Nadu, Andhra Pradesh, and Kerala are more fitting for tree crops like cashew nuts.
Laterite soils are extensively cut as bricks for usage in house development.
These soils have principally evolved in the higher regions of the Peninsular plateau.
Karnataka, Kerala, Tamil Nadu, Madhya Pradesh, and the mountainous stretches of Odisha and Assam generally host the presence of laterite soils.

Arid Soil

Arid soils vary from red to brown in color.
They are commonly sandy in composition and saline in nature.
Nitrogen is lacking and the phosphate content is average.
The growing calcium content downwards fills the lower horizons of the soil with ‘kankar’ bands.

Forest Soil

Forest soils are developed in forest areas where ample rainfall is available.
They are loamy and silty on valley sides and grainy on the higher inclines.
In the snow-isolated areas of the Himalayas, they encounter denudation and are acidic with low humus content.
The soils observed in the lower valleys are rich.

Peaty Soil

Areas with abundant rainfall and unusual humidity, where there is a healthy growth of vegetation, exhibit the presence of peaty soils.
Thus, a large quantity of dead organic matter accumulates in these areas, and this gives rich humus and organic content to the soil.
The northern part of Bihar, the southern part of Uttaranchal, and the waterfront areas of West Bengal, Orissa, and Tamil Nadu extensively host the presence of laterite soils.

Soils of India