In this article, you will know about the classification of soil found in India.
Classification of Soil in India
Based on its formation, classification of soil:
Sedimentary or Residual Soil: When soil is formed in its original position by fragmentation of the parent rock, it is called in situ or residual soil. This includes black soil, red soil, laterite soil, and desert soil.
Transported Soil: These soils are formed after being transported and deposited by various agents of erosion such as water and wind. This includes alluvial soil. The soil in India can be classified based on its texture, thickness, age, chemical, and physical properties.
- It is formed by the deposition of sediments brought down by the rivers. Very fine particles of soil called alluvium are deposited by the rivers in plains.
- It is also called riverine soil because it is mainly found in the river basins. It consists of sand, clay, and silt known as loam.
- It has been deposited by the three Himalayan river systems—the Ganga, the Indus, and the Brahmaputra. It is also found in deltas formed by rivers Mahanadi, Godavari, Krishna, and Kaveri.
- Alluvial soil is classified into two types—khadar and bhangar.
Characteristics of Alluvial Soil
- It is formed by the deposition of sediments by the rivers as it flows from its upper to its lower course.
- While in the upper plains of the river valleys, the soil is coarse; it has fine soil particles in the lower river valleys.
- While the alluvial soil is dry, porous, sandy, and faint yellow in the lower Ganga Valley, it becomes compact, less coarse, and moist in West Bengal and Bangladesh.
- It is fertile as it is rich in minerals such as lime and potash. It is suitable for the growth of Kharif and rabi crops.
- It is however deficient in nitrogen and humus. Only the alluvial soil of the Ganga delta is rich in humus.
- The alluvial soil is alkaline in drier areas.
This soil is also known as regur soil or black cotton soil (it is suitable for the growth of cotton). It is a residual soil as it is formed at the place of its origin.
Characteristics of Black Soil
- It is clayey and is finely textured soil.
- Because it is formed from weathered lava rocks, it is black.
- It has about 50% of clayey material and hence is highly water retentive.
- When the soil becomes wet, it expands making ploughing difficult. During the dry season, the black soil shrinks and develops cracks which help in air circulation.
- The soil is suitable for the cultivation of cotton, jowar, sugarcane, wheat, linseed, and gram. Besides, it is suitable for the growth of oilseeds, pulses, cereals, tobacco, and vegetables.
- Its subsoil has moisture content even during the rainy season.
Ancient crystalline and metamorphic rocks of the Peninsular Plateau fragmented to form the red soil. This soil differs from place to place on the basis of the parental rocks. They are red as they contain large amounts of iron oxide. It looks yellow when it occurs in a hydrated form.
Characteristics of Red Soil
- It is porous and contains large quantities of iron oxide.
- It is shallow, loose, and aerated.
- It is a deficit in nitrogen, phosphorus, potassium, and organic matter. Small quantities of soluble salt are present in it.
- Because it is not very fertile, fertilizers are added to it.
- The soil requires irrigation.
- Red soil is suitable for the cultivation of rice, ragi, tobacco, groundnut, and potatoes.
- It is formed because of the atmospheric weathering of rocks caused by high temperatures and high rainfall. This residual soil is formed by leaching because of tropical rains.
- Leaching is a process in which the nutrients of the soil percolate down into the soil because of heavy rainfall. This makes the topsoil infertile. This is also called desilication.
- There are two types of laterite soils—upland laterites and lowland laterites. The former is formed over hills and uplands. When these soils are transported by streams of rivers to lowlands, it is called lowland laterites.
Characteristics of Laterite Soil
- It is red because of the presence of iron oxide formed during leaching.
- It has a coarse texture and is porous.
- It is deficient in lime, magnesium, and nitrogen.
- It is not fertile as it does not retain moisture.
- It is acidic because of the leaching of alkalis.
The mountain soil is found in the hilly mountainous regions. This includes peat, meadow, forest, and hill soils.
It is sandy soil. It is formed because of weathering of rocks in the desert regions.
Saline and alkaline soils
It has a large number of salts and alkalis. It is formed when the tidal water accumulates in areas located near the coasts because of poor drainage.
This soil is found in waterlogged areas, especially in coastal regions or near the deltas. It contains iron and organic matter.
Classification of soil
Also, Read What is Soil Erosion?