SOILS IN INDIA
The India council of agricultural Research has classified Soils in India into the following categories.
- Areas in the Indo-Gangetic Plain were formed by the periodic deposition of silt brought down by the rivers. Almost a quarter of the Indian soil is alluvial soil, which is very fertile. Alluvial soils are intensively cultivated and are conducive for the cultivation of a variety of crops, especially cereals and pulses. Besides these, commercial crops like cotton, sugarcane and jute are also grown.
- Alluvial soils are found in the Plains of Punjab, Haryana, Uttranchal, Uttar Pradesh, Bihar, Jharkhand and West Bengal as well as in the plains of Assam and the coastal strips of South India, along the river beds.
- Alluvial soils contain calcareous concretions (kankars) which have been traditionally used for whitewashing houses on the villagers of the plains, and now form a good source of raw material for the cement plants. In the upper and the middle Ganga plains, two different type of alluvial soils have developed, namely, khaddar and bhangar.
Khadar is a newer alluvium developed behind the leaves of the numerous streams flowing in this section of the Ganga plains. It is sandier and is susceptible to the annual floods, which enriches it by depositing fine silts.
Bhangar represents a system of older alluvium developed on the upper reaches of the streams where floods generally do not reach. They are dry soils.
BLACK SOILS( Soils in India )
Black soil is also known as regur. They are derived from two groups of rocks: the Deccan trap and the ferruginous gneiss and schist rocks. Black soils of Tamil Nadu have developed largely on the ferruginous rocks. These were formed by the deposition of lava ejected by the volcanoes several million years ago. These soils contain clay by minerals that are black in colour. They swell when wetted and shrink when dried. The land develops wide cracks during the dry season where loosened soil particles get accumulated. Thus, there occurs a kind of ‘self ploughing’. Because of this character of slow absorption and slow loss of moisture, blacks soils retain the moisture for a very long time, helping the crops, especially the rain-fed ones, to sustain even during the dry season. It is rich in minerals but poor in organic matter and retains moisture for longer period than the other soils. Black soils are suitable for growing cotton. It is found in Maharashtra, Gujarat, west Madhya Pradesh, Chhattisgarh, Andhra Pradesh and Tamil Nadu.
RED AND YELLOW SOIL
This soil is formed through the weathering of ancient metamorphic and crystalline rocks. It is a red in colour because of the high iron content. Very often, the surface layer is red and lower horizon yellow. The texture ranges from sandy to clayey with loamy being a common texture. Red and black soils are often adjacent to each other. Normally, red soils occurs in uplands and black soils in lowlands. It is good for the cultivation of pulses and coarse grains are also widely grown on these soils. Besides these, chillies and groundnut are also grown on this soil. It is found in Madhya Pradesh, Chhattisgarh, Orissa, Andhra Pradesh, Karnataka and north eastern hill states.
LATERITE SOIL( Soils In India )
Formed by the weathering of laterite rock, this is the typical soil of the tropical regions with heavy seasonal rainfall, which promotes leaching away the soil. With the rain, the lime and silica are leached away the soil rich in iron oxide and aluminium compounds are left behind. The humus content of this soil is removed fast by the bacteria that thrive well in a high temperature.
The low levels of organic matter, nitrogen, phosphate and calcium, and high levels of iron oxide and potash make it unsuitable for crop growth; however, with proper application of manure and fertilizers this soil can be made useful for crops like cashew nuts and tapioca are grown on this soil. The major application of laterite soil is for cutting bricks, for use in the construction of houses. It is found in the areas occupied by the Deccan, Andhra Pradesh, Eastern Ghats, Mysore, Tamil Nadu, Kerala, coast of Orissa and Meghalaya.
SALINE AND ALKALINE SOILS
Found in the dry tracts of the north, especially in Bihar, Uttar Pradesh, Punjab and Rajasthan. Rajasthan has the largest inland saline wetland in India. This type of soil is harmful to the crops. It is also known as Usar soil. This soil contains large proportions of sodium, potassium and magnesium, and thus, is poor and infertile. It acquires more salts because of the dry climate and poor drainage. Its structure ranges from sandy to loamy.
PEAT AND MARSHY SOILS
Found in Kerala, the coastal tracts of Orissa, the Sunderbans and some parts of Bengal, north Bihar and south-east Tamil Nadu, this soil is found in the areas of heavy rainfall and high humidity, where there is good growth of vegetation. A large amount of dead organic matter accumulates in these areas and this gives rich humus and organic content to the soil. These soils are normally heavy and black in colour and used for the cultivation of light and less soil exhaustive crops.
ARID SOIL (Desert Soil)
Desert soil is found in the arid regions that receive a poor water supply, such as western Rajasthan. The soil colour ranges from red to brown, and its texture is generally sandy and alkaline. In many areas, the salt content is so high that common salt can be obtained by simply evaporating the saline water. These soils are poor and contain less humus and organic matter. They are generally use in the cultivation of coarse grains like jowar, bajra, ragi and oilseeds.
FOREST SOIL( Soils In India )
The hilly areas of Assam, Uttar Pradesh, the sub-Himalayan tract and Coorg in Karnataka have this type of soil. It is formed by the deposition of organic matter derived from the forests. This soil varies in structure and texture, depending on the mountain environmental where it is formed. The soil is found in the lower valley is fertile and is used for the cultivation of rice and wheat.