INDIAN SOILS- Notes

 

INDIAN SOILS

Meaning and Importance : Soil is the thin surface layer of the earth comprising of closely intermixed mineral and organic substances. It is a very important natural resource of India, because agriculture is the main occupation of the people. Agricultural production is basically dependent on the fertility of the soil. Soil formation of India is mainly related to the parent rock, relief, climate and natural vegetation. So there is a wide variety of soils in India. Types of Soils : Soils of India can be classified into six main types : 1. Alluvial soil, 2. Black soil. 3. Red soil. 4. Laterite soil. 5. Desert soil and 6. Mountain soil. 1. Alluvial soil : The soil that are composed of alluvium are called alluvial soil. They are formed from the sediments deposited by the rivers as in the Indo-Gangetic plain and by the sea waves in coastal plain. Alluvial soil the very extensive and very important in India. They contribute greatly to the development of agriculture in the country. They cover an area of about 15 lakh km2. The main crops grown on this type of soils are wheat, paddy, sugarcane, cotton, jute, potato, and vegetables.

 

2. Black soils : This soil is also known as ‘Regur’ and black cotton soil as they are best suited for cotton cultivation. They are derived from the basalt rock. So they are dark grey to black in colour, with high clay content. They are highly retentive of moisture and extremely compact. They are best suited for the cultivation of cotton, sugarcane, jowar, maize, pulses, wheat, and chillies. Black soils are largely found in the Deccan basalt trap region including Maharashtra, Madhya Pradesh, Parts of Telangana, Northern part of Karnataka, parts of Gujarat and Tamil Nadu. They occupy about 5.46 lakh km2 in India. 3. Red soils : They are formed from the weathering of granite, gneiss and other crystalline rocks. The colour of these soils is generally red or redish brown. They are more sandy and less clayey. So, they do not retain moisture. They cover a vast area of about 5.2 lakh km2. These soils are spread extensively in Tamil Nadu. They are also found in Southern Karnataka. Parts of Maharashtra, Madhya Pradesh, Odisha, Kerala, Goa, Bihar, Uttar Pradesh, Assam, Manipur, Nagaland, West Bengal etc. Red soils are ideal for the cultivation of ragi, millets, groundnuts, tobacco and potato. A variety of crops can grown in these soils if there are irrigation facilities

4. Laterite Soils : These soils are formed in tropical areas under the conditions of high temperature and rainfall. These soils are cover an area of 2.48 lakh km2. They are mainly found in the uplands of Western Ghats, Eastern Ghats, the Chotanagpur plateau, Meghalaya plateau, the Rajmahal hills, Vindhyas and Satpuras. They are leached soils, not fertile and are of limited use for agriculture. Crops like cashew, rubber, tea, coffee and paddy can be grown in this soils.

5. Desert Soils : These soils are formed under desert and semi desert, conditions. They are largely found and in the north-western part of India. ie. A major parts of Rajasthan, southern Haryana, Punjab and the northern part of Gujarat. They are fairly friable, have a high content of soluble salt. They are sandy and low in moisture and humus. These are not suitable for the cultivation of many crops. Some crops can be grown where irrigation facilities are available. They occupy about 1.42lakh km2. 6. Mountain Soils : These soils are mainly found on the slopes of mountains and hills covered by forests. They are mostly formed due to the decomposition of organic matter. Hence they are rich in humus and are fertile. They are useful for plantation crops. eg. tea, coffee and fruits. They are largely found in Jammu and Kashmir, Himachal Pradesh, Manipur states and along the Western Ghats. These soils cover an area of 2.85 lakh km2. Soil Erosion Soil erosion refers to the removal of top soil by natural agents. The rivers, glaciers, winds, sea waves etc. remove the top layer of fertile soil and deflete the fertility of the soil. Soil erosion is one of the important problems in India. Causes of soil erosion :

The main causes of soil erosion are : a) deforestation, b) overgrazing, c) shifting cultivation, d) faulty methods of cultivation, e) use of top soil for making bricks, tiles etc., Effects of soil erosion : The important effects of soil erosion are : i) Loss of soil fertility and fall in agricultural productivity. ii) It leads to silting and floods, change of the course of rivers, and reduction of capacity of the reservoirs. iii) Ground water level is lowered and there is decrease in soil moisture. iv) Vegetation covers dries up and drought increase. v) Economy as a whole suffers a great set back.

Conservation of soil : Protection of soil from erosion and preservation of fertility of the soil is called ‘soil conservation’. Several measures are adopted for conserving soil. They are: 1) Afforestation and reforestation. 2) Controlled over grazing. 3. Contour farming. 4. Construction of check dams. 5. Contour bunding. 6. Gully control and bench terracing. There is an urgent need to conserve soil under the five year plans much importance given for this aspect.