Various methods have been practised to check soil erosion and to improve soil fertility. Methods by which soil is prevented from being eroded constitute what is known as soil conservation.
In order to reverse the process of land degradation and resource depletion, appropriate soil conservation measures are to be adopted for bringing more areas under crops, forests and grasses.
All methods of soil conservation aim at reducing the amount and velocity of surface runoff and of the erodability of the soil. Some of the important measures usually adopted are as follows:-
1. Agronomic methods
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These method are employed in protecting the top-soil by special method and scheme of crop cultivation. They include-
(a) Rotation of crops.
(b) Contour farming.
(c) Strip farming.
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2. Mechanical methods
They include contour terracing, under which a series of properly spaced ridges and drainage channels are formed along contours by construction of suitable mounds of earth.
Apart from this, various types of artificial channels (ditches) are exacavated at suitable locations for the removal of excess water from approaching the field. Also, dams are constructed for checking the velocity of water.
3. Change in land use pattern
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It consists of growing suitable crops in place of low yielding crop and in making best utilization of the land by putting it to the use for which it is best fitted.
4. Common methods
(a) Since vegetation cover protects the soil from erosional processes more effectively, these methods mainly aim at creation of protective surface through afforestation and reforestation, Both these methods are quite effective more specifically on slopes where trees retard the surface runoff and bind the soil.
(b) Cultivation of soil binding crop
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Crop like Peas, Jowar, Bajra, gram and other legumes and fodder plants like guar, alfafa, clover, berseem should be encouraged while erosion inducing and soil depleting crops such as tobacco, cotton, potato, maize etc. should not be cultivated on the eroded land.
(c) Control of shifting cultivation through the following ways-
(i) Reclaiming land and providing irrigation and other inputs and services so as to encourage settled cultivation.
(ii) Identifying areas suitable for plantation crops.
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(v) Development of grass lands and areas for supporting animal husbandry programmes, and agricultural operations as well as commercial forest plantation.
(d) Control on the grazing of animals
Over-grazing causes a picking of the soil. Therefore preventive measures should be adopted to check the intensive grazing of an area, particularly on the slopes. Fencing of worst affected areas may also be tried.
(e) Flood control measures
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Soil erosion, as we know, is particularly severe where heavy rainfall and steep sloping ground favour the rapid loss of any soil exposed by agriculture. Construction of embankments etc also protects the land from being eroded.
(f) Reclammation of ravine lands
Small channels are made on the terraces for safely carrying the runoff water downwards into big ravines. It is accomplished by placing a series of terraces across the slope, one below the other.
To prevent wind erosion, shelter belts of trees are to be planted to check the force of the wind. Ploughing of land at right angles to the direction of wind further serves to prevent wind erosion.
All the above methods are useful in the process of soil conservation.