Some of the steps we can take to control soil erosion are as follows:
Soil erosion can be controlled by adopting land management practices and also by changing the pattern of some human activities which accelerate soil erosion.
(i) Contour farming:
Contour farming may be defined as ploughing, seeding, cultivating and harvesting across the slope, rather than with it.
Thomas Jefferson, who wrote in 1813, “we now plough horizontally, following the curvature of the hills …. Every furrow thus acts as a reservoir to … retain waters … scarcely an ounce of soil is now carried off.”
(ii) Strip cropping:
On land with a dissected slope, planting crops on contour strips will be an effective erosion deterrent. For effective control the width of the contour strip should vary inversely with the length of the slope. Strip cropping should be combined with crop rotation, so that a strip planted to a soil depleting, erosion-facilitating corn crop one year will be sown to a soil-enriching and protecting strip of legumes the next year.
The practice of terracing has been common in ancient China. The flat, step-like bench terraces are now not useful. The modern terrace is an embankment of earth constructed across a slope in such a way as to control water run-off and minimise erosion. To be effective, terrace must check water flow before it affairs sufficient velocity to loosen and transport soil.
(iv) Gully reclamation:
Gullies are danger signals that indicate that land is eroding rapidly and may become a wasteland as in the case of vast areas along the rivers Chambal and Yamuna. If a gully is small, it may be ploughed in and then seeded to quick growing crop like barley, maize, jowar and wheat in order to check erosion.
In case of severe gullying, small check dams of manure and straw constructed at 5 metre distance may be effective, because silt will collect behind the dams and gradually fill in the channel. Earthen, stone and even concrete dams may be built along the gully. Once dams have been constructed and water run-off has been restrained, soil may be stabilised.
(v) Shelter belts:
These are the ‘green belts’ of trees which help to break the force of strong winds and thus prevent or cut to a minimum the blowing away of the loose topsoil. In areas where wind erosion is more, rows of trees may be helpful to check the flow of winds. Apart from this, these trees will also add colour to the landscape and help to control the desert spread.
Soil blowing away can also be controlled if local shrubs and small trees planted in a systematic way.
Even useful trees can be planted and harvested after a regular interval of two to three years. Other methods of soil conservation are:
(i) Expansion of vegetative cover and protective afforestation,
(ii) controlled grazing,
(iii) Flood control,
(iv) Prohibition of shifting cultivation,
(v) Proper land utilisation,
(vi) Maintenance of soil fertility,
(vii) Land reforms, reclamation of wasteland,
(viii) Establishment of soil research institute and training of soil scientists, and
(ix) Effective agencies for soil management.