Define soil erosion. Give its causes, effects and preventive measures.
Soil erosion is a method of removing and transporting the top layer of soil from its original place to some other place under the effect of strong winds and fast running water.
Following are the causes of soil erosion:
(i) Strong winds
(ii) Heavy rains
(iii) Improper farming and suspended cultivation
Following are the effects of soil erosion:
(i) It leads to the loss of soil fertility and desertification.
(ii) It causes landslides in hilly areas.
(iii) It leads to famines in areas, making them unfit for the cultivation of crops.
Following are the means of preventing soil erosion:
(i) Intensive cropping- In this method, soil is totally covered with crops and is not exposed to winds and rains.
(ii) Terrace farming- In this method, a large number of flat fields slow down the flow of water.
(iii) Contour bunding- Small dikes or bunds are raised on the edges of fields to prevent the loss of soil.
(iv) Conservation tillage- Herein, reduced or no tillage is practised, which prevents soil erosion.
(v) Wind breaks- Rows of trees and shrubs are planted at right angle to the direction of the prevailing wind flow to check erosion by wind.
(vi) Drainage canals around field- Excess water is removed through small drainage canals built around the field.
(vii) Strong embankments along river banks- Strong embankments made of stones or sand bags along the sides of a river check soil erosion by fast-moving river water.