Question

State two methods of controlling the erosion of soil caused by running water.

Answer 1

Hint: - These methods hold the top layer of soil tightly and thus prevent its erosion due to various eroding agents.
- The central government has been giving various incentives to the states which are following these methods to combat soil erosion and turn a badland into useful land.

Complete Answer:
Introduction: Soil erosion is a usual procedure in which the top layer of soil of any fallow is carried away by physical factors such as wind and water. It is a natural procedure of eroding the topsoil but nowadays human efforts have accelerated this process. Overuse of land for farming, mining and construction lead to an acceleration in soil erosion.

Causes of soil erosion -
1. Rainfall: Rainfall and water flow causes soil erosion. The water gets dispersed in the soil and weakens the bond of the top layer sand. It causes - gully erosion, sheet erosion, splash erosion, rill erosion.
2. Grazing: overgrazing of animals removes vegetation from land and churns up the roots and loosens the grip of roots of the soil.
3. Wind: During the dry weathers or in the semi-arid regions the winds carry the minute particles if the top layer of soil minute particles is carried away.

Two Methods of controlling soil erosion are -
1. Afforestation: Which involves the avoidance of the removal of trees, along with the cultivation of fresh forests or the expansion of forest areas. For soil and water protection, a minimum area of 20 to 25 percent of forest land has been deemed healthy for the entire country. In the second five-year plan, it was increased to 33 percent - 20 per cent for the plains and 60 per cent for hilly and mountainous areas.
2. Crops grown in strips: In alternating strips, parallel to each other, crops can be cultivated. Any strips may be permitted to lie fallow, whilst they may be sown in other distinct crops. At varying times different crops are harvested. This means that the whole region is not left bare or uncovered at any time of the year. The tall-growing crops serve as windbreaks, and by slowing down erosion, the strips that are always parallel to the contours tend to maximise water absorption by the soil.

- Other methods of controlling soil erosion are a check on shifting cultivation and overgrazing, to plough in the correct direction and intercropping etc.

Note: - Practice of shifting cultivation is named differently in different regions such as in Indonesia as Ladang, Central America and Mexico as Milpa, in Srilanka as Chena etc. It was very prevalent among the primitive people and even today a large chunk of people practice this. Along with being bad for the soil, this practice also pollutes the air.
- Because of the practice of afforestation, the forest cover of India raised to 22.67 percent of the total geographical area. In 2017 it was 21.54 percent.