Soil erosion and its Conservation
Soil erosion
Soil erosion is a gradual process that occurs when the impact of water or wind detaches and removes soil particles, causing the soil to deteriorate. Soil deterioration and low water quality due to erosion
Soil Erosion by Water:
Raindrop erosion
They are like tiny particles that falls on exposed soil, displaces soil particles, and destroys the structure of the soil.
Sheet erosion
This is the type of erosion that results from the runoff that spreads across the surface of the soil, which means when the rate of infiltration has been exceeded during rainfall.
The detachment and transportation of soil particles from the surface by flowing rainwater are called sheet erosion.
Rill erosion
Rill erosion is caused by the concentrated flow of water in small rivulets. Here, finger-like rills appear on the cultivated land after it has undergone sheet erosion.
Over a period of time, these rills start getting more wider and deeper.
Gully Erosion
When Rills increase in size, they are called Gullies. It is deeper and has wider cuts. Gullies further if kept unchecked become more entrenched and thus deep gullies which are known as Ravines.
Soil Erosion by Wind
Soil erosion due to the wind is very common in areas where there is a lack of natural vegetation. It occurs mainly in dry and arid regions along the sandy shores of oceans, lakes and rivers.
The soil particles after getting loose are blown and carried away by the wind in the following ways:
Siltation
Drainage is poor and high temperatures prevail in the arid regions of low rainfall resulting in evaporation of water leaving behind the salts.
Salt accumulation occurs mostly in lowlands around the oceans that are mainly composed of chlorides, sulfates, carbonates, and nitrates.
Suspension
The smaller soil particles are suspended in the air and move like a fine crust with the wind and are transported long distances.
Surface creep
The heavier particles of soil that are not easily thrown up by wind are simply pushed or spread along the surface by the wind
Impacts of Soil Erosion:
Fertility of topsoil will be lost.
Nutrient content will decline as they are washed away by erosion.
Underground water level will be reduced.
Loss of vegetation and habitat.
Drought and floods become frequent.
Rivers get dried off.
Adversely affect the economy and culture.
Natural hideouts are formed when gully erosion occurs
Soil Conservation
It is the prevention of soil from erosion or reduced fertility caused by overuse, acidification, salinization or other chemical soil contamination. Soil erosion is the greatest threat to Indian agriculture and animal husbandry.
Some of the soil conservation Methods are:
Afforestation
Crop Rotation
Building Dams
Contour Planning
Reduced Overgrazing
Mulching
Contour barriers
Terrace farming
1. Afforestation
It is the prevention of forest destruction along with growing new forests or increasing area under forests.
A minimum area of 20 to 25 percent of forest land is considered healthy for soil and water conservation for the whole country.
2. Crop Rotation
Sustainable agricultural practices adoption is the most important measure which helps to conserve soil.
Under Crop rotation, different crops are cultivated on a piece of land each year which helps in the conservation of soil fertility as different crops require different nutrients from the soil and provide enough time to restore lost nutrients.
3. Building Dams
Soil erosion by river floods can be avoided by constructing dams across the rivers at proper places.
4. Contour Planning
Under this, the many banks along the contours are constructed which divide the hill slope into numerous small slopes to check the flow of water and promote absorption of water by soil thus prevent soil from erosion.
5. Reduce Overgrazing
During the dry period when there is a shortage of fodder, the grass is grazed to the ground and torn out to the roots by animals. All this leads to the weak top thus lead to soil erosion.
Thus, overgrazing needs to be checked to prevent soil erosion which can be done by creating separate grazing grounds and producing larger quantities of fodder for animals.
6. Mulching
The topsoil between plants is covered with a protective layer of organic matter like grass clippings, straw, etc. protects the soil from erosion and helps to retain soil moisture.
It helps to maintain soil temperature and prevents weed growth.