SOIL EROSION – HOW IT OCCURS, ITS TYPES AND EFFECTS

Soil erosion is the removal of fertile top layer of soil by wind, rain and water. Soil erosion leads to loss of fertility of land and makes it unsuitable for farming.

Soil is one of the most valuable natural resources of earth. Soil supports roots of plants and provides them nutrients. Thus, soil is the foundation of all life on earth. We must therefore, preserve it.

CAUSES OF SOIL EROSION

RUNNING WATER

Heavy rain and running water washes away the top soil and causes soil erosion. This is more prominent in hilly areas. Washed off soil from hills accumulate over plains and can result in change in course of rivers.

WIND

Strong winds carry away top soil with it. Areas devoid of plants are more prone to soil erosion by wind.

DEFORESTATION

Cutting down of trees and plants loosens the top soil which can be easily carried away by wind or running water.

OVERGRAZING

Overgrazing by cattle makes soil loose so that it gets removed by agents like water and wind.

PLOUGHING ON HILL SIDE

Soil over hills is more vulnerable to soil erosion being on slope.

TYPES OF SOIL EROSION

SPLASH / RAINDROP EROSION

The erosion caused by drops of falling rain on soil surface.

SHEET EROSION

It is the uniform removal of top soil caused by blowing wind.

RILL EROSION

This is the most common form of soil erosion. It occurs during heavy rain through hill cuts and streamlets.

GULLY EROSION

It occurs due to runoff of surface water along drainage lines.

STREAM BANK EROSION

It is the washing away of soil from banks of rivers and streams.

EFFECTS OF SOIL EROSION

LOSS OF SOIL FERTILITY

When soil gets eroded by wind or water, the essential organic matter and humus gets washed away. making the soil less productive for farming.

DAMAGE TO CROP

Decreased fertility of soil hinders crop and plant growth.

WATER POLLUTION

The eroded soil that enters rivers, lakes and streams contaminates the water with chemicals and pesticides. This can harm aquatic plants and animals.

AIR POLLUTION

Dust particles are blown away by wind which causes air pollution.

INCREASED FLOODING

Accumulated soil sediments in river beds raises water levels increasing risk of floods.

POOR DRAINAGE

Soil deposits can block drainage systems.

METHODS TO PREVENT SOIL EROSION

• Afforestation
• Growing cover crops like grass and creepers
• Cutting hill slopes into steps
• Building embankments along river banks
• Covering bare soil with pebbles or wood
• Leaving crop residue on surface (conservation tillage)
• Prevent overgrazing
• Contour farming – ploughing along natural elevation lines of a slope rather than straight up and straight down.
• Crop rotation