How to prevent soil erosion Class 7

Table of Contents

Soil Erosion Definition

“Soil erosion is the natural process in which the topsoil of a field is carried away by physical sources such as wind and water.”

What is Soil Erosion?

In this process, the soil particles are loosened or washed away in the valleys, oceans, rivers, streams or far away lands. This has been worsening due to human activities such as agriculture and deforestation.

Soil erosion is a continuous process that occurs either slowly or at an alarming rate. It results in a continuous loss of topsoil, ecological degradation, soil collapse, etc.

Let us have a detailed look at the causes, effects and prevention of soil erosion.

Also Read: What is Soil?

Cause of Soil Erosion

Following are the important causes of soil erosion:

Rainfall and Flooding

Higher intensity of rainstorms is the main cause of soil erosion. Four types of soil erosion are caused by rainfall:

  • Rill erosion
  • Gully erosion
  • Sheet erosion
  • Splash erosion

The raindrops disperse the soil, which is then washed away into the nearby streams and rivers. Regions with very heavy and frequent rainfall face a large amount of soil loss. The flowing water during floods also erodes a lot of soil by creating potholes, rock-cut basins, etc.

Agriculture

The farming practices are the major cause of soil erosion. The agricultural activities disturb the ground. The trees are cleared and the land is ploughed to sow new seeds. Since most of the crops are grown during the spring season, the land lies fallow during winters. Most of the soil is eroded during winters.

Also, the tyres of tractors make grooves on the land, making a natural pathway for water. Fine soil particles are eroded by wind.

Grazing

The grazing animals feed on the grasses and remove the vegetation from the land. Their hooves churn up the soil. They also pull out plants by their roots. This loosens the soil and makes it more prone to erosion.

Logging and Mining

A large number of trees are cut down to carry out the logging process. Trees hold the soil firmly. The canopy of the trees protects the soil from heavy rainfall. The leaf litter that protects the soil from erosion, is also lost during logging.

Mining activities also disturb the land and leave the soil more prone to erosion.

Construction

The construction of roads and buildings exposes the soil to erosion. The forests and grasslands are cleared for construction purposes, which exposes the soil making it vulnerable to erosion.

Rivers and Streams

The flowing rivers and streams carry away the soil particles leading to a V-shaped erosion activity.

Heavy Winds

During dry weather or in the semi-arid regions, the minute soil particles are carried away by the wind to faraway lands. This degrades the soil and results in desertification.

Also Read: Types of Pollution

Effects of Soil Erosion

The major effects of soil erosion include:

Loss of Arable Land

Soil erosion removes the top fertile layer of the soil. This layer is rich in the essential nutrients required by the plants and the soil. The degraded soil does not support crop production and leads to low crop productivity.

Clogging of Waterways

The agricultural soil contains pesticides, insecticides, fertilizers, and several other chemicals. This pollutes the water bodies where the soil flows.

The sediments accumulate in the water and raise the water levels resulting in flooding.

Air Pollution

The dust particles merge in the air, resulting in air pollution. Some of the toxic substances such as pesticides and petroleum can be extremely hazardous when inhaled. The dust plumes from the arid and semi-arid regions cause widespread pollution when the winds move.

Desertification

Soil erosion is a major factor for desertification. It transforms the habitable regions into deserts. Deforestation and destructive use of land worsens the situation. This also leads to loss of biodiversity, degradation of the soil, and alteration in the ecosystem.

Destruction of Infrastructure

The accumulation of soil sediments in dams and along the banks can reduce their efficiency. Thus, it affects infrastructural projects such as dams, embankments, and drainage.

Also Read: Difference between erosion and weathering

Soil Erosion Prevention

Soil erosion is a serious environmental issue. Steps should be taken to curb this problem. Following are some of the methods of soil erosion prevention:

  1. Plant trees on barren lands to limit erosion of soil.
  2. Add mulch and rocks to prevent the plants and grass underneath to prevent soil erosion.
  3. Mulch matting can be used to reduce erosion on slopes.
  4. Put a series of fibre logs to prevent any water or soil from washing away.
  5. A wall at the base of the slope can help in preventing the soil from eroding.
  6. Every household should have a proper drainage system so that water flows down into proper water collecting systems.

Key Points of Soil Erosion

  • It is the natural process of wearing away topsoil, but human activities have accelerated the process.
  • It is usually caused due to the removal of vegetation, or any activity that renders the ground dry.
  • Farming, grazing, mining, construction and recreational activities are some of the causes of soil erosion.
  • The effects of soil erosion are not just land degradation. It has led to a drastic increase in pollution and sedimentation in rivers that clogs the water bodies resulting in a decline in the population of aquatic organisms.
  • Degraded lands lose the water holding capacity resulting in floods.

The health of the soil is of utmost importance to the farmers and the population that depends upon agriculture for food and employment. There are several challenges to resist soil erosion, but there are solutions to prevent it as well.

Also Read: Deforestation

To know more about soil erosion, its definition, causes, effects and prevention measures, keep visiting the BYJU’S website or download the BYJU’S app for further reference.

Soil erosion is the process of wearing away of the surface layer, or topsoil, by the transportation of the surface particles under the mechanical actions of agents like wind, river, or even glaciers.

Yes, soil erosion removes the fertile top layer of the soil. This exposes the hard rocky lower layers which are less fertile and have less humus, thus affecting the fertility of the soil.

The removal and transportation of the top layer of soil from its original position to another place, under the effect of strong winds and fast running rainwater is called soil erosion. Soil erosion can be prevented by :

  1. Intensive cropping
  2. Sowing grasses and planting xerophytes.
  3. Terrace farming.
  4. Contour bunding.

Top soil is the upper fertile biologically active layer of soil which is rich in minerals, organic matter, and microorganisms (bacteria, fungi, earthworms and other animals).

Question 1 What is meant by soil erosion?

Question 2 What are the causes of soil erosion?

Question 3 What are the effects of soil erosion?

Question 4 What is meant by soil pollution?

Question 5 How can soil pollution be prevented?

Question 6 How can soil erosion be prevented?

Soil Erosion

The removal of fertile top soil land by wind or water is called soil erosion.

Soil erosion occurs easily in those areas of land which are not covered by vegetation (trees and other plants) or have very little vegetation.

1) Due to the binding of soil particles by the roots of trees and plants, the blowing wind and flowing rainwater are not able to carry away top-soil and hence soil erosion does not occur. The soil not covered by vegetation (trees and other plants) is easily eroded because there are no roots of trees and plants in it which can bind the soil particles together and prevent them from being carried away by strong winds or flowing rainwater.

2) If there is vegetation (trees and other plants) on land, then much of the falling rain hits the trees and plants before it hits the soil. The cover of vegetation softens (or reduces) the effect of heavy rains on the soil. The soil does not become loose easily and the flowing rainwater is not able to carry away top-soil. Due to this, soil erosion does not occur. If there is no vegetation (trees and other plants) on land to soften the effect of heavy rains, the bare soil becomes loose quickly by the force of falling rainwater and erodes easily. This is because, being loose, it is easily carried away by flowing, rainwater or strong winds.

Cause of Soil Erosion

Soil erosion is caused mainly by the large scale cutting down of forest trees and other plants.(which is called deforestation).

A large number of forest trees are cut down everyday for obtaining wood for burning as fuel (firewood), for building purposes (timber) and for the manufacture of paper.

When the forest trees and other plants are cut down, then the top soil gets exposed and becomes loose because there are no roots to bind soil and no cover to soften the effect of falling rain. Blowing wind and flowing rainwater can then carry away this loose soil easily causing soil erosion.

Effects of Soil Erosion

The important effects of soil erosion are as follows:

1) Soil erosion can turn lush green forests into deserts and spoil the environment: When the fertile top-soil in a forest gets removed by soil erosion, then the infertile sub-soil is left behind. No forest plants can grow in this remaining infertile soil due to which the once lush green forest can gradually turn into a desert.

2) Soil erosion can lead to famines (excessive scarcity of food): When the fertile top-soil is removed by soil erosion, then the food crops do not grow well in the remaining infertile soil. And due to bad crops, there is an excessive shortage of food-grains in that area.

3) Soil erosion can cause floods: The soil carried away from land by the flowing rainwater gradually deposits on river beds (decreasing their depth). So. when it rains heavily, the river cannot take away all the rainwater quickly Due to this, river water overflows from its banks and causes severe floods by submerging surrounding areas.

Prevention of Soil Erosion

Soil erosion can be prevented in the following ways:

1) Soil erosion can be prevented by preventing large scale cutting down of forest trees. The large scale cutting down of forest trees is called deforestation. So soil erosion can be prevented by deforestation.

2) Soil erosion can be prevented by afforestation (large scale growing of forest trees in place of cut down trees).New trees should be planted in place of the cut down trees. And this tree cover will prevent soil erosion of the forest land.

3) Soil erosion can be prevented by increasing the green cover (vegetation) around us by planting more trees and plants ourselves.

Soil pollution

The contamination of soil with waste materials (especially used polythene bags and plastics), pesticides, fertilisers, acid rain and industrial chemical wastes, etc., is called soil pollution.

The various sources of soil pollution and their effects are as follows:

1) Dumping of waste materials (such as polythene bags plastics, glass and metal objects) causes soil pollution. Some waste materials (like paper and vegetable wastes) rot after some time and become harmless. But the waste materials such as polythene bags and other plastics (plastic bottles, etc.) do not rot on their own and remain as such indefinitely. They also kill the living organisms. The used glass and metal objects also do not rot in nature and cause soil pollution.

2) The use of pesticides in agriculture causes soil pollution: Pesticides are the poisonous chemical substances which are sprayed on standing crops to save them from the harmful insects and diseases. So, the grains, fruits and vegetables grown in this polluted soil contain pesticides. When we eat such contaminated grains, fruits or vegetables, the pesticides present in them enter our bodies and damage our health in the long run.

3) The excessive use of fertilisers in agriculture causes soil pollution:  Chemical fertilisers are added to soil in the fields to increase food production. The excessive use of chemical fertilisers makes the soil acidic or alkaline. When the soil becomes highly acidic or alkaline it is said to be polluted. This soil becomes unfit for the growth of crop plants.

4) Acid rain causes soil pollution: Acid rain makes the soil highly acidic. This acidic soil becomes toxic or poisonous) for plant growth. In this way, pollution caused by acid rain makes the soil less fertile.

5) Dumping of industrial wastes causes soil pollution: Many industries (or factories) dump their waste products containing harmful chemicals on soil. These chemicals cause soil pollution and harm plants which grow in it and the cattle which graze on it.

Prevention of Soil Pollution

The soil pollution can be prevented in the following ways :

(1) The use of polythene bags should be avoided to prevent soil pollution. This can be done by using bags made of paper, cloth or jute.

(2) Plastic objects should be sent to factories for recycling to prevent soil pollution. Discarded glass and metal objects can. also be recycled.

(3) The use of pesticides in agriculture should be minimised to reduce soil pollution.

(4) The use of excessive chemical fertilisers should be avoided in agriculture to prevent soil pollution.

(5) Steps should be taken to reduce the emission of acidic gases like sulphur dioxide and nitrogen oxides from factories which cause acid rain.

(6) The industrial chemical wastes should be treated properly to make them harmless before dumping into soil.