[Biology Class Notes] on Soil Erosion Pdf for Exam

Soil Erosion is often defined because the situation when the soil particles are loosened or washed away within the oceans, rivers, valleys, streams, or lands distant. This erosion takes place and also becomes worse due to human activities like deforestation and agriculture. erosion is an ongoing process that takes place either slowly or at an alarming rate. It results in endless erosion of topsoil, ecological degradation, soil collapse, etc.

What are the Causes of Soil Erosion?

Following are the important causes of soil erosion:

Rainfall and Flooding

High levels of rainstorms are the main reasons for soil erosion. Four sorts of soil erosion that are caused by rainfall are:

• Rill Erosion: Rill erosion is a form of erosion that produces little streams with distinct boundaries. It occurs when rainwater does not sink into the soil but instead flows across it. When water flowing over the surface of the ground collects in a natural depression in the soil, erosion is intensified as the water runs through the depression, forming rolls or narrow channels (typically just 30cm deep).

• Gully Erosion: Gully erosion is the removal of soil along drainage lines by surface water runoff. Unless steps are taken to stabilise the disturbance, gullies will continue to move by headward erosion or by slumping of the side walls. It’s far easier and more economical to do repair work in the early stages of newly formed gullies. Large gullies that have been left unchecked are difficult and costly to repair.

• Sheet Erosion: Sheet erosion causes considerable soil loss in both cultivated and non-cultivated situations, although being difficult to detect. Sheet erosion occurs when a shallow ‘sheet’ of water flows across the ground surface, causing a uniform layer of soil to be removed from the surface. Sheet erosion causes considerable soil loss in both cultivated and non-cultivated situations, although being difficult to detect. Sheet erosion occurs when a shallow’sheet’ of water flows across the ground surface, causing a uniform layer of soil to be removed from the surface.

• Splash Erosion: The initial step of erosion is splash erosion, also known as raindrop impact. The bombardment of the soil surface by rain droplets causes splash erosion. When rain droplets fall on exposed or naked soil, they act like small bombs, shifting soil particles and disrupting soil structure. According to studies conducted in the United States, splattered particles can rise up to 0.6 metres above the ground and travel up to 1.5 metres horizontally. Splash erosion causes the creation of surface crusts, which inhibit infiltration and cause runoff to begin.

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

Soil erosion of any kind may be a concern in agriculture because it results in the loss of topsoil, which holds the majority of the nutrients required to grow crops. This soil is home to a variety of creatures that interact with the minerals in the rocks to form productive soil. Erosion, in whatever form, means the removal of rich soil from the top layer.

Agriculture

The farming practices are the main reasons for soil erosion. The agricultural activities disturb the bottom layer. The trees are cleared and therefore the land is ploughed to sow new seeds. Since most of the crops are grown during the spring season, the land becomes unfertile during winters. Also, the tyres of tractors make grooves on the land making a natural pathway for water making it easy for the soil particles to erode easily. 

Grazing

The grazing animals prey on the grasses and take away the vegetation from the land. Their hooves disgust the soil. They also pull out plants by their roots. This loosens the soil and makes it more vulnerable to erosion.

Logging and Mining

A large number of trees are hampered to carry out the logging process. Trees hold the soil firmly. The shade of the trees protects the soil from getting eroded because of heavy rainfall. The leaf litter that protects the soil from erosion is almost lost during logging. Mining activities also disturb the land and leave the soil more vulnerable 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 susceptible to erosion.

Rivers and Streams

The flowing rivers and streams take away the soil particles that deduct the V-shaped erosion activity.

Heavy Winds

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

Effects of Erosion of Soil 

The major effects of soil erosion include:

Loss of Arable Land

Soil erosion washes the highest layer of the soil. This layer is rich with essential nutrients required by the plants and also the soil. The degraded soil doesn’t support crop production and resulted in low crop productivity.

Clogging of Waterways

The agricultural soil contains pesticides, insecticides, fertilizers, and a variety of other chemicals. This contaminates the water bodies where the soil flows. The sediments accumulate within the water and lift the water levels leading to flooding.

Air Pollution

The dust particles merge within the air resulting in pollution by a number of the toxic substances just like the pesticides and petroleum are often extremely hazardous when inhaled. 

Desertification

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

Destruction of Infrastructure

The piling up of soil sediments in dams and along the banks can reduce their efficiency. Thus it affects infrastructural projects like dams, embankments, and drainage.

Soil Erosion Prevention

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

1. Plant trees on unfruitful lands to limit erosion of soil.

2. Add mulch and rocks to prevent the plants and grass underneath to prevent erosion .

3. Mulch matting usually won’t reduce erosion on the slopes.

4. A wall at the rock bottom of the slope can help in preventing the soil from eroding.

5. Every household should have an accurate waste management system in order that water flows down into proper water collecting systems.

Key Points of Erosion

• It is the natural action of erosion of the topsoil, but human activities have accelerated the method .

• It is usually caused thanks to the removal of vegetation, or any activity that renders the bottom dry.

• Farming, grazing, mining, construction and recreational activities are a variety of causes of erosion .

• The effects of erosion aren’t just land degradation. It’s led to a drastic increase in pollution and sedimentation in rivers that clogs the water bodies resulting in a decline within the population of aquatic organisms.

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