Soil Erosion and Degradation: Types, Causes, and Prevention- Frontier IAS
mobile-whatsapp-img
9817390373,8295688244
Baljit Dhaka
hcs prelims testseries image
hcs prelims mains testseries image
HCS Mains test series
upsc ias image
upsc ias image
upsc ias image

Soil Erosion and Degradation: Types, Causes, and Prevention

Validity: 9 Months
What you will get
Course Highlights
  • Based on latest Pattern
  • English Medium eBooks
Click to Bookmark
GEOGRAPHY

Soil Erosion and Degradation: Types, Causes, and Prevention

Geography for Civil Services

What are soil erosion and soil degradation? Although soil erosion is a natural process, human activities over the past decades have greatly accelerated it. In fact, according to the UNESCO, land degradation is undermining the well-being of two-fifths of humanity, driving species extinct and intensifying climate change. 

Problems of Indian soils:

  • Soil degradation
  • Soil erosion
  • Deficiency infertility
  • Desertification
  • Waterlogging
  • Salinity and alkalinity
  • Wasteland

Soil degradation:

  • Soil degradation is the decline in soil quality caused by its improper use, usually for agricultural, pastoral, industrial, or urban purposes.
  • Soil degradation is the main factor leading to the depleting soil resource base in India. 
  • The degree of soil degradation varies from place to place according to the topography, wind velocity, and amount of rainfall.

Soil erosion:

  • Soil erosion is the removal of topsoil (which has most of the nutrients necessary for a plant’s growth) by agents like wind and water.
  • Over-dependence on agriculture and improper land management is also the leading cause.
  • Wind and water are powerful agents of soil erosion because of their ability to remove soil and transport it.

i. Soil erosion by Water:

  • Water erosion takes place mainly in the form of sheet and gully erosion.
  • When the entire top sheet of soil is washed away by heavy rainwater, leaving behind a barren rock, it is called sheet erosion. 
  • Sheet erosion attacks a large area of topsoil and renders the land almost unfit for cultivation.

  • Gully erosion is the removal of soil along drainage lines by surface water runoff. 
  • Gully erosion is common on steep slopes. 
  • Gullies deepen with rainfall, cut the agricultural lands into small fragments, and make them unfit for cultivation.
  • When a gully bed is eroded further, the bed gradually deepens and flattens out and a ravine is formed like in the Chambal basin.

ii. Soil erosion by Wind:

  • Wind erosion or Aeolian erosion is quite significant in arid and semi-arid regions.
  • Winds usually blow at high speeds in deserts due to the absence of trees.
  • Suspension, saltation, and surface creep are the three types of soil movement which occur during wind erosion. 
  • While soil can be blown away at virtually any height, the majority (over 93%) of soil movement takes place at or below one meter.

Factors affecting Soil Erosion:

  • Intensity and duration of rainfall
  • Wind speed
  • Nature of soil and the physiography
  •  Strong winds in dry areas
  • Deforestation
  • Overgrazing
  • Faulty methods of agriculture
  • Diversion of natural drainage courses
  • The wrong orientation of roads and railways, embankments and bridges.

Effects of Soil Erosion:

  • Erosion of fertile topsoil.
  • Loss of mineral nutrients because of flooding and leaching.
  • Lowering of Groundwater level
  • Decrease in soil moisture.      
  •  Increased frequency and intensity of floods and drought.
  •  Rivers, canals, and tanks are silted and their water holding capacity decreases.

soil conservation:

  • Soil conservation is the prevention of soil from erosion or reduced fertility caused by overuse, acidification, salinization, or other chemical soil contamination.

Some methods of soil conservations are:

  1. Afforestation,
  2. Checking Overgrazing
  3. Constructing dams
  4. Changing agricultural practices

Methods of soil Conservation:

1. Afforestation:

  • prevention of forest destruction along with growing new forests or increase the area under forests.
  • By stopping indiscriminate felling of trees.

2. Checking Overgrazing:

  • By creating separate grazing grounds and producing larger quantities of fodder.
  • By educating villagers about the consequences.

3. Constructing dams:         

  • Dam construction checks the speed of water and saves soil from erosion.
  • But indiscriminate dam construction can worsen the condition by creating floods and landslides like it happens in the Himalayan region.

4. Changing agricultural practices:

  • Crop rotation
  • Strip cropping
  • Contour Ploughing
  • Terracing and contour bunding
  • Mulching
  • Checking Shifting cultivation

1. Crop rotation:

  • Crop rotation is a practice in which a different crop is cultivated on a piece of land each year.
  • Sowing the same crop leads to exhaustion of certain nutrients in the soil making it infertile.
  • Crop rotation helps to conserve soil fertility as different crops require different nutrients from the soil.

2. Strip Cropping:

  • Crops are cultivated in alternate strips, parallel to one another. Some strips may be allowed to lie fallow while in others different crops may be sown.
  • Various crops are harvested at different intervals. This ensures that at no time of the year the entire area is left bare or exposed.
  •  The tall-growing crops act as windbreaks and the strips which are often parallel to the contours help in increasing water absorption by the soil by slowing down runoff.

3. Contour Ploughing

  • If ploughing is done at right angles to the hill slope, following the natural contours of the hill, the ridges and furrows break the flow of water down the hill.
  • This prevents excessive soil loss as gullies are less likely to develop and also reduce run-off so that plants receive more water.

4. Terracing and Contour bunding

  • In terracing, a number of terraces are cut along the hill slope.
  • These are made on steep slopes so that flat surfaces are available to grow crops. They can reduce surface run-off and soil erosion.
  • Contour bunding involves the construction of banks along the contours.
  • Terracing and contour bunding divide the hill slope into numerous small slopes, check the flow of water, promote absorption of water by soil and save soil from erosion.

5. Mulching

  • The bare ground (topsoil) between plants is covered with a protective layer of organic matter like grass clippings, straw, etc.
  • Protects the soil from erosion.
  • It helps to retain soil moisture.
  • Reduces compaction from the impact of heavy rains.
  • Conserves moisture, reducing the need for frequent watering.

6. Checking Shifting cultivation

  • Checking and reducing shifting cultivation by persuading the tribal people to switch over to settled agriculture is a very effective method of soil conservation.
  • This can be done by making arrangements for their resettlement which involves the provision of residential accommodation, agricultural implements, seeds, manures, cattle, and reclaimed land.

Way forward:

  • Integrated land-use planning seems to be the best technique for proper soil conservation. 
  • Lands should be classified according to their capability. 
  • land use maps should be prepared and lands should be put to the right uses.
  • The final responsibility for achieving the conservation of land will rest on the people who operate on it and receive the benefits.