Soil Erosion and Degradation

Mains Marks Booster     5th August 2023        
Samadhaan

Introduction

  • The erosion of the top layer of the soil which is also known as topsoil is referred to as soil erosion. Many variables influence the pace of soil erosion, including the composition of the soil, vegetation, the strength of wind and rain and anthropogenic factors.
  • Soil erosion can be a sluggish process that goes unnoticed for a long time, or it can happen quickly and cause a significant loss of topsoil. Soil loss on farms may result in diminished agricultural production potential, worse surface water quality, and impaired drainage systems. Sinkholes might also be caused by soil erosion. 

Causes

  • Natural and anthropogenic factors contribute to soil erosion in fields, including wind and water run-offs, as well as poor farming management. 

Natural Factors

  • Strong winds: Heavy winds remove dry microscopic soil particles, which is a common problem in semi-arid locations, leading to desertification.
  • Climate change: Abnormal rainfall or temperature swings devastate the field surface. Another consequence of climate change on soil erosion is reduced plant growth, which diminishes field cover and exposes it to rains and winds.
  • Rainfall and Flooding: Excessive rain washes away topsoil particles, while huge raindrops impact the field surface and damage it with forceful splashes. Running currents during floods are another source of soil erosion.
  • Wildfires: Water runoff is slowed by trees and plants. When forests or buffer zones are burned by wildfires, water streams have no impediments. 

Anthropogenic factors

  • Poor Farming Practices: Soil erosion is primarily caused by poor farm management practices such as excessive fertilization, conventional tillage, mono-cropping, and overgrazing.
  • Mono-cropping involves growing the same crop for multiple seasons, causing field depletion and soil erosion. Conventional tillage, such as moldboard plowing, can cause erosion in fields, while no-till farming prevents it.
  • Excessive use of mineral fertilizers can lead to dehumidification and destruction of soil structure, making it more vulnerable to erosive processes. Irrigation can also cause soil erosion, especially surface irrigation, which removes nutrients and topsoil particles from uneven fields due to gravity.
  • Overgrazing, a common issue, can destroy topsoil cover, but rotational grazing and cover crops can help. Terrace farming, on the other hand, prevents erosion by slowing down water streams on platforms.
  • Deforestation: Any tree felling, whether for wood or to expand agricultural fields for oil palm production, might hasten erosive processes. Clear-cutting, which involves removing all or most of the trees, exposes the forestlands the most. 

Impact of soil erosion

  • Agriculture: Heavy machinery and overgrazing contribute to field salinization, worsening water infiltration and erosion. Over time, eroded farmlands degrade, causing negative effects like depletion of topsoil, planting material, water pollution, and acidification.
  • Loss of biodiversity: Eroded lands cause vegetation decay, affecting flora and fauna, leading to ecosystem imbalance and loss of natural habitats, affecting both flora and fauna.
  • Clogging and pollution: Siltation and blockage of waterways are long-term impacts of soil erosion. In addition, eroded particles choke dams and water pumps. Water currents from fields frequently carry pollutants that are harmful to humans, animals, and the environment. They also contaminate drinking water.
  • Desertification: Desertification is largely caused by soil erosion. It turns the areas with a living environment into deserts. Additionally, this results in soil deterioration, biodiversity loss, and different ecological changes. 

Soil erosion prevention

  • Planting vegetation, including grass, trees, and shrubs, effectively prevents soil erosion by binding soil together, reducing raindrop and wind impact, and absorbing excess water, slowing runoff and allowing infiltration.
  • Applying layer of mulch protects soil from raindrops, reduces runoff, retains moisture, promotes healthier plant growth, and protects soil surface.
  • Efficient irrigation practices, like drip irrigation or precision sprinklers, minimize soil runoff, prevent erosion, and maintain stability by managing timing and avoiding over-irrigation.
  • Raising soil conservation awareness, educating farmers, and promoting sustainable land management practices contribute to long-term soil preservation. 

Conclusion

  • It's vital to keep in mind that depending on the region, temperature, soil type, and land use practices, different solutions may be required to address soil erosion. The most successful method for preventing soil erosion and preserving this important natural resource is often to combine these measures and adapt them to the local conditions. 
Samadhaan