India's Soil Erosion Crisis | 12 Apr 2024

Source: DTE

Why in News?

A recent study has shed light on the concerning state of soil erosion across India, revealing significant challenges and implications for agricultural productivity and environmental sustainability.

• The researchers employed the Revised Universal Soil Loss Equation (RUSLE) for pan-India soil erosion estimation. The equation considers factors like predicted crop loss, rainfall, soil erodibility, and land management practices.

What are the Key Highlights of the Study?

• 30% of India's landmass is experiencing "minor" soil erosion, 3% facing "catastrophic" topsoil loss.
  • Brahmaputra Valley in Assam is identified as the country's biggest hotspot for soil erosion.
  • Odisha highlighted as another hotspot for "catastrophic" erosion due to anthropogenic interventions.
    • Catastrophic erosion is defined as over 100 tonnes of soil lost per hectare annually.

What is the Status of Soil Erosion in India?

• About: Soil erosion refers to the process by which soil is moved or displaced from one location to another.
  • It can occur at varying rates depending on factors such as climate, topography, vegetation cover, and human activities.
• Factors Contributing Soil Erosion:
  • Natural Causes:
    • Wind: Strong winds can pick up loose soil particles and carry them away, especially in dry areas with sparse vegetation.
    • Water: Heavy rainfall or fast-flowing water can detach and transport soil particles, particularly on sloped land or where there's little vegetation cover.
    • Glaciers and Ice: The movement of glaciers can scrape and transport massive amounts of soil, while freezing and thawing cycles can cause soil particles to break apart and become more susceptible to erosion.
  • Human-Induced Factors:
    • Deforestation: Clearing forests removes trees and other vegetation that hold soil in place with their root networks.
      • This exposes the soil to the full force of wind and rain, making it more prone to erosion.
    • Poor Agricultural Practices: Conventional farming methods like excessive tilling can break down soil structure and leave it vulnerable to erosion.
      • Practices like leaving fields bare during fallow periods or using inadequate crop rotation also contribute to the problem.
    • Overgrazing: When livestock graze an area too heavily, they can damage vegetation cover, leaving the soil exposed and susceptible to erosion.
    • Construction Activities: Land clearing and excavation during construction projects disturb the soil and make it more prone to erosion, especially if proper precautions are not taken.
• Degraded Soil in India: According to the National Bureau of Soil Survey and Land Use Planning, around 30% of the soil in India is degraded.
  • Of this, around 29% is lost to the sea, 61% is transferred from one place to another, and 10% is deposited in reservoirs.

What are the Challenges Related to Soil Health in India?

• Low Organic Carbon Content: Indian soils typically have very low organic carbon content, which is crucial for fertility and water retention.
  • The soil organic carbon (SOC) content in Indian soils has declined from 1% to 0.3% in the past 70 years.
• Nutrient Deficiencies: A significant portion of Indian soils suffer from deficiencies in major nutrients like nitrogen, phosphorus, and potassium.
  • Over-reliance on chemical fertilisers exacerbate this problem.
• Water Management Issues: Both water scarcity and improper irrigation practices harm soil health. Insufficient water can lead to salinisation, while over-irrigation can cause waterlogging, both impacting soil fertility and structure.
  • Around 70% of irrigation water in India is wasted due to the poor management of the farmer.
• Socioeconomic Factors: Land fragmentation due to population pressures and economic constraints can make it difficult for farmers to adopt sustainable practices that improve soil health.
  • The average landholding size in India is 1-1.21 hectare.

What Measures can be Adopted to Prevent Soil Erosion and Improve Soil Health?

• Biochar and Biofertilizers: Combining biochar application with biofertilizers can be a powerful strategy.
  • Biochar holds nutrients and water, while biofertilizers improve nutrient availability and soil health. This can reduce reliance on chemical fertilisers and enhance soil fertility.
    • Biochar is a charcoal-like substance produced by pyrolysis (heating in absence of oxygen) of organic materials like crop residues, manure, or weeds.
  • Biofertilizers are live microorganisms that can improve soil fertility and plant growth.
• Drone Technology for Precision Agriculture: Namo Drone Didi Scheme can be linked with soil conservation.
  • Drones equipped with multispectral sensors can map soil health parameters like nutrient levels, organic matter content, and moisture levels across large fields.
  • This data can be used for precision application of fertilisers and amendments, minimising waste and maximising effectiveness.
  • Drones can also be used for targeted seeding and weed control, further reducing soil disturbance.
• Regenerative Agriculture Practices: Integrating no-till farming and using compost can create a customised approach for different areas.
  • Additionally, exploring innovative cover cropping techniques like multi-species cover cropping can provide additional benefits like weed suppression and improved soil structure.