Why in the news?

  • A detailed study conducted by ICAR scientists found that Climate change and unsustainable fertilizer use has effected loss of natural soil Carbon.

Degradation of Soil Organic Carbon (SOC) in India

  • Soil Organic Carbon (SOC):
    • It refers to the carbon component of organic compounds present in soil, derived from decayed plants, animals, and microorganisms.
    • It is a key indicator of soil health, fertility, and ecosystem productivity.
  • Significance of SOC:
    • Enhances soil structure, aeration, and water retention.
    • Acts as a nutrient reservoir (N, P, S).
    • Supports microbial diversity and soil biota.
    • Major carbon sink, contributing to climate change mitigation.
    • Influences agricultural productivity and food security.
  • Key Findings of the ICAR Study 2025:
    • Declining SOC in arable lands, particularly Indo-Gangetic plains and central India.
    • Unscientific fertilizer use, reduced organic inputs, and climate stress are primary causes.
    • Soils of forest and hilly regions maintain comparatively higher SOC.
    • Average SOC stock in Indian soils: less than 0.5%, far below the desired 1–1.5% for healthy soils.
  • Causes of SOC Degradation:
    • Intensive Agriculture: Overuse of chemical fertilizers and pesticides as well as poor incorporation of organic matter.
    • Deforestation and Land-Use Change: Conversion of forests to croplands/pasture reduces biomass input to soil.
    • Erosion and Degradation: Topsoil loss through wind and water erosion removes carbon-rich layers.
    • Monocropping & Reduced Crop Residue Return: Limits organic input and microbial activity.
    • Climate Change: Rising temperatures and erratic rainfall accelerate decomposition and oxidation of SOC.
  • Restoration Strategies:
    • Adoption of Conservation Agriculture: Minimum tillage, crop rotation, residue retention.
    • Organic and Integrated Nutrient Management: Compost, farmyard manure, biochar, green manuring
    • Agroforestry and Afforestation: Enhances biomass and carbon input.
    • Soil Health Management Scheme: Promotes balanced fertilizer use and organic carbon restoration.
    • National Mission for Sustainable Agriculture (NMSA): Focus on soil health, carbon sequestration, and water-use efficiency.
    • Carbon Farming and Payment for Ecosystem Services (PES): Incentivises farmers to enhance SOC stocks.
  • Global and National Initiatives:
    • UN’s “4 per 1000” Initiative (COP 21): Aims to increase global SOC by 0.4% annually to offset CO₂ emissions.
    • ICAR’s Long-Term Fertilizer Experiments (LTFE).
    • National Soil Health Card Scheme (2015).
    • Bharatiya Prakritik Krishi Paddhati Yojana (BPKP) under Paramparagat Krishi Vikas Yojana promotes natural carbon-enriching practices.