Study on Organic Carbon Degradation in India's Soils

A team of scientists from the Indian Council of Agricultural Research (ICAR) conducted a comprehensive study to examine the impact of fertilizers and climate change on the degradation of organic carbon in India's arable areas. The study involved 254,236 soil samples from 620 districts and took place over six years, beginning in 2017.

Key Findings

• Unscientific fertilizer use and climate change are major contributors to organic carbon degradation.
• Organic carbon is crucial for soil health, influencing its physics, chemistry, and biology.
• Low organic carbon levels correlate with high micronutrient deficiencies.
• Organic carbon levels positively correlate with land elevation and negatively with temperature.
• Temperature, rainfall, and elevation are critical factors determining organic carbon concentration.

Agri-Ecological Base Map

The scientists developed an 'agri-ecological base' map covering 20 regions to assess cropping system impacts on organic carbon.

• Rice-based and pulse-based systems show higher organic carbon content compared to wheat and coarse grains.
• Imbalanced fertilizer use, especially skewed towards urea and phosphorus, reduces organic carbon levels.

Impact of Climate Change

• Organic carbon is highly negatively correlated with temperature increases.
• Higher temperatures may lead to reduced organic carbon, affecting soil health and carbon credit mechanisms.
• More carbon in soil aids in heat absorption, while less carbon results in increased heat reflection, exacerbating greenhouse effects.

Policy Recommendations

• Promote organic carbon sequestration, especially in soils with less than 0.25% carbon.
• Implement carbon credit incentives for farmers who enhance carbon sequestration.
• Develop diverse crop management options for climate change mitigation.