Impact of Fertilizers on Soil Health

Summary Notes on ICAR Study on Soil Organic Carbon

Study Overview

• Conducted by: Indian Council of Agricultural Research (ICAR), led by Director General Mangi Lal Jat.
• Duration: Six-year study commenced in 2017.
• Scope: Analysis of 254,236 soil samples from 620 districts across 29 states in India.
• Publication: Findings published in the international journal Land Degradation & Development.

Key Findings

1. Factors Affecting Organic Carbon:

   • Unscientific use of fertilizers and climate change are major contributors to organic carbon degradation in agricultural land.
   • Organic carbon levels are inversely correlated with temperature; higher temperatures associated with lower organic carbon content (e.g., Rajasthan, Telangana).
   • Organic carbon is positively correlated with elevation.

2. Cropping Systems Influence:

   • Cropping systems significantly impact organic carbon content.
   • Regions with rice and pulse-based systems show higher organic carbon levels compared to those dominated by wheat and coarse grains.
   • High microbial activities in rice cultivation enhance carbon sequestration.

3. Geographical Implications:

   • Specific areas (Haryana, Punjab, Western Uttar Pradesh) face higher organic carbon depletion due to imbalanced fertilizer use, primarily favoring urea and phosphorus.
   • In contrast, Bihar exhibits better conditions with balanced fertilizer application.

4. Climate Change Impact:

   • Rising temperatures predicted to further decrease soil organic carbon levels, affecting soil health, carbon credits, and greenhouse gas emissions.

Policy Recommendations

1. Soil Management:

   • Promote organic carbon sequestration in soils with low carbon content (below 0.25%).
   • Encourage development of cropping systems supported by improved irrigation.

2. Incentives:

   • Propose carbon credit schemes to incentivize farmers who effectively enhance soil organic carbon.

3. Mitigation Strategies:

   • Explore diverse crop management options targeting climate change mitigation.

Environmental Significance

• The study underscores the critical role of soil health in achieving sustainable agriculture and combating climate change.
• It advocates for systematic agricultural practices to restore soil health and improve carbon capture, essential for offsetting greenhouse gas emissions.

Conclusion

This extensive study highlights the interplay between agricultural practices, climate change, and soil health, calling for urgent policy measures and farmer incentives to address soil degradation and enhance organic carbon levels in India.