By Abbas Nazil
A study by the Indian Council of Agricultural Research (ICAR) has revealed that climate change and the unscientific use of fertilisers are accelerating the loss of organic carbon in India’s agricultural soils, posing a serious threat to soil health and food production.
The six-year research, coordinated by the ICAR-Indian Institute of Soil Science in Bhopal, analysed over 254,000 soil samples across 620 districts in 29 States.
The findings, recently published in the international journal Land Degradation & Development, show that organic carbon levels are declining in many arable regions due to rising temperatures and imbalanced fertiliser use.
Project coordinator Dr. Arvind K. Shukla explained that organic carbon is crucial for maintaining the physical, chemical, and biological integrity of soil.
He noted that low levels of organic carbon lead to micronutrient deficiencies, weakening soil fertility.
The study found a strong correlation between organic carbon and altitude, rainfall, and temperature.
Regions at higher elevations recorded richer organic carbon content, while areas like Rajasthan and Telangana, with higher temperatures, had significantly lower levels.
The scientists developed an “agri-ecological base” map covering 20 agro-ecological regions to assess how cropping patterns and fertiliser application affect soil carbon.
They observed that rice and pulse-based systems retained more carbon than wheat and coarse-grain systems due to higher microbial activity in water-intensive crops.
The study also identified regions such as Haryana, Punjab, and Western Uttar Pradesh where excessive use of urea and phosphorus-based fertilisers reduced soil carbon.
Conversely, balanced fertiliser use in States like Bihar showed better soil health.
Dr. Shukla warned that rising temperatures could further reduce soil carbon, increasing ground heat reflection and worsening greenhouse gas emissions.
The team urged policymakers to promote carbon sequestration in soils with less than 0.25% carbon content, expand crop coverage, and encourage large-scale plantations.
They recommended incentives for farmers who successfully trap carbon in the soil through sustainable practices and advocated research into climate-resilient cropping systems.
