At a time when various measures have failed to find a solution to stubble burning, scientists from Punjab Agriculture University (PAC) and Jawaharlal Nehru University (JNU) may hold a ray of hope: Biochar.
Biochar is granular material obtained by heating crop residue at 400°C to 600°C in a kiln-shaped structure in the absence of oxygen. It is used as fertiliser to improve soil health and water-holding capacity of agriculture land.
Rajeev Kumar Gupta, senior scientist at PAC, said biochar can reduce greenhouse gas emissions by 70%. “With help from ICAR a year ago, PAC set up structures at four Krishi Vigyan Kendras in Punjab to produce biochar. We’ve been demonstrating the technology to farmers.”
He estimated that the project in Punjab may cost Rs 400-500 crore. In 2018-19, the Centre disbursed Rs 300 crore for in-situ management of stubble in Punjab. “Around 12,857 villages in Punjab burn stubble. Each village should have at least 5-8 structures,” he added.
Each structure costs Rs 35,000-Rs 40,000 and is 10 ft in diametre and 14 ft in height. It can process 1.2 tonnes of stubble in 8-10 hours.
JNU professor at School of Environmental Sciences, Dinesh Mohan, said: “Biomass contains many nutrients such as carbon. When you heat it, carbon gets sequestered in biochar, which gets transferred to soil.” Punjab Agriculture Secretary K S Pannu said: “We’re looking at economically viable technologies; biochar is one of them. More research is needed to take it to farmers.”