Paddy straw and wheat residues are usually burned by farmers in Punjab and Haryana in the absence of affordable alternatives to dispose them of. Every year, in November and February , burning of agricultural res idue in these states causes severe air pollution
According to Climate Foundation India's proposal for the Urban Labs Innovation Challenge, nearly 60 mega tonnes of rice straw is burnt openly annually . Haryana and Punjab comprise 48% of total emissions due to rice straw burning across India. "During the months rice straw is burned, PM 2.5 (fine, respirable pollution particles) levels commonly exceed 400 parts per million," it said.
The team at Climate Foundation India proposes to make biochar out of the agricultural residue instead. Inspired by scientist James Lovelock's Gaia theory, which explained how the soil can act as an effective sink for greenhouse gases, Brian's team developed a "charvester"-an equipment that harvests grain and cuts the straw at the same time.
"It can also collect the straw and put it through pyrolysis to make biochar," says Herzen, adding that "the biochar that is rich in carbon can then be buried into the soil where it will remain for thousands of years.This will also improve the soil quality immensely ."
His team in Delhi is in talks with the Central Soil Salinity Research Institute (CSSRI) in Karnal for this project. It has also visited villages in Haryana to understand whether farmers will accept the biochar technology . "CSSRI has already helped address soil salinity in about 2 million acres of land in UP , Haryana and Punjab. An important part of the restoration process was ensuring carbon is put back into the soil. Charvesters are going to do just that."
The organisation had used a similar technology to produce biochar with bi omass waste in Bangalore a few years ago. Says Hitesh Arora, who is based in Delhi, "We know that biochar can be effectively made from paddy and wheat straw. Our team has already met farmers in Haryana who have expressed interest. Now we will have to demonstrate it and see how the technology can be made affordable for them."
Haryana and Punjab have already prohibited agricultural residue burning under the Air Act. In order to ensure effective enforcement of the law, the Environment Pollution Control Authority has directed state governments to start imposing penalty and prosecution for all incidents of stubble burning through district level special teams, to launch awareness campaigns before the paddy harvesting period, and asked state remote sensing agencies to stay vigilant.