Biochar culture to address depleted soils, improve crop yields

Biochar, a carbon-rich organic farm product, which is obtained through high temperature treatment of locally available plant charcoal blended with low quantities of inorganic elements, could help repair and rejuvenate the depleted agriculture soils, and also raise crop yields in the country, according to the International Biochar initiative.

With local experimental field trials showing gain in yield at 30-80 per cent, and with the active interest of state agri varsities, farmer producer groups and NGOs, so far 100,000 acres farm area had been covered with biochar culture in the country, including in Jammu & Kashmir, Uttarakhand, Bundelkhand, Karnataka, Telangana and Andhra.

Sai Bhaskar Reddy, an IIT-Bombay Applied Geology professional, who has pioneered its spread in India, says biochar culture, which has a minimum 100 years life, will create an organic soil habitat leading to better soil fertility, greater microbial activity besides absorption of atmospheric nitrogen and phosphorus in the soils.

In his studies involving biochar application at Jangaon in Warangal district and Kothur in Mahbubnagar, in Telangana, he found farmers were able to produce 16 bags of paddy from a half-acre land, as against 5-6 bags earlier. Studies were also held in grapevines in Maharashtra, Gujarat and Punjab recently.

The process is suited for all soil types, including dry and semi-arid. The cost of farmer-produced biochar using biomass created during harvest and from other economical sources comes to around Rs 5 a kg. Commercially, it is also available for Rs 9-13 a kg, Reddy said. For sustained results, he suggested constant annual application of biochar over a five-year period.

But critics say a boom market for biochar would encourage destruction of forests and giving up farmland to grow crops exclusively for biochar. To this, Reddy said the forests could be spared if only the local plant life is used, and suggested a local plant Tropofis Jurifloraor 'sarkar tumma', which can be used for producing charcoal for biochar. Apart from this, he has introduced a low-cost and smoke-free stove costing Rs 100-250, that produces biochar during cooking. He claims the smoke is reduced by 80 per cent as against the traditional chullah.

Biochar also lets lower levels of methane back to the atmosphere and avoids emission of greenhouse gas nitrous oxide. It is a permanent soil solution as does not decompose for a few centuries, unlike soil conditioners like farm yard manure and vermicompost.

He said the biochar had been quickly adopted by farmers in the US, Europe and Australia, and the domestic trend was encouraging. According to him, the International Biochar initiative is in the process of coming up with guidelines on practices and processes.

However, speaking to Business Standard, Suhas Wani, research programme director for Resilient Dryland Systems at Icrisat said the fundamental problem with biochar was the availability of organic matter and suggested exploring other low-energy sources. "Most of the farmers have competitive uses for biomass for fuel and livestock. As carbon going into the soil is important, we recommend application of organic matter through composting using rapid composting and vermi compost," said Wani, adding for developing countries low-energy sources make the right option.

As of now very few companies are involved in the commercial production of biochar. At the International Crops Research Institute for Semi-Arid Tropics (Icrisat)'s Agri Business Incubator (ABI) programme, C6 Agrisciences India Pvt Limited is working with a Karnataka-based NGO, Vruthi, and a few farmer producer groups to take up studies in Zaheerabad and coffee estates in Karnataka before setting up commercial production for biochar.

"We have plans to start a unit. We are having few pyrolysis process designs for producing biochar. However, we need to first create demand through extension activities," said C6 agrisciences chief financial officer Pranav Rao.