Madeleine Cuff in New Scientist:
China’s production of staple food crops such as wheat and corn could become a net carbon sink if farmers start widely applying biochar to soil.
Instead of returning raw biomass, like straw, to the soil at the end of the growing season, farmers could take it to pyrolysis plants, where the material is heated at a very high temperature in an oxygen-free chamber to create biochar, a charcoal-like solid rich in carbon.
Studies have shown that applying it to soils not only locks the carbon away, but also improves the health of soil and its ability to retain water. Creating biochar also produces bio-oil – a possible substitute for petrol – and syngas – a mixture of hydrogen and carbon monoxide that can be used to generate electricity.
Pete Smith at the University of Aberdeen in the UK and his colleagues assessed the potential impact of the mass application of biochar in the farming of staple crops in China.