Biochar overview

Biochar is the carbon-rich solid product resulting from the heating of biomass in an oxygen-limited environment. As part of bioenergy production, it is the solid co-product, that can be used for energy, carbon sequestration or agronomic applications.  Biochar is chemically and biologically more stable compared with the organic matter from which it was made.

While some studies suggest biochar applications improve soil fertility and water holding capacity and increase soil organic carbon, carbon sequestration and crop productivity, there is little information on the effectiveness of a range of different biochars to do this in various cropping or land management situations.

Answering key biochar questions

Two major projects – one funded by the Grains Research & Development Corporation (GRDC) in conjunction with the University of Western Australia, and another by the Australian Department of Agriculture, Fisheries and Forestry (DAFF) – are helping to answer some of the key questions about the potential of biochar for carbon sequestration and agricultural productivity.

The current CSIRO-led national research projects aim to close these knowledge gaps in areas such as the:

• specific chemical, physical and biological characteristics of different biochars
• response of crops in different soil types to each biochar type
• interactions between char, soil humus, minerals and fertilisers
• effects of biochar on soil microbes and mineralisation and nutrient release
• effects on production and release of nitrous oxide
• net carbon costs and savings from biochar production and use.