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CSIRO will coordinate a A$1.4m ($1.1m), three-year research project to assess biochar as a carbon sequestration tool and agricultural input.

Created by heating natural organic materials in the absence of oxygen - pyrolysis - biochar is chemically and biologically more stable than the materials from which it is made, retaining its carbon content for hundreds to thousands of years when added to soil.

Its physical properties are determined by the feedstock and the parameters of the heat treatment applied. Biochar made from manure has a higher nutrient content than biochar from wood waste but a lower level of aromaticity, making it less stable.

Biochar produced at 700 °C has a much greater adsorptive capacity and higher degree of micro-porosity than that produced at 400 °C, providing greater potential for adsorption of toxic substances and rehabilitation of contaminated environments.

Other potential benefits include storing more nutrients and water in soil and reducing acidity, while the syngas byproduct from pyrolysis can be used to generate electricity and heat.

The research proposal was submitted in September 2008 in the first round of applications under the Australian Government’s Climate Change Research Program.

The technology subsequently became part of Australia’s political climate change debate when the Leader of the Opposition, Malcolm Turnbull, championed biochar as a means to capture and store CO₂ that would otherwise be emitted into the atmosphere.

Announcing the funding, the minister for agriculture, fisheries and forestry, Tony Burke, said it is known that some biochars can inhibit plant growth and some biochar/soil mixes can generate toxic byproducts.

“Research is key – and we believe the findings from this project will be important in global discussions on how biochar can be used in agriculture,” says Burke.