Biochar is charcoal produced for agricultural purposes. Organic feed stocks, ideally small diameter wood wastes, are heated in the absence of oxygen to produce charcoal in a process called pyrolysis. The process releases organic gasses and oils, which can be burned to produce electricity or used to propel the pyrolysis process, making the process self-sustaining. Charcoal in soil is very stable, resulting in carbon sequestration, and increases cation exchange capacity among other processes, reducing nutrient leaching, and increasing crop production under some circumstances.
- http://csanr.wsu.edu/publications-library/energy/biochar/ - WSU has been conducting research to test and evaluate biochar as a soil amendment through its "Waste to Fuels Partnership"
- This 2018 report by Ecology describes a variety of ongoing research including an assessment of forestland to agricultural field transfers of carbon while providing energy production.