Biochar is produced from organic waste at temperatures of between 400 and 700 °C whilst excluding oxygen. This so-called process of pyrolysis yields a very carbon-rich, aromatic, black product which can serve as a sponge for nutrients and a habitat for microorganisms. Because of its high stability in the soil, it is regarded as a potential CO2 sink. What’s more, the use of biochar could influence the cycling of nutrients – particularly nitrogen – in the soil, as well as increase water-storage capacity.
The application of biochar can reduce nitrous oxide (N2O) emissions from soils used for agricultural purposes, which points to a change in the activity of soil microorganisms. The reduction of N2O emissions is of great importance for the greenhouse-gas balance of soils used for agricultural purposes, since nitrous oxide has a 300-times-higher global warming potential than CO2.
In a resource project within the context of the AgroCO2ncept Flaachtal programme, Agroscope is currently examining the potential for increasing the humus content of intensively managed agricultural soils through the application of biochar.