Biochar (BC) is a carbon-rich material produced via pyrolysis of biomass with limited oxygen that can be used as a soil conditioner and as a means to sequester carbon. It is produced by the pyrolysis of biomass, i.e. by heating biomass in an oxygen-free or low-oxygen environment so that it does not (or only partially does) undergo combustion. An advantage of this process is that it also produces gases that can be captured as bioenergy and fed back into the energy grid, making it a carbon negative process overall. Biochar is one of the most stable biologically produced carbon sources that we can add to soil. Due to its chemical structure biochar is very difficult for microbes in the soil to break down, preventing the carbon sequestered in the char to be released quickly back into the atmosphere. This is a clear distinction between biochar and other organic matter, or pools of carbon, in the soil.