Biochar is form of charcoal that is created at a very high temperature over an extended period under controlled conditions called pyrolysis. A huge amount of carbon is captured in the process. In soil, Biochar lasts for thousands of years before breaking down. It is highly porous, meaning that it holds onto water and nutrients, and is colonised by microbes. It is a highly stable way of adding organic matter to sandy soils, and has long term benefits; reducing fertiliser requirements and leaching.