Biochar is charcoal used as a soil amendment. Biochar is defined simply as charcoal that is used for agricultural purposes. It it created using a pyrolysis process, heating biomass in a low oxygen environment.
Pre-Columbian Amazonians are believed to have used biochar to enhance soil productivity. They produced it by smoldering agricultural waste (i.e., covering burning biomass with soil) in pits or trenches.
Biochar can be used for a range of applications as an agent for soil improvement, improved resource use efficiency, remediation and/or protection against particular environmental pollution and as an avenue for greenhouse gas (GHG) mitigation.