Black carbon—possible source of highly aromatic components of soil humic acids

Structural features and chemical composition of highly aromatic soil humic acids strongly suggest that these humic acids are derived from black carbon (charred plant residues, soot) and not from native plant materials. Humic acids from laboratory-oxidized black carbon show remarkable similarities to highly aromatic soil humic acids in their spectroscopic properties and chemical composition. Thus, black carbon is considered to be a possible source of the chemically most stable, aromatic soil carbon pool.