Stable carbon compounds in soils: Their origin and functions

Abstract

The sources, formation conditions, and composition of stable carbon compounds in soils are considered in this review. It has been shown that the stable carbon compounds contain lithogenic carbon-containing components and pyrogenic material, as well as some stable compounds resulting from the biochemical transformation of biomass in the soil. The presented data indicate that pyrogenic components (black carbon) play the major role in the formation of stable carbon compounds in the soil; in most soils, the products of biomass combustion prevail over the technogenic emissions resulting from the combustion of fossil fuel. Methods for the separation and analysis of stable carbon compounds have been considered; the specificity of markers used for the diagnostics of carbon compounds of different genesis has been discussed. A tentative scheme has been proposed for the classification of carbon compounds in the soil depending on their genesis and stability. The contribution of black carbon to the development of soil morphology and properties has been discussed; the hypothesis about the deciding role of pyrogenic components in the formation of chernozemlike soils in Middle Europe has been challenged. The suitability of biocarbon application to soils for improving their properties and fixing carbon in the soil has been shown.