Soil organic matter is considered as a system of interlinked pools. Structural (particulate organic matter (C-POM), mineral-associated organic matter (C-MAOM) and chemically inert organic matter (C-IN)) and process-related (potentially mineralizable organic matter (C-PM), microbial biomass (C-MB) and chemically oxidizable organic matter (C-OX)) pools are isolated by biophysicalchemical fractionation, and functional (active, slow, passive) pools are conceptually distinguished based on different turnover rates of the carbon contained in these pools. Agricultural use leads to the loss of organic carbon by arable soil and proportional depletion of all carbon pools compared to virgin lands. The organic fertilizer system, compared to the mineral system, promotes recarbonization of arable soil with the accumulation of carbon mainly in POM and in the slow pool of soil organic matter. The scales of low, medium and high carbon content of structural and process-related soil pools were proposed.
V. M. Semenov (Wed,) studied this question.