The Fate of ~(14)C-Labelled Maize Residues within Physically Gained Soil Fractions - Distribution and Decomposition of Organic Carbon

摘要

A classical procedure for separating and characterising organic carbon (C_(org)) compounds from soil is based on chemical fractionation approaches. However, these extraction methods can substantially modify the C_(org) compounds themselves and the nature of their association with the soil's mineral components. Therefore, the use of physical fractionations in studies of organic matter (OM) turnover in soil has increased steadily over the past two decades. In addition functional approaches have attempted to describe organic matter dynamics by incorporation of residues labelled with radioactive ~(14)C or stable ~(13)C in combination of particle-size fractionation. However these studies focused to trace the fate of C released into soil, but have not discussed structural changes of the organic carbon pools during decomposition processes with the help of physicochemical analyses.