The impact of anthropogenic carbon types on the chemical composition of soil organic matter

In the Lusatian mining district, organic matter of recultivated mine soils under forest consists of a mixture of lignite, lignite ash, lignite dust (anthropogenic carbon) and organic matter derived from decomposing plant material. The aim of the study was to assess the impact of anthropogenic carbon types on the chemical composition of the soil organic matter. Bulk soil samples and physical fractions were analysed for structural composition by C-13 CPMAS NMR spectroscopy and for lignite content by C-14 activity measurements. Both methods yield corresponding results. C-13 CPMAS NMR spectrometry shows that anthropogenic carbon types contribute greatly to the chemical composition of the soil organic matter, leading to an increase of alkyl and aromatic carbon species (0-45 and 110-160 ppm). In contrast to natural soils the contribution of carbon species characteristic for plant litter increases with age in the surface soil horizon.