Microbial Biomass-C in Reclaimed Soil of the Rhineland (Germany) and the North Bohemian Lignite Mining Areas (Czech Republic): Measured and Predicted Values

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Address correspondence to L. Růžek, email ruzek@af.czu.cz

Abstract

This article compares reclaimed soils in the Rhineland lignite mining area, Germany (RA) and in the north Bohemian brown coal basin, Czech Republic (NBB). Because of highly significant differences of physical and chemical characteristics (RA was characterized by lower content of sand, clay, soil organic carbon, and total nitrogen) between both analyzed areas, the content of microbial biomass carbon (CMB) differs significantly (p < 0.01): RA: 241.17 ± 96.50 μg C/g dry soil; NBB: 424.42 ± 136.23 μg C/g. Extracellular microbial carbon (CEX) was also significantly higher in RA than NBB. The measured CMB values from both mining areas were verified using two empirical mathematical models. Because our former model (used for evaluation of NBB) did not fit soils with low organic carbon content (0.10–0.80%), a new model was proposed. For evaluation of RA reclaimed sites the measured, model-predicted, and calculated values were used. The best site in RA was Dürwiss Deponie (site 18 near Eschweiler), reclaimed in 1965 and characterized by good soil physical parameters (sand 4%, silt 77%, and clay 19%). In NBB undisturbed soils were the best, together with the site of Úžín (site 2 near Ústí and Labem), reclaimed in 1964, where high-quality reclamation management resulted in high biological activity. According to biological criteria, the best management practice in NBB was use of high-quality loam overlaying montmorillonite clayey subsoil. In RA direct reclamation of high-quality loess with low content of sand also gave good results.

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