The early years of soil genesis during mine spoil reclamation are critical for vegetative establishment and may help predict reclamation success. Mine spoils in the Halle-Leipzig region of Germany were analyzed for microbial changes following a hay mulch-seeding treatment without topsoil or fertilizer application. Microbial biomass carbon (Cmic) and dehydrogenase activity (DHA) of spoils were measured each year in the first 3 yr after treatment. In the third year, bacterial community DNA fingerprints were compared with those from a reference soil. Microbial indicators were measured at three depths in the upper 10 cm of spoils at three sites with contrasting parent materials: glacial till (sandy loam), limnic tertiary sediments (high-lignite sandy clay loam), and quaternary sand and gravel (loamy sand). Before reclamation, Cmic means and standard deviations of surface spoils (0-1 cm) were 9 ± 6, 39 ± 11, and 38 ± 16 mg kg -1 for the loamy sand, high-lignite sandy clay loam, and sandy loam spoils, respectively. Within one year, mean Cmic at the surface increased to 148 ± 70, 229 ± 64, and 497 ± 167 mg kg -1, respectively, and was significantly higher at 0 to 1 cm than at lower depths. Highest DHA and DNA yields were obtained in the 0- to 1-cm depth of the sandy loam spoils. Microbial biomass C values exhibited significant correlations with DHA, DNA yield, and extractable C for all three mine spoils. Soil microbial indices were more responsive than plant measurements to differences in parent materials.
All Science Journal Classification (ASJC) codes
- Soil Science