Mine soil health on surface mined lands reclaimed to grassland

Appalachian states of the USA have over 15,000 km(2) of surface mined land. Many mine sites in northern Appalachia were reclaimed with salvaged topsoil to aid revegetation and few studies have measured soil health of reclaimed mine soils in this region of Appalachia with topsoil replaced and grassland established. The objective of this study was to assess soil quality by using six soil health indicators from two methodologies (NRCS Soil Quality Test Kit vs Standard laboratory/field methods) on four reclaimed mine sites. On these sites, three of the six soil health indicators gave similar results between methodologies: infiltration (INFIL) (NRCS: 0.117 vs Standard: 0.114 cm min(-1)), pH (6.6 vs 6.4), and soil respiration (RESP) (45 vs 57 kg CO2-C ha(-1)day(-1)); but two were different: bulk density (BD) (1.30 vs 1.46 Mg m(-3)) and electrical conductivity (EC) (0.113 vs 0.226 dS m(-1)). Wet aggregate stability (WA) showed similar trends between methodologies but could not be statistically analyzed because of different measurement units. The four sites differed in age since reclamation which offered an opportunity to assess soil quality changes over time. BD decreased, and WA, INFIL, pH, EC and RESP increased with age. The results showed that soil health indicators determined with the NRCS Soil Quality Test Kit provided similar results and trends to Standard methodologies and can be used to evaluate soil quality of mine soils. Both methodologies verified that mine soil health indicators improve with time since reclamation.

Automated summary

This study assessed the soil quality of four reclaimed mine sites in the Appalachian states of the USA. The results showed that soil health indicators determined with the NRCS Soil Quality Test Kit provided similar results and trends to Standard methodologies and can be used to evaluate soil quality of mine soils. Both methodologies verified that mine soil health indicators improve with time since reclamation.