The development of topsoil properties under different reclaimed land uses in the Pingshuo opencast coalmine of Loess Plateau of China

A better knowledge on soil development under different land use/cover is critical for restoring eco-environmental integrity in degraded mining areas. This study aims at evaluating the impacts of different reclaimed land uses on topsoil properties over time in an opencast coalmine located at Pingshuo, Shanxi province, China. Over two hundred soil samples at the depth of 0-30 cm were collected and analyzed by using descriptive statistic, spatial statistic, and geostatistical method. The results showed that significant differences existed in soil particle distribution, organic carbon (OC), total nitrogen (N), available potassium (AK), and cation exchangeable capacity (CEC) between reclaimed and unmined lands. However, pH, N, total phosphorus (P), available phosphorus (AP) and AK significantly differentiated from each other under different reclaimed land uses, while OC and N were the highest in cultivated soil, followed by forest, grass and barren soils. In addition, the results showed a strong global autocorrelation for pH, OC, N, P, AP and AK. Moreover, the changes of OC and N exhibited U-shape trajectory under forest and grass land, indicating that approximate 20 years were required for reclaimed forest and grass land to restore OC and N comparable to unmined land.