Characteristics of Physical and Chemical Properties of Soil in Different Reclamation Years of Opencast Coal Mine Dump in Grassland

Abstract

Taking the reclamation waste dump of the open-pit mining area in the east of Inner Mongolia Steppe as our study area, we sampled field investigation and laboratory measurements to study the changes of soil physical and chemical properties in the waste dump of the open-pit mining area during its recovery years. The objective of this study was aiming to provide theoretical support for the ecosystem restoration and reconstruction in the open-pit mining area of grasslands in the Northwest of China. The results showed that: 1) the mechanical composition of soil all layers in different reclamation years was mainly composed of silt, except for 20-30cm; the silt content was significantly higher than the control area (CK), and the silt content of surface soil (0-5cm) in reclamation 3 years (2016) was significantly higher than CK, but the sand content was significantly lower than CK; 2) In the early stage of vegetation restoration and succession, the physical and chemical properties of soil in different reclamation years were significantly different. With the increase of reclamation years, TOC and TN content decreased, but TP content did not change significantly during reclamation years. Based on the above results, the change characteristics of soil physical and chemical properties in the early stage of vegetation restoration succession were discussed. The research results have certain theoretical significance and practical guidance value for the ecological restoration and reconstruction of open-pit mining areas in the north of Northwest China.