Spatial distribution of water and salt in soil layer and microbial remediation effect of reconstructed soil layer in quasi-energy dump site

In order to alleviate the problems of restoration success rate and ecosystem resilience under the condition of water shortage in the dump area in western our country, the Zhunneng Heidaigou open-pit mine was selected as the study area, and different soil layer reconstruction methods (three-layer structure and mixed structure) were used in the dump site, and different microbial combinations (AM, DSE, AM DSE, CK) were combined for ecological reconstruction to study the water retention, water culvertability, and spatial distribution of water and salt in the reconstructed soil layer. Effects of microorganisms on plant growth and water use strategies. The results show that the ground penetrating radar verifies the physical characteristics of the three-layer structure and the mixed structure, the soil moisture of the three-layer structure is distributed in layers, the surface loess layer (ecological layer) increases with depth, the middle coarse sandstone layer (culvert layer) has a balanced water distribution and the moisture content reaches 12%, the bottom sandy clay layer (aquifer) has the function of blocking water infiltration, and there is no spatial difference in the water distribution of the mixed structure. The water retention capacity of the three-layer structure treatment increased by 43.1%, and significantly increased the water absorption of 50-100 cm soil layer, thereby promoting the water utilization of plant roots, and the utilization efficiency reached 71.1%. Compared with CK, the water use efficiency of alfalfa was increased by 42.7% and the coverage was increased by 1.2 times. Therefore, the combination of three-layer structure and AM DSE treatment has significant ecological restoration potential in the arid and semi-arid mining areas in western China, and this study provides new ideas and technical support for the ecological restoration of mining areas, which is conducive to the sustainable development of mining areas in western our country.