Changes in Reconstructed Soil Physicochemical Properties in an Opencast Mine Dump in the Loess Plateau Area of China

Abstract

Soil construction and revegetation are essential for ecological restoration in mining areas. The influence of vegetation on the horizontal and vertical distribution patterns of soil properties should be fully understood. However, most studies on reconstructed soils in mining areas only concentrate on the surface soil, without exploring the vertical variations in soil properties. Overall, this study aims to explore the potential mechanisms by which surface vegetation exerts some influence on the spatial distribution of soil physicochemical properties, and to provide some insight into revegetation and soil reclamation in mining areas. Descriptive statistics and one-way analysis of variance (one-way ANOVA) were employed to evaluate the differences in the soil physicochemical properties in horizontal and vertical directions under different land-use types in the south dump of Antaibao opencast mine in Pingshuo, Shanxi Province, China. The main results of this study are as follows: (1) In the horizontal direction, except for the strong variation (variation coefficient ≥ 100%) in soil organic matter (SOM) content at some depths, the degree of variation in other soil physicochemical properties at various depths was moderate or weak (variation coefficient < 100%). The soil physicochemical properties gradually remained constant after years of reclamation. In the vertical direction, the soil bulk density (SBD), soil porosity, SOM content, soil C/N ratio, soil total nitrogen (STN) content, soil available phosphorus (SAP) content, and soil available potassium (SAK) content showed significant variations (p < 0.05) between soil depths. In contrast, no significant difference was found for other physicochemical properties. (2) The SBD, STN, SAK, soil porosity, and soil clay content were significantly different (p < 0.05) under different vegetation cover types, but the influence of vegetation on other soil physicochemical properties seemed to be limited. The results reveal that trees have a stronger ability to reduce soil grain sizes and enhance SAP contents than shrubs or herbs; however, the beneficial effects of herbs on the physicochemical properties of shallow soil are more obvious than those of trees and shrubs. (3) This study indicates that more shrubs and trees should be planted in the areas with low vegetation coverage, and more measures should be taken to improve soil physicochemical properties in order to prevent the occurrence of large-scale degradation. The reconstruction of soil structure should be preferentially considered in the process of soil reconstruction and revegetation in areas under similar conditions. Herbs should first be planted in the early reclamation stage. At the same time, shrubs or trees can be adopted in the middle and late stages of vegetation reconstruction in order to achieve comprehensive revegetation.

Changes in Physical and Water Retention Properties of Technosols by Agricultural Reclamation with Wheat–Rapeseed Rotation in a Post-Mining Area of Central Poland

“…In the control (0-NPK) soils, the AC horizon was dominated by subangular structure partially breaking down into granular, while the CA horizon had both subangular and angular. This change in structure from massive (in 1978) to granular/subangular (in 2021) in the surface horizons indicates a major role of plants in the development of pedogenic structure, as also found in other studies [6,12,16,22,40,42,43]. Comparing the structure of Ap1 to the Ap2 subhorizon of fertilized and to the AC horizon of unfertilized soils, it can be concluded that in Ap1, the higher impact of biologic agents and processes on the soil structure transformation was marked, as highlighted by other studies [44,45].…”

“…This soil take is also connected with opencast mining activities during lignite extraction, as this type of fossil fuel is still an important source of global energy worldwide [3,4]. Poland continues to produce about 28% of its electricity from opencast lignite [5], widely used in many countries around the world [6]. During opencast operations, the natural landscape is damaged along with soils developed over thousands of years and new anthropogenic landforms (e.g., external or internal dumps) with mixed lignite overburden materials are created.…”

Research on Adaptive Management of the Social–Ecological System of a Typical Mine–Agriculture–Urban Compound Area in North Shanxi, China

“…The above-mentioned mine–agriculture–urban compound area is located in Pinglu District, Shuozhou City, Shanxi Province of China (39°21′–39°58′ N, 111°52′–112°41′ E) ( Figure 1 ), which is located in the Loess Plateau hills of north Shanxi Province, where the topography is higher in the northwest than southeast [ 12 , 37 ]. This area is in the northern temperate semi-arid continental monsoon climate zone, where the climate is cold, dry, windy, and sandy with an average annual temperature of 4.50 °C [ 12 ].…”

“…This area is in the northern temperate semi-arid continental monsoon climate zone, where the climate is cold, dry, windy, and sandy with an average annual temperature of 4.50 °C [ 12 ]. The zonal soil type is loessial soil and chestnut soil, and the zonal vegetation type is steppe vegetation [ 12 , 37 , 38 ]. There are many mountains and deep ditches, and there is minimal flat land, serious soil erosion and water loss, low vegetation coverage, and a fragile ecosystem background [ 12 ].…”

Response of Vegetation and Soil Property Changes by Photovoltaic Established Stations Based on a Comprehensive Meta-Analysis

“…Based on previous studies [46][47][48], the soil physicochemical properties were selected as depicted in Figure 6. The results indicated that apart from SWC, which showed a significant positive response to PV power stations, soil physicochemical properties were not significant.…”