Meitan xuebao (Jul 2023)
Ecological effects of humus layer reconstruction on the restoration of degraded soil in western mining areas
Abstract
With the national strategy of retreating from the east to the west in coal mining, the high intensity mining of coal resources has exacerbated the problem of ecological environment damage in mining areas, seriously affecting the coordinated development of large-scale development of regional coal resources and environmental protection in the western region. It is necessary to eliminate the negative environmental effects brought about by resource development through ecological restoration. Therefore, these feasibility studies have been subjected to humus layer reconstruction technology to repair the degraded soil sites in the grassland dust deposition area of the mining area, design three restoration modes of plant breakage + water logging (YS), plant breakage + water logging + film mulching (YF), and plant breakage + water logging + film mulching + activator (YFJ) and analyze the experimental data. The research results showed that the soil bulk density in the degraded habitat restoration area decreased by 8.26%, 7.98%, and 15.24%, respectively, compared to the control area. The porosity increased by 39.42%, 99.68%, and 124.24%, and the water content increased by 28.16%, 31.21%, and 71.19%. The saturated water holding capacity increased by 19.66%, 20.66%, and 42.29%, respectively, compared to the control area. In terms of soil nutrients, the content of hydrolyzed nitrogen was 20.77, 9.73, and 54.45 mg/kg higher than that of the control site. The content of available phosphorus was 5.30, 5.06, and 14.04 mg/kg, respectively. After remediation, the soil available potassium content increased by 49.61%, 27.31%, and 236.53%. The content of soil water-stable aggregates after remediation was 13.00%, 17.14%, and 83.60% higher than that of the control site, respectively. YS, YF, and YFJ remediation modes could all increase soil water enzyme activity in degraded sites. After remediation, soil sucrase activity is 23.65%, 79.88%, and 93.91% higher than that in the control area, respectively. There was no significant difference in catalase activity and urease activity among the three remediation techniques. They were 23.69%−31.81% and 19.35%−20.46% higher than the control site, respectively. The soil phosphatase activity increased by 14.73%, 33.28%, and 39.25% after remediation. The Shannon-Weiner index of plant community in the restoration site was 68.32%, 38.61% and 45.54% higher than that in the control site. The vegetation coverage increased by 12.50%, 81.25%, and 120.00% compared to the control site, respectively. The biomass of the restoration area was 39.90%, 373.49%, and 887.77% higher than that of the control site, respectively. The plant moisture content increased by 12.74% and 36.43% compared to the control area. The comparative analysis revealed the three restoration modes could effectively improve the degradation status of heavy dust settling area. Except soil organic matter and diversity index, YFJ had the best restoration effect in the other indexes. These indicated the humus layer reconstruction technology could effectively improve soil structure, enhance soil nutrients, activate soil microflora and function, and repair the broken habitat of shrubs, and provide reference for the restoration of degraded soil in the heavy dust settlement area,among them, YFJ restoration model was the best.
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