Test Study On Soil Nutrient Cycling Of Coal Mining Subsidence Area And Its Impact On The Ecological Environment

The original surface morphology has been destroyed by the ground subsidence caused the rapid and stable development of Northwest coal industry. As well as, soil erosion also accelerated, leading to serious soil erosion, reducing the rate of vegetation cover and a series of ecological and environmental problems has been induced.Taking Shenfu - Dongsheng mining area as an example, the rule of changes of soil nutrient cycling under the conditions of coal mining subsidence and the influence of changes of soil nutrient cycling on the local ecological environment have been in-depth study by survery of vegetation in field combined with analysis of soil nutrient in room, which provides theoretical basis for quantitative analysis of the influence degree of coal mining subsidence on soil nutrient loss, accurate evaluation and reasonable development of the mining area of land resources, the realization of the reconstruction of mine reclamation and the ecological environment and so on. The main achievements are as follows:(1) The cracks, slopes, and collapse pits created by coal mining subsidence will increase the loss of soil nutrition. Once the collapse is ultimately stabilitated, the ground fissures will gradually disappear on the effects of natural weathering, making the collapse and subsidence pit and subsidence slope gradually become stabilization and flat, which will last for two or three years;(2) Vegetation has a strong aggregation role on soil nutrition so that the restoration of vegetation has an positive sense to soil fertility. After the stabilization of collapse, vegetation begins to recover. Ten years after the collapse, both of the delayed-action soil nutrition or available nutrition and soil buffer capacity are significantly improved. At the same time the content of soil clay is increased and corrosion resistance enhances;(3) The relationship between coal mining subsidence, soil nutrient cycling and vegetation is interactive. It means that coal mining subsidence can destroy soil nutrient cycling and the vegetation; vegetation, in reverse, can repair the damage generated by coal mining subsidence and improve soil fertility. Moreover, soil nutrition is inseparable with vegetation growth. When the vegetation's repair capacity is insufficient, manual intervention such as afforestation, increasing green space, is required, leading the eco-development of mining area into the healthy track.