Study On Evaluation Methods And Standards Of Soil Quality Of Reclaimed Agricultural Land In Open-pit Coal Mine In Loess Area

Coal is the main energy substance in China.In recent years,open-pit mining activities in mining areas have been increasing.While promoting economic development,it has also caused serious damage to the mining area and the surrounding ecological environment.Open-pit coal mining will change the original ecological surface and soil internal structure,destroy topsoil vegetation,disrupt local ecosystems,and carry out land reclamation and ecological reconstruction as an effective means to improve the ecological environment of the mining area.As an important part of the ecosystem,soil plays a key role in the reconstruction of the mining area ecosystem.Studying the soil quality evaluation standards of the mining area has scientific guidance significance for the land restoration and reconstruction in the mining area.China’s current soil environmental quality standards can no longer meet the actual needs of soil environmental management,and it is very urgent and necessary to study and put forward a suitable soil quality standard value system in China.This study takes the open-pit coal mine in the loess area as the research area,and summarizes previous studies on soil quality to collect relevant data on reclamation coal mines in the loess area.Starting from the three types of cultivated land,cultivated land,forest land,and grassland,the seven indexes of effective soil layer thickness,soil bulk density,gravel content,soil texture,pH value,soil organic matter,and total nitrogen were analyzed.Among them,the effective soil layer thickness,soil bulk density,and soil texture are used as hard indicators,and the evaluation criteria for the quality of reclaimed soil in open-pit coal mines in the loess area are established and compared with the existing soil quality evaluation standards.Conduct empirical research on the established evaluation criteria for the quality of the reclaimed soil,and select four coal mines in the Antaibao,Anjialing open-pit coal mines in Pingshuo,Heidaigou in Ordos,Inner Mongolia,and the Yongli open-pit coal mine in Inner Mongolia as research areas,and select 66 samples to evaluate the quality of the reclaimed soil,and classify the recultivation results into five levels: unqualified,poor,qualified,good,and excellent.The results showed that the reclamation soil quality of the Pingshuo open-pit coal mine during the reclamation period and the protection period after the reclamation were all It can pass the test,and basically can achieve good or even excellent in 3-6 years,and the effect of reclamation is remarkable.It shows that the established soil quality evaluation standards for open-pit coal mines in the loess area are practical and can more accurately reflect the quality status of the reclamation soil in the mining area,and provide a reference for improving China’s reclamation soil quality evaluation standard system.