Effect Of Different Microbial Agents On Soil Matrix Improvement Of Reclaimed Land In Mining Area

As one of the important energy resources,coal resources bring energy and resource benefits.At the same time,the waste produced in the mining process and the abandoned mining area have brought great harm to the ecological environment.As a part of the abandoned land of coal mine,the ecological restoration of dump and waste dump has become an important part of the sustainable development of the mining area.The combined phyto-microbial remediation technology has attracted more and more attention from scholars in the research of mining area reclamation due to its characteristics of high efficiency,low consumption,simple operation and significant ecological benefits.In this study,pot experiments were conducted on alfalfa to compare and analyze the effects of single inoculation with Trichoderma harzianum(TH),Trichoderma viride(TV),Bacillus mucilaginosus(BM),Arbuscular Mycorrhizal Fungi(AMF),and double inoculation with TH+BM,AMF+TH,AMF+BM,and the inoculation with Three Bacteria TH+BM+AMF microbial agents on the soil and gangue matrix improvement in the dump.The results can provide a theoretical basis and technical support for the reclamation soil improvement and ecological restoration in Haizhou Open Pit Mine and similar mining areas.The main research results are as follows:(1)Single inoculation,double inoculation and triple inoculation with microbial inoculum in the soil and coal gangue matrix of the dump had good growth promoting effect on alfalfa.Compared with single inoculation,double inoculants could further promote the growth of alfalfa,and there was a synergistic effect between the inoculants.Compared with double inoculation,triple inoculation had no significant effect on the promotion of plant growth.(2)The microbial inoculum can regulate that p H value of the soil and the gangue matrix of the dump,greatly improve the content of the available nutrient of the soil,increase the enzyme activity,the respiratory intensity,the MBC and MBN content and the bacterial content of the soil and the matrix.There were some differences in the improvement effect of single index of soil among the treatments.In general,the improvement effect of double inoculation treatment was better than that of single inoculation and three-bacteria inoculation treatment.The double inoculation treatment could effectively improve the reclamation effect of abandoned land in mining areas,and had a synergistic effect.The effect of inoculation with three bacteria on the improvement of nutrients,enzyme activity and microbial biomass of reclaimed matrix was lower than that of double inoculation.After the three microorganisms were inoculated at the same time,there was an antagonistic effect between the microorganisms.(3)A comprehensive evaluation of the improvement effects of the nine treatments on the soil and coal gangue matrix of the dump was conducted using the Soil Comprehensive Evaluation Index(SQI).The results showed that the addition of microbial agents could improve the reclamation effect of the mining area very well.The order of SQI of the soil in the dump was AMF+TH > TH+BM+AMF > AMF+BM > TH+BM > AMF > BM > TH > TV > CK of the control group from large to small.The order of SQI of gangue matrix from large to small was AMF+TH > AMF+BM > TH+BM > AMF > TH+BM+AMF > TH > TV > BM > CK control group.(4)In summary,the effect of double inoculation of microbial inoculum on the mining area soil was better than that of single inoculation.Compared with other treatments,the double inoculation of arbuscular mycorrhizal fungi had the best maturation degree and improvement effect on the soil of dump and coal gangue matrix.It could improve the soil of mining area abandoned land and strengthen plant growth,and had certain application potential in the vegetation recovery and treatment of mining area abandoned land.