Effects Of Different Fertilization Treatments On Soil Microorganisms And Enzyme Activities And Vegetation Characteristics On Surface Residue In Alpine Mining Areas

To solve the problems of nutrient deficiency and high p H of surface coalmine debris in the ecological restoration process of Muli coalmine in Qinghai,a two-factor controlled experiment with application of organic fertilizer and ferrous sulfate was designed to explore the effect of different fertilization measures on p H improvement of residual soil in Muli coalmine.The organic fertilizer（M）treatment was set at four levels:0 kg·m^-2（M0）,1 kg·m^-2（M1）,2 kg·m^-2（M2）,and 3 kg·m^-2（M3）.The ferrous sulfate（F）treatment was set at three levels:0 g·m^-2（F0）,50 g·m^-2（F1）and 100 g·m^-2（F2）.This study compared the effects of different application levels of organic fertilizer and ferrous sulfate on vegetation height,coverage,above-ground biomass,physical and chemical properties,microbial and enzymatic activities of the residue soil to provide theoretical reference for ecological restoration of residual soil improvement and vegetation restoration in alpine coalmine area.The main research results are as follows:（1）The treatment of F1M3 could significantly increase vegetation height,coverage and above-ground biomass（p<0.05）.The F2M3 treatment could significantly increase the content of organic matter in residual soil and reduce the p H of the residual soil.（2）The results of significant relationship analysis between physicochemical properties and enzyme activities of mine residue showed that the available phosphorus,alkali-hydrolyzable nitrogen,maximum water content of the debris pile were significantly positively correlated with catalase and protease.Bulk density and dehydrogenase were significantly positively correlated.In the second year of fertilization,p H can promotes alkaline phosphatase activity,and a significant positive correlation among urease activity,organic matter and maximum water content（p<0.05）,It shows that the environmental factors of the muck have an important influence on the promotion of enzyme activity.（3）Vegetation height,coverage,and above-ground biomass were positively correlated with Shannon index of bacteria in the first year of fertilization（p<0.05）.p H had a significant positive correlation with fungalα-diversity in the second year（p<0.05）.Fertilization combined with F0M3 treatment could effectively improve theα-diversity of bacteria and fungi,and theα-diversity of fungi was mainly affected by ferrous sulfate.（4）Non-metric multidimensional scaling（NMDS）results showed that the most significant differences were found between the treatments of F0M0 and F0M3 for bacteria and between the treatments of F0M0 and F1M3 for fungi in the first year of fertilization.The most significant differences were found between the F2M0 and F2M1treatments for bacteria in the second year of fertilization.（5）The dominant phyla of bacteria were Actinomycetes,Anaplasma,and Green Curvularia.The dominant phyla of fungi were Ascomycetes,Streptomycetes,and Potamomycetes.The dominant phyla of bacteria in the second year were Anaplasma,Actinomycetes,and Anaplasma,with the highest relative abundance of 46.6%for Anaplasma and 29.6%for Anaplasma.The dominant phyla of fungi were Ascomycetes,Potamomycetes,and Streptomycetes.The highest abundance of Ascomycetes was70.3%,and the highest abundance of Oleurobacteria was 57.3%.（6）The increase of vegetation height,cover,aboveground biomass and organic matter content can significantly increase the relative abundance of Bacteroidetes,and Catalase is an important factor affecting the community of Actinobacteria.The bulk density of soil and soil water content are important factors affecting Firmicutes community,and p H had a great influence on the relative abundance of Basidiomycota.Combined with the above results,the combination of F0M3 and F1M3 treatments could significantly improve vegetation height,coverage and above-ground biomass.Chemical properties such as total nitrogen,total phosphorus,alkaline soluble nitrogen,available phosphorus,organic matter and soil p H of the debris pile,as well as physical properties such as bulk density,maximum water content and soil water content could also effectively improve theα-diversity of microorganisms in the pile soil.Therefore,in the later promotion and application,the F0M3 fertilization combination and F1M3fertilization combination can be selected according to the acidity and alkalinity of the pile soil in alpine coalmine area.The F0M3 fertilization treatment can be selected when the soil p H of the debris pile is low,and the F1M3 fertilization treatment can be selected when pH is higher.