施用改良剂和种植栾树对锰矿渣微生物群落的影响

施用改良剂可降低矿区重金属污染对植物的胁迫，但其对根际环境的影响机制尚不明晰。以栾树(Koelreuteria paniculata)为供试植物、以某锰尾矿区矿渣为基质，比较CK(100%矿渣)、S0(90%矿渣+5%蘑菇渣+5%凹凸棒)和S1(90%矿渣+5%蘑菇渣+5%凹凸棒，种植栾树)等3个处理重金属赋存状态和微生物多样性等的差异，探究施用改良剂和种植栾树等对矿渣中重金属拦截效果的影响。结果表明，施用改良剂(即蘑菇渣和凹凸棒)提高了矿渣pH，增强了其肥力和持水性；而种植栾树可降低重金属的生物有效性，Mn、Pb、Zn的残渣态比例显著提升，较S0分别提升了5.73%、13.5%和6.47%，较CK分别提升了4.98%、12.8%和6.01%。实验前、后各基质中Mn、Pb、Zn随雨水径流的流失量差异显著，表现为S1Bacteroidota)、酸杆菌门(Acidobacteriota)、担子菌门(Basidiomycota)和子囊菌门(Ascomycota)的相对丰富显著增加，腐生和富养菌等有益菌的相对丰度和多样性提升明显，有利于保持土壤肥力和促进栾树生长，提高其抗逆性和修复效率。

Effects of modifier application and Koelreuteria Paniculata planting on the microbial community of a manganese slag

The application of amendments can reduce the stress of heavy metal pollution on plants in mining areas, but the mechanism of its impact on the rhizosphere environment is still unclear. In this study, Koelreuteria paniculata was taken as the test plant and a manganese tailings slag was taken as the substrate, the differences in the occurrence status and microbial diversity of heavy metals in CK (100% slag), S0 (90% slag+5% spent mushroom slag+5% attapulgite), and S1 (90% slag+5% mushroom slag+5% attapulgite, planting Koelreuteria paniculata trees) were compared, and the effects of application of modifiers and planting Luan tree on the interception of heavy metals in slag were explored. The results showed that the application of modifiers (i.e. mushroom residue and attapulgite) increased the pH of the slag, enhanced its fertility and water holding capacity. Planting Koelreuteria paniculata trees could reduce the bioavailability of heavy metals, and significantly increased the residual proportions of Mn, Pb, and Zn, which were 5.73%, 13.5%, and 6.47% higher than S0, and 4.98%, 12.8%, and 6.01% higher than CK, respectively. A significant difference occurred in the amount of Mn, Pb, and Zn loss with rainwater runoff in each substrate before and after the experiment, and the corresponding order was S1Koelreuteria paniculata trees and applying amendments had a significant impact on the microbial community structure of slag, and slight difference occurred in bacteria between S0 and S1 treatments, while the significant differences appeared in fungal α diversity. Compared with CK and S0, S1 treatment significantly increased the relative abundance of Bacteroidota, Acidobacteria, Basidiomycota and Ascomycota, as well as the relative abundance and diversity of beneficial bacteria such as saprophytic and eutrophic bacteria, which was conducive to maintaining soil fertility and promoting the growth of Koelreuteria paniculata trees, improving their stress resistance and repair efficiency.