甲磺隆污染土壤的微生物生态效应

Ecological Effect of Metsulfuron-methyl on Soil Microbe

通过实验室培养试验研究了甲磺隆除草剂对土壤微生物活性和多样性的影响。结果表明,甲磺隆除草剂10mg·kg-1浓度处理释放的CO2与对照无明显差异,根据危害系数法的分级方法其属于无实际危害级农药;甲磺隆除草剂处理土壤微生物生物量碳、氮测定结果显示,甲磺隆除草剂10mg·kg-1浓度处理在初始阶段明显降低土壤微生物生物量碳、氮,随培养时间延长土壤微生物生物量先有所恢复,随后又有所下降,在30d后其变化趋于平缓;甲磺隆除草剂对土壤微生物群落结构和多样性产生一定影响,其影响随培养时间不同而异,反映出微生物学指标在一定程度上可作为除草剂污染土壤环境质量变异的有效指标。

An incubation experiment was conducted to study the dynamic response of soil microbial activity in a paddy soil taken from paddy field added metsulfuron-methyl of 10 mg·g-1 soil. The amount of emission CO2, microbial biomass carbon, microbial biomass nitrogen and microbial diversity were determined during the incubation. These soil microbial features varied with the incubation time. There existed no significant difference in the amount of emission CO2 between the treatment and the control. Microbial biomass C and N decreased in the early culture period, compared with the control, decreasing averagely 14.58% and 24.69% on the 7 day; while, after 14 days of culturing, the microbial biomass C and N increased. The structure of microbial community also changed after metsulfuron-methyl application, as indicated by Biolog data and Canonical Variate Analyses of Biolog community metabolic profiles. Soil microbial metabolic profiles (AWCD) values decreased from 1 day to 14 day after herbicide application, and then it recovered slowly after 14 days. It was suggested that the decline of soil microbial community functional diversities would occur in the soil contaminated by herbicides. So the microbial activities can effectively indicate soil environmental quality transition from contaminated soil to uncontaminated soil.