除草剂硝磺草酮对土壤微生物生态效应研究

采用室内培养试验,研究了硝磺草酮对土壤酶活性和微生物群落功能多样性的影响.结果表明,土壤过氧化氢酶和蔗糖酶活性随硝磺草酮浓度增加呈现先增加后降低的趋势,但比对照处理都有所升高,分别增加了22.6%~41.0%和3.4%~54.2%,且在硝磺草酮浓度为50mg/kg时达到最大.与之相反,尿酶活性则降低了12.0%~18.6%,但差异性不明显(P0.05).施用一定浓度的硝磺草酮激活了土壤微生物活性,微生物群落丰富度、均匀性和多样性都呈增长趋势,单孔的平均颜色变化率(AWCD)值和利用速率均随硝磺草酮浓度增加而增大,微生物群落对碳水化合物类、氨基酸类、多聚物类、羧酸类、胺类和酚酸类利用率整体上均有所提高,与对照相比,最大增幅分别达到5.3、1.0、4.4、3.2、0.2和6.8倍,但不同浓度硝磺草酮处理下土壤微生物在利用碳源的类型上是存在一定的差异.

Ecological Effects of herbicide mesotrione on soil microbial communities

The influence of mesotrione on soil enzyme activities and microbial community functional diversity in soils were investigated. The results showed that the activities of catalase and invertase first enhanced and then decreased with the increase of the concentration of mesotrione, while catalase and invertase activities under different treatments of mesotrione were higher than those of the control soil, resulting in from 22.6% to 41.0% and from 3.4% to 54.2%, respectively, increase when compared with CK. By contrast, urease activity was suffering from 12.0% to 18.6% reduction in comparison with the control, but there was no significantly different among the treatments of 0~100mg/kg mesotrione. The application of mesotrione inspired the activity of microbial community, and the abundance, diversity and evenness of soil microbial community were increased in soil. The values of average well color development (AWCD) and variation rate increased with increasing of mesotrione. Meanwhile, the utilization efficiency of carbohydrate, amino acid, polymer, aamine, carboxylic acid phenolic acid by soil microorganisms were increased as a whole, with the maximum of 5.3, 1.0, 4.4, 3.2, 0.2 and 6.8 times in contrast with the control group, but there were certain differences in the type of utilizing carbon by soil microbes under a serial contents of mesotrione.