除草剂2,4-D对土壤微生物类群的影响

Effects of Herbicide 2,4-D on Soil Microbial Population

为了评价除草剂2,4-D对土壤生态系统的影响,采用构建人工微生态的方法,在42d内动态评估供试土壤中微生物类群的变化。结果表明:当2,4-D使用浓度为5mg/kg时,对土壤细菌及放线菌均没有显著影响,对真菌的影响也可以较快地恢复;浓度为25mg/kg和50mg/kg的处理,细菌和真菌总数均表现下降,但细菌的适应性更强;放线菌总数则表现出一定的波动性。2,4-D处理浓度越高,对真菌的抑制作用也越强。因此,建议将土壤中真菌总数作为评估除草剂2,4-D污染土壤生态环境效应的敏感指标。

In order to assess the effects of herbicide 2,4-D on soil microecological systems,the dynamic changes of soil microbial population were evaluated during 42 days incubation times by constructing manual micro-ecology.The results showed that bacteria and actinomyces were not suffered significant effects,and the influence on fungus was recovered soon when soils were treated with 5 mg/kg 2,4-D.Whenever 25 mg/kg and 50 mg/kg of 2,4-D were added to the soils,the number of bacteria and fungus was decreased, whereas the adaptability of bacteria was stronger than fungus.Meanwhile actinomyces number was risen and fallen,too.And the inhibition on fungus was increased with the higher treated concentration of 2,4-D.It suggested that fungus number could be a sensitive indicator which assessed the ecological effect of environment herbicide 2,4-D polluted.