二甲戊灵对棉田土壤微生物的影响

以土壤微生物为研究对象,采用平板计数法分别对不同深度土壤细菌、真菌、放线菌数量进行统计,探究二甲戊灵处理后土壤微生物种群变化。结果表明,土壤深度为0~15 cm时,二甲戊灵对细菌、真菌、放线菌多为抑制作用,其中放线菌种群对表现的最为明显,呈持续抑制状态;细菌次之,呈阶段性抑制状态;而真菌对二甲戊灵具有一定抗性,随着时间的推移抑制和激活均不明显。土壤深度为15~20 cm时,二甲戊灵对3种微生物有不同程度激活作用。二甲戊灵对土壤微生物的影响随微生物种类和二甲戊灵浓度和土壤深度而异。正常使用浓度下,对微生物的影响是暂时的,其稳定系统不易破坏,但长期施用二甲戊灵会引起土壤微生物的失衡。

Effects of pendimethalin on Cotton Soil Microorganism

Soil microorganism was used as the research object,the number of bacteria,fungi and actinomy?cetes in different depths of soil were determined by using the plate counting method to explore the influences of pendimethalin on soil microbial population.The results showed that fungi and actinomycetes were mostly inhibi?ted.Actinomycetes was the most sensitive microorganism,the inhibition effect of the pendimethalin on it was continuous.Pendimethalin had secondarily inhibition on bacteria with a phased inhibition. Fungus had resist?ance to pendimethalin,the inhibition and activation didn’t vary with lasting time after application.At the soil depth of 15-20 cm, pendimethalin had different degrees of activation on three kinds of microorganism. The effects of pendimethalin on soil microorganisms varied with the microorganism spices,concentrations of pendim?ethalin and soil depth.Under the concentration for normal use,the influence of pendimethalin on the microor?ganism was temporary,not apt to damage its stable structure.Long?term application of pendimethalin would in?fluence the balance of soil microbe.