覆盖作物不同利用方式对猕猴桃园土壤微生物群落结构的影响

为探讨覆盖作物不同利用方式对猕猴桃园土壤微生物群落结构的影响，通过磷脂脂肪酸（PLFA）方法，研究覆盖作物处理对猕猴桃园土壤微生物群落结构的影响。试验设置3个处理，分别为种植覆盖作物+覆盖作物刈割后留在土壤表面自然腐解（T1）、种植覆盖作物+覆盖作物刈割后从园中清除（T2）和清耕对照（CK）。结果表明，T1、T2处理土壤微生物PLFAs总量和微生物量碳、氮均显著高于CK（P<0.05）；土壤pH和碳氮比是影响猕猴桃园土壤微生物群落的主要环境因子，pH与土壤微生物PLFAs总量呈极显著正相关（P<0.01），与细菌PLFAs量、革兰氏阴性菌PLFAs量呈显著正相关（P<0.05），碳氮比与革兰氏阳性菌PLFAs量/革兰氏阴性菌PLFAs量呈极显著正相关（P<0.01）。研究表明，猕猴桃园种植覆盖作物改变了土壤环境因子，影响土壤微生物群落结构组成。研究可为丹江口水源涵养区果园生态管理模式的探索提供理论依据。

Effects of different cover crop treatments on soil microbial community composition in kiwifruit orchard

In order to provide a theoretical basis for ecological management model in an orchard, we investigated the characteristics of soil microbial community composition under cover crop treatments in a kiwifruit orchard in the water source conservation area of Danjiangkou. We used the phospholipid fatty acid(PLFA)method to analyze the effects of different treatments(T1:Cover crop left on soil after cutting; T2:Cover crop and removed after cutting; CK:Clean tillage)on soil microbial community structure. The results showed that the total PLFAs, microbial biomass carbon, and nitrogen of cover crop treatments(T1 and T2)were significantly higher than that of CK(P<0.05).Soil microbial community was influenced mainly by soil pH and carbon/nitrogen ratio. Soil pH was positively correlated with total PLFAs, bacteria PLFAs, Gram-negative bacteria PLFAs. And there was a positive relationship between Gram-positive bacteria PLFAs/Gram-negative bacteria PLFAs ratio and carbon/nitrogen ratio. In summary, intercropping cover crop in kiwifruit orchard changed soil environmental factors and impacted soil microbial community composition.