覆盖作物多样性对猕猴桃园土壤微生物群落功能的影响

以丹江口水源涵养区猕猴桃园为研究对象,运用Biolog微平板技术,研究不同种类覆盖作物处理(2、4、8种和清耕对照)下土壤微生物群落功能多样性的差异。结果表明,覆盖作物处理土壤微生物群落对碳源的利用程度、功能多样性指数和丰富度指数均高于清耕对照。覆盖作物及清耕对照处理土壤微生物Shannon-Wiener多样性指数、丰富度指数与土壤含水量、有机碳、pH、微生物量碳氮呈显著正相关关系。主成分分析与碳代谢图谱分析表明,猕猴桃园增加覆盖作物种类提高了土壤微生物对碳源的利用能力,且对D-甘露醇、L-精氨酸、L-天门冬酰胺、L-苯丙氨酸、γ-羟丁酸、α-丁酮酸、4-羟基苯甲酸、吐温40的利用能力显著高于清耕对照。此外,4种覆盖作物处理对猕猴桃园土壤生态环境的影响优于2种和8种。研究表明,猕猴桃园增加覆盖作物多样性改变了土壤环境因子,影响了土壤微生物群落的代谢活性和功能多样性。

Effects of cover crop diversity on soil microbial community functions in a kiwifruit orchard

In this paper,we used the Biolog micro plate technique to analyze the effects of cover crop diversity(C2,two cover crop species;C4,four cover crop species;C8,eight cover crop species;CK,no cover crop)on functional diversity of soil microbial communities in a kiwi fruit orchard in the water source conservation area of Danjiangkou.The results showed that the carbon utilization degree,functional diversi ty index,and richness index of the soil microbial community in cover crop treatments were higher than in the untreated control.The Shan non index and richness index were positively correlated with soil moisture content,organic carbon,microbial biomass carbon,and nitrogen.The principal component analysis and the fingerprints of the physiological carbon metabolism of the microbial community demonstrated that carbon source metabolic ability of the soil microbial communities was improved by increasing cover crop species,and compared with the clear tillage,the utilization rate on D-Mannitol,L-Arginine,L-Asparagine,L-Phenylalanine,γ-Hydroxybutyric acid,α-keto butyric acid,4-Hydroxybenzoic acid,and Tween 40 was improved significantly.In addition,the effect of four kinds of cover crop treatment on the soil ecological environment of kiwifruit orchard is superior to that of two species and eight species.In summary,increasing cover crop diver sity in a kiwifruit orchard changed the soil environmental factors and had a great influence on the metabolic activity and functional diversity of the microbial communities.