玉米-大豆轮作对土壤酶和根系微生物群落多样性的影响

Effects of Maize Soybean Rotation on Soil Enzyme and Root Microbial Community Diversity

为探寻玉米-大豆轮作模式对东北地区土壤微生物多样性的影响,本文以玉米与大豆轮作体系为研究对象,设置玉米连作(CK1)、大豆连作(CK2)、玉米-大豆-玉米(MSM)和玉米-大豆-大豆(MSS)轮作共4个种植模式,测定分析各处理收获期土壤β-葡糖苷酶、纤维素酶、脲酶和硝酸还原酶活性,及根系微生物群落多样性关系。结果表明:轮作模式显著提高了土壤中β-葡糖苷酶、纤维素酶和脲酶的活性,硝酸还原酶活性较玉米连作提高了42.11%;前茬种植作物类型不同导致土壤β-葡糖苷酶活性差异显著;MSS轮作模式提高了土壤微生物群落的香农多样性指数、辛普森指数、均匀度指数和McIntoch指数,说明此模式改善了根系土壤微生物群落结构组成;利用Biolog技术和主成分分析结果表明,轮作和连作模式下土壤微生物的碳源利用模式出现分异,主要利用碳源为糖类和羧酸类物质。轮作种植体系增强了土壤酶活性,提高了土壤微生物群落的多样性,改变了根际土壤微生物群落功能利用能力和碳源的利用种类。

In order to explore the effect of maize soybean rotation mode on soil microbial diversity in Northeast China,the maize soybean rotation system was taken as the research object,four cropping modes were set up,including maize continuous cropping(CK1),soybean continuous cropping(CK2),maize soybean maize(MSM)and maize soybean soybean(MSS)rotation.The activities of soilβ-glucosidase,cellulase,urease and nitrate reductase,and the relationship between the diversity of root microbial community were analyzed.The results showed that the activities ofβ-glucosidase,cellulase and urease in soil were significantly increased by rotation mode,and the activity of nitrate reductase was 42.11%higher than that of maize continuous cropping;the difference of soilβ-glucosidase activity was significant due to different types of previous crops;MSS rotation model improved the Shannon diversity index,Simpson index,evenness index and McIntoch index of soil microbial community,indicating that the model improved the structure of soil microbial community structure.The results of Biolog and principal component analysis showed that the carbon source utilization patterns of soil microorganisms under rotation and continuous cropping were different,and the main carbon sources were sugars and carboxylic acids.Rotation system enhanced soil enzyme activity,improved the diversity of soil microbial community,and changed the function utilization ability and carbon source utilization types of rhizosphere soil microbial community.