长期施肥对大麦-双季稻种植方式中大麦根际土壤微生物群落功能多样性的影响

Effects of Different Long-term Fertilization Treatments on Rhizospheric Soil Microbial Community Functional Diversity of Paddy Field in Barley-double Cropping Rice System

【目的】微生物群落功能多样性是土壤质量变化的敏感指标,施肥措施与土壤微生物群落功能多样性关系密切。本文的目的在于探明不同施肥措施对土壤微生物群落功能多样性的影响。【方法】以双季稻主产区肥料长期定位试验田为研究对象,应用Biolog技术分析了化肥(MF)、秸秆还田+化肥(RF)、30%有机肥+70%化肥(LOM)、60%有机肥+40%化肥(HOM)、无肥对照(CK)不同施肥处理对大麦成熟期双季稻田根际土壤微生物功能多样性的影响,从根际土壤微生物功能多样性的角度评价施肥对土壤质量的影响。【结果】MF、LOM和HOM处理大麦根际土壤微生物对碳源的利用程度均显著高于其他处理,而RF处理大麦根际土壤微生物对碳源的利用程度低于CK处理。在大麦成熟期,Richness和Shannon指数大小顺序均表现为:HOM>LOM>RF>CK>MF,Mc Intosh指数均以HOM和LOM处理为最高,其次为RF和CK处理,MF处理最低。土壤微生物碳源利用的主成分分析结果表明,各施肥处理大麦根际土壤微生物群落利用的碳源主要为氨基酸类和糖类,不同施肥处理间碳源利用类型存在明显的差异。【结论】不同施肥处理对大麦根际土壤微生物功能多样性产生了不同影响,长期有机无机肥配施有利于维持稻田根际土壤微生物群落多样性。

【Objective】Microbial community functional diversity is a sensitive indicator of soil quality.There has a closely relationship between the fertilizer practices and the microbial community functional diversity of paddy fields. Therefore,our objective was to explore the effects of different fertilizer practices on rhizosphere soil microbial community functional diversity in a double-cropping rice system.【Method】There has a long-term experiment was established in 1986,and five different fertilizer treatments were applied:(1)no fertilizer input(CK);(2) mineral fertilizer alone(MF);(3)rice residue plus mineral fertilizer(RF);(4)30% organic matter and 70% mineral fertilizer(LOM);(5)60% organic matter and 40% mineral fertilizer(HOM). We analyzed the rhizosphere soil microbial community functional diversity of the fields at barley mature stages with the above five treatments using Biolog system.【Results】The results showed that the average well color development(AWCD)were increased with MF,LOM and HOM treatments,while the AWCD with RF treatment were lower than that of CK. In addition,the indices of Richness,Shannon and Mc Intosh under different fertilization treatments were ordered as follows:HOM>LOM>RF>CK>MF at mature stages of barley. PCA analysis indicated that there were different carbon-substrate-utilization patterns among different fertilizer treatments. Amino acids and carbohydrates were the main carbon resources utilized by rhizosphere soil microbes. Meanwhile,there were significant differences in carbon-substrateutilization patterns among different fertilizer treatments.【Conclusion】The combined application of chemical fertilizer with organic manure could significantly increase the rhizosphere soil microbial community functional diversity at mature stages of barley.