长期有机与无机肥配施的黄壤稻田土壤细菌群落结构特征

Bacterial community structure and composition under long-term combined application of organic and inorganic fertilizers in a yellow paddy soil

【目的】比较长期施用不同肥料黄壤稻田土壤细菌群落结构的差异,剖析不同肥料维持土壤细菌群落多样性的作用及其机理,为农田施肥管理提供理论依据。【方法】以农业农村部贵州耕地保育与农业环境科学观测试验站为依托,采用高通量测序技术,分析连续24年不施肥(CK)、全量化肥(NPK)、1/4牛厩肥+3/4化肥(1/4M+3/4NP)、1/2牛厩肥+1/2化肥(1/2M+1/2NP)和全量牛厩肥(M)处理黄壤稻田土壤细菌群落组成及多样性,并揭示其主要环境影响因子。【结果】不同施肥处理土壤细菌α多样性指数分析结果显示,长期施用有机肥提高了土壤细菌多样性指数(Shannon)、优势度指数(Simpson)和均匀度指数(Pielou),对丰富度指数(Chao1)影响较小。与CK相比,长期施肥不同程度地提高了变形菌门(Proteobacteria)的相对丰度,化肥的作用更明显。与CK和NPK相比,施用有机肥处理降低了棒状杆菌门(Rokubacteria)和亚硝酸盐氧化菌门(Nitrospinae)相对丰度,提高了拟杆菌门(Bacteroidetes)相对丰度,其他菌门变化不明显(P<0.05)。土壤细菌群落结构主成分分析结果表明,施用有机肥1/4M+3/4NP和1/2M+1/2NP处理土壤环境较为相似,细菌群落组成相似度较高,而CK和NPK处理土壤环境相似,细菌群落组成相似度高。土壤细菌群落结构组成与土壤环境因子冗余分析显示,土壤理化性质对细菌群落结构的影响重要性由大到小依次为全氮、碱解氮、速效钾、pH、有效磷、全磷,其中全氮、碱解氮和速效钾是关键因素。【结论】长期施用有机肥能够提高黄壤稻田土壤肥力,改变细菌生长环境,进而改变细菌群落结构组成,提高细菌群落多样性,促进土壤生态系统稳定和健康。

【Objectives】Comparing the differences in the bacterial community structure of yellow paddy soil when applying different fertilizers over a long time,and analyzing the effect and mechanism of long-term combined application of organic and inorganic fertilizers on sustaining soil bacterial diversity.【Methods】The study relied on the long-term experiment located in Scientific Observation and Experimental Station of Arable Land Conservation and Agricultural Environment(Guizhou),Ministry of Agriculture and Rural Affairs.Soil samples were collected from five treatments,no fertilizer control(CK),chemical fertilizer(NPK),1/4 manure N plus 3/4 chemical fertilizer(1/4M+3/4NP),1/2 manure N +1/2 chemical fertilizer(1/2M+1/2NP),and total manure N(M).High-throughput sequencing technology was used to analyze the microbial composition and diversity of colonies.The influence factors were discussed.【Results】Analysis of soil bacterial α diversity index of different fertilization treatments showed that long-term application of organic fertilizers increased the Shannon,Simpson and Pielou,with limited effect on Chao1 index.Compared with CK,long-term fertilization increased the relative abundance of Proteobacteria at varying degrees,and the effect of chemical fertilizers was more significant.Compared with CK and NPK,the application of organic fertilizers reduced the relative abundance of Rokubacteria and Nitrospinae,and increased the relative abundance of Bacteroidetes.The difference in other bacterial phyla was not significant(Pavailable nitrogen>available potassium>pH>available phosphorus>total phosphorus.Total nitrogen,available nitrogen,and available potassium were the key factors.【Conclusions】Long-term application of organic fertilizer improves the fertility of yellow paddy soil,changes the growth environment of bacteria,further alters the structure of bacterial community,increases the diversity of bacterial community,and promotes the stability and health of the soil ecosystem.