不同施氮水平下再生水灌溉对土壤细菌群落结构影响研究

微生物是土壤环境变化的敏感因子,为探明再生水灌溉和氮素减量施用对土壤环境的影响,以温室棚栽番茄为研究对象,借助Miseq高通量技术,比较研究了再生水灌溉下氮素常规施肥和氮肥减量施用对土壤细菌群落结构所产生的影响,并采用冗余分析(Redundancy Analysis,RDA)方法分析导致土壤细菌群落结构差异的因素.结果表明:再生水灌溉对土壤硝化螺菌门(Nitrospirae)、芽单胞菌门(Gemmatimonadetes)、厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)和放线菌门(Actinobacteria)群落结构的影响明显;再生水灌溉土壤细菌共53个属,其中41个属是再生水灌溉和清水灌溉土壤的共有菌属,其余12个属是再生水灌溉土壤的特有菌属.随氮素施用水平的降低,土壤细菌种群优势度呈先增加后降低然后再增加的趋势,减少氮肥施用有利于土壤细菌种群丰富度和多样性的增加.土壤微生物群落结构受土壤化学特性的影响.再生水灌溉能够促进与土壤碳、氮转化相关的微生物的增长,改变土壤微生物的群落结构.

Impact of reclaimed water irrigation and nitrogen fertilization on soil bacterial community structure

Microbial communities were sensitive to changes of soil environmental conditions. Taking the greenhouse tomatoes as the research object, the effect of the characteristics of bacterial community structure and the impact of environmental factors were studied under reclaimed water irrigation with conventional nitrogen fertilization and reducing nitrogen topdressing. Miseq high-throughput technology was performed and the formation of different soil bacterial community structure were determined by Redundancy Analysis(RDA). The results indicate that the community structure of Nitrospirae, Gemmatimonadetes, Firmicutes, Proteobacteria and Actinobacteria were significantly influenced by reclaimed water irrigation. The bacteria in soil irrigated with reclaimed water was 53 genera, including 41 common genera in reclaimed water irrigation and clean water irrigation soils, 12 endemic genera in reclaimed water irrigation soil. With the decreasing of nitrogen, bacterial Simpson index showed that first increase then decrease and increase again. It was beneficial to the improvement of species richness and diversity in soil bacterial community by reducing nitrogen fertilizer application. The structure of soil microbial community was influenced by soil chemical properties. It was more conducive to the growth of soil bacteria, which had the ability of degradation and regeneration of organic carbon and nitrogen, and thus to change the soil microbial community structure.