农业环境科学学报2017，Vol.36Issue(4)：709-717,9.DOI:10.11654/jaes.2016-1267
长期氮添加对贝加尔针茅草原土壤微生物群落多样性的影响
Effects of different long-term nitrogen addition on soil microbial diversity of Stipa baicalensis steppe in Inner Mongolia, China
摘要
Abstract
To reveal the responses of soil microbial biomass carbon, soil microbial nitrogen and functional diversity of soil microbe to long term nitrogen additions in Stipa baicalensis steppe, chloroform fumigation extraction method and Biolog Ecoplate were used to study the changes in soil microbial diversity under different N treatments, including N0(0 kg N·hm-2), N15(15 kg N·hm-2), N30(30 kg N·hm-2), N50(50 kg N·hm-2), N100(100 kg N·hm-2), N150(150 kg N·hm-2), N200(200 kg N·hm-2), N300(300 kg N·hm-2). Soil samples were separately collected from the 0∽10 cm and 10∽20 cm soil layer. The results showed that long-term applications of inorganic nitrogen re-duced the soil microbial biomass carbon, while higher nitrogen treatments enhanced the microbial biomass nitrogen, thus significantly re-duced the microbial quotient. The AWCD values of the soil microbial communities in 0∽10 cm soil layer varied as follows:N50>N30>N100>N15>N0>N200>N150>N300. Within same nitrogen treatment, soil microbial biomass carbon and microbial biomass nitrogen and the overall trend AWCD value in 0∽10 cm soil layer was higher than those in 10∽20 one. At 0∽10 cm soil layer, higher nitrogen treatments(N100, N150, N200, N300)reduced the Shannon index and increased the evenness index, but not for dominance index. Principal component analy-sis showed that there were very significant differences between higher nitrogen treatments and lower nitrogen treatments and the control in the carbon utilization ability of soil microbial community. Soil parameters, including pH, total nitrogen, total phosphorus, microbial biomass N, microbial quotient, microbial biomass C/N and nitrate nitrogen, had close relationships with microbial functional diversity. Moreover, 100 kg N·hm-2 was the threshold with which the effect on microbial activity shift from stimulation to inhibition after long-term nitrogen addition in the study area.关键词
贝加尔针茅草原/氮添加/土壤微生物生物量/土壤微生物多样性Key words
Stipa baicalensis steppe/nitrogen addition/soil microbial biomass/soil microbial diversity分类
农业科技引用本文复制引用
刘红梅,张海芳,皇甫超河,李洁,周广帆,杨殿林..长期氮添加对贝加尔针茅草原土壤微生物群落多样性的影响[J].农业环境科学学报,2017,36(4):709-717,9.基金项目
国家自然科学基金项目(31170435) The National Natural Science Foundation of China(31170435) （31170435）
