紫云英季土壤固氮微生物对外源碳氮投入的响应  

Responses of Soil Diazotroph Community to Rice Straw, Glucose and Nitrogen Addition During Chinese Milk Vetch Growth

作　　者：杨璐[1,2] 曾闹华[2] 白金顺[2] 周兴[3] 周国朋 高嵩涓 聂军[5] 曹卫东[2,4] YANG Lu;ZENG NaoHua;BAI JinShun;ZHOU Xing;ZHOU GuoPeng;GAO SongJuan;NIE Jun;CAO WeiDong(Graduate School,Chinese Academy of Agricultural Sciences,Beijing 100081;Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences/Key Laboratory of Plant Nutrition and Fertilizer,Ministry of Agriculture and Rural Affairs,Beijing 100081;Crop Research Institute of Hunan Province,Hunan Academy of Agricultural Sciences,Changsha 410125;College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095;Soil and Fertilizer Institute of Hunan Province,Hunan Academy of Agricultural Sciences,Changsha 410125)

机构地区：[1]中国农业科学院研究生院,北京100081 [2]中国农业科学院农业资源与农业区划研究所/农业农村部植物营养与肥料重点实验室,北京100081 [3]湖南省农业科学院作物研究所,长沙410125 [4]南京农业大学资源与环境科学学院,南京210095 [5]湖南省农业科学院土壤肥料研究所,长沙410125

出　　处：《中国农业科学》2020年第1期105-116,共12页Scientia Agricultura Sinica

基　　金：国家绿肥产业技术体系(CARS-22);中国农业科学院科技创新工程、现代农业人才支撑计划(Grant Ref:BB/N013484/1)

摘　　要：【目的】分析不同外源有机物料(稻草、葡萄糖)及氮素投入对紫云英季土壤固氮微生物的调控作用,为我国南方紫云英-水稻轮作体系中秸秆还田及化肥减施增效提供支持。【方法】采用盆栽试验,共设7个处理,即CK(对照,不添加有机物料和氮)、稻草等量添加并配施不同量氮素(分别表示为Rs、RsN1和RsN2,对应C/N比分别为66、25和13);等秸秆碳量添加葡萄糖并配施不同量氮素(即Glc、GlcN1、GlcN2)、调整C/N比与秸秆添加相应处理保持一致。采集紫云英快速生长期土壤样品,利用Illumina Miseq PE300高通量测序和绝对定量PCR技术分析固氮功能基因nifH及固氮微生物群落特征。【结果】单独添加外源秸秆或葡萄糖处理的土壤C/N与对照无明显差异,但增施氮肥后C/N比呈下降趋势,GlcN2处理土壤C/N显著低于对照;对于土壤速效养分,Rs和RsN1处理土壤NO3--N含量与CK类似,但RsN2处理明显增加了60%;而添加葡萄糖处理土壤NO3--N含量整体较高(增幅为35%-79%);稻草单独添加或与氮素配施对土壤速效磷含量无明显影响,添加葡萄糖处理则显著降低其含量,降幅为16%-24%,但不同氮水平之间无明显差异。不同处理土壤nifH基因拷贝数为80.4×106-140.5×106 g-1土,稻草和葡萄糖添加处理nifH基因拷贝数较CK呈增加趋势,而增施氮素后有所下降。外源碳、氮添加导致固氮微生物α-多样性较CK整体降低,但α-多样性对氮素的响应因碳源种类而异,即稻草添加后增加氮素供应(RsN1和RsN2)处理土壤固氮微生物物种数目和Chao 1指数较Rs显著降低,降低幅度分别为6%-11%和13%-15%,而添加葡萄糖后增施氮肥则对α-多样性有一定促进作用。PCoA结果显示土壤固氮微生物群落结构主要因碳源种类差异而聚集为不同组别,受氮水平供应的影响相对较小。属水平上不同物种对外源碳、氮添加的响应存在明显差异:慢生根瘤菌(Bradyrhizobium)相对丰�【Objective】This study was to reveal the regulating roles of carbon(C) sources(rice straw vs. glucose) and nitrogen(N) addition in soil diazotroph community during growth of Chinese milk vetch(Astragalus sinicus L.), which is crucial for the management of crop residue and mineral fertilizer application in Chinese milk vetch – rice rotation system in southern China. 【Method】A pot experiment was conducted with seven treatments, including CK(no exogenous C and N addition), rice straw(Rs) plus various rates of N inputs(Rs, RsN1 and RsN2, corresponding to C/N ratios of 66, 25 and 13, respectively), and glucose(Glc) addition plus different N rates(Glc, GlcN1, and GlcN2) with same C quantity and C/N ratios in Rs-included treatments. Soils were sampled during the fast-growing phase of Chinese milk vetch, and destined for characterization of nifH gene marker and diazotroph community by using the Illumina Miseq PE300 sequencing and PCR techniques.【Result】Soil C/N ratios were similar between the CK and the treatments with straw or glucose addition alone, while tended to decrease with increasing N input, and significant decrease was observed in the GlcN2 relative to CK. Regarding to the available nutrients, comparable soil NO3--N contents were observed under treatments of CK, Rs, and RsN1, but it was significantly increased by 60% under the RsN2 treatment. Compared to the CK, Glc-included treatments increased soil NO3--N content by 35%-79%. There were limited variations of soil available phosphorous(P) content under the CK and Rs-included treatments. 16%-24% decrease of soil available P content was found in the Glc-included treatments than that under CK, but not affected by N rates. The copy number of nifH gene ranged from 80.4× 106-140.5×106 g-1 soil under all treatments. Compared to the CK, nifH gene copy number tended to increase under treatments with both Rs and Glc addition, while a downward trend was observed with increasing N inputs. Exogenous C and N addition resulted in an overall decrease of diazotro

关 键 词：固氮微生物 水稻秸秆 葡萄糖 氮 紫云英 NIFH 

分 类 号：S551.9[农业科学—作物学] S511