不同麦秸还田模式对稻田土壤微生物活性和微生物群落组成的影响  

Effects of different models of wheat straw return on paddy soil microbial activities and community compositions

作　　者：王宁[1] 罗佳琳 赵亚慧 李勇 于建光[1,2,4] WANG Ning;LUO Jia-lin;ZHAO Ya-hui;LI Yong;YU Jian-guang(Institute of Agricultural Resources and Environment,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;College of Resources and Environment Sciences,Nanjing Agricultural University,Nanjing 210014,China;Soil and Fertilizer Technical Guidance Station of Jintan District,Changzhou 213200,China;Scientific Observing and Experimental Station for Farmland Conservation(Jiangsu),Ministry of Agriculture and Rural Affairs,Nanjing 210014,China)

机构地区：[1]江苏省农业科学院农业资源与环境研究所,南京210014 [2]南京农业大学资源与环境科学学院,南京210014 [3]江苏省常州市金坛区土壤肥料技术指导站,江苏常州213200 [4]农业农村部江苏耕地保育科学观测实验站,南京210014

出　　处：《农业环境科学学报》2020年第1期125-133,共9页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(41601261);公益性行业(农业)科研专项(201503136)~~

摘　　要：为探讨典型稻麦轮作区土壤微生物活性和群落组成对麦秸还田的响应规律,开展大田试验研究了麦秸直接还田、麦秸与氮肥配施、麦秸泡田还田三种模式下,稻田土壤微生物量碳和微生物量氮含量、酶活性和微生物群落组成的变化响应规律。结果表明:三种麦秸还田模式均显著提高稻田土壤微生物量碳(251 mg·g^-1vs 263~282 mg·g^-1)、氮(16.9 mg·g^-1vs 24.6~27.6 mg·g^-1)含量,降低微生物量碳氮比(14.9 vs 8.58~10.7),提高土壤中多酚氧化酶活性(16.7 mmol·g^-1·h^-1vs 21.5~24.8 mmol·g^-1·h^-1),但对于酸性磷酸酶活性并无显著影响。稻田土壤中过氧化氢酶、蔗糖酶和脲酶活性的变化在不同麦秸还田模式下存在显著差异,秸秆直接还田和麦秸与氮肥配施还田显著提高过氧化氢酶活性;麦秸泡田还田对过氧化氢酶活性无影响,但显著提高蔗糖酶活性;而秸秆直接还田和麦秸泡田还田则显著降低脲酶活性。基于高通量测序,稻田土壤中优势细菌是绿弯菌门(Chloroflexi,24.2%~25.5%)、放线菌门(Actinobacteria,21.5%~24.1%)、变形菌门(Proteobacteria,18.2%~21.1%)、酸杆菌门(Acidobacteria,9.5%~11.1%)和厚壁菌门(Fimicutes,7.1%~8.4%)。与未施用麦秸土壤相比,麦秸还田显著提高了土壤中变形菌门的相对丰度,提升幅度为13.9%。非度量多维尺度分析(NMDS)结果显示,与未施用麦秸还田相比,麦秸直接还田和麦秸与氮肥配施还田改变了土壤中细菌群落组成,而麦秸泡田还田则未能改变土壤中细菌群落组成。综合分析认为,麦秸还田为微生物提供了充足的碳源和能源,提高了土壤微生物量,而酶活性和土壤细菌群落组成对不同秸秆还田模式的响应不同。To explore the responses of microbial activities and community compositions to wheat straw return in paddy soils during ricewheat rotation, changes in microbial biomass carbon and nitrogen, enzyme activities, and bacterial community compositions were assessed in paddy fields under three models of wheat straw return:direct straw return(S), straw return coupled with nitrogen fertilization(SN), and straw return with ponding(SP). Results showed that all three models increased the content of microbial biomass carbon(251 mg·g^-1 vs.263~282 mg·g^-1)and nitrogen(16.9 mg·g^-1 vs. 24.6~27.6 mg·g^-1), but significantly decreased the ratio of the microbial biomass carbon to nitrogen(14.9 vs. 8.58~10.7). Activity of polyphenol oxidase(16.7 mmol·g^-1·h^-1 vs. 21.5~24.8 mmol·g^-1·h^-1)was enhanced by all three models of straw return, whereas acid phosphatase activity was not affected. However, the responses of catalase, invertase, and urease activities varied significantly depending on the straw return model. Catalase activity was significantly(P<0.05)enhanced in S and SN treatments, whereas SP did not affect catalase activity but significantly(P<0.05)increased invertase activity. Urease activities were significantly(P<0.05)reduced in S and SP treatments. Based on Illumina sequencing, chloroflexi 24.2%~25.5%), actinobacteria(21.5%~24.1%), proteobacteria(18.2%~21.1%), acidobacteria(9.5%~11.1%), and fimicutes(7.1%~8.4%)were the predominant phyla in paddy soils. Compared to the control treatment, the relative abundance of proteobacteria was significantly(P<0.05)enriched by 13.9% with straw return.Nonmetric multidimensional scaling analyses showed that S and SN treatments were different from the control treatment, whereas SP was overlapped with the control. This suggests that S and SN considerably altered soil bacterial community compositions, whereas no effect was observed from SP. Overall, this study showed that straw return significantly increased the microbial biomass by providing a carbon source for microbes. However,

关 键 词：麦秸还田 微生物量碳 微生物量氮 酶活性 微生物群落 

分 类 号：S154.3[农业科学—土壤学]