稻麦轮作体系长期秸秆还田对土壤真菌群落结构及秸秆降解潜力的影响  

Effects of long-term straw incorporation on soil fungal community structure and straw decomposition potential in a rice–wheat rotation system

作　　者：纪程 孙玉香 孟圆 刘耀斌 徐聪 张永春[1,2] 谷益安 汪吉东[1,2] JI Cheng;SUN Yuxiang;MENG Yuan;LIU Yaobin;XU Cong;ZHANG Yongchun;GU Yian;WANG Jidong(Institute of Agricultural Resources and Environment,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China;College of Food Science and Light Industry,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]江苏省农业科学院农业资源与环境研究所/农业农村部江苏耕地保育科学观测试验站,南京210014 [2]南京农业大学资源与环境科学学院,南京210095 [3]南京工业大学食品与轻工学院,南京211816

出　　处：《农业环境科学学报》2022年第4期819-825,共7页Journal of Agro-Environment Science

基　　金：国家自然科学基金青年基金项目(42007088,41907069);江苏省重点研发计划项目(BE2019378);财政部和农业农村部国家现代农业产业技术体系(CARS-10-B9)。

摘　　要：还田秸秆腐解不及时极大程度地影响了下茬作物生长,但长期秸秆还田是否能富集秸秆腐解微生物从而促进秸秆进一步降解尚未系统阐明。本研究依托江苏省典型稻麦轮作种植区的长期秸秆还田试验(10 a),研究了秸秆还田对土壤化学性质的影响,并利用扩增子高通量测序技术分析了秸秆还田土壤的真菌群落组成,最后通过秸秆埋盆试验测定了土壤微生物群落对小麦秸秆的降解潜力。结果表明:与未还田土壤相比,秸秆还田显著降低了土壤pH而提高了电导率,同时土壤可溶性有机碳、总磷和总碳含量分别提高了23%、24%和2%。此外,秸秆还田明显改变了土壤真菌群落组成,秸秆还田土壤中真菌群落多样性降低,优势菌子囊菌门(Ascomycota)的相对丰度提高了25%,Schizothecium、Sarocladium、Gibberella、Rhizophlyctis、Cryptococcus、Lindtneria和Myrothecium等潜在秸秆降解真菌属的相对丰度显著提高,增幅为2.5~132.3倍。秸秆还田土壤对小麦秸秆的腐解效率高于对照土壤,增幅达37%,冗余分析表明这一结果与秸秆还田对潜在秸秆降解真菌类群的富集作用有关。上述研究结果表明稻麦轮作体系下长期秸秆还田可通过提高潜在秸秆降解真菌类群丰度促进秸秆降解。Slow decomposition of straw returned to the field greatly affects crop growth in the next season.However,whether long-term straw incorporation can enrich the straw-decomposing microorganisms and further promote straw degradation efficiency remains unclear.This study investigated the effects of straw incorporation on the soil chemical properties based on a long-term straw incorporation experiment in a typical rice–wheat rotation cropping field in Jiangsu Province.Additionally,this study explored the effects of straw incorporation on the fungal community composition using the high-throughput amplicon sequencing method,and tested the wheat straw degradation rates using the buried bag method.Results showed that straw incorporation significantly decreased soil pH,while increased soil electrical conductivity(EC).Soil dissolved organic carbon,total phosphorus,and total carbon contents increased by 23%,24%,and 2%,respectively.Additionally,straw incorporation substantially altered the fungal community structure.The diversity of soil fungal community was significantly decreased following straw incorporation.Ascomycota was the dominant phylum in the soils and its relative abundance was significantly increased by 25%following straw incorporation.At the genus level,the relative abundances of Schizothecium,Sarocladium,Gibberella,Rhizophlyctis,Lindtneria,Cryptococcus,and Myrothecium were also significantly increased by 2.5~132.3 times.The enriched fungal taxa induced by straw incorporation increased the rates of wheat straw degradation by 37%,compared with those in the soils without straw incorporation.These results reveal that long-term straw incorporation can increase straw decomposing rate via increasing the abundance of potential straw-decomposing fungal taxa.

关 键 词：秸秆还田 秸秆降解率 真菌群落组成 土壤化学性质 稻麦轮作 秸秆降解真菌 长期田间试验 

分 类 号：S153[农业科学—土壤学]