潮土中残留小麦和玉米秸秆养分含量差异及与微生物群落组成的关系  

Differences of Nutrient Contents in Residual Wheat and Maize Straws and Their Relationship with Microbial Community Composition in Fluvo-Aquic Soil

作　　者：田胜营 李慧敏 陈金林[1] 赵炳梓 李丹丹 李增强[2] 黄真真 冯文瀚 TIAN Shengying;LI Huimin;CHEN Jinlin;ZHAO Bingzi;LI Dandan;LI Zengqiang;HUANG Zhenzhen;FENG Wenhan(Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China;State Experimental Station of Agro-Ecosystem in Fengqiu,State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]南京林业大学南方现代林业协同创新中心,南京210037 [2]封丘农田生态系统国家实验站,土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008

出　　处：《土壤》2021年第1期55-63,共9页Soils

基　　金：江苏高校优势学科建设工程项目(PAPD);国家自然科学基金面上项目(41977102);现代农业产业技术体系建设专项资金项目(CARS-03)资助。

摘　　要：黄淮海平原典型潮土上小麦和玉米收获后的秸秆往往直接还田,但驱动它们在不同质地潮土(砂质、壤质、黏质)中分解的微生物是否与残留秸秆养分含量有关尚不清楚。本研究基于尼龙网袋法,通过10个月的田间培育试验,监测秸秆分解率、残留秸秆养分含量及微生物群落组成,评估各指标在秸秆类型和土壤质地之间的差异,探究残留秸秆养分与微生物群落组成之间的关系。结果表明:小麦和玉米秸秆的分解率均随着土壤质地变黏重而增大,二者在砂质、壤质、黏质土壤中的平均分解率分别为73.66%和75.43%、74.19%和76.63%、77.68%和78.05%。小麦残留秸秆的平均氮、磷、钾含量分别比玉米残留秸秆的平均氮、磷、钾含量低12.0%、34.4%、16.7%(P<0.05),但两者的碳含量无显著差异;在不同质地潮土间,除秸秆磷含量随土壤变黏重显著增加外,其余养分含量变化不显著。基于磷脂脂肪酸(PLFA)的微生物群落组成分析表明,小麦和玉米秸秆中的细菌、真菌、放线菌含量无显著差异,但小麦秸秆中革兰氏阳性菌(G^(+))含量比玉米秸秆低20.26%,而革兰氏阴性菌(G^(–))含量比玉米秸秆高16.35%,同时,G^(+)/G^(–)、真菌/细菌、单不饱和脂肪酸/饱和支链脂肪酸比在两种秸秆间存在显著差异;小麦和玉米秸秆在黏质潮土中的细菌、真菌、总PLFA的平均含量分别比砂质潮土中低25.1%、30.3%、22.9%(P<0.05),而放线菌含量平均比砂质潮土高93.8%(P<0.05)。冗余分析(RDA)分析表明,小麦与玉米残留秸秆中的微生物群落组成显著不同,主要与其G^(+)和G^(–)不同有关,其中小麦秸秆的微生物群落组成主要与秸秆的C/N、C/P、C/K比值有关,而玉米秸秆则主要与秸秆的氮、磷、钾含量和分解率有关,说明影响小麦和玉米秸秆微生物群落组成的养分参数不同。The wheat(Triticum aestivum L.)and maize(Zea mays L.)straws are often returned to the field directly in the typical fluvo-aquic soils of the Huanghuaihai Plain,however,it is unclear whether the microorganisms that drive the straw decomposition in fluvo-aquic soils of different textures are related to the nutrient contents in the residual straws.In this study,a 10-month field decomposition experiment of wheat and maize straws with nylon bag method was conducted in fluvo-aquic soils of sandy,loam and clayey textures,the decomposition ratios of straws,the nutrient contents and the microbial community compositions in the residual straws were measured and their differences were compared and analyzed.The results showed that both the decomposition ratios of wheat and maize straws were increased with increasing clay content.The decomposition ratios of wheat and maize straws were 73.66%and 75.43%,74.19%and 76.63%,77.68%and 78.05%in soils of sandy,loam and clayey textures(P<0.05),respectively.The average nitrogen(N),phosphorus(P)and potassium(K)contents in wheat straws were 12.0%,34.4%and 16.7%lower than those in maize straws(P<0.05),respectively,but there was no significant difference in carbon(C)contents between wheat and maize straws.The contents of C,N and K in wheat and maize straws were not influenced significantly by soil texture,but P content significantly increased with increasing clay content.The phospholipid fatty acid(PLFA)analysis showed that no significant differences in the populations of bacteria,fungi and actinomycetes were observed between wheat and maize straws.The population of gram-positive bacteria(G^(+))in wheat straws was 20.26%lower than that in maize straws,while the population of gram-negative bacteria(G-)in wheat straws was 16.35%higher than that in maize straws(P<0.05).Meanwhile,G^(+)/G^(–),fungi/bacteria,monounsaturated fatty acids/saturated branched fatty acids were significantly different between wheat and maize straws.The average populations of bacteria,fungi and total PLFA in wheat and m

关 键 词：土壤质地 秸秆分解 秸秆养分 磷脂脂肪酸 微生物群落 

分 类 号：S154.3[农业科学—土壤学]