玉米秸秆连续还田对土壤微生物群落组成的影响  

Effects of continuous maize straw return on soil microbial community composition

作　　者：何亚玲 崔慧珍 王兵兵 马琨[2] He Yaling;Cui Huizhen;Wang Bingbing;Ma Kun(School of Agriculture,Ningxia University,Yinchuan 750021,China;National Key Laboratory Breeding Base of Northwest Land Degradation and Ecological Restoration,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学农学院,宁夏银川750021 [2]宁夏大学西北土地退化与生态恢复国家重点实验室培育基地,宁夏银川750021

出　　处：《农业科学研究》2022年第4期27-35,共9页Journal of Agricultural Sciences

基　　金：国家自然科学基金(31660132);宁夏回族自治区重点研发计划(2018BBF03002,2019BBF03011)。

摘　　要：为探究玉米连续秸秆还田对土壤微生物群落的驱动机制,采用单因素随机区组设计,开展了秸秆还田量分别为0 t/hm^(2)(M0)、0.3 t/hm^(2)(M200)、0.6 t/hm^(2)(M400)、0.9 t/hm^(2)(M600)、1.2 t/hm^(2)(M800)的田间试验。采用磷脂脂肪酸(PLFAs)和宏基因组测序的方法,研究玉米秸秆连续还田6年后,土壤微生物群落结构在玉米关键生育时期的变化特征、土壤微生物群落组成、多样性与土壤理化性状间的相互关系。结果表明:秸秆还田后,土壤微生物的PLFAs总量显著增加。玉米收获期土壤中革兰氏阴性菌、放线菌、丛枝菌根真菌的PLFAs较玉米大喇叭口期土壤增长了25.75%、22.14%、83.33%;真菌/细菌(F/B)、革兰氏阳性菌/革兰氏阴性菌(G+/G-)的比值随时间的延长而增加;除玉米大喇叭口期对应土壤的F/B外,同一时期内,其他各处理间均无显著差异。在门分类水平上,细菌优势菌群为Proteobacteria(变形菌门)和Acidobacteria(酸杆菌门),占比为47.05%~50.47%;在属水平上,Sphingomonas(鞘氨醇单胞菌属)、Pedosphaera、Gemmatirosa和Gemmatimonas(芽单胞菌属)在各处理中占比为3.90%~4.73%,为细菌优势菌群。冗余分析表明,土壤全氮、碱解氮与土壤总PLFAs量、细菌、真菌和放线菌的PLFAs量有较强的相关性。秸秆连续还田第6年,土壤微生物的PLFA含量在玉米关键生育期内具有明显变化特征;土壤全氮是驱动土壤细菌群落相对丰度变化的主要因素;土壤全氮、碱解氮是影响微生物PLFA含量变化的主要因子。To explore the driving mechanism of continuous maize straw return on soil microbial community,a single factor randomized block design was used to carry out field experiments with straw returning amount of 0 t/hm^(2)(M0),0.3 t/hm^(2)(M200),0.6 t/hm^(2)(M400),0.9 t/hm^(2)(M600)and 1.2 t/hm^(2)(M800).The phospholipid fatty acids(PLFAs)method and metagenomic sequencing were used to analyze the changes of soil microbial community structure at key growth stages of maize after 6 years of continuous maize straw returning,and the relationship between soil microbial community composition,diversity and soil physical and chemical properties.The results show that the total PLFAs of soil microorganisms increased significantly after straw returning.The PLFAs of Gram-negative bacteria,actinomycetes and arbuscular mycorrhizal fungi in the soil corresponding to the maize harvest period increased by 25.75%,22.14%and 83.33%compared with the soil corresponding to the large bell stage of maize.The ratio of fungi/bacteria(F/B)and Gram-positive bacteria/Gram-negative bacteria(G+/G-)increased with time.Except the F/B of soil corresponding to the big trumpet stage of maize,there was no significant difference among the treatments in the same period.At the phylum level,the dominant bacteria were Proteobacteria and Acidobacteria,accounting for 47.05%to 50.47%.At the genus level,Sphingomonas,Pedosphaera,Gemmatirosa and Gemmatimonas account for 3.90%to 4.73%in each treatment.Redundancy analysis results show that soil total nitrogen and available nitrogen were strongly correlated with total soil PLFAs,bacteria,fungi and actinomycetes PLFAs.The PLFA content of soil microorganisms in the sixth year of continuous straw returning showed obvious changes during the critical maize fertility period.Soil total nitrogen was the main factor driving changes in the relative abundance of soil bacterial communities;total nitrogen and alkaline soluble nitrogen were the main factors affecting changes in PLFA content of soil microorganisms.

关 键 词：秸秆还田 土壤微生物群落 磷脂脂肪酸 宏基因测序 

分 类 号：Q938.1[生物学—微生物学]