垄作灌溉和减施氮肥对稻田CH_(4)排放、土壤有机酸含量和酶编码基因表达量的影响  

Effects of ridge irrigation and nitrogen reduction on paddy field CH_(4)emission,soil organic acid content and expression of enzyme encoding genes

作　　者：李熠凡 李伏生[1] 罗维钢 黄挺 LI Yifan;LI Fusheng;LUO Weigang;HUANG Ting(College of Agriculture,Guangxi University,Nanning 530005,China;Nanning Irrigation Experimental Station,Nanning 530001,China)

机构地区：[1]广西大学农学院,广西南宁530005 [2]南宁市灌溉试验站,广西南宁530001

出　　处：《华南农业大学学报》2024年第1期42-51,共10页Journal of South China Agricultural University

基　　金：国家自然科学基金(42167035)

摘　　要：【目的】研究不同垄面宽度的垄作灌溉和不同时期减施氮肥对稻田甲烷(CH4)排放、土壤有机酸含量以及CH4形成和转化相关酶编码基因(产CH4古菌中甲基辅酶M还原酶编码基因mcrA和CH4氧化菌中CH4单加氧酶编码基因sMMO)表达量的影响,揭示土壤有机酸以及mcrA和sMMO表达量对稻田CH4通量的影响。【方法】开展3种灌溉模式(淹水灌溉,垄宽分别为80、100 cm的垄作灌溉)和3种施氮处理(常规施氮:135 kg·hm^(−2),其中苗肥47.25 kg·hm^(−2)、分蘖肥54.00 kg·hm^(−2)和穗肥33.75 kg·hm^(−2);返青期减氮:110 kg·hm^(−2),其中苗肥22.25 kg·hm^(−2)、分蘖肥54.00 kg·hm^(−2)和穗肥33.75 kg·hm^(−2);孕穗期减氮:110 kg·hm^(−2),其中苗肥47.25 kg hm^(−2)、分蘖肥54.00 kg hm^(−2)和穗肥8.75 kg hm^(−2))的田间试验,测定生育期内稻田CH4通量、土壤有机酸含量以及mcrA和sMMO表达量,分析稻田CH4通量、土壤有机酸含量以及mcrA和sMMO表达量之间的相互关系。【结果】相同施氮处理下,垄作灌溉稻田CH4排放量较淹水灌溉显著降低,相同灌水模式下,返青期减氮稻田CH4排放量较常规施氮显著降低。垄宽为80 cm的垄作灌溉+常规施氮处理在施肥后10 d土壤总有机酸含量较施肥前高71.7%,淹水灌溉和常规施氮处理高28.8%。返青期减氮下,垄宽为80 cm的垄作灌溉土壤mcrA表达量整体低于淹水灌溉,sMMO表达量除移栽后25 d外均高于淹水灌溉。稻田CH4通量与土壤mcrA表达量和总有机酸含量显著相关(P<0.01),相关系数分别为0.644和−0.348,土壤总有机酸含量与mcrA、sMMO表达量显著相关(P<0.05),相关系数分别为−0.240和0.197。【结论】垄宽80 cm垄作灌溉+返青期减氮处理降低了稻田CH4通量,土壤总有机酸含量和mcrA表达量显著影响稻田CH4通量,sMMO表达量可能间接影响稻田CH4通量。【Objective】To investigate the effects of ridge irrigation with different ridge widths and reduced nitrogen fertilizer at different growth stages on methane(CH_(4))emissions,soil organic acid content and expression of enzyme encoding genes related to CH_(4)formation and transformation(including methyl coenzyme M reductase gene mcrA in methanogenic archaea,and methane monooxygenase gene sMMO in methane oxidizing bacteria)in paddy fields,and reveal the effects of soil organic acid content and the expression of mcrA,sMMO on CH_(4)fluxes in paddy fields.【Method】A field experiment was conducted with three irrigation modes(flooding irrigation,ridge irrigation with ridge widths of 80,100 cm)and three nitrogen treatments(conventional nitrogen application:135 kg·hm^(−2),including seedling fertilizer 47.25 kg hm^(−2),tillering fertilizer 54.00 kg hm^(−2)and booting fertilizer 33.75 kg hm^(−2);Nitrogen reduction at seedling stage:110 kg·hm^(−2),including seedling fertilizer 22.25 kg hm^(−2),tillering fertilizer 54.00 kg hm^(−2)and booting fertilizer 33.75 kg hm^(−2);Nitrogen reduction at booting stage:110 kg·hm^(−2),including seedling fertilizer 47.25 kg hm^(−2),tillering fertilizer 54.00 kg hm^(−2)and booting fertilizer 8.75 kg hm^(−2)).The paddy field CH_(4)fluxes,soil organic acid content and mcrA,sMMO expression levels in different treatments were measured,and the relationships among them were analyzed.【Result】Under the same nitrogen treatment,ridge irrigation significantly reduced CH_(4)emission from paddy fields compared with flooding irrigation.Under the same irrigation mode,nitrogen reduction at seedling stage significantly reduced CH_(4)emission from paddy field compared with conventional nitrogen application.The total organic acid content of soil in ridge irrigation with ridge width of 80 cm+nitrogen reduction at seedling stage treatment was 71.7%higher than that before fertilization on the 10th day after fertilization,and 28.8%higher in flooding irrigation+conventional nitrog

关 键 词：垄作灌溉 减氮施肥 有机酸 CH_(4)排放 mcrA表达量 sMMO表达量 

分 类 号：S36[农业科学—作物栽培与耕作技术] X511[农业科学—农艺学]