摘要
气态氮[一氧化氮(NO)、氧化亚氮(N_(2)O)和氮气(N_(2))]的释放是土壤氮损失的一种重要途径。硝化和反硝化作用是土壤气态氮损失的主要微生物过程,但是异养硝化作用、共反硝化作用和厌氧氨氧化过程对土壤气态氮损失的贡献尚不清楚。本研究利用15N标记和配对法,结合硝化抑制剂双氰胺(DCD),通过土壤培养试验来量化厌氧条件下各种微生物过程对NO、N_(2)O和N_(2)产生的贡献。结果表明:在厌氧条件下培养24 h后,土壤孔隙含水率为65%时,3种气体总的15N回收率最高,占加入15N总量的20.0%。反硝化过程对NO、N_(2)O和N_(2)产生的贡献率分别为49.9%~94.1%、29.0%~84.7%和58.2%~85.8%,是产生3种气体的主要过程。异养硝化过程也是产生NO和N_(2)O的重要过程,特别是在土壤孔隙含水率很低时(10%)对两种气体产生的贡献率分别为50.1%和42.8%。,共反硝化过程对N_(2)O产生的贡献率为10.6%~30.7%,共反硝化和厌氧氨氧化过程对N_(2)产生的总贡献率为14.2%~41.8%,表明共反硝化过程在N_(2)O和N_(2)产生中的作用不可忽视。15N标记和配对法是区分气态氮损失的各种微生物过程的有效手段。
Gaseous nitrogen(N)emission[nitric oxide(NO),nitrous oxide(N_(2)O),and nitrogen(N_(2))]is an important pathway of soil N loss.Nitrification and denitrification are the main processes of gaseous N production in soil.However,the contribution of heterotrophic nitrification,co-denitrification,and anammox to gaseous N production remains uncertain.In a laboratory soil incubation experiment,we used the 15N labelling and pairing technique,combining the nitrification inhibitor dicyandiamide(DCD),to quantify the contribution of different microbial processes to soil NO,N_(2)O and N_(2)production under anaerobic conditions.The results showed that after 24 h anaerobic incubation,the highest total 15N recovery of three gases occurred at 65%water filled pore space(WFPS),accounting for 20.0%of total added 15N.Denitrification contributed 49.9%-94.1%,29.0%-84.7%,and 58.2%-85.8%to the production of NO,N_(2)O and N_(2)respectively,suggesting that denitrification was the predominant process of those three N gases emission.Heterotrophic nitrification was an important pathway of NO and N_(2)O production,particularly at conditions with low soil water content(10%WFPS),with its contribution to those two N gases production being 50.1%and 42.8%,respectively.Co-denitrification contributed 10.6%-30.7%of N_(2)O production.For N_(2)production,the total contribution of co-denitrification and anammox was 14.2%-41.8%.The role of co-denitrification can not be ignored for N_(2)O and N_(2)production.Our results demonstrated that the 15N labelling and pairing technique is a promising tool to quantify the contribution of different microbial processes to gaseous N loss.
作者
李靳
康荣华
于浩明
王莹莹
姚萌
方运霆
LI Jin;KANG Rong-hua;YU Hao-ming;WANG Ying-ying;YAO Meng;FANG Yun-ting(Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Stable Isotope Techniques and Applications,Shenyang 110016,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2021年第6期1989-1997,共9页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(41807320)资助。
