典型旱作农田土壤氧化亚氮排放的氨氧化微生物相对贡献
Relative Contribution of Ammonia-oxidizing Microorganisms to Nitrous Oxide Emissions in Upland Agricultural Soils
杨钰 1赵永鉴 1宋晓桐 2张丽梅 2巨晓棠1
作者信息
- 1. 海南大学热带作物学院,海口 570228
- 2. 中国科学院生态环境研究中心,北京 100085
- 折叠
摘要
氨氧化过程对氧化亚氮(N2O)排放具有重要贡献.在不同土壤类型和农田管理下,氨氧化微生物类群对 N2O 排放的相对贡献组成规律还缺乏系统的研究.选取典型农田耕层土壤(潮土、黑土、砖红壤和红壤),以及有机肥改良的砖红壤剖面土壤,采用选择性抑制法(乙炔和辛炔)研究氨氧化细菌(AOB)、氨氧化古菌和全程硝化菌(AOA+comammox)以及异养硝化菌对土壤硝化潜势、净硝化速率及N2O排放的相对贡献.结果表明,在耕层的潮土、黑土、砖红壤和红壤中,硝化潜势随土壤由酸性至碱性显著提高(P<0.05),分别为N 32.5、6.6、4.8和2.3 mg.kg-1.d-1,AOB主导四种土壤的硝化潜势(58%～100%).对耕层的潮土、黑土和砖红壤进一步分析,表明净硝化速率和N2O排放均随pH的增加显著提高(P<0.05),与硝化潜势的规律一致.在潮土和砖红壤中,AOB和AOA+comammox对净硝化速率贡献相当(均在30%～40%),而黑土的净硝化速率由AOB主导(72%).在潮土、黑土和砖红壤中,N2O排放均由AOB主导(58%～92%).在有机肥改良的砖红壤剖面土壤中,随土壤由深层至表层,pH、硝化潜势、净硝化速率及N2O排放显著提高(P<0.05).AOA+comammox主导表层硝化潜势及净硝化速率的提高(分别贡献63%和54%),AOB主导N2O排放的增加(贡献54%).研究结果为制定与土壤氨氧化特性及土壤性质相匹配的N2O减排措施提供了新的科学依据.
Abstract
[Objective]Ammonia oxidizers make an important contribution to N2O emissions.However,the composition of their relative contribution to N2O emission in different soils and agricultural management systems has not been systematically studied.[Method]We studied the contributions of AOB,AOA+comammox and heterotrophic nitrifiers to the potential nitrification rate,net nitrification rate and N2O emission in typical upland surface soils(fluvo-aquic soil,black soil,latosol,red soil),and in latosols from soil profile under organic fertilizer amendment.[Result]In the surface fluvo-aquic soil,black soil,latosol and red soil,potential nitrification rate significantly increased with soil pH(P<0.05),and was 32.5,6.6,4.8 and 2.3 mg.kg-1.d-1,respectively.AOB dominated the potential nitrification rate in the above surface soils,with contributions ranging 58%-100%.Further analyses of the fluvo-aquic soil,black soil and latosol indicated that net nitrification rate and N2O emission both significantly increased with soil pH(P<0.05),which were consistent with potential nitrification rate.For the net nitrification rate,AOB and AOA+comammox contributed equally(30%-40%)in the fluvo-aquic soil and latosol,while AOB dominated in the black soil(72%).N2O emissions from the fluvo-aquic soil,black soil and latosol were all dominated by AOB(58%-92%).For soils from the organic fertilizer-amended latosol profile,pH,potential nitrification rate,net nitrification rate and N2O emission significantly increased from the subsurface to surface layer(P<0.05).The increase in potential nitrification rate and net nitrification rate was dominated by AOA+comammox(contributing 63%and 54%)and the increase in N2O emission was dominated by AOB(contributing 54%).[Conclusion]This study provides new evidence for developing reduction measures of N2O emissions that match the soil ammonia oxidation characteristics and soil properties.
关键词
自养氨氧化/异养硝化/氧化亚氮/氨氧化微生物/有机肥改良Key words
Autotrophic ammonia oxidation/Heterotrophic nitrification/N2O/Ammonia oxidizing microorganisms/Organic fertilizer amendment引用本文复制引用
基金项目
国家自然科学基金青年项目(42107320)
中国博士后科学基金特别资助项目(2022T150683)
海南省重点研发计划项目(ZDYF2021XDNY184)
出版年
2024
国家科技期刊平台
NSTL
万方数据