摘要
为探讨双氰胺(DCD)减少铵态氮肥施用后氧化亚氮(N_(2)O)的排放机制,通过开展好氧培养试验,研究DCD配施铵态氮(NH_(4)^(+)N)或亚硝态氮(NO_(2)^(-)-N)对潮土土壤N_(2)O排放的影响,同时添加不同浓度NO_(2)^(-)-N模拟NO_(2)^(-)-N累积对N_(2)O和CO_(2)排放的影响。结果表明:DCD仅对NH_(4)^(+)N氧化过程中N_(2)O排放有抑制作用,对NO_(2)^(-)-N还原过程中产生的N_(2)O没有影响;培养前7 d,DCD显著抑制NH_(4)^(+)N的氧化过程,降低净硝化速率,而在添加NO_(2)^(-)-N土壤中加入DCD后净硝化速率显著增加,培养30 d后,DCD对NH_(4)^(+)N和NO_(2)^(-)-N氧化过程均没有影响;添加外源NO_(2)^(-)-N明显促进了N_(2)O排放,其排放通量显著高于不施肥的对照处理;N_(2)O累积排放量同NO_(2)^(-)-N浓度呈正相关,CO_(2)累积排放量同NO_(2)^(-)-N浓度呈显著负相关。研究表明,DCD可以避免NO_(2)^(-)-N大量累积而产生的毒害作用,但仅对氨氧化过程N_(2)O减排有效果,因此亟待研发适于抑制NO_(2)^(-)-N产生NO_(2)的新型抑制剂。
This study explores the mechanisms underpinning the dicyandiamide(DCD)-reducing nitrous oxide(N_(2)O)emissions.This was carried out using two aerobic incubation experiments to examine the effects of DCD on the production of N_(2)O from NO_(2)^(-)-N by adding DCD combined with NH+4-N or NO_(2)^(-)-N.Then,the effects of NO_(2)^(-)-N accumulation on N_(2)O emissions was determined by adding different amounts of NO_(2)^(-)-N.The results showed that DCD only inhibited N_(2)O emissions during the oxidation of ammonium nitrogen(NH+4-N)and had no effect on N_(2)O emissions during the reduction of NO_(2)^(-)-N.DCD significantly inhibited the oxidation of NH+4-N and decreased the net nitrification rate at 7 d following incubation;however,the net nitrification rate increased significantly following the addition of DCD to NO_(2)^(-)-N soil.Following 30 d of culture,DCD had no effect on the oxidation of NH+4-N and NO_(2)^(-)-N.The addition of exogenous NO_(2)^(-)-N significantly promoted N_(2)O emissions,and these emission rates were significantly higher than those of the control treatment.Cumulative N_(2)O emissions were significantly positively correlated with the NO_(2)^(-)-N concentrations,whereas the cumulative CO_(2) emissions demonstrated the opposite relationship.These results indicate that DCD may eliminate the toxicity caused by the accumulation of NO_(2)^(-)-N,although it is only effective in reducing N_(2)O emissions during the oxidation of ammonia oxidation.Therefore,new inhibitors that restrict N_(2)O production from NO_(2)^(-)-N are urgently needed.
作者
马兰
李晓波
马舒坦
MA Lan;LI Xiaobo;MA Shutan(Shandong Institute of Sericulture,Yantai 264002,China;School of Ecology and Environment,Anhui Normal University,Wuhu 241002,China;State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;Engineering and Technology Research Center for Agricultural Land Pollution Integrated Prevention and Control of Guangdong Higher Education Institutes,College of Resources and Environment,Zhongkai University of Agriculture and Engineering,Guangzhou 510225,China;South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2021年第12期2801-2808,共8页
Journal of Agro-Environment Science
基金
国家自然科学基金项目(41807083)
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)开放基金(Y812000007)
安徽省高校自然科学研究项目重点项目(KJ2019A0495)
国家自然科学基金项目(41977097)。
关键词
氧化亚氮
双氰胺
亚硝态氮
硝化细菌反硝化
nitrous oxide
dicyandiamide
nitrite nitrogen
nitrifier denitrification
