尿素穴施削减麦田NH_(3)挥发、NO和N_(2)O排放  

Eliminating NH_(3),NO and N_(2)O emissions simultaneously in a wheat field by urea point placement

作　　者：德吉卓玛 曾科 尹斌[3] 李琪[1] 姚元林 Dekyi Droma;ZENG Ke;YIN Bin;LI Qi;YAO Yuan-lin(School of Ecology and Applied Meteorology,Nanjing University of Information Science and Technology,Jiangsu Key Laboratory of Agricultural Meteorology,Nanjing Jiangsu 210044;Institute of Agricultural Resources and Environment,Guangdong Academy of Agricultural Sciences,Guangzhou Guangdong 510640;Institute of Soil Science,Chinese Academy of Sciences,State Key Laboratory of Soil and Sustainable Agriculture,Nanjing Jiangsu 210008)

机构地区：[1]南京信息工程大学生态与应用气象学院,江苏省农业气象重点实验室,江苏南京210044 [2]广东省农业科学院农业资源与环境研究所,广东广州510640 [3]中国科学院南京土壤研究所,土壤与农业可持续发展国家重点实验室,江苏南京210018

出　　处：《中国土壤与肥料》2024年第6期18-26,共9页Soil and Fertilizer Sciences in China

基　　金：国家自然科学基金青年科学基金项目(42007210);江苏省碳达峰碳中和科技创新专项(BE2022425);广东省重点计划项目(2023B0202010027)。

摘　　要：传统的尿素表施往往导致大量的活性氮损失,如NH_(3)和NO_(x)排放,加剧了我国城市的空气污染,特别是在冬季。将尿素集中穴施于土下,可能对NH_(3)和NO_(x)的排放有深远的影响。但对于冬小麦田,这方面的研究欠缺。基于此,在冬小麦田开展了田间试验,设置了3个处理:传统的尿素3次表施(CT);尿素一次性穴施(PP);不施氮的对照处理(CK)。结果表明,尿素一次性穴施模式下,NH_(4)^(+)-N扩散到土壤表层的程度很小,从而使穴施处理麦季的NH_(3)挥发总量比表施处理低80%,与CK处理相同,仅占总施氮量的0.7%。穴施处理明显减少了NO日排放通量,穴施麦季的NO排放总量仅占施氮量的0.1%。相比表施处理,穴施处理使麦季的N_(2)O排放量降低了25%,占总施氮量的0.6%。穴施处理消除NO和N_(2)O排放主要在于NH_(4)^(+)扩散的范围小(仅在土下4~13 cm),肥点附近高浓度的NH_(4)^(+)-N和冬季低温不利于微生物的硝化作用。由于尿素穴施延长了肥效,穴施处理的小麦产量并未减产,与表施相似。因此,在冬小麦种植系统中,尿素穴施可以提升环境效益而不牺牲小麦产量。Traditional surface application of urea often leads to the large amount of reactive nitrogen(N)losses,such as NH_(3) and NO_(x) emissions,which have substantial impacts on the air pollution of Chinese cities,especially in winter.Urea point placement may have profound influences on NH_(3) and NO_(x) emissions due to the concentrated N-fertilizer under root zone,but there has no such information available in winter wheat fields.A field experiment in a winter wheat field conducted which included three treatments:traditional 3-split urea broadcasting(CT);one-time urea point placement(PP),and CK without N.The results demonstrated that the total loss of NH_(3) from the point placement was negligible due to minimal NH_(4)^(+)-N diffusion into the surface soil layer,which was only 0.7%of the total applied N and 80%lower than that of the broadcasting treatment.The point placement treatment notably minimized the daily NO fluxes,and its total NO emission only accounted for 0.1%of the applied N.Compared with the broadcasting treatment,the point placement treatment reduced the wheat seasonal N_(2)O emission by 25%,which accounted for 0.6%of the total nitrogen application.Negligible NO and N_(2)O emission in the point placement treatment was attributable to the narrow range of NH_(4)^(+) movement(4-13 cm below the soil surface),high concentration around fertilizer placement and low winter temperature suppressed the microbial nitrification.The point placement treatment produced similar wheat yield compared to broadcasting due to the long-lasting fertilization effects.In conclusion,urea point placement could provide environmental benefits without sacrificing wheat yield in winter wheat cropping systems.

关 键 词：尿素穴施 NH_(3)挥发 NO排放 N_(2)O排放 集约化小麦种植系统 

分 类 号：S512.1[农业科学—作物学] X144[环境科学与工程—环境科学]