尿素穴施削减麦田NH3挥发、NO和N2O排放
Eliminating NH3,NO and N2O emissions simultaneously in a wheat field by urea point placement
德吉卓玛 1曾科 2尹斌 3李琪 1姚元林1
作者信息
- 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
- 折叠
摘要
传统的尿素表施往往导致大量的活性氮损失,如NH3 和NOx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NH3 和NOx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,NH4+-N扩散到土壤表层的程度很小,从而使穴施处理麦季的NH3 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N2O排放量降低了 25%,占总施氮量的 0.6%.穴施处理消除NO和N2O排放主要在于NH4+扩散的范围小(仅在土下4～13 cm),肥点附近高浓度的NH4+-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.
Abstract
Traditional surface application of urea often leads to the large amount of reactive nitrogen(N)losses,such as NH3 and NOx emissions,which have substantial impacts on the air pollution of Chinese cities,especially in winter.Urea point placement may have profound influences on NH3 and NOx 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 NH3 from the point placement was negligible due to minimal NH4+-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 N2O emission by 25%,which accounted for 0.6%of the total nitrogen application.Negligible NO and N2O emission in the point placement treatment was attributable to the narrow range of NH4+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/NH3挥发/NO排放/N2O排放/集约化小麦种植系统Key words
urea point placement/NH3 volatilization/NO emission/N2O emission/intensive wheat cropping system引用本文复制引用
基金项目
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)
出版年
2024
国家科技期刊平台
NSTL
万方数据