摘要
为了解西藏农田系统氮肥施用对青稞产量和氨挥发氮损失的影响规律,通过田间随机区组试验,设置了N0~N3共4个施氮水平,采用田间原位测定-通气法,研究了土壤氨挥发通量、变化规律及其与产量的关系。结果表明:青稞产量与施氮量呈显著正相关(P<0.05),氮肥贡献率高达32.13%,氮肥农学效益为3.62~4.78 kg·kg^-1。氨挥发总累积量为3.38~21.51 kg·hm^-2,氨挥发导致的氮肥损失率为10.75%~15.49%,与施氮量呈极显著相关(P<0.01)。青稞农田氨挥发主要发生在基肥期,基肥氨挥发周期44 d,第10天开始陆续出现挥发峰,追肥氨挥发集中在施肥后7 d内。综合考虑生产效益和以氨挥发为指标的环境安全,该区域青稞农田纯N建议施用量为:基肥40.02 kg·hm^-2,拔节追肥13.32~26.70 kg·hm^-2,抽穗追肥40.02 kg·hm^-2。
Ammonia volatilization from highland barley fields can contaminate the atmosphere and lead to the reduction of nitrogen use efficiency.Field trials were conducted to estimate the influences of different levels of nitrogen application on ammonia volatilization flux,NH 3 volatilization loss,nitrogen efficiency and grain yield in highland barley farmland ecosystem in Tibet.Results show that the yield of highland barley is significantly and positively correlated with nitrogen application(P<0.05).The contribution rate of nitrogen fertilizer was 32.13%,and the agronomic benefit of nitrogen fertilizer was 3.62-4.78 kg·kg^-1;The total accumulation of ammonia volatilization was 3.38-21.51 kg·hm^-2,The nitrogen loss rate caused by ammonia volatilization was 10.75%-15.49%,which increased significantly with the increase of nitrogen application(P<0.01);Ammonia volatilization mainly occurred in the basal fertilizer period,the ammonia volatilization stage of basal fertilizer was 44 days,and the volatilization peak appeared successively on the 10th day,and the ammonia volatilization of topdressing fertilizer was concentrated with 7days after fertilization.Comprehensively considering the production benefits and environmental safety based on ammonia volatilization,it is suggested that the application amount of pure N in this region is 40.02 kg·hm^-2 for base fertilizer,13.32-26.70 kg·hm^-2 for top-dressing during knotting,40.02 kg·hm^-2 for top-dressing during heading grain.
作者
李雪
李荣荣
侯亚红
刘国一
谢永春
LI Xue;LI Rong-rong;HOU Ya-hong;LIU Guo-yi;XIE Yong-chun(State Key laboratory of Hulless Barley and Yak Germplasm Resources and Genetic Improvement/Institute of Agricultural Resources and Environment,Tibet Academy of Agricultural and Animal Husbandry Sciences,Lhasa 850000,China;Tibet Agricultural Technology Popularization Center,Lhasa 850000,China)
出处
《生态与农村环境学报》
CAS
CSCD
北大核心
2020年第8期1006-1014,共9页
Journal of Ecology and Rural Environment
基金
西藏自治区自然科学基金(XZ2018ZRG-44)。
关键词
西藏
青稞
施氮水平
氨挥发
产量
Tibet
highland barley
nitrogen application levels
ammonia volatilization
yield
