摘要
提出了能够原位测定农田土壤-植物体系NH3排放的准动态箱法,并开展了一系列实验对其进行评估。该方法的回收率为89.0%±4.9%,与风洞法一致;对农田裸地施肥后的NH3挥发测定结果与有限流通密闭室法具有显著一致性(r<0.05);休闲裸地1日内的NH3挥发与气温呈显著指数相关(r<0.05)。根据NH3挥发的日变化和逐日动态规律,准动态箱法测定农田日NH3挥发的最佳时间为9时(北京时间,下同)左右或16时左右,对单次施肥引起的NH3挥发最佳观测周期为施肥后1～2星期。且实验表明,山西冬小麦拔节期追施(撒施)尿素后,采用准动态箱法测定的NH3挥发N损失率为3%～5%。
The authors proposed a quasi-dynamic chamber method for measurement of NH3 emission from a soil-plant system.This method showed that the recovery rate is 89.0%± 4.9% for measurement of NH3 volatilization,which is in agreement with the recovery rate of a wind-tunnel method.It can also yield results consistent with those measured by a limitedly ventilated close chamber method.There is a significant exponential correlation between diurnal NH3 emissions and temperature(r<0.05).The optimum time for an intermittent measurement using the quasi-dynamic chamber method was proposed at around 0900LST or 1600LST.The NH3 emission caused by an N fertilization event could be best captured after 1-2 weeks using the quasi-dynamic chamber method.Using the quasi-dynamic chamber method,the NH3-N losses from the applied urea into a wheat field in Shanxi Province during the wheat jointing stage were observed at 3%-5%.
出处
《气候与环境研究》
CSCD
北大核心
2009年第4期373-382,共10页
Climatic and Environmental Research
基金
国家杰出青年科学基金项目40425010
中国科学院知识创新工程重要方向性项目KZCX2-YW-204
关键词
NH3挥发
准动态箱法
农田
尿素
土壤-植物系统
NH3 volatilization,quasi-dynamic chamber method,cropland,urea,soil-plant system
