title: [Use of open-path TDL technique and the backward Lagrangian stochastic model to monitor ammonia emission from summer maize field].
abstract: The backward Lagrangian stochastic dispersion model in conjunction with open-path tunable diode absorption spectroscopy was used to quantify ammonia emissions from farmland based on the high-temporal resolution data, aiming to provide innovative achievements to diagnose patterns of ammonia flux. The results indicate that the bLS dispersion technique using open-path lasers to measure atmospheric ammonia concentrations is suitable for determining ammonia emissions from farmland continuously, especially for characterizing diurnal characteristics of NH3 emissions. The ammonia emissions have a significant diurnal pattern with two emission peaks from urea applied to maize on a calcareous sandy loam fluvo-aquic soil in the North China Plain. We believe that the first peak starting at approximately 9:00 am is due to NH3 absorbed by the dew re-emission at night as the dew evaporates. The maximum of ammonia flux at 14:00 corresponds to the peak of soil temperature and solar radiation. The ammonia emission increased rapidly, but the duration of emission peaks lasted approximately 4 d. Cumulative NH3 emission was 25.3% of the applied N over the entire measurement period. The NH3 emissions measured with bLS dispersion technique and venting method had certain difference.
authors: Fengqiu Agro-ecological Experimental Station, State Key Laboratory of Soil and Sustainable Agriculture (Institute of Soil Science, Chinese Academy of Sciences), Nanjing 210008, China. yangwl1987@163.com
authors: Wen-Liang
authors: WL
authors: Yang
authors: An-Ning
authors: AN
authors: Zhu
authors: Jia-Bao
authors: JB
authors: Zhang
authors: Yu-Jun
authors: YJ
authors: Zhang
authors: Ying
authors: Y
authors: He
authors: Li-Ming
authors: LM
authors: Wang
authors: Xiao-Min
authors: XM
authors: Chen
authors: Wen-Chao
authors: WC
authors: Chen
mesh_terms: D000641:Ammonia / Q000032:analysis*; D004784:Environmental Monitoring; D008962:Models, Theoretical; D012987:Soil / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*; D003313:Zea mays / Q000254:growth & development*
chemical_list: D012987:Soil; D000641:Ammonia