Comparison of Ammonia Emission Estimation between Passive Sampler and Chamber System in Paddy Soil after Fertilizer...

Ammonia (NH₃) is an important precursor for particulate secondary aerosol formation. This study was conducted to evaluate the applicability of a passive sampler (PAS) for estimating the NH₃ emission from chemical fertilizer application (85 kg-N·ha^-1) at field scale and to compare the results with a chamber system for the calculation of NH₃ emission flux at lab scale. The application of chemical fertilizer increased the ambient NH₃ concentration from 7.11 to 16.87 μg·m^-3. Also, the ambient NH₃ concentration measured by the PAS was found to be highly influenced by not only the chemical fertilizer application but also the weather (temperature and rainfall). Wind rose diagram data can be useful for understanding the distribution of ambient NH₃ concentration. In the case of a chamber with few environmental variables, NH₃ was emitted very quickly in the early stages and gradually decreased, whereas it was delayed at intervals of about one week at the site. It was found that daily temperature range, atmospheric disturbance by wind and rainfall, changes in soil moisture, and the presence of a flooded water table were the main influencing factors. The PAS data and the chamber system data were observed to have significant differences in spatial-temporal scale. In order to reduce the gap, it seems to be necessary to further develop a chamber system, in order to improve the precision of field analysis and to strengthen the connection between experimental results.