Wang Jie-Fei, Zhu Xiao, Shen Jian-Lin, Zeng Guan-Jun, Wang Juan, Wu Jin-Shui, Li Yong
Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
Huan Jing Ke Xue. 2017 Jun 8;38(6):2264-2272. doi: 10.13227/j.hjkx.201610177.
Ammonia (NH) is the most abundant alkaline gas in the ambient air, and it is also one of the important precursors for the ammonium salts in aerosol and rainwater. Though the emission intensities of NH and acidic gases are high, the concentrations and deposition rates of atmospheric ammonia-nitrogen (NH-N), particulate ammonium-nitrogen (NH-N) and rainwater ammonium-nitrogen (NH-N) in double rice regions in subtropical China are still less known. In this study, atmospheric concentrations of NH-N, NH-N in PM and NH-N and related meteorological parameters were observed simultaneously in a typical double rice region in the subtropical hilly region of China, with the aim to clarify the characteristics and influencing factors of atmospheric NH/NH-N concentrations and to quantify the wet and dry deposition rates of atmospheric NH/NH-N. The results showed that the annual mean concentrations of nitrogen in NH-N, NH-N and NH-N were 5.7 μg·m, 12.8 μg·m and 0.8 mg·L, respectively, and their deposition rates were 8.38, 5.61 and 9.07 kg·(hm·a), respectively. The NH-N concentration was significantly increased after application of nitrogen fertilizer in the paddy field, and had a significant positive correlation with the air temperature. The NH-N concentration did not show significant correlation with NH-N concentration, indicating that atmospheric NH-N concentration was not the main limiting factor for the NH-N pollution in the studied region. The NH-N concentration was positively correlated with the NH-N concentration but negatively correlated with precipitation. The high concentrations and deposition rates of atmospheric NH-N/NH-N in the studied region indicated that the atmospheric NH/NH-N pollution was serious, and atmospheric deposition of NH/NH-N was an important nitrogen source in paddy fields, which should be considered in cropland nitrogen nutrient management.
氨（NH₃）是环境空气中含量最丰富的碱性气体，也是气溶胶和雨水中铵盐的重要前体物质之一。尽管氨和酸性气体的排放强度较高，但中国亚热带双季稻区大气氨氮（NH₃-N）、颗粒态铵氮（NH₄⁺-N）和雨水铵氮（NH₄⁺-N）的浓度及沉降速率仍鲜为人知。本研究在中国亚热带丘陵地区的一个典型双季稻区同步观测了大气NH₃-N、PM中NH₄⁺-N以及NH₄⁺-N的浓度和相关气象参数，旨在阐明大气NH₃/NH₄⁺-N浓度的特征及影响因素，并量化大气NH₃/NH₄⁺-N的干湿沉降速率。结果表明，NH₃-N、NH₄⁺-N和NH₄⁺-N中氮的年均浓度分别为5.7 μg·m⁻³、12.8 μg·m⁻³和0.8 mg·L⁻¹，其沉降速率分别为8.38、5.61和9.07 kg·(hm²·a)⁻¹。稻田施用氮肥后NH₃-N浓度显著增加，且与气温呈显著正相关。NH₄⁺-N浓度与NH₃-N浓度无显著相关性，表明大气NH₃-N浓度不是研究区域NH₄⁺-N污染的主要限制因素。NH₄⁺-N浓度与NH₃-N浓度呈正相关，但与降水量呈负相关。研究区域大气NH₃-N/NH₄⁺-N的高浓度和沉降速率表明，大气NH₃/NH₄⁺-N污染严重，大气NH₃/NH₄⁺-N沉降是稻田重要的氮源，在农田氮素养分管理中应予以考虑。
