A Decadal Change in Atmospheric Nitrogen Deposition at a Rural Site in Southern China
Kaige Ren,
Yalan Zhou,
Jiarui Liu,
Ziyin Yu,
Xin Ma,
Ruotong Si,
Zhang Wen,
Wen Xu,
Aohan Tang,
Jianlin Shen,
Keith Goulding,
Xuejun Liu
Affiliations
Kaige Ren
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Yalan Zhou
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Jiarui Liu
Yali Middle School, Changsha 410007, China
Ziyin Yu
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Xin Ma
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Ruotong Si
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Zhang Wen
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Wen Xu
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Aohan Tang
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Jianlin Shen
Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
Keith Goulding
Rothamsted Research, Harpenden AL5 2JQ, UK
Xuejun Liu
State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Green Agriculture Development, China Agricultural University, Beijing 100193, China
Elevated atmospheric reactive nitrogen (Nr) emissions and the subsequent nitrogen (N) deposition have negatively impacted the global environment, particularly in China. In order to assess the long-term trends in atmospheric N deposition in the south of China, Taojiang County in Hunan Province was selected as a representative rural area for study. We analyzed interannual variation in atmospheric Nr, including gaseous ammonia (NH3), nitrogen dioxide (NO2), nitrate acid (HNO3) vapor, particulate ammonium (NH4+), and nitrate (NO3−) in air and NH4+-N and NO3−-N in precipitation from 2011 to 2020. The 10-year average atmospheric wet-plus-dry N deposition was 41.9 kg N ha−1 yr−1, which decreased by approximately 24% after 2012, indicating that NH3 and NOx emissions were effectively reduced by emission controls introduced in 2013. Wet deposition accounted for approximately 74% of the total N deposition and was significantly influenced by annual precipitation amount. Reduced N (NH3, pNH4+, and NH4+ in rainwater) was the dominant form, comprising approximately 58% of the total N deposition, while oxidized N (pNO3−, NO2, HNO3, and NO3− in rainwater) accounted for 42% of the total N deposition. Atmospheric HNO3, NO2, and NH3 concentrations and deposition declined by 30–80% over the decade, while particulate NH4+ and NO3− concentrations and deposition remained at relatively stable levels, which suggests that ongoing research and policy should focus on rural particulate pollution. Future strategies must concentrate on the integrated control of NH3 and NOx emissions to mitigate air pollution and protect human health, particularly in rural areas because current abatement efforts are primarily directed toward urban areas and the industrial sector, whereas non-point source NH3 pollution, influenced mainly by agricultural activities, dominates in rural regions.
