Atmospheric Nitrogen and Phosphorus Deposition at Three Sites in Nanjing, China, and Possible Links to Nitrogen Deposition Sources

Abstract

AbstractAtmospheric deposition is a global and increasing threat to ecosystem function. Here, we analyzed bulk and wet deposition of inorganic N, total phosphorus (TP) and δ15N of NH4–N and NO3–N at three sites in Nanjing from March 2010 to February 2012. Results showed that bulk deposition fluxes of inorganic N and TP averaged 54.82 kg N ha–1 year–1 and 1.82 kg P ha–1 year–1, respectively. The N/P bulk deposition ratio reached 30/1, leading ecosystems toward P‐limitation. Wet deposition fluxes of inorganic N and TP were 25.65 kg N ha–1 year–1 and 1.29 kg P ha–1 year–1, respectively, suggesting the potential contribution of inorganic N from dry deposition. Based on the δ15N values of NH4–N and NO3–N and model results, we found that chemical fertilizers and animal manures contributed to the reduced N deposition and fossil fuel and soil emissions contributed to the oxidized N deposition, depending upon the time and site. Agriculture sector contributed almost twice as industry while animal manures contributed significantly within agriculture.