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

摘要

Atmospheric deposition is a global and increasing threat to ecosystem function. Here, we analyzed bulk and wet deposition of inorganic N, total phosphorus (TP) and d 15 N of NH 4 –N and NO 3 –N at three sites in Nanjing from March 2010 to February 2012. Results showed that bulk deposition fluxes of inorganic N and TP averaged 54.82kgNha –1 year –1 and 1.82kgPha –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 25.65kgNha –1 year –1 and 1.29kgPha –1 year –1 , respectively, suggesting the potential contribution of inorganic N from dry deposition. Based on the d 15 N values of NH 4 –N and NO 3 –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.