Fluxes, patterns and sources of phosphorus deposition in an urban-rural transition region in Southwest China

Abstract. Understanding the patterns of atmospheric phosphorus (P) deposition is essential for assessing the global P biogeochemical cycle. The atmospheric phosphorus (P) is an essential source of P in agricultural activities as well as eutrophication in waters; however, the information on P deposition is relatively less paid attention, especially in the anthropogenic influencing region. Therefore, this study chose a typical urban-rural transition as a representative to monitor the dry and wet P depositions for two years. The results showed that the fluxes of atmospheric total P deposition (ATD) ranged from 0.50 to 1.06 kg P hm^-2 yr^-1, and the primary form was atmospheric dry P deposition (ADD) (76.13 %, 0.76~0.84 kg hm^-2 yr^-1). Moreover, it was found that the monthly variations of P deposition were strongly influenced by meteorological factors, including precipitation, temperature, and relative humidity. However, the fluxes of ADD and ATD were more affected by land use, which increased with the agro-facility, town, and paddy field areas, but decreased with the forest and country road areas. These findings suggested that ADD was the primary form of ATD, and P deposition could be both affected by meteorological factors and land use types. Thus, proper management of land use may be helpful for mitigating the pollution caused by P deposition.