title: Phosphorus and water budgets in an agricultural basin.
abstract: Water and phosphorus (P) budgets of a large agricultural basin located in South Florida (Everglades Agricultural Area, EAA) were computed from 2005 to 2012. The annual surface outflow P loading from the EAA averaged 157.2 mtons originating from Lake Okeechobee (16.4 mtons, 10.4%), farms (131.0 mtons, 83.4%), and surrounding basins (9.8 mtons, 6.2%) after attenuation. Farms, urban areas, and the adjacent C-139 basin contributed 186.1, 15.6, and 3.8 mtons/yr P to the canals, respectively. The average annual soil P retention was estimated at 412.5 mtons. Water and P budgets showed seasonal variations with high correlation between rainfall and P load in drainage and surface outflows. Moreover, results indicated that the canals acted as a P sink storing 64.8 mtons/yr. To assess the P loading impact of farm drainage on the canals and on the outflow, dimensionless impact factors were developed. Sixty-two farms were identified with a high and a medium impact factor I1 level contributing 44.5% of the total drainage P load to the canals, while their collective area represented less than 23% of the EAA area (172 farms). Optimizing the best management practice (BMP) strategies on these farms could minimize the environmental impacts on the downstream sensitive wetlands areas.
authors: Science Department, Everglades Foundation , Palmetto Bay, Florida 33157, United States.
authors: Sayena
authors: S
authors: Faridmarandi
authors: Ghinwa M
authors: GM
authors: Naja
mesh_terms: D000383:Agriculture; D005431:Florida; D019015:Geologic Sediments / Q000032:analysis; D060106:Lakes; D010758:Phosphorus / Q000032:analysis*; D012621:Seasons; D012987:Soil / Q000737:chemistry; D014867:Water
chemical_list: D012987:Soil; D014867:Water; D010758:Phosphorus