title: Modeling a phosphorus credit trading program in an agricultural watershed.
abstract: Water quality and economic models were linked to assess the economic and environmental benefits of implementing a phosphorus credit trading program in an agricultural sub-basin of Lake Okeechobee watershed, Florida, United States. The water quality model determined the effects of rainfall, land use type, and agricultural management practices on the amount of total phosphorus (TP) discharged. TP loadings generated at the farm level, reaching the nearby streams, and attenuated to the sub-basin outlet from all sources within the sub-basin, were estimated at 106.4, 91, and 85 mtons yr(-)(1), respectively. Almost 95% of the TP loadings reaching the nearby streams were attributed to agriculture sources, and only 1.2% originated from urban areas, accounting for a combined TP load of 87.9 mtons yr(-)(1). In order to compare a Least-Cost Abatement approach to a Command-and-Control approach, the most cost effective cap of 30% TP reduction was selected, and the individual allocation was set at a TP load target of 1.6 kg ha(-1) yr(-1) (at the nearby stream level). The Least-Cost Abatement approach generated a potential cost savings of 27% ($1.3 million per year), based on an optimal credit price of $179. Dairies (major buyer), ornamentals, row crops, and sod farms were identified as potential credit buyers, whereas citrus, improved pastures (major seller), and urban areas were identified as potential credit sellers. Almost 81% of the TP credits available for trading were exchanged. The methodology presented here can be adapted to deal with different forms of trading sources, contaminants, or other technologies and management practices.
authors.affiliation: Department of Earth and Environment, Florida International University, 11200 SW 8th St. Miami, FL 33174, United States; Science Department, Everglades Foundation, 18001 Old Cutler Road, Suite 625, Palmetto Bay, FL 33157, United States.
authors.forename: Juliana
authors.initials: J
authors.lastname: Corrales
authors.affiliation: Science Department, Everglades Foundation, 18001 Old Cutler Road, Suite 625, Palmetto Bay, FL 33157, United States. Electronic address: mnaja@evergladesfoundation.org.
authors.forename: G Melodie
authors.initials: GM
authors.lastname: Naja
authors.affiliation: Department of Earth and Environment, Florida International University, 11200 SW 8th St. Miami, FL 33174, United States.
authors.forename: Mahadev G
authors.initials: MG
authors.lastname: Bhat
authors.affiliation: Department of Earth and Environment, Florida International University, 11200 SW 8th St. Miami, FL 33174, United States.
authors.forename: Fernando
authors.initials: F
authors.lastname: Miralles-Wilhelm
mesh_terms: D000383:Agriculture / Q000191:economics / Q000379:methods; D003132:Commerce; D018556:Crops, Agricultural; D003612:Dairying; D005431:Florida; D060106:Lakes; D018803:Models, Economic; D008962:Models, Theoretical; D010758:Phosphorus / Q000032:analysis; D045483:Rivers; D014481:United States; D060753:Water Quality
chemical_list: D010758:Phosphorus
keywords: Best management practices (BMP); Command-and-Control approach; Credit price; Least-Cost Abatement solution; Total phosphorus (TP) reduction; Trading ratios