A mandatory Best Management Practices (BMP) program was implemented on Everglades Agricultural Area (EAA) farms in 1995 as required by the Everglades Forever Act to reduce phosphorus (P) loads from drainage waters that enter the Everglades ecosystem. All farms in the EAA basin implement mandatory BMPs. Our objective was to determine long-term P load trends of the basin as well as ten individual farms after implementing BMPs for 7 to10 yr. Mann-Kendall trend analysis was used to determine the degree of change in water quality trends. Decreasing trends in P loads were observed in the outflow of the basin and two of its sub basins, the S5A and S8. A decreasing trend in P load was observed on sugarcane farms, while mixed crop farms showed either decreasing or insignificant trends. The insignificant trends are likely related to management practices of mixed crop systems. The EAA Basin P load reductions have consistently exceeded the 25% reduction required by law, indicating the success of the program. Differences in P load reduction exist between farms and sub-basins due to differences in cropping and management systems, and environmental factors. Key Words Best Management Practices (BMP), phosphorus (P), Everglades agricultural area (EAA), South Florida, Everglades Forever Act (EFA). Introduction The Everglades in south Florida is the largest contiguous body of organic soils in the continental United States (Stephens 1956) originally occupying approximately 778,000 ha (Jones 1942). A portion of the northern Everglades was drained at the beginning of the 20 th century for agricultural and urban purposes, becoming what is known today as the Everglades Agricultural Area (EAA). The EAA basin is located south and east of Lake Okeechobee and north and west of Water Conservations Areas (WCA) in Florida, U.S. (Figure 1). The EAA comprises an area of approximately 283,300 ha and is planted predominantly to sugarcane (Saccharum spp.) with the remaining arable land planted to winter vegetables, sod and rice (Oryza sativa L.). The EAA basin has four sub-basins (S5A, S2/S6, S2/S7, and S3/S8).The soils of the EAA, classified as organic (soil order: Histosol), were formed under anaerobic conditions (Snyder and Davidson 1994). Drainage of organic soils has caused the loss of soil through decomposition leading to soil subsidence and variable soil depths. Soils are deepest in the S5A sub-basin and shallowest in the S3/S8 sub-basin. To farm successfully, growers in the EAA actively drain their fields via an extensive array of canals, ditches, and large volume pumps. Excess water is pumped off farms into South Florida Water Management District (SFWMD) conveyance canals, from which it is pumped to Stormwater Treatment Areas (STA). After treatment, water is sent southward to the WCAs and the Everglades National Park (ENP). Concerns about the quality of drainage water leaving the basin and entering the ENP prompted the Florida legislature to adopt the Everglades Regulatory program, part of the Everglades Forever Act (EFA). The main objective of the program is to reduce P loads from the EAA basin by 25% or greater compared to a ten-year, pre-Best Management Practices (BMP) baseline period which spans from 1978 to 1988.

 

Authors: Samira H. Daroub, Timothy A. Lang and Stuart Van Horn

University of Florida/IFAS, Everglades Research and Education Center and Soil and Water Science Dept, Belle Glade, FL.

Full Article can be found here: https://www.researchgate.net/publication/228520604_Best_Management_Practices_in_South_Florida_A_Success_Story

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