Nutrient Evaluation for Sod Production within the Lake Okeechobee Watershed

Abstract Nutrient pollution from agricultural production is an environmental concern in the Everglades Agricultural Area. Sod farms within the Lake Okeechobee watershed in south Florida were surveyed to determine their production and fertilizer practices, and to determine the nitrogen (N) and phosphorous (P) impacts for the watershed. Ten of twenty sod farms participated in the in-person survey for a 50% response rate. Bahiagrass (Paspalum notatum) was grown on the greatest area at 5,463 ha (13,500 acres), followed-by St. Augustinegrass (Stenotaphrum secundatum) at 3,726 ha (9,208 acres), bermudagrass (Cynodon dactylon × C. transvaalensis. at 188 ha (465 acres), and zoysiagrass (Zoysia japonica) at 121 ha (299 acres). Growing and harvest cycle duration varied by turfgrass species. All farms follow guidelines for best management practices using fertilizer recommendations published by Florida’s Department of Agriculture and Consumer Services. The predominate nitrogen (N) source used was ammonium sulfate, and diammonium phosphate was the most commonly utilized phosphorous (P) source. Survey results indicated that 90% of sod farms had net exports of N and 100% of sod farms had net export of P. Thus, sod production provides a route for removing these two nutrients from this fragile hydrologically-linked ecosystem. Species used in this study: bahiagrass (Paspalum notatum Flüggé), bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy, St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze), zoysiagrass (Zoysia japonica Steud.).