Fertilization of St. Augustinegrass And Environmental Implications

climate-controlled greenhouse at the G.C.Horn turf field laboratory at the University of Florida in Gainesville. Floratam St.Augustinegrass is being compared with a mix of ornamentals including canna, nandina, ligustrum and allamanda. Plant material is growing in 80-gallon plastic pots in an Arredondo fine sand. There are three fertilizer treatments (16-4-8 quick-release, 15-0-15 quick-release, 8-4-12 slow-release) applied at 1.0 lb. N/1000 sq. ft. every other month. There are four replications. Leachate is collected at three intervals following treatment and analyzed for nitrate and phosphate content. Quality ratings are taken weekly and multispectral reflectance readings are taken biweekly. Water is applied to meet the evapotranspiration. Turfgrass tubs are mowed biweekly by hand. In this preliminary work, turf was more responsive than ornamentals to fertilizers and preliminary data indicate best turfgrass response from quick release 16-4-8 and 15-0-15 treatments. During the establishment period, water use was lower in turf than ornamentals.