Effect of controlled‐release nitrogen fertilizer on St. Augustinegrass during the summer fertilization prohibition period for lawns in Florida

Abstract

AbstractSt. Augustinegrass (Stenotaphrum secundatum [Walter] Kuntze) is the most commonly produced turfgrass sod in Florida and also represents the predominately used species for lawns and landscapes in Florida. The “Florida Friendly Fertilizer Use” law prohibits the use of fertilizers containing nitrogen (N) and phosphorus (P) from June 1 through September 30. Two field studies were conducted to evaluate the effect of a controlled‐release N fertilizer on St. Augustinegrass lawn growth and health during the summer fertilizer prohibition period. Polyon‐coated granular fertilizers with 44.5, 43, 42, or 41%N‐0%P2O5‐0%K2O were applied prior to the prohibition period. Each fertilizer was coated to produce a different controlled N release time. In both studies, replicated test plots were evaluated for visual turfgrass quality, yield (i.e., oven‐dry clipping weight), and leaf N content. All fertilizer treatments provided acceptable St. Augustinegrass quality during the fertilizer prohibition period. Higher yields and higher leaf N content were associated with Polyon 41, which may be attributed to the longer N release characteristics of that fertilizer. Applying a controlled‐release N source prior to the fertilization prohibition period could be beneficial to maintaining St. Augustinegrass during the June 1 through September 30 fertilizer prohibition period.