Abstract Water and fertilizer restrictions challenge turfgrass management, requiring alternative strategies that balance sustainability and performance. A 2‐year study was conducted in Davie, FL, to evaluate the potential of humectants in maintaining soil water content and turfgrass performance of Floratam St. Augustinegrass Stenotaphrum secundatum (Walter) Kuntze managed under reduced irrigation frequency, deficit irrigation, and a fertilizer restrictive blackout period (BO). Irrigation treatments included 40% or 100% reference evapotranspiration (ET O ) replacement applied either twice per week (2d wk −1 ) or daily. Humectants, applied as granular or soluble formulations, were compared to an untreated control. Fertilization was set at 196 kg N ha − 1 year − 1 using a 75% controlled‐release N source, with or without a BO from May 15 to October 31. Turfgrass quality, normalized difference vegetation index, percent green cover, dark green color index, soil volumetric water content, and moisture uniformity were assessed biweekly. Clippings were collected quarterly for growth assessment and total leaf nitrogen (TLN) analysis. Humectants had no effect on turfgrass performance or soil water content, though the granular formulation improved soil moisture uniformity under daily irrigation. The fertilizer BO treatment had improved turfgrass performance and TLN before the restrictive period but reduced percent cover during period when the application of fertilizer was restricted. Higher performance was observed at 100% ET O , though in the second year, daily irrigation at 40% ET O achieved similar results. The findings suggest that St. Augustinegrass performance can be sustained under water and fertilizer restrictions.
Augustinus et al. (Sun,) studied this question.