Abstract Limpograss Hemarthria altissima (Poir.) Stapf & C.E. Hubbard is the second most planted forage species in Florida, widely used in hayfields for its superior production. Phosphorus (P) management is challenging in Florida's sandy and poorly drained soils. The objective of this study was to evaluate the effects of P fertilization on forage characteristics, nutritive value, and tissue P responses of Gibtuck and Floralta limpograss cultivars in hayfields. The study was conducted in a limpograss hayfield at the Range Cattle Research and Education Center, Ona, FL, in 2022 and 2023. Treatments were a split‐plot with two limpograss cultivars (Floralta and Gibtuck, main plots) and three P fertilization levels (0, 9.6, and 19.2 kg P ha −1 harvest −1 , subplots) arranged in a randomized complete block design with four replicates. Gibtuck had 34% and 28% greater herbage accumulation (HA) than Floralta in 2022 and 2023, respectively. Phosphorus fertilization did not impact HA (mean = 3600 kg dry matter ha ‒1 ), canopy height (mean = 64 cm), light interception (mean = 90%), in vitro digestible organic matter (mean = 508 g kg −1 ) or crude protein (mean = 100 g kg −1 ). In contrast, P fertilization increased tissue P concentration and accumulation, with greater P recovery observed at 9.6 than 19.2 kg P ha −1 harvest −1 . These results indicate that the current P recommendation (9.6 kg P ha −1 harvest −1 ) sustains limpograss hayfield productivity when P is limiting and that tissue P concentration of 1.9 g kg −1 appears sufficient for limpograss production.
Lazarin et al. (Sun,) studied this question.