Physiological and turf quality responses of tall fescue to varying irrigation levels and nitrogen doses under Mediterranean climate conditions.

BACKGROUND: Water scarcity and growing environmental concerns have increased the need for effective irrigation and fertilization practices in turf management. This study investigated the effects of different irrigation levels (IL) and nitrogen doses (ND) on turf quality, color, clipping yield, and selected physiological parameters of tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] under Mediterranean climate conditions. The experimental design was randomized blocks in a split‒split plot design with three replications. The irrigation levels were set at 25% (IL1), 50% (IL2), 75% (IL3), and 100% (IL4) pan evaporation, while nitrogen doses of 0.00, 1.25, 2.50, and 5.00 g m-2 were applied. RESULTS: The irrigation level and nitrogen application significantly affected turf color, quality, clipping yield, leaf relative water content, chlorophyll content, turgor loss, and electrolyte leakage. Increased irrigation and nitrogen levels increased the leaf RWC and chlorophyll content while reducing turgor loss and electrolyte leakage, ultimately improving plant tolerance to environmental stress. CONCLUSIONS: Our findings suggest that acceptable turf color and quality throughout the year can be achieved with a 50% irrigation level and a nitrogen dose of 5.00 g m-2. A more economical and environmentally friendly alternative may be the combination of 50% irrigation and 2.50 g m-2 nitrogen, which is particularly effective in spring and autumn. In contrast, the combination of 25% or 50% irrigation with 1.25 g m-2 nitrogen did not result in acceptable turf quality in any season. However, acceptable turf color and quality can still be maintained in water-limited regions, especially during spring and autumn, by applying 5 g m-2 nitrogen under 25% irrigation.