Impact of Fertilizer Restriction Period on Bermudagrass Traffic Tolerance and Recovery

Seasonal fertilizer restriction periods (blackouts) are commonly implemented in Florida to reduce potential nutrient losses during the summer rainy season; however, their effects on sports turf performance under traffic stress are not well documented. A two-year field study (2022–2023) was conducted in Citra, FL, to evaluate the influence of nitrogen (N) fertilization timing and frequency on ‘Bimini’ bermudagrass (Cynodon dactylon L. Pers.) traffic tolerance and post-traffic recovery. Treatments included bi-weekly (24.4 kg N ha−1) and monthly (48.8 kg N ha−1) N applications, a pre-blackout (97.6 kg N ha−1) N application, and a non-treated control. Simulated traffic was applied using a modified Baldree traffic simulator for a total of 60 traffic events each year. Turfgrass performance during traffic and recovery was assessed using percent green cover (PGC), dark green color index (DGCI), soil moisture, surface hardness, and rotational resistance. In both years, bi-weekly and monthly N applications consistently resulted in greater PGC and DGCI during traffic and recovery compared to the pre-blackout and non-treated treatments. The pre-blackout treatment provided limited and inconsistent benefits, particularly under prolonged traffic stress. Fertilizer effects on soil moisture and surface hardness varied between years, while rotational resistance was unaffected by treatment. These results indicate that reliance on pre-blackout fertilization alone may be insufficient to maintain bermudagrass traffic tolerance and recovery during periods of sustained traffic stress. Under sustained traffic pressure, applying a single fertilizer treatment just before the restriction period was less effective and produced inconsistent improvements in turfgrass coverage and color compared with staged fertilization during the growing season, reinforcing that routine N fertilization is necessary when turfgrass experiences sustained traffic.