Herbage dynamics of tallgrass prairie under short duration grazing

Abstract

Simulated 8-pasture short duration grazing systems were studied in 1985-86 to determine the effect of timing and intensity of grazing on seasonal herbage dynamics. Treatments consisted of 3 grazing schedules (2, 3, or 4 rotation cycles per 152 day grazing season) and 2 stocking rates (1.3X and 1.8X the recommended normal). Average seasonal standing crop increased from 4-cycle to 2-cycle grazing at the light stocking rate but did not respond to grazing schedule at the heavy stocking rate. Within the grazing season, herbage standing crop was affected by grazing schedule in late summer in 1985 but not in 1986. Favorable growing conditions resulted in light forage utilization which averaged 30% over all treatments. Net herbage accumulation rates were not affected by any experimental factor and averaged 34 kg ha-1 d-1 over all treatments. Time trends for net herbage accumulation rate from May to September were also similar across treatments. Total herbage disappearance and herbage disappearance per animal-unit-day (AUD) were significantly higher under 4-cycle grazing at the heavier stocking rate than under all other treatments.