Vegetation and soil responses to short-duration grazing on fescue grasslands

Abstract

The effects of animal impact on soil chemical and physical properties as well as range condition were measured over a 5-year period to test the hypothesis that animal impact can improve the nutrient and water status of the soil and promote grassland succession. A seventeen-pasture short-duration grazing system was established in 1981 on 972 ha. The pastures were stocked on average with 278 cows with calves from 1982 to 1986, which was about twice to triple the recommended rate of 0.8 AUM/ha. Increased grazing pressure reduced range condition as reflected by a loss of desirable species such as rough fescue (Festuca scabrella Torr.). Soil moisture was always higher in soils of ungrazed exclosures. Soil bulk density increased while hydraulic conductivity decreased with grazing. Litter was not significantly incorporated into the soil with hoof action. Chitin-N, as a measure of fungal biomass, decreased significantly under the increased grazing pressure. The hypothesis that animal impact would improve range condition was rejected since impact, in the manner applied during the study, resulted in retrogression of the grasslands.