Patch Burning Improves Forage Quality and Creates Grass-Bank in Old-Field Pasture: Results of a Demonstration Trial
2014
McGranahan, Devan Allen | Henderson, Charlotte B. | Hill, Jonas S. | Raicovich, Gina M. | Wilson, W Nathan | Smith, C Kenneth
Ecosystem benefits of heterogeneity-based rangeland management have been widely documented, but little research has explored ecologically based grazing systems from the livestock perspective. Fire and grazing management can advance conservation goals in old-field pasture stands in the southeastern US, but the viability of fire-based grazing for natural areas management remains unknown. Fire is a natural process in the southeastern US that can increase the forage quality of native vegetation. We report results from a patch-burn—grazing trial on a 16-ha pasture in eastern Tennessee, in which we predicted that fire would increase the crude-protein content of the stand and grazing would be concentrated in the burned patch. We measured crude protein content for the entire grazing season (April–September), expecting forage quality to decrease as forage matured. We also sampled fecal-pat density, tiller height, and frequency of herbivory in the burned and unburned areas in May and July to describe the spatial distribution of grazing before and after a four-week drought. Crude-protein content decreased as biomass increased following the fire, and in both sampling periods, fecal-pat density and frequency of herbivory were higher and tiller height was lower in the burned patch. Although the dominant native grass is widely perceived to have low forage quality, fire substantially increased crude-protein content in this study. We discuss how limited productivity between sampling events drove grazing in the unburned area, which acted as a grass-bank.
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