Spatial Variation in Spoil and Vegetative Characteristics of Pastures on Reclaimed Surface Mined Land

摘要

Kentucky has large areas of reclaimed surface mined land that could provide grazing for livestock. Research is needed to determien optimal stocking dnesities and to evalaute the sustainability of such grazing systems for this region. A long-term grazing study was initiated in 1997 on 151 ha of reclaimed land near Chavies, KY to determien spatial and temporal variation with stocking densities of 0, 0.28, 0.42, or 0.83 beef cow-calf units ha~-1. Global Positioning System and GIS technologies were used to establish pasture boundaries, locate permanent sampling markers at a density of 1 per 0.4 ha, and interpolate maps of physical, spoil, and vegetative pasture characteristics. Herbage and spoil samples were collected around the permanent markers in May of 1997. Stepwise regression was used to determine factors affecting the vegetative characteristics of the site. Biomass density ranged from 0 to 2500 kg ha~-1 with a mean of 570 kg ha~-1. Factors affecting biomass included legume and weed proportions in the sward, grazing activity, soil potassium, elevation, and potential acidity, cumulatively accounting for 32