A beef cattle-pasturing system involving four rotationally grazed summer pastures with winter-feeding on one pasture was studied on sloping upland watersheds in Ohio to determine its effect on chemical quality of water. The concentrations of chemicals in runoff from the pastures, which were summer-grazed only, increased relative to that of incoming precipitation but not enough to significantly impair water quality. No measurable sediment was lost from the pastures used only for summer grazing, allowing no chemical movement via that pathway. Much soil and plant-cover disturbance on the pasture used for winter-feeding, however, resulted in increased runoff, some surface erosion, and more chemical movement as compared with the pastures grazed only in summer. Considerably more chemicals moved in subsurface than in surface flow from the summer pastures while amounts of chemicals transported from the winter-feeding pasture were equally as great in surface runoff and subsurface flow. Watershed surface management was a key factor in determining the flow route of water in excess of that used for evapotranspiration and, hence, the pathways and amounts of chemical transport from the pastures.; A beef cattle-pasturing system involving four rotationally grazed summer pastures with winter-feeding on one pasture was studied on sloping upland watersheds in Ohio to determine its effect on chemical quality of water. The concentrations of chemicals in runoff from the pastures, which were summer-grazed only, increased relative to that of incoming precipitation but not enough to significantly impair water quality. No measurable sediment was lost from the pastures used only for summer grazing, allowing no chemical movement via that pathway. Much soil and plant-cover disturbance on the pasture used for winter-feeding, however, resulted in increased runoff, some surface erosion, and more chemical movement as compared with the pastures grazed only in summer. Considerably more chemicals moved in subsurface than in surface flow from the summer pastures while amounts of chemicals transported from the winter-feeding pasture were equally as great in surface runoff and subsurface flow.
