Environmental Effects of a Medium-Fertility 12-Month Pasture Program: I. Hydrology and Soil Loss
1982
Owens, L. B. | van Keuren, R. W. | Edwards, W. M.
Four small, sloping upland watersheds in Ohio (0.5–1.1 ha) were studied for 5 years to investigate hydrologic and soil erosion changes resulting from a beef cattle pasturing program. The cattle grazed all four pastures rotationally during the summer (May–October) and were wintered on hay (November–April) on the same pasture each year. The long-term record for these pastures, which had been in meadow and light pasturing during the previous years, showed average annual surface runoff to be approximately 15 mm. During the 5 years of the grazing project, the three summer-grazing-only pastures showed a slight increase in surface runoff and a trace of soil loss. However, the winter-feeding/summer-grazing area showed a large increase in surface runoff (131 mm/year) and soil loss (1,355 kg/ha per year). Eighty-one percent of the soil loss occurred during the dormant season. Large runoff events, although a small percentage of the total number of events, produced most of the runoff volume and most of the soil loss. Water balance studies indicated that subsurface flow was relatively unchanged by the grazing program. The increase in surface runoff was offset by a decrease in the evapotranspiration.
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