Groundwater and stream response times to fertility management changes in pastures

Excerpt

Over the years, the federal government has spent great sums of money through various conservation programs to implement best management practices (BMPs) to conserve water and soil. To assess the effectiveness of these programs, measurements need to be made to determine how the implementation of BMPs affect water quality and soil loss from the areas receiving the practices. For large watersheds (multiple square miles in area), this is a difficult, expensive, and multiple-year task. Although several years may be involved in assessments on small watersheds (a few acres), such measurements may give valuable insights for responses of BMPs on large watersheds. Of course, “scaling up” is also a challenge.

To interpret the effects of BMPs on water quality and response times between small watersheds and medium-sized watersheds, data from the North Appalachian Experimental Watershed near Coshocton, Ohio, were used. Surface runoff from was sampled from small, rotationally grazed pasture watersheds (1 to 4 ha [2.5 to 10 ac]) when it occurred. Groundwater discharge was sampled monthly from springs developed near where underlying clay layers outcropped at the soil surface. In four medium-sized watersheds (18 to 123 ha [44 to 303 ac]) with perennially flowing streams, stream flow was measured and …