Cattle production practices in a small grazed watershed of central Kentuck

Controlling agricultural nonpoint source pollution from livestock grazing is a necessary step to improving the water quality of the nation's streams. The goal of enhanced stream water quality will most likely result from the implementation of an integrated system of best management practices (BMPs).;To evaluate the effect of BMPs on cattle position preference and subsequently stream water quality and streambank erosion, research pastures were developed along two perennial streams located on the University of Kentucky Animal Research Center (ARC) in Woodford County, Kentucky. The project site consisted of two replications of three treatments: (1) BMPs (alternate water source, alternate shade source, and forage improvements such as strategic fertilizer and herbicide applications) and a fenced riparian area to exclude cattle from the stream except at a 3.7 m wide stream crossing, (2) BMPs with free stream access, and (3) limited BMPs (e.g. natural shade) with free stream access (control). The effects of BMP systems (with and without a fenced riparian buffer) on altering cattle position preference were examined via GPS collars. Results indicated that the BMP systems did not affect cattle position preference during the daytime or the nighttime. However, significant time effects were noted for some pasture features, namely cooling features, dry bedding areas, and potentially areas of higher forage quantity and/or quality. Water quality trends were monitored using grab samples collected from the upstream and downstream edges of each pasture plot (i.e. treatment). Analyses of the data indicated that minimal water quality benefits were incurred by implementing a BMP system (with or without a partially excluded riparian zone). However, these results might differ if cattle were completely excluded from the stream (i.e. no stream crossing) or if the BMP system was implemented at a site with larger pastures, different geology (nonkarst), soils (low in phosphorus), or stream morphology (nonbedrock bottom channel). Streambank erosion rates were monitored at fifty permanent cross sections that were established throughout the project site. Erosion levels increased as stream flow, cattle activity and treatment level (1 = greatest number of BMPs to 3 = control) increased. Results from this project highlight the importance of examining grazing management from a holistic viewpoint rather than from a component oriented format.