Impacts of Management Intensive Rotational Grazing on stream ecology and water quality
Posted December 1996
News from the Grazing Dairy Systems Network
December 15, 1996
Contributed by Laura Paine
University of Wisconsin-Madison, Department of Agronomy
One important way to control nonpoint source pollution on farms has been to manage riparian areas carefully. The traditional way to achieve this is by establishing filter strips of vegetation. The problem? This approach takes land out of production and requires fencing and vegetation maintenance.
Rotational grazing may be an attractive alternative to protecting streams with filter strips. In this way rotational grazing could be a compromise between complete exclusion of livestock along streambanks and continuous grazing systems which tend to cause water pollution and degrade streambank areas.
An ongoing study sponsored by the Agricultural Ecosystems Research Project of Wisconsin is evaluating management options for riparian areas. Laura Paine and her research team are conducting the study on spring-fed trout streams on 19 farms in the driftless area of southwestern Wisconsin. The purpose of the study is to evaluate these potential best management practices for riparian areas: ungrazed vegetative filter strips and rotationally grazed pasture, and to compare them to continuosly grazed riparian areas.
Information about the fish and aquatic insect populations of the streams is being collected to evaluate the overall health of the stream. Stream bank characteristics are being measured to determine the soil erosion potential of different management options. Forage production and vegetation structure are monitored over the course of the grazing season. Wildlife species groups being studied include birds, amphibians, and small mammals.
Together, the data collected will provide ideas for managing riparian areas to allow profitable use of riparian pastures by farmers while protecting natural resources and promoting healthy game and fish populations. Emphasis is being placed on identifying specific rotational grazing management techniques that can achieve these goals.
The first season of this 2- to 3-year study is completed. Initial results from this first stage should be available by early 1997. At this stage, it appears that fish and aquatic invertebrate communities seem less affected by local land use practices than by the overall condition of the watershed (the effects of what is going on upstream have a bigger influence than what is going on at the study site), whereas terrestrial wildlife are responding to local management of the riparian area at the study site.
For more information, contact:
UW Agronomy Department
1575 Linden Drive
Madison, WI 53706
GDS Updates compiled and written by Mary Hobbs.