Rotational grazing may be the best of both worlds, say researchers at the University of Wisconsin-Madison and the Wisconsin Department of Natural Resources. The researchers have finished comparing the ecological effects of grassy buffer strips, woody buffer strips, continuous grazing and rotational grazing along trout streams.
Results from the two-year study indicate that grassy buffers slightly outperformed rotational grazing in a series of tests looking at water and habitat quality. However, rotational grazing is more realistic and practical over time than buffer strips, said John Lyons, researcher and watershed ecologist with the DNR.
“After 30 years of trying to get grassy buffer strips installed, it”s clear that many farmers are reluctant to put them in place,” Lyons said. “And, we”re a long way from where we need to be in improving stream bank conditions.”
The results of the study indicate that rotational grazing is slightly better than woody buffer strips and much better than continuously grazed riparian areas. However, overall watershed conditions are the most important factor for the large effects needed to improve trout habitat.
“The watershed is the driving factor for the fish community,” said Laura Paine, agronomy research specialist with the College of Agricultural and Life Sciences. “How many stream miles do you need to convert to best management practices to see a difference in a fish community? That”s the remaining question.”
Paine and Lyons were among a team of researchers that evaluated fish communities, aquatic insects, stream bank conditions, forage production, and wildlife species on 19 farms in southwestern Wisconsin.
The streams running through the farms were all swift-flowing, spring-fed trout streams, but the catch rates were low overall – just 10 percent of what they should have been, said Lyons. Trout abundance was worst on continuously grazed sites and best on grassy buffers. Rotationally grazed sites and woody buffers were comparable, but not much higher than continuous.
According to Paine, these results are not surprising, considering the degraded condition of the watersheds overall. However, rotational grazing and grassy buffer strips are comparable in terms of the aquatic habitat they create. Erosion on continuously grazed sites was two to three times more than the erosion on rotationally grazed sites, grassy buffers, or woody buffers.
Using aquatic insects as indicators of organic pollution in the streams, the researchers also found that rotational grazing, grassy buffers and woody buffers were all comparable and better than continuous grazing.
“Cattle and the stream can co-exist under certain conditions,” said Lyons. “Rotational grazing looks pretty good.”
The team of researchers and farmers involved in the project are using the information they gained to develop a set of guidelines for managing rotational grazing on riparian areas. The bulletin, Grazing Management of Streamside Pastures (currently in draft form), stresses that forage along streambanks can be harvested by livestock, but good management is crucial to prevent damage to the stream environment.
“The guidelines were developed at the request of a group of farmers, using their input and review,” said Dan Undersander , CALS agronomist and extension specialist involved in the research. “The guidelines are intended for farmers so they can manage stream banks environmentally.”
The guidelines cover the basic principles of rotational grazing, paddock layout, fencing, water systems, stream crossings, and managing trees in riparian areas. The researchers hope to make the guidelines available to producers this year.
“The limiting factor to better management of streamside pastures is knowledge and experience,” said Dan Patenaude, a farmer who was involved in the project and manages 40 streamside acres with rotational grazing. Patenaude says that rotational grazing clearly grows more grass and can lessen the impact of his animals on the environment.
Other researchers involved in the project included CALS wildlife ecologist Chris Ribic and graduate students Brian Weigel, Roz Renfrew, and Erik Chapman. For more information about the grazing guidelines contact Laura Paine at (608) 262-6203 or firstname.lastname@example.org