Livestock Grazing to Control Invasive Plants

by Tracy Brewer, Research Assistant Professor of Range Science, Joe Skeen Institute for Rangeland Restoration, Dept. of Animal and Range Sciences, Montana State University

Invasive plants are not a new problem in Montana. In 2004, noxious weeds infested 8.2 million acres in Montana (about 9% of the state’s total land acreage) and they continue to degrade the productivity and biological diversity of Montana’s rangelands. Every Montana county reported the presence of at least one noxious weed species and other invasive plants that are not deemed “noxious”, such as cheatgrass, in 2004.

Current methods used to control invasive plants include herbicides, mechanical treatments, prescribed fire, biological control, and livestock grazing. Because of the vast expanses of weed infestations in Montana and the ever-increasing costs to control them, the relative cost and benefits of the various control methods must be continually reevaluated. More and more, resource managers and landowners are shifting their mindsets regarding invasive plants and, wherever eradication is not feasible, beginning to explore ways to turn weeds into a usable resource. An example of this is the use of livestock grazing for weed control. The benefits of using livestock grazing to control invasive species are two-fold: the invasive plant provides a source of forage for livestock
and the livestock provide a source of weed control.

Livestock grazing for weed control is not a new idea. Although this tool has not received widespread use, some Montana ranchers have used livestock grazing to control weeds for the past 60 years. One reason for its limited application is that people who have used this tool successfully have had to develop their own grazing prescriptions through trial and error over many years. In response, Montana State University scientists have recently increased their research focus on using livestock, primarily sheep and goats, for vegetation management and weed control. Through the Montana Sustainable Rangeland Livestock Task Force, several new research and demonstration projects are currently targeting spotted knapweed, leafy spurge, dalmation toadflax, and ponderosa pine encroachment. The objective of these projects is to develop and refine appropriate livestock grazing prescriptions for controlling weeds and sustaining
Montana’s rangeland resources. The Task Force is the MSU contribution to a new collaborative effort between MSU, New Mexico State University, and Texas A&M University called the Joe Skeen Institute for Rangeland Restoration. This information is for educational purposes only. Reference to commercial products or trade names does not imply discrimination or endorsement by the Montana State University Extension Service.

This information is for educational purposes only. Reference to commercial products or trade names does not imply discrimination or endorsement by the Montana State University Extension Service.

Return to regular view	Text-only	Updated: 08/29/2006