Demonstration of Leafy Spurge Management Using Sheep Grazing in a Leafy Spurge Barrier Zone

Demonstration of Leafy Spurge Management Using Sheep Grazing in a Leafy Spurge Barrier Zone

Summary

Leafy spurge continues to be a primary noxious weed of concern on the 8,320-acre Log Cabin Ranch in southeastern Prairie County. The ranch is positioned between a leafy spurge infestation of more than 2,500 acres and relatively noxious- weed-free rangeland. This Western SARE project has allowed this ranch to become a barrier zone demonstration site where more intensive leafy spurge management techniques such as grazing and herbicide applications are in the process of being implemented to contain and reduce the spread of leafy spurge. The knowledge gained from these management techniques is being shared with area producers.

Objectives/Performance Targets

• Implement a sheep grazing project on leafy spurge. The targeted grazing time is June, before leafy spurge seed set, on heavier infestations along Cabin Creek. Utilization plots will be used to measure the success of the grazing project.
• Control 100 acres of smaller satellite infestations on leafy spurge with herbicide.
• Share information on leafy spurge management techniques with 50 area ranchers.

Accomplishments/Milestones

So far, the project team has been unable to secure a herder to graze sheep on leafy spurge on Log Cabin Ranch. The owner/herder who agreed to graze the sheep was unable to fulfill the commitment because of the high amount of leafy spurge he was committed to graze prior to the SARE project. The team has succeeded in establishing monitoring plots to provide baseline data on weed density and plant composition.

Eighty acres of satellite leafy spurge infestations have been treated with picloram and monitored by Clifford Householder and hired personnel.

Two field tours of the demonstration site have been conducted in the past two years attended by 120 producers from three counties. Tour participants visited grazing monitoring plots where Montana Sheep Institute staff discussed timing and duration of sheep grazing and anticipated results. USDA ARS Fort Keogh Range and Livestock Research Laboratory scientists discussed a leafy spurge clipping study intended to simulate the effects of grazing timing. Participants also heard testimonial from another rancher who has combined sheep and cattle grazing to manage weeds. Additional tour topics included range management, herbicide use, and sprayer calibration.

Impacts and Contributions/Outcomes

The Montana Sheep Institute has helped establish monitoring plots within the intended sheep grazing area. At the end of June 2005, Plot 001 consisted of 26% leafy spurge, 63% perennial grass and 11% forbs. At the end of May 2006, Plot 001 consisted of 53% leafy spurge, 46% perennial grass and 1% forbs. Plot 002 consisted of 24% leafy spurge, 54% perennial grass, 9% annual grass and 13% forbs. These data show how much leafy spurge growth takes place between May and June, reinforcing the importance of early grazing of leafy spurge.

The satellite infestations remained controlled with herbicide for 2005 and 2006.

It is estimated that 120 producers gained knowledge on using grazing to manage leafy spurge, range management and herbicide use.

Collaborators: