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Leafy Spurge Grazing Demonstration Study

 Tim Faller

Question 1. What major problem or issue is being resolved and how are you resolving it?

The invasion of leafy spurge (Euphorbia esula L.) has drastically effected the carrying capacity of the rangeland in the Northern Great Plains region, which has reduced the economic value of rangeland on private and public lands. Chemicals continue to be the primary method of attempting to control leafy spurge. According to recent reports it is not economically feasible to control large tracts of land infested by leafy spurge with herbicides. The majority of the herbicides available to the landowners are not labeled for the use on environmentally sensitive areas, such as water ways. Therefore, many land managers are looking for alternative control methods. The past decade biological control using grazing animals have become a more popular tool. It is not clear, however, which grazing treatment (such as, twice-over rotation and seasonlong) in a multi-species (cattle and sheep) approach will provide the greatest control. According to a recent report there is also a lack of knowledge of in management and equipment needs to implement sheep into an operation. The establishment and results of this study will allow use to explain these key issues. This multi-species demonstration study will look at the interaction of leafy spurge controlling insects and multi-species grazing (cattle and sheep) under different grazing treatments. Research has shown that sheep grazing used in combination with biological control agents increases the activity of the biological control agents by creating an ideal microclimate for the insect. The results of the demonstration study, near Sentinel Butte ND, will allow us to answer some of the important questions concerning the interactions between control methodologies and the benefits that can be gained by using an integrated pest management approach in this vegetative zone.

Question 2. How serious is the problem? Why does it matter?

Leafy spurge is a noxious weed occupying more than 400,000 hectares of North Dakota, primarily rangeland. According to a report released in 1994, at least 458 counties in twenty-six states and six Canadian provinces are infested with leafy spurge and about 657,000 hectares are infested in the four-state region of Montana, North Dakota, South Dakota, and Wyoming alone. Rangelands infested in this region are easily over-grazed if managers have not carried out proper range management practices. Better knowledge of proper stocking rates that account for multi-species grazing interactions (sheep with cattle and insects) will be beneficial to local ranchers and other land managers and increase native plant community structure/health.

Question 3. How does it relate to the National Program(s) and National Program Component(s)?

The TEAM Leafy Spurge project is a part of the USDA/ARS Area-Wide Management Program. It is component of Crop and Commodity Pest Biology, Control and Quarantine (304). TEAM Leafy Spurge complements efforts to develop new and improved pest control technologies and assess component technologies for integrated pest management (IPM) systems.

Question 4. What was your most significant accomplishment this past year?

The invasion of leafy spurge (Euphorbia esula L.) has drastically effect the carrying capacity of the rangeland in the Northern Great Plains region, which has reduced the economic value of rangeland on private and public lands. We are evaluating the effects and the interaction of leafy spurge controlling insects and multi-species grazing (cattle and sheep) under different grazing treatments in western, North Dakota. Vegetative and livestock data were collected for the third year allowing us to compare baseline vegetative data and two years of grazing data to detect any significant changes in leafy spurge stem densities, species richness and diversity, and livestock efficiency and performance. We intend to show that a multi-species grazing approach will increase the rate of leafy spurge control and increasing the income earn from the land.

Question 5. Describe your major accomplishments over the life of the project, including their predicted or actual impact.

Evaluate the impact that multi-species grazing (cattle and sheep) have on leafy spurge, species composition, and the interaction with the flea beatle populations using two different grazing treatments (Seasonlong and Twice-over rotation). Project investigators expect to see at least a 40% reduction in leafy spurge stem density after the fourth year of grazing. An increase use of graminoid species within leafy spurge infested areas by 50%. Increase insect activity and presence of species of insects within treatments from sheep grazing leafy spurge. Investigators anticipate seeing a difference within grazing treatments in livestock performance, plant species richness, plant species frequency and density, and percent basal cover. We intend to show that a multi-species grazing approach will increase the rate of leafy spurge control and increasing the income earn from the land.

Question 6. What do you expect to accomplish year by year, over the next three years?

Determine which grazing treatment decreased or increased leafy spurge stem densities on the demonstration study and which treatment increased graminoid use within leafy spurge infested sites. Monitor species composition over four grazing seasons and compare between grazing treatments and determine which grazing treatment has affected the presence of insect species after four years of grazing. Evaluate which grazing treatment increased or decreased livestock performance.

Question 7. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology?

Information collected from this study will be provided to ranchers and land manager in journal articles, brochures, newsletters, meeting (such as: Western Dakota Sheep Day, North Dakota Lamb and Wool Producer conference, North Dakota Cow/Calf conference, County and State Fairs, and to county weed board meetings), and on site field tours. We will concentrate on delivering the information to ranchers and farmers primarily. We will write brochures and newsletters in a style that is easily understood by producers, such as all measurements and production in standard measurements. Refereed journal articles will be produced for an academic audience, while non-refereed journal articles will be produced as references for ranchers and farmers.

Distribution of the first year results are currently available. Subsequent reports will be available to the public throughout the duration of the study which will allow land managers to follow the progress of the study. Each year we will conduct an on site field tour to allow producers and land managers to visit the demonstration grazing study.

Question 8. List your most important publications in the popular press (no abstracts) and presentations to non-scientific organizations, and articles written about your work (NOTE: this does not replace your peer-reviewed publications which are listed below).

Leafy Spurge News (Volume XXI, Issue 3 September 1998) presented a short introduction to the multi-species grazing demonstration study.

Steve Merritt, ARS-Sidney MT, published an article titled USDA's multi-species grazing project targets leafy spurge , in The Billing Gazette 20 September 1998.

A poster of the demonstration grazing study was shown 7 October 1998 at the TEAM Leafy Spurge Conference, in Rapid City SD. Attendance included state and federal land managers, and producers.

A poster was presented at the 1999 Market Place Show, in Bismarck, ND. Attendance included the general public, local land managers, state and federal land managers, and producers.

Timothy C. Faller gave a brief introduction to the attendance at a Multi-species grazing field tour in Mandan, ND 3 June 1999. A poster was presented 29, 30 June 1999 and 1 July 1999 at Spurgefest 99, in Medora, ND.

A field tour of the demonstration site was given on the 30 June 1999.

An article was written by Lyndon Johnson, graduate student of Animal and Range Sciences at North Dakota State University, and published in the proceedings of the Western Dakota Sheep Day.

A presentation was given at the Hettinger Research Extension Center board of directors meeting on 6 July 1999. This talk gave a brief introduction to the board of directors and personnel from North Dakota State University.

Leafy Spurge News (Volume XXII, Issue 2, May 2000) presented an update on the progress of the study.

A presentation was given to the Hettinger Research Extension Center board of directors meeting on 11 July 2000, updating the board on the progress and some of the preliminary result found after two grazing seasons.

Question 9. Scientific publications

None.

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