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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?

Herbicides continue to be the primary method of attempting to control and/or eradicate leafy spurge (Euphorbia esula L.) (Lym et al. 1995), however, it is not economically feasible to control large infestations (Bangsund et al. 1996). Most herbicides which provide effective control of leafy spurge are not labeled for the use in environmentally sensitive areas. This noxious weed, which is extremely persistent and competitive, has contributed significantly to economic losses to the livestock industry (Leitch et al. 1994).

Use of grazing as a biological control for leafy spurge has become more acceptable in the past ten years. Goats have been shown to be an excellent tool to control and reduce leafy spurge infestations (Hanson 1994, Prosser 1995, Sedivec et al. 1995). The use of sheep as a biological control method was proven back in the late 1930's and early 1940's by Helgeson and Thompson (1939), and Helgeson and Longwell (1942). However, there has been many disagreements in literature concerning utilization of leafy spurge by sheep (Landgraf et al. 1984), due to the aversive chemicals found in the latex of leafy spurge. Research by Lym and Kirby (1987) has also shown that cattle totally or partially avoid leafy spurge infested sites and intensify use non-infested sites.

Multi-species grazing, the concurrent use of rangeland by more than one kind of animal, has been advocated to maximize animal production (Merrill and Miller 1961). It is an important concept in rangeland management because rangelands usually consist of one or more classes of vegetation (Merrill et al. 1966). However, it is not clear which grazing treatment (such as, twice-over rotation and seasonlong) in a multi-species (cattle and sheep) will provide the greatest control of leafy spurge.

According to a recent report there is also a lack of knowledge in equipment and management needs to implement sheep into an operation. The establishment and results of this study, however, will allow use to demonstrate some of these key issues. This multi-species demonstration study is also looking at the interaction of leafy spurge controlling insects and multi-species grazing (cattle and sheep) under different grazing treatments. The results of the demonstration study, near Sentinel Butte ND, will allow us to answer some important questions that wouldn’t have been answered without conducting such a project.

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. On a larger scale, they have reported leafy spurge in at least 458 counties in twenty-six states and six Canadian provinces, infesting about 657,000 hectares in the four-state region of Montana, North Dakota, South Dakota, and Wyoming, according to a report in 1994. Rangelands infested in this region are easily over-grazed if managers have not carried out proper range management skills. Better knowledge of proper stocking rates and understanding of grazing sheep with cattle and implementing two different grazing treatments with the presence of insects will be beneficial to local ranchers and other land managers.

Question 3: How does it relate to the National Program(s) and National Program Component(s) to which it has been assigned?

The TEAM Leafy Spurge project is a part of the USDA/ARS Area-Wide Management Program. It is a 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 were the most significant accomplishments this past year?

The most significant accomplishment this past year was the collection of vegetative results after one grazing season, along with second year results of livestock efficiency and performance.

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

FY97 and 98
The fall of 1997 several contacts were made between the Hettinger Research Extension Center and Ranchers within the Little Missouri Watershed. Three local ranchers (Dennis Dietz, Maurice Lardy, and Dale Maus) agreed to the development of an integrated pest management demonstration study using cattle, sheep, and biocontrol insects on Section 35, T141N, R103W and the N of Section 29, T141N R103W of Golden Valley County.

In October of 1997 two technicians (Connie O’Brien and Jack D. Dahl) were hired to assist in the development and collection of data on the study sites. Timothy C. Faller, Kevin S. Sedivec, and Connie O’Brien conducted a ground check on where the cross fences would be implemented to conduct the research. Fencing of the boundary fence started on Section 35, T141N, R103W.of Golden Valley County.

During the winter of 1998 Timothy C. Faller and Jack D. Dahl designed a sign to place at each section within the study area. The intent was to make it easier for individuals to find the study area and to let them know who’s involved in the demonstration grazing study. Signs were placed at study sites the third week of July.

Project investigators finalized scientific protocols by March of 1998 and stocking rates were set for each grazing treatment (Seasonlong and Twice-over rotation). A contractor (Custom Fencing & Welding Inc.) was hired to complete the cross fence of Section 35, T141N, R103W, and the N of Section 29, T142N, R104W of Golden Valley County boundary and cross fences. Custom fencing & Welding Inc. completed the fencing by the middle of June. Four water developments were also established, in June, on the N of section 29 to provide adequate water supply to livestock during the grazing season.

Vegetative transects were selected and marked systematically throughout the grazing treatments in May of 1998. A total of fifty transects and four one acre enclosure were selected to follow changes in plant species richness and diversity throughout the duration of the study. Preliminary leafy spurge stem counts and vegetative data was collected by the end of July. Analysis of the this data was conducted during the winter of 1999. A total of 128 utilization cages were also distributed throughout the different treatments to monitor the degree of disappearance of plant species during the grazing season. Utilization data was collect the end of September to determine the production and disappearance of plant species.

All livestock classes were weighed prior to turn out. Yearling white face ewes (never exposed to leafy spurge) were released on 15 May and cow/calf pairs 1 June. A grazing rotation plan was developed by Kevin S. Sedivec and Jack D. Dahl to determine proper grazing days in each rotational pasture. Due to the lack of precipitation during the grazing season of 1998, cow/calf pairs were removed from grazing treatments and weighed on 18 August 1998. Yearling ewes remand on treatments to defoliate and acquire a taste for leafy spurge until 30 September 1998. The reasoning behind this was to reduce the diet overlap in 1999 that occurred in 1998 and increase the utilization of leafy spurge in the grazing season of 1999.

The months of January through March of 1999 grazing demonstration study project investigators met to discuss and work out a few of the problems that occurred in the 1998 grazing season. Investigators also discussed future educational materials on Integrated Pest Management. During this time several contacts were made with the public (Sheep Day and Work Shops) informing them of the project and providing information to them on the results found in the 1998 grazing season.

In May of 1999 a corral system was built at the Northwest corner of Pasture 1 (Section 35 T141N, R103W of Golden Valley County). The corral was built so that both Scott Kronbergs study and our study will have the access to use the corral to treat animal if need.

On 17 May ewes were weighed and released on to grazing treatments. Prior to turn out of ewes, boundary and cross fence repairs were done. Leafy spurge stem counts were conducted and all utilization cages were stacked down. The first of June cow/calf pairs were weighed and released into grazing treatments. Peak production clipping was conducted the third week of July and plant species richness and diversity data was collected during the month of August.

Timothy C. Faller and Jack D. Dahl presented some of the results found after one grazing season at Spurgefest 99's field tours and also present a poster throughout the session of Spurgefest 99, held in Medora, ND 29, 30 June and 1 July 1999.

The 11 August cow/calf pairs were removed from treatments due to the degree of use on the seasonlong grazing treatment on the N Section of T141N, R104W of Sentinel Butte. Ewes remand on treatments to defoliate leafy spurge until 15 September 1999.

Question 6: What do you expect to accomplish, year by year, over the next 3 years?

Determine the impact of multi-species grazing on leafy spurge, plant community composition and diversity, and the interaction of livestock grazing on the flea beetle populations on 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 individuals that a multi-species grazing system will increase their use of the natural resources available while increasing their income they earn off that land, and controlling invasive weeds.

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 products?

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 none refereed journal articles will be produced as references for ranchers and farmers. Distribution of the first year results will be available to the public on request in 1999. Reports of this study will be available to the public throughout the duration of the study, which will allow them to follow the progress of the study. Each year we will be conducting an on site field tour to allow producers and land managers to visit the demonstration grazing study.

The major constraints of the adoption of this technology are list in R.S. Sell, D.A. Bansund, F. L. Leistritz, and D. Nudell (1998). These constraints included the lack of knowledge in the proper equipment, sheep compete for the same forage, expertise and knowledge to work with sheep, and sheep are too time consuming to use.

Question 8: List your most important publications in the popular press and presentations to non-scientific organizations and articles written about your work.

-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.
-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 10 February 1999.
-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.
-A presentation was given by Lyndon Johnson at the Hettinger Research Extension Center board of directors meeting on 6 July 1999. The presentation gave a brief introduction to the board of directors and personnel from North Dakota State University.

Question 9: Scientific Publications

-No scientific/peer-reviewed publications have been made since the data from the first grazing season is still being colleted.
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