Training cattle to graze medusahead and avoid velvet lupine: A new tool to sustain the economic viability of livestock operations in the Western US

Training cattle to graze medusahead and avoid velvet lupine: A new tool to sustain the economic viability of livestock operations in the Western US

Summary

Medusahead is an invasive weed which threatens biodiversity, value of land and livestock operations in the channeled scablands of eastern Washington. We investigated whether the nutritional context created by establishing cool-season perennial grasses and selected forbs (forage kochia) enhances use of medusahead by cattle. Grazed infested areas were then seeded with cool-season perennial grasses and forage kochia to further reduce the competitive advantage of medusahead, creating a positive feedback cycle of grazing-restoration across the landscape. During 2015, heifers grazing an improved pasture (cool-season perennial grasses and forage kochia) and then rotated to medusahead-infested rangeland (treatment) utilized medusahead and other annuals to a high extent (i.e., > 95% of the grazing events recorded), similar to that found in Control animals which just grazed medusahead-infested plots. During 2016, treatment heifers increased intake of medusahead (8 bites/min) compared to Control animals (3 bites/min) when abundance of the weed was high. Plant establishment in seeded plots will be assessed during 2017. We also determined whether the improvement in the nutritional quality of medusahead through the application of an herbicide (e.g., glyphosate) would increase use of this weed by cattle. A grazing study conducted in 2016 showed greater utilization of glyphosate-treated medusahead plots by cattle relative to Control plots. Finally, we are assessing the spatial and temporal spread of medusahead in the region with remote sensing technologies. Using a multi-scale approach, research has been successful in developing a model that predicts continuous fractional cover of medusahead from Landsat imagery. Using the high temporal resolution of Landsat imagery, efforts are being made into achieving historical trend data of medusahead invasion in the area. A MS and a PhD student have been recruited for the project and presentations have been made to conferences and meetings. This research is providing ranchers with low-cost and environmentally sound tools to enhance ecosystem services including biodiversity, improved animal nutrition, welfare and health.

Objectives/Performance Targets

1. Investigate a grazing program on restored land, which will provide the appropriate nutrients to enhance utilization of medusahead, and reduce use of lupine by grazing cattle.
2. Use grazing by cattle as a tool to “clean” medusahead invaded areas and increase establishment of perennial grasses and forage kochia, thus creating a positive feedback cycle of grazing-restoration which will expand the abundance of perennial grasses and beneficial forbs across time and space (Figures 1 and 2).
3. Figure 1 
4. Figure 2

Accomplishments/Milestones

Organizational activities and Field Day. May 19-21, 2015. PI and Co-PIs met with Producer Team Members at their ranches in the scablands of eastern Washington to coordinate initial activities. During the same period, one of the Co-PIs of this project (Kip Panter) organized a field day for his ending SARE Professional + Producer Project-OW13-005. This field day was a great opportunity to introduce the new project to several producers of the region. The field day was highly attended (> 50 producers) and our new project was very well received as producers are looking for sustainable solutions to the problem of medusahead invasion and lupine infestation in their ranches. This was also a good opportunity to meet the new extension agent, Dr. Paul Kruber from Washington State University. He replaced Tom Platt, the Extension Outreach representative for the project who retired in Spring of 2015.

Organizational activities and site preparation. August 9-12, 2015. Trip to the study site. PI and Co-PIs met with Branden Spencer, Dick Coon and Luke MacRae to strategize areas for experiments and demonstration sites on their ranches.

Student recruitment. Fall 2015. A PhD (Casey Spackman) and a MS student (Tim Bateman) were recruited for the project. The PhD student is conducting the proposed grazing studies and the MS student is using remote sensing to assess and better understand the spatial and temporal spread of medusahead in ranches of Team Members and in the region. One Technician (Hope Braithwaite) was recruited for the field trial.

Field Trial. Fall 2015.  A grazing trial was conducted at Branden Spencer’s ranch (Team Member; Figure 3). Branden also provided the animals for this experiment. Beef heifers (12) were assigned to two treatments in 6 plots of 0.2 ha each (2 animals/plot): 1) Treatment animals grazed improved rangeland for 45 min/day and then they grazed medusahead-infested rangeland (SUP; n=3 plots) on a daily basis and 2) Control animals just grazed medusahead-infested rangeland (CTRL; n=3 plots). The study was conducted from October 29 to November 7, 2015. The incidence of foraging events on medusahead and other functional groups in the plant community was measured at 2-minute intervals using scan-sampling (Figure 3). Biomass and composition of the plant community was assessed before, during and after the grazing experiment. Activity for all treatment groups was measured using automatic behavior recorders (IceTags). Preliminary data shows that 32 ±4.2, 66 ±4.4 and 2 ±0.2% of the scans recorded during the grazing trial corresponded to grazing medusahead, other annual grasses, and forbs, respectively (Figure 4).

Figure 3

Figure 4

Field Trial. Fall 2016. Grazing trials were conducted in 2 ranches (Branden Spencer: Experimental plots and Luke Mac Rae: Demonstration plots). The studies were conducted from October 7 to 16, 2016. Beef heifers were assigned to the same treatments described above. Heifers grazing an improved pasture (forage kochia and perennial grasses) for 45 min/d and then moved to a medusahead-infested pasture for 8 h/d (treatment) increased intake of medusahead compared to Control (non-supplemented) animals when abundance of the weed was high (Figure 5). As medusahead was depleted in the medusahead-infested plots, both groups ingested similar amounts of medusahead and increased the use of thatch (Figure 6). The ingestion of perennial grasses and forage kochia in the improved pastures was high relative to the previous year (Figure 6). Grazing and trampling in medusahead-infested plots were used as disturbance agents to seed perennial grasses (Crested wheatgrass, Sandberg bluegrass, Siberian wheatgrass) and forage kochia. Plant establishment will be evaluated during 2017.

Figure 5

Figure 6

“Real time” feedback from interaction with producers. These interactions allowed us to incorporate 2 new facets in our field experiments:  1) Assess the spatial and temporal spread of medusahead in the region, and 2) Determine the influence of glyphosate on the nutritional quality and use of medusahead. Producers are reporting a significant use of glyphosate-treated medusahead by cattle. This critical information could enhance the impact of grazing as a revegetation tool to combat medusahead and lupine infestations in the region. 

Assess the spatial and temporal spread of medusahead in the region. Ground analyses were conducted on the ranch to understand, relate and identify different land cover types according to the spectral signatures from the National Agriculture Imagery Program(NAIP) aerial images. Research has been successful (R²0.82) in developing a model that predicts continuous fractional cover (fCover) of medusahead from Landsat imagery (Figure 7). Using the high temporal resolution of Landsat imagery, efforts are being made into achieving historical trend data of medusahead invasion in the area.

Figure 7

Determine the influence of glyphosate on the nutritional quality and use of medusahead. Six medusahead-infested plots (0.054 ha each) were divided into three 6 m by 30 m strips and randomly assigned to the following treatments: 1) application of glyphosate (RT 3) at a rate of 394g ae ha-1, 2) potassium chloride (KCl; salt in RT 3) at a rate of 174g ai ha^-1, and 3) Control (CTRL, no chemical application). Seven days after treatment, beef steers (n=12) were randomly paired and assigned to each of the 6 plots in a complete randomized design with repeated measures. Animals were allowed to graze from 0800 to 1700 from June 11 to June 18, 2016. Silica content was lower (10 vs. 15%) and fiber digestibility greater (55 vs. 45%) in glyphosate-treated plots, which led to greater utilization of glyphosate-treated medusahead by cattle (Figure 8).

Figure 8

In summary, we learned that improved pastures or glyphosate-treated medusahead provide the nutritional context needed to enhance the use of medusahead by cattle. Thus, cattle can be used as a “sustainable tool” to reduce medusahead abundance in medusahead-infested rangelands.

During 2017 we will determine whether this “cleaning effect” can be used in combination with trampling to create the mechanical disturbance needed to establish perennial grasses (Crested wheatgrass, Sandberg bluegrass, Siberian wheatgrass) and forage kochia leading to a positive feedback cycle of grazing-restoration across the landscape (Figure 1). Seeds were broadcasted during and after cattle grazed medusahead-infested rangeland in research and demonstration plots during fall of 2016. A field day to show the outcome of these studies is planned for 2017.

Impacts and Contributions/Outcomes

This research is providing ranchers with low-cost and environmentally sound tools to enhance ecosystem services including biodiversity, improved animal nutrition, welfare and health. Producers in the team are already applying the approach at larger scales in their operations. The knowledge gained from these activities will reduce reliance on season-long grazing and stimulate producers to conduct rotations in their land, which will allow recovery for perennials while combating medusahead invasion through grazing. In addition, producers are being engaged in sustainable restoration efforts which will enhance rangeland health and increase productivity in their operations.

Invited Presentations:

Villalba, J.J. 2016. Grazing as a tool to control medusahead: Does it work? Sagebrush Ecosystem Conservation: all Lands, all Hands. Joint Conference of the Great Basin Consortium and a WAFWA-Sponsored Sagebrush Science and Management Meeting. Salt Lake City, Utah, February 23-26, 2016.

Villalba, JJ. 2016. Adaptive Toolbox for Medusahead Control: An Integration of Novel and Traditional Approaches. Society for Range Management – Utah Section 2016 Meetings, Richfield, Utah. November 3-4, 2016.

Contributed Presentations:

Spackman, C., Panter, K., Stonecipher, C., and Villalba, J.J. 2016. Grazing rotations on restored land as a new tool for medusahead control. Sagebrush Ecosystem Conservation: all Lands, all Hands. Joint conference of the Great Basin Consortium and a WAFWA-Sponsored Sagebrush Science and Management Meeting. Salt Lake City, Utah, February 23-26, 2016.

Bateman, T., Villalba, J.J. 2017. Developing a model that predicts the continuous fractional cover of Medusahead in the Channeled Scablands of Eastern Washington Using Remote Sensing Techniques. 70th Annual Meeting of the Society for Range Management. St George, UT, January 29-February 2, 2017.

Spackman, C., Panter, K., Stonecipher, C., and Villalba, J.J. 2017. Glyphosate Application and Cattle Grazing: An Integrated Approach to Control Medusahead. 70th Annual Meeting of the Society for Range Management. St George, UT, January 29-February 2, 2017.

Collaborators: