- Additional Plants: native plants
- Animals: bovine
- Animal Products: meat
- Animal Production: feed/forage, grazing management, grazing - rotational, pasture renovation, rangeland/pasture management
- Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research
- Natural Resources/Environment: biodiversity, habitat enhancement
- Pest Management: cultural control
Medusahead is an invasive weed which threatens biodiversity, value of land and livestock operations in the channeled scablands of eastern Washington. Our research aimed at managing the nutritional environment to enhance medusahead use by cattle, thus creating a virtuous cycle of medusahead control through grazing followed by restoration through seeding. During 2016 and 2017 we investigated whether the nutritional context created by establishing cool-season perennial grasses (PG) and selected forbs (forage kochia) enhances use of medusahead by cattle. Beef calves (12) were assigned to two treatments in 6 plots (2 animals/plot) on private land in the scablands of eastern Washington. Treatment animals (SUP; n=3 plots) grazed improved rangeland for 45 min/d and then they grazed medusahead-infested rangeland for 8 h/d and 2) Control animals grazed medusahead-infested rangeland only for 8 h/d (CTRL; n=3 plots). Individual animals were focally sampled for successive 5-min periods through the bite count method for use of medusahead, annual grasses, perennial grasses and forbs in the plant community. Results show that grazing the improved pasture (SUP) enhanced use of medusahead and reduced utilization of perennial grasses in the medusahead-infested plant community relative to the CTRL treatment. Thus, rotations from improved pastures to medusahead-infested pastures represent a new tool to mitigate medusahead spread in the invaded scablands of eastern Washington.
Grazed infested areas were then seeded with cool-season perennial grasses, small burnet and forage kochia to further reduce the competitive advantage of medusahead and improve rangeland health, creating a positive feedback cycle of grazing-restoration across the landscape. Results show small burnet and some perennial grasses established and persisted in the seeded areas.
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. Grazing studies conducted in 2016, 2017 and 2018 showed greater utilization of glyphosate-treated medusahead plots by cattle relative to Control plots. This preference was explained through an improvement of the nutritional quality and digestion of glyphosate-treated medusahead. We also found that application of glyphosate at the early reproductive phenological stage is the most effective timing for enhancing utilization by cattle.
We assessed 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. Using the high temporal resolution of Landsat imagery we obtained historical trend data of medusahead invasion in the region, showing highly dynamic time line with fluctuations from “high” to “low medusahead cover” years with peak “high” years increasing in magnitude with time. Watering points, corrals, and anthropogenic structures were identified to be “high-risk” dispersal pathways. Additionally, precipitation during January-March and June, as well as temperatures in May represent key periods which affected medusahead cover on the temporal dataset of this research.
A field day was organized at the research and demonstration sites where Team members (ranchers, scientists and extension personnel) presented the aforementioned findings and distributed seven fact sheets with information emerging from this project.
A website was created to disseminate findings from the present project, and another website was created to synthetize information about medusahead control in the western US.
This project trained a MS student (2017), a PhD student (a defense is planned for Spring of 2019) and eight undergraduate students. In addition, one of the undergraduate students received in 2018 an Undergraduate Student Opportunity Award and a graduate student a Graduate Student Opportunity Award to conduct research under the framework of the present project.
The knowledge gained with our research and extended through our education activities is providing ranchers low-cost and environmentally sound tools to enhance ecosystem services including biodiversity and improved animal welfare and nutrition.
- 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.
- 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).
Create an outreach and education program to extend findings from the proposed project involving producers and extension personnel in the selection of demonstration sites, research sites, workshops and presentations.