Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 9/30/2005
Publication Date: 2/10/2006
Citation: Johnson, D.A., Bhattarai, K., Jones, T.A., Gardner, D.R., Cane, J.H. 2005. Basalt milkvetch: a promising north american legume for rangeland rehabilitation, conservation, and forage production. Society for Range Management Meeting Abstracts. Interpretive Summary:
Technical Abstract: Land managers have few options for seeding legumes that naturally occur in western North America. Basalt milkvetch (Astragalus filipes) is a North American legume that occurs on a diversity of sites in six western states, British Columbia, and Mexico. Seed collections and associated site data were obtained for 72 sites across western North America. Annual precipitation at the collection sites ranged from 127 mm in Nevada to more than 500 mm in northern California. Elevations at the collection sites ranged from 200 to 2,500 m. Forage collected from the field plants was analyzed for nitrotoxins (3-nitropropanol), selenium, and swainsonine. All three toxic properties were non-detectable or extremely low for all collections, indicating that plant toxicity with this species is not a major concern for grazing animals. Six rhizobial strains were isolated from fresh root nodules. These six rhizobial strains were tested in a greenhouse to determine which strains exhibited the best infectiveness and effectiveness at nitrogen fixation. One rhizobial strain consistently outperformed the others in our greenhouse tests. In 2004, seedlings of each of the collections were transplanted to field sites in northern Utah. In 2005, plants were harvested at the field sites for biomass and seed production. Results from these studies indicated that several collections of basalt milkvetch from Oregon were particularly noteworthy in their growth characteristics. Although basalt milkvetch is a good seed producer, seed weevils (Tychius spp.) and seed beetles (Acanthoscelides spp.) may require control during seed production. Our results suggest that basalt milkvetch appears to have promise for use in rehabilitation, conservation, and forage production applications in western North America.