2008-03-12_PERMIT FILE - C1981018A (8)

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aggressive perennial introduced species is necessary to help overcome the competitiveness of the cheatgrass. Seed mixes found previously in this Section reFlect this strategy. It should be noted that even the competitive perennial introduced species may not out compete the cheatgrass on some soils. For the refuse areas where both topsoil and subsoil are salvaged for replacement, reverse sequencing of the soil material replacement appears to be a feasible means of limiting cheatgrass establishment. The nutrient and/or geochemical properties of the subsoil are less hospitable to the cheatgrass while still within the tolerance level for the perennial species. Limited fertilization is anticipated with this use of the subsoil. Excess nitrogen tends to trigger a response from the cheatgrass which could be detrimental to the long term success of the revegetation. Use of fertilizers should be limited. Cheatgrass, as well as other weedy annual species, has a much more pronounced response to fertilizer, primarily nitrogen, than the perennial seeded species. Fertilizer application should be limited to an as-needed basis, often waiting for stress response from the perennial seedlings prior to fertilizer application. Use of herbicides to treat annual weeds for reclamation purposes requires careful consideration. Timing and application rates are generally critical to avoid harming the desired vegetation while controlling the target weed. Many scenarios are possible related to the reclamation process. The following are only examples as unique situations seem to frequently arise requiring deviation from the generic plans. Special consideration needs to be given to the potential impacts to diversity and stand establishment from both the herbicide and the weeds. Scenario example #1: A short term disturbance is resloped and prepared for reseeding in mid- summer. Some native plants that survived in the topsoil have begun to reestablish. Later in the fall cheatgrass is also observed in sufficient density to be a concern for reclamation. In this example we would attempt to preserve the existing vegetation while controlling the cheatgrass to the best of our ability. Cheatgrass is a winter annual or annual. The herbicides approvable by the BLM as of this writing (4/2006) do not include imazapic (Plateau or Journey). Thus, post-emergent treatment with glyphosate (Roundup) would be advisable. We delay reseeding and spray just prior to freeze up. Cheatgrass is typically the last plant to go dormant and first to break dormancy. Delayed spraying allows the maximum emergence of cheatgrass seedlings while allowing other desirable species to go dormant reducing their susceptibility to the herbicide. Reseeding occurs late in the fall to early winter following the plant-back intervals on the herbicide product label. Under this scenario one can expect additional sprouting of cheatgrass in the spring but the reduction in cheatgrass stand density will hopefully be sufficient to aid the establishment of the desired species. Use of imazapic on BLM lands is currently part of the 'preferred alternative' on BLM's Draft Programmatic Environmental Impact Statement (PETS) addressing herbicide use on the lands 4 they manage. BLM approval of this herbicide would provide additional options under this MR131 (5/2006) V-68