2002-03-04_REVISION - M1986015 (8)

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RECLAMATION PLAN perennial weeds will be controlled by methods appropriate for those species, generally by chemical spraying. Examination of the site prior to mining revealed an extremely high abundance of weeds, particularly annual weeds such as Kochia and Salsola. Noxious weeds, although present, seem to have a limited presence, but may expand after disturbance. Without any doubt, the seed bank in the soil contains an incredible number of weed seeds. When the soil is redistributed it is expected that annual weeds will be a severe problem. Control of these weeds is absolutely essential to the success of the revegetation. With annual weeds two procedures are often effective in reducing the adverse effects from this growth. First, high nitrogen fertilizer should not be applied at the time of planting the seed mixture as a high fertility soil often enhances the weed problem. Second, keeping the weeds mowed to a height of not more than six to eight inches and, in particular, mowing just as the weeds are beginning to flower, prevents the weeds from producing large amounts of seed than can perpetuate the population. Fertilizing in the fall of the year helps the desired vegetation while reducing the boost to the weeds. Continued and frequent mowing of weed infested areas until the desired vegetation has become established, combined with nutrient management, is often all that is needed to virtually eliminate annual weeds. Unfortunately, perennial weeds, such as the noxious species, cannot be controlled effectively using these methods and require more drastic action, usually in the form of herbicides. Herbicide usage should be kept to a minimum on this site due to the proximity of the site to the groundwater. General treatment over wide areas of weed growth with herbicides will be avoided as much as possible to prevent water contamination. Irrigation: Irrigation during the first year may be used in the Riparian Forest and Shrub/Scrub revegetation areas. This irrigation will be by means of flooding. Because the land in this area will slope downward from west to east, applying the water on the west end and allowing it to flow eastward will efficiently and economically irrigate the entire area. Irrigation of this land will only be done if needed. Irrigation elsewhere will probably be done with sprinklers, although the dryland pasture, if irrigation is needed to establish it, could be done by flooding. In all cases, irrigation will not be applied unless it is necessary to establish growth. Experience elsewhere indicates that such an approach is often needed in the Pueblo area, particularly during June which is often drier than July and August (see Exhibit K -Climate Information). Pueblo East Pit Amendment Exhibit E Page 15