2010-11-12_PERMIT FILE - C1981010 (4)

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4.5 CROPLAND Croplands are discussed in Sections 3.6.2 and 4.2.1. In order to determine whether successful reclamation has been achieved on reclaimed cropland (non -irrigated pasture and hayland), reclaimed croplands will be compared against an adjacent cropland reference area situated on unmined lands. Hayland production may differ greatly from year to year as described in correspondence from the Soil Conservation Service (Figure 4.5-1) and Colorado State University Extension (Figure 4.5-1a). Variations in annual precipitation totals as well as late spring freezing temperatures can have a profound effect on hay production from one year to the next. Thus, a comparison of reclaimed croplands against an adjacent unmined reference area, which is managed in a similar fashion, and where both areas are subjected to the same precipitation and climactic variations is the most logical bond release approach for croplands. Soils that are replaced on areas being reclaimed for cropland are similar to those found on adjacent unmined areas used for farming. Soils found on the affected cropland acres and adjacent unmined cropland areas were described by the Soil Conservation Service (1975) during a Soil Survey of Trapper Mine (refer to Appendix G). Soil textures for both areas are predominantly loam, clay loam, and silty clay loam. Slopes are similar between the two areas, (i.e. those areas to be returned to cropland and the adjacent unmined areas to be used for comparison) being generally less than 12%. The overall aspect for both areas is northern. 4.5.1 Conceptual Plan for Testing Success of Crosland Restoration Successful reclamation of croplands (non -irrigated pasture and hayland) will be determined by comparison of reclaimed croplands against an adjacent cropland reference area (Figure 4.5-2). (Historical map M49 gives possible cropland comparison areas that was later refined in Figure 4.5-2. Figure 4.5-2 gives the definitive cropland reference area.) Actual hay production will be determined from dipped plots. Plots will be randomly located on both the reclaimed area block and the reference area. Optimum plot size will be determined on a site-specific basis, but plot size will remain consistent far any given sampling regimen. A sufficient number of plots will be clipped to provide a statistically valid sample for both reclaimed and reference areas. The material, once clipped, will be bagged and allowed to air dry to a relatively constant weight. 4-142