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RULE 4 PERFORMANCE STANDARDS <br />..................... . <br />The study design took into consideration the possible limitations to shrub establishment. The treatments <br />vary at each mine to accommodate the reclamation techniques and material availability for each site, but <br />certain similar treatments were included at each mine. To evaluate effect of the herbaceous competition, <br />seed mixes were designed so that shrubs contributed the majority of the seed mix. Two seed mixes were <br />evaluated at each mine: <br />1) a native grass, forb and shrub seed mixture and <br />2) a seed mixture of unpalatable native shrubs and low-competitive native grasses and forbs. <br />At each mine, one treatment included alternating strips seeded with only the shrub/forb component of the <br />mix. At Seneca Mine, treatments included seedling transplants, for tall shrub species that have proven to <br />be particularly difficult to establish from seed. <br />Typical topsoil replacement depths varying from 12 - 20 inches creates an ideal environment for grass <br />establishment. Therefore, the depth of topsoil on the plots was varied to evaluate shrub and forb response <br />to topsoil depths ranging from 0 inches to 20 inches. <br />Composite soil and overburden samples were taken from each treatment at each mine. Overall, the soils <br />(topsoil and spoil) at all three-mine sites have good physical and chemical properties. Soil pH ranges <br />from 6.9 to 7.8, macronutrients appear to be adequate for sustained plant growth, organic matter contents <br />are relatively high (3.7% to 6.3%), salt levels are low (EC ranges from 0.6 to 1.6 mmhos/cm and SAR <br />ranges from 0.3 to 1.8), cation exchange capacity (CEC) is in a normal range, and textures are clay loam <br />and sandy clay loam. Overall, topsoil and spoil at all mine sites have favorable characteristics and <br />provide a suitable plant growth medium. <br />At Colowyo, soil pH ranges from 7.5 to 7.8, macronutrients appear to be adequate for sustained plant <br />growth, organic matter contents are relatively high (3.7% to 4.8%), salt levels are low (EC ranges from <br />0.6 to 1.2 mmhos/cm and SAR ranges from 0.3 to 1.6), cation exchange capacity (CEC) is in a normal <br />range, and textures are clay loam and sandy clay loam. The detailed soil and overburden analysis for the <br />Colowyo Mine is provided below. <br />Parameter Plot la Plot 2 Plot 3` Plot 4 Plot 5e <br />pH 7.5 7.5 7.5 7.7 7.8 <br />% OM 4.1 4 4.8 4.1 3.7 <br />NH4-N <br />mg/kg 4.9 4.6 6 6.1 8.7 <br />N03-N <br />mg/kg 24.1 19.1 22.3 13.7 18.1 <br />P mg/kg 15 9.6 12 7.8 29 <br />K mg/k9 191 210 201 95.1 105 <br />Ca meq/L 4.9 4.1 4.4 3.5 5.5 <br />Mg meq/L 2.6 1.6 2 2.4 4.1 <br />Na meq/L 0.8 0.6 1.3 1.9 3.5 <br />K meq/L 0.2 0.5 0.4 0.2 0.2 <br />EC mmhos/cm 0.7 0.6 0.7 0.7 1.2 <br />SAR 0.4 0.3 0.8 1.1 1.6 <br />Rule 4 Performance Standards 4.15-4 Revision Date: 6/23/08 <br />Revision No.: MR-91