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chemical properties. Soil pH ranges from 6.9 to 7.8, macronutrients appear to be <br />adequate for sustained plant growth, organic matter contents are relatively high (3.7% to <br />6.3 %), salt levels are low (EC ranges from 0.6 to 1.6 mmhos /cm and SAR ranges from <br />0.3 to 1.8), cation exchange capacity (CEC) is in a normal range, and textures are clay <br />loam and sandy clay loam. Overall, topsoil and spoil at all mine sites have favorable <br />characteristics and provide a suitable plant growth medium. <br />At Colowyo, soil pH ranges from 7.5 to 7.8, macronutrients appear to be adequate for <br />sustained plant growth, organic matter contents are relatively high (3.7% to 4.8 %), salt <br />levels are low (EC ranges from 0.6 to 1.2 mmhos /cm and SAR ranges from 0.3 to 1.6), <br />cation exchange capacity (CEC) is in a normal range, and textures are clay loam and <br />sandy clay loam. The detailed soil and overburden analysis for the Colowyo Mine is <br />provided below. <br />Parameter <br />Plot la Plot 2' <br />Plot 3` <br />Plot 4' <br />Plot 5e <br />pH <br />7.5 7.5 <br />7.5 <br />7.7 <br />7.8 <br />% OM <br />4.1 4 <br />4.8 <br />4.1 <br />3.7 <br />NH4 -N mg /kg 4.9 4.6 <br />6 <br />6.1 <br />8.7 <br />NO3 -N mg /kg 24.1 19.1 <br />22.3 <br />13.7 <br />18.1 <br />P mg /kg <br />15 9.6 <br />12 <br />7.8 <br />29 <br />K mg/kg <br />191 210 <br />201 <br />95.1 <br />105 <br />Ca meq /L <br />4.9 4.1 <br />4.4 <br />3.5 <br />5.5 <br />Mg meq /L <br />2.6 1.6 <br />2 <br />2.4 <br />4.1 <br />Na meq /L <br />0.8 0.6 <br />1.3 <br />1.9 <br />3.5 <br />K meq /L <br />0.2 0.5 <br />0.4 <br />0.2 <br />0.2 <br />EC mmhos /cm 0.7 0.6 <br />0.7 <br />0.7 <br />1.2 <br />SAR <br />0.4 0.3 <br />0.8 <br />1.1 <br />1.6 <br />CEC meq /100g 26.8 22.1 <br />22.9 <br />27 <br />23.3 <br />% Sand <br />41 51 <br />48 <br />39 <br />41 <br />% Silt <br />23 23 <br />23 <br />23 <br />25 <br />% Clay <br />36 26 <br />29 <br />35 <br />35 <br />Texture <br />clay loam sandy clay loam <br />sandy clay loam <br />clay loam <br />clay loam <br />aPlot 1 = <br />18 inches of topsoil, strip seeding in alternate rows. <br />bPlot 2 = <br />6 inches of topsoil and surface <br />manipulation, seeded with native <br />shrubs and <br />low competitive forbs. <br />'Plot 3 = <br />6 inches of topsoil, strip seeding in alternate rows. <br />aPlot 4 = <br />Non - topsoiled spoil, strip seeding in alternate rows. <br />'Plot 5 = <br />Non - topsoiled spoil, seeded <br />with unpalatable native <br />shrubs <br />and low <br />competitive forbs and grasses. <br />To evaluate <br />the impact from wildlife browsing, elk proof fencing <br />was constructed on one- <br />half of each <br />treatment. <br />4.15 -7 Revision Date: 6/21/11 <br />Revision No.: TR -84 <br />