REP48747 - Laserfiche WebLink

Home Browse Search

. are low (EC ranges from 0.6 to 1.2 mmhos/cm and SAR ranges from 0.3 to 1.6), cation exchange capacity (CEC) is in a normal range, and textures are clay loam and sandy clay loam (Table 6). Physical and chemical properties of topsoil and spoil are similar at Colowyo. The pH of topsoil is 7.5 and the spoil pH ranges from 7.7 to 7.8. Nitrate-nitrogen levels range from 19.1 to 24.1 mg/kg in the topsoil and 13.7 to 18.1 mg/kg in the spoil. Ammonium-nitrogen levels in the spoil are similar or slightly higher in spoil (6.1 to 8.7 mg/kg) compared to topsoil (4.6 to 6.0 mg/kg). Phosphorus levels vary greater in the spoil (7.8 to 29 mg/kg) and less so in the topsoil (9.6 to IS mg/kg). Potassium levels aze substantially lower in spoil (95 to ]OS mg/kg) compared to topsoil {191 to 210 mg/kg). Electrical conductivity, SAR, CEC, and texture are similaz between topsoil and spoil. The only chemical property that appears to be markedly different between topsoil and spoil at Colowyo is potassium. Soils at the Trapper Mine have physical and chemical properties similaz to Colowyo (Table 7). Soil pH ranges from 6.9 to 7.7. Macronutrients appeaz to be adequate for sustained plant growth, except for phosphorus. Phosphorus levels are substantially lower at Trapper (0.2 to 3.1 mg/kg) compared to Colowyo (7.8 to 29.0 mg/kg}. A phosphorus level wnsidered to be adequate for plant growth is about 7 mg/kg. Organic matter levels are higher at Trapper compared to Colowyo, with values ranging from 4.8% to 6.5%. Salt wncentrations are low (EC ranges from 0.6 to 1.6 mmhos/cm and SAR ranges from 0.6 to 1.8) and CEC is in a normal range. Textures are clay loam and sandy clay loam. Comparisons between topsoil and spoil at Trapper indicate that pH is slightly higher in spoil (7.6 to 7.7) compared to topsoil (6.9 to 7.1), Nlla-N levels average about the same between spoil and topsoil and NO3-N levels are higher in topsoil (6.8 to 15 mg/kg) compared to spoil (6.3 to 7.7 mg/kg). Phosphorus levels are substantially lower in spoil (0.2 to 0.5 mg/kg) compared to topsoil (2.6 to 3.1 mg/kg) and both are considered to be low. Potassium levels are also much lower in spoil (76 to 118 mg/kg) compared to topsoil (193 to 428 mg/kg). Electrical conductivity, SAR, CEC and texture are similar between topsoil and spoil The only chemical properties that appear to be markedly different between topsoil and spoil aY Trapper are NO3-N, phosphorus, and potassium levels. Soils at the Seneca Mine are also similaz to Colowyo and Trapper (Table 8). Soil pH ranges from 6.8 to 7.6. Macronutrients appear to be adequate for sustained plant growth, except for phosphorus. Phosphorus levels are more similar to Trapper than Colowyo. Phosphorus concentrations range from 0.4 to 4.3 mg/kg at Seneca. Organic matter levels are lowest at Seneca and range from 3.2% to 3.9%. Salt concentrations are low (EC ranges from 0.3 to 0.9 mmhos/cm and SAR ranges from 0.3 to 0.6) and CEC is in a normal range. Textures are clay loam and loam. Spoil material at Seneca has lower pH than topsoil (6.8 compared to an average of 7.5) and lower phosphorus levels (0.4 compared to an average of 3.1 mg/kg). Ammonium-nitrogen levels are similaz between topsoil (4.1 to 5.1 mg/kg) and spoil (4.6 mg/kg), as are NO3 N levels (4.6 to 13.1 mg/kg in topsoil and 7.5 mg/kg in spoil). Organic matter levels in topsoil range fiom 3.2 to 3.9% and the organic matter level in spoil is 3.2%. Potassium levels, CEC, EC, and SAR are all similar between topsoil and spoil Texture of spoil is loam and clay loam in topsoil. Phosphorus and pH are the only two soil properties that appear to be different between topsoil and spoil at Seneca. In summary, topsoil and spoil at all mine sites were found to have favorable characteristics for plant growth, with the possible exception of phosphorus at Trapper and Seneca. However, plant growth from previous reclamation efforts has not shown evidence of phosphorus deficiencies and so it has been assumed that phosphorus levels are adequate. 12