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eh <br />ESPEY, HUSTON 8 ASSOCIATES, INC. <br />r1 <br />U <br />3.4 SOIL RECONSTRUCTION MATERIAL FOR DRASTICALLY DISTURBED <br />LAND <br />3.4.1 Method of Evaluation <br />An SCS guideline for evaluating soil as a plant growth medium is <br />presented in Table I-5. The table includes SAR, EC, toxic materials, pH, available <br />water capacity, erosion factor, wind erosion group, texture and percent coazse <br />fragments. <br />When the soil materials are properly used in reconstruction, a good <br />rating means vegetation is relatively easy to establish and maintain, the surface is <br />stable and resists erosion, and the reconstructed soil has good potential productivity. <br />Material rated fair can be vegetated and stabilized by modifying one or more <br />properties. Top dressing with better material or application of soi] amendments <br />• may be necessary for satisfactory performance. Material rated oor has such severe <br />problems that revegetation and stabilization is very difficult and costly. Top <br />dressing with better material is necessary to establish and maintain vegetation. <br />Excessive amounts of substances that restrict plant growth, such as <br />sodium and salt and boron create problems in establishing vegetation, and therefore <br />also influence erosion and the stability of the surface. Other substances such as <br />selenium and molybdenum get into the food chain and aze toxic to animals that eat <br />the vegetation. Of all these substances, only sodium and salt aze criteria in the <br />guide. If relatively high levels of toxic substances are in the reconstruction <br />material, the material should be rated poor. <br />Laboratory tests of boron, molybdenum, and selenium were conducted on <br />the Northern No. 2 (P-Seam) and No. 3 (J-Seam) Mines soils. The County Extension <br />Agent for Rio Blanco County, reports that there have been no reported cases of <br />selenosis or molybdenosis in Rio Blanco County (Mikesell, 1979) in the five yeazs of <br />• his appointment. He knows of no previous record of either of these cattle diseases <br />having been diagnosed. The vegetation survey has not shown any species of <br />astragalus, which are selenium indicators, to be present. <br />I-61 <br />