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• based on soil tests for N and P in semiarid grassland soils may be of limited value. <br />However, to promote growth on croplands, P and N are supplemented. Spoil material at Trapper Mine <br />typically ranges from <0.1 to 7.8 ppm P with an average of 5.5 ppm P (Steams-Roger, Inc., 1974) <br />whereas B-14 ppm is considered a medium level for crop production of wheat and alfalfa (Ludwick at al, <br />1977). Phosphorus levels range from <0.1 to 7.8 ppm in topsoils at Trapper Mine (Steams-Roger, 1974) <br />and therefore P2O5 is applied to the topsoil surface at about 50 Ibs per acre in the form of 100 Its per <br />acre of 0-48-0 or 87 Ibs per acre of 11-52-0 prior to discing and seeding. <br />Topsoil and spoil at Trapper Mine typically contain averages of 8.3 ppm and 5.5 ppm available N <br />respectively (Steams-Roger, Inc., 1974) whereas 12 ppm is considered adequate for plant growth <br />(Workman, 1980). If needed, N Is applied at 50 Ibs/acre in the form of 150 Ibs per acre 34-0-0 on the soil <br />surface. N is usually applied during the spring and/or early summer. Aerial application, a spin spreader, <br />or similarly effective piece of equipment, is used to disperse the fertilizers. Fertilizers are applied mainly <br />during the snow free months. <br />During future reclamation, these fertilizer quantities may vary depending on analyses of soil samples <br />• conducted by a qualified laboratory and measured plant responses. <br />• 3-72 - <br /> <br />