1995-10-11_REVISION - M1977493 (3)

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• • • The literature contains many examples of improved reclamation using sewage sludge as a soil amendment. Brown (1976), and Brown and Jackson (1984) reported 10 to 20 tons per acre of anaerobically digested sewage sludge (2-3% N) applied over 30 tons per acre wood chips produced optimal plant growth at the Urad tailings (elevation 10,400 feet) in central Colorado. Personal communication with Brown (1995) indicates that 20 tons per acre remains the suggested application rate 20 years after the initial application. Maintenance applications, he indicated, are required for several years afterward. Other research in arid climates (Fresquez, et al. 1990) and in the northern Rockies (Vodehnal, 1993) found similar response using directly applied sewage sludge and composted biosolids respectively. At the Climax Mine, vegetation cover in response to biosolids is 1.5 to 2.5 greater than chemical fertilizer treatments at rates ranging from 20 to 40 tons per acre (Berg et al. 1986) seven years following initial treatment. One time applications above this amount may result in excessive salt contributions that may adversely effect plant growth (Topper and Sabey, 1986). Sewage sludge application raises soil temperature and moderates humidity differences between leaf and atmosphere (Grossnickle and Reid, 1984) thereby preventing plant desiccation. Skousen (1988) applied 35 dry tons of municipal biosolids per acre in a high rainfall zone in West Virginia and determined that plant cover and biomass improved while metals in the biosolids did not affect vegetation or migrate into water supplies. Similar results were reported by Melchert et al. (1994) for mine tailings in Northern Minnesota. • Literature Cited Berg, W.A., M. Guillaume, and J.T. Herron. 1986. Effect of fertility treatments and mulches on revegetation of alpine disturbances. In Proceedings: High Altitude Revegetation Workshop No. 7. Colorado State University, Fort Collins, CO. Brown, L.F. Reclamation at Climax, Urad and Henderson Mines. 1976. Mining Congress Journal. Brown, L.F., and C.L. Jackson. 1984. Reclamation of the Urad Molybdenum Mine, Empire, Colorado. Minerals and Environment. 6(2):77-82. Brown, L.F. Personal communication. February 6, 1995. Fresquez, P.R., R.E. Francis, and G.L. Dennis. 1990. Sewage sludge effects on soil and plant quality in a degraded, semiarid grassland. J. Environ. Qual. 19:324-329. Grossnickle, S.C., and C.P.P. Reid. The influences of reclamation practices on the microclimate of a high elevation mine site, and their effect on water relation patterns of Pinus contorta seedlings. 1984. Reclamation and revegetation Research. 3(1):31-48. Melchert, G.D., A.P. Eger, Z. Kassa, and S.W. Dewar. 1994. Reclaiming coarse taconite . tailing with municipal solid waste compost. p. 175-183.. In International Land Reclamation and Mine Drainage Conference and Third International Conference on the