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Erosion Runoff Study con[. <br />Page 4 <br />when comparing erosion potential prior to any conservation measures to <br />that three years following seeding to permanent vegetation. On the <br />winter wheat/stubble mulch and winter wheat/stubble mulch/land imprinting <br />plots, the amount of soil saved in tons/acre/year was 61.7 and 58.4, <br />respectively. The perennial seeding/straw mulch and perennial seeding/- <br />land imprinting treatments provided 66.9 and 66.2 tons/ac/year of soil <br />savings, respectively, when compared to exposed topsoil areas with no <br />soil conservation performance. This data also indicates immediate plant- <br />ing of disturbed areas to permanent vegetation is more desirable, from a <br />soil savings standpoint, than establishing a cover crop (wheat) prior to <br />permanent vegetation seeding. <br /> When comparing the soil loss on the perennial seeding treatments (after <br /> three years) to that of the native sage-grass rangeland, the perennial <br /> seeding plots have less erosion than do native undisturbed areas. The <br />~ "T" factor or the tons of soil loss any particular soil can withstand <br /> without affecting its productivity and natural soil-building character <br /> diEEers~greatly among soil families.(1) Savage soils have a "T" Factor <br /> of "5," so any erosion losses greater than "5" would have a negative <br /> impact on that soil's ability to rebuild itseif. In this inscance, <br /> Savage soils on undisturbed sage-grass sites are at equilibrium, that is <br /> erosion losses are equivalent to the amount of new soil generated. How- <br /> ever, through good conservation practices and the establishment of perma- <br /> nent vegetation, many of which are introduced plant species, [he amount <br /> of soil lost on treatment areas is below [he established "T" value. This <br />'. implies there is more active soil building on revegetated areas than on <br /> undisturbed sage-grass sites. <br />5.0 Trapper Mine employs many of the previously discussed conservation prac- <br />tices to their present mine land reclamation program. in addition, con- <br />servaCion practices such as diversion ditches, erosion control dams, <br />waterways, windbreak establishment, contour strip cropping, pasture and <br />hayland management, and livestock ponds all contribute to reductions in <br />sheet and rill erosion and improved water quality. <br />(l) From Soils of Colorado. Loss factors and erodibility hydrologic grouping. <br />1983. USDA, SCS. <br />~ WA/jb <br />~ 9/30/85 <br />Attachments <br />