Laserfiche WebLink
Colorado, Mcginnies and Nicholas, 1982, demonstrated with field and greenhouse studies <br />• that vegetation stands, herbage yield, and root production all increased linearly as <br />topsoil depths increased from 0 to 1.5 feet. Barth (1984) found that production of <br />perennial grasses on bare spoil with no adverse properties, was as great as when spoil was <br />covered with soil of any thickness. <br />DePUi t, 1984, points out that plant community composition and diversity for rangeland is <br />often reached at shallower topsoil depths than what is required for maximum production. <br />This phenomenon apparently exists at the Seneca Mine in northwestern Colorado where <br />Pfannenstiel and Yendt (7985) demonstrated that 0.5 feet of topsoil applied to Vad9e spoil <br />in 1976 has produced a native looking sagebrush grassland community with a shrub density <br />of 1,450 stems/acre. Proper topsoil handling techniques used in combination with suitable <br />spoil replacement end topsoil/spoil scarification, where needed to reduce compaction, ere <br />more effective in reestablishing minesoil productivity than 50 years of succession on poor <br />quality minesoils (Schafer et al., 7979). <br />A mean topsoil replacement depth of approximately 7.3 feet over final graded spoil at <br /> Seneca II-V Mine will be beneficial to establishing a good seedbed and rooting medium. <br />• This c onclusion is supported by the above referenced literature, premine soil survey (Tab <br /> 9), and vegetation inventories (Tab 1 0), as well as on-site data from Peabody's Seneca II <br /> Mine. The anticipated loamy topsoil texture will likely have favorable infiltration and <br />water holding characteristics. Also, the spoil medium immediately below the topsoil will <br />typically have desirable chemical and physical characteristics for plant growth including <br />a loamy texture, low sodicity and salinity, and moderately low saturation percentage for <br />acceptable water holding characteristics, end no minor element toxicity problems (see Tab <br />6, Geology end Overburden Assessment). <br />Maintenance and Testing Procedures. Prior to distribution of topsoil in the Lennox coal <br />outcrop sampling area shown on Exhibit 6-6, final graded areas (on which topsoil is to be <br />applied) will be sampled to confirm spoil suitability (see Tab 21, Overburden/Spoil <br />Handling Plan for more details). The density and physical characteristics of the replaced <br />topsoil and upper spoil will be observed. Past experience at Peabody's Seneca II Nine has <br />shown that scarifying all spoil roads will correct the significant compaction problems. <br />A topsoil resource quality control program will be implemented to insure that topsoil is <br />• salvaged and replaced as recommended. The optimum soil salvage depth for each soil map <br />31 Revised 04/24/91 <br />