Laserfiche WebLink
t <br />NSH - PART II <br />~ 40J.6(a) Continued <br />1 <br />Materials that are extremely acid or have the potential upon oxidation of becoming <br />extremely acid arc difCicu It and expensive to vegetate, and contribute to poor <br />quality of water, both in runoff or in ground water. hln teriale high in pyrite and <br />marcasite without off-setting bases have high potential acidity. Laboratory tests <br />may be needed to properly identify these materials. <br /> Vegetation is difficult to establish on soils with high pH. Many of these soils <br /> also have a high sodium adsorption ratio which indicates potential instability and <br /> water transmission prcblems. <br /> Available water capacity also is important in establishing vegetation. Soils with <br /> low available water capacity may require irrigation for establishment of vegetation. <br /> The stability of the soil depends upon its erod ibility by water and wind and its <br />• strength. Water erodibili[y is indicated by the K factor; wind erod ibiltiy is <br /> rated according to the wind erodibili[y group. Potential slippage hazard is re- <br /> lated [o soil texture, and although other factors also contribute, [he ratings of <br /> soil texture represent one important factor. <br /> USDA texture also influences a number of properties listed above such as available <br /> water capacity and erodibility by wind or water. Texture also influences soil <br /> structure and consistence, water intake rate, runoff, fertility, workability, and <br /> [rafficabili[y. <br /> Fraction 13 inches is a weight percentage of rock fragments in [he material used <br /> for soil reconstruction. Rock fragments influence the ease of excavation, stock- <br /> piling and respread ing, and suitability for [he final use of the land. A certain <br />r amount of rock fragments can be tolerated depending upon size and [he intended use <br /> of the reclaimed area. If the size of rock fragments exceed 10 inches, [he prob- <br /> lems are more severe. <br /> This guide does no[ cover all the soil features required in planning soil recon- <br /> struction, for example, slope, thickness of material, ease of excavation, potential <br /> slippage hazard, and soil moisture regime. Slope of the original soil may influence <br /> [he method of stripping and stockpiling of reconstruction material but may have <br /> little effect on the final contour and therefore, on the stability and productivity <br /> of [he reconstructed soil. Therefore, slope is not a criteria in this guide. <br />• <br /> Thickness of material suitable for reconstruction and ease of excavation are <br /> important criteria in planning soil reconstruction operations. However, they are <br /> so dependent on the method of mining operations that they cannot be used as criteria <br />• in this guide. Potential slippage hazard is related to soil texture, slope, <br /> differential permeability between layers, rainfall, and other factors which are not <br /> included in the guide. Soil moisture regime climate and weather influence the kind <br /> of vegetation to plant and the race of reve getative growth. They are not used as <br /> criteria because the relative ranking does not change with variable moisture regimes, <br /> that is, the best soil in a moist environment is the best soil in a dry environment. <br /> Furthermore, the soil may be irrigated ro establish vegetation. <br />NSH Notice 24 - 3/71/?8 <br />~`d TA~NMET~~~ I3 <br /> <br /> <br />