Laserfiche WebLink
23-Norriston extremely cobbly loam, 15 to 40 percent slopes. This is a deep, <br />somewhat excessively drained soil on terraces and fans. It formed in glacial outwash. <br />Elevation is 8,400 to 9,000 feet. The average annual precipitation is 16 to 20 inches, the <br />average annual air temperature is 40 to 44 degrees F, and the frost -free season is 55 to <br />75 days. <br />Typically, the surface layer is brown very cobbly sandy loam 6 inches thick. The subsoil <br />extends to a depth of 23 inches. It is brown extremely cobbly sandy loam in the upper 5 <br />inches, light brown extremely gravelly sandy loam in the middle 7 inches, and light brown <br />extremely gravelly loamy sand in the lower 5 inches. The substratum is light brown <br />extremely cobbly loamy sand in the upper 11 inches and is light brown extremely cobbly <br />sand to a depth of 60 inches or more. The soil is neutral. <br />Included with this soil in mapping are areas of Libeg extremely cobbly sandy loam on less <br />sloping parts of the landscape. They make up about 10 percent of the map unit. <br />Permeability of this Norriston soil is rapid, and the available water capacity is very low. The <br />effective rooting depth is 60 inches or more. Surface runoff is medium and hazard if <br />erosion is slight. <br />Most of the acreage is rangeland. <br />The potential native vegetation is mainly Arizona fescue, needleandthread, and mountain <br />muhfy. As the range deteriorates, slimstem muhly, blue grama, Kentucky bluegrass, sun <br />sedge, granite gilia, and rabbitbrush increase. The use of a planned grazing system, cross <br />fencing, and livestock water development helps to prevent range deterioration and <br />promotes the production of the more desirable plants. Broadcasting seed is the only <br />practical method, because slopes are steep and a large number of rock fragments are near <br />the surface. <br />This soil is poorly suited to use as homesites. Slope is the principal limiting feature. <br />