PERMFILE69367 - Laserfiche WebLink

Home Browse Search

Exhibit J March 16, 1983 Vegetation Inventory: The previous vegetation survey (November 27, 1982) information could essentially cover the new areas to be mined or disturbed. Blue Grama is the major forage producer, especially on the deep soil soils of the KM and KC mapping units. On the shallow, gravelly side slopes of the KC unit, blue grama is still a major component of the plant community but makes up an average of 30 percent of the total annual air dry forage, as opposed to 70 percent on the deep soils. Alkali sacaton, sand dropseed, red threeawn, vine mesquite and cheatgrass occur in trace amounts with the blue grama. Shrub and half-shrub production is also present in trace amounts with yucca, buck- wheat species, prickly pear, cholla, four-wing saltbush, and snakeweed being the most common species. Vegetation density (ground cover) and production vary widely, depending on slope, aspect, position and soil characteristics. An average ground cover would be 35 percent. Production on the blue grama ranges from 500 to 1100 pounds per acre with an overall average around 650 pounds. The median production for the majority of the deep soil and level to gently sloping areas is 800 to 900 pounds per acre. On the slope tops and on the steep slopes of the KC mapping unit the plant community changes in terms of plant species and diversity. Needleandthread/New Mexico feather- grass becomes the dominant grass species. The proportion of sand dropseed increases but is still minor in the total production. Isolated patches of sideoats grama, vine mesquite, or western wheatgrass occur. The relative percentage of grass production decreases somewhat from the level top areas but still averages roughly 1000 pounds per acre where ground cover percentages are at or near 30 percent. The previously mentioned shrubs, half-shrubs and forbes occur on the sideslopes, plus other species such as skunkbush sumac, hoptree, pinyon, juniper, cudweed sagewort, tall rabbitbrush, and winterfat. Annual air-dry forage produced by shrubs and forbs is about 350 to 400 pounds per acre. Reclamation Considerations: Seedbed Preparation - Ripping to a depth of twenty to twenty-four inches after the final topsoil is applied to the graded slopes may provide a better opportunity to improve soil cohesion and water holding capacity. A minimum of eighteen inches of suitable plant growth medium is needed to provide adequate water holding capa- city for Yevegatation. The growth medium may ba three to five inches of topsoil plus suitable subsoil material. 1 doubt that ten inches of actual "topsoil" is available for reclamation on the entire site. The covering with subsoil and final topping of topsoil would more accurately reflect the actual reclamation process. The seedbed should then be firmed with a weighted harrow or roller packer prior to seeding. Fertilizer - If possible it would be preferable to fertilize the reclaimed site at the end of the first growing season or at the beginning of the second growing season. This is especially tine where topsoil is collected from a very weedy area. Fertilizer and favorable growing conditions may encourage heavy weed growth and cause the failure of grass seedlings.