2015-12-07_GENERAL DOCUMENTS - M1974132

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34 Typically, the surface layer is very pale brown silty clay loam 3 inches thick. The next layer is light yellowish brown silty clay loam 8 inches thick. The underlying material is yellow to gray silty clay loam 15 inches thick. Clayey shale is at a depth of 26 inches. Depth to shale ranges from 20 to 40 inches. The soil is calcareous throughout. Included in this unit are small areas of Abor clay loam, Kobar silty clay loam, and Moyerson stony clay loam. The Abor soil is in the higher lying areas on ridge crests, and the Moyerson soil is in the higher lying areas on foot slopes. Included areas make up about 15 percent of the total acreage. The percentage varies from one area to another. Permeability of the Dollard soil is slow. Available water capacity is low. Effective rooting depth is 20 to 40 inches. Runoff is rapid, and the hazard of water erosion is high to very high. Most areas of this unit are used for livestock grazing and wildlife habitat. A few areas are used for nonirrigated small grain. The potential plant community on this unit is mainly western wheatgrass, prairie junegrass, big sagebrush, and low rabbitbrush. Smaller amounts of Indian ricegrass and milkvetch commonly are also present in the potential plant community. The production of forage is limited by rapid runoff and restricted rooting depth. The average annual production of air-dry vegetation is about 800 pounds per acre. If the range is overgrazed, the proportion of preferred forage plants decreases and the proportion of less preferred forage plants increases. Therefore, livestock grazing should be managed so that the desired balance of preferred species is maintained in the plant community. Management practices suitable for use on this unit are proper range use, deferred grazing, rotation grazing, and brush management. Grazing should be delayed until the soil in the unit has drained sufficiently and is firm enough to withstand trampling by livestock. Brush management improves deteriorated areas of range that are producing more woody shrubs than were present in the potential plant community. The suitability of this unit for rangeland seeding is fair. The main limitations are low precipitation, slow permeability, and rapid runoff. For successful seeding, prepare a seedbed and drill in the seed. The plants selected for seeding should meet the seasonal requirements of livestock or wildlife, or both. If this unit is used for nonirrigated small grain, the main limitations are low precipitation, slow permeability, and rapid runoff. Because precipitation is not sufficient for annual cropping, a cropping system that includes small grain and summer fallow is most suitable. Compaction and excessive cloddiness occur if the soil n this unit is cultivated when it is too moist. Excessive .. ultivation can result in the formation of a tillage pan. Soil survey This pan can be broken by subsoiling when the soil is dry. Returning crop residue to the soil or regularly adding other organic matter improves fertility, reduces crusting, and increases the water intake rate. Maintaining crop residue on or near the surface reduces runoff, reduces soil blowing, and helps to maintain soil tilth and organic matter content. Crusting of the surface and compaction of the soil can be reduced by returning crop residue to the soil. This map unit is in capability subclass IVe, nonirrigated. It is in Clayey Foothills range site. 31—Dollard silty clay loam, 15 to 40 percent slopes. This moderately deep, well drained soil is on foothills and ridges. It formed in clayey residuum derived dominantly from shale. Areas are long and narrow and are 30 to 100 acres. The native vegetation is mainly grasses and low shrubs. Elevation is 5,800 to 6,800 feet. The average annual precipitation is 14 to 16 inches, the average annual air temperature is 42 to 45 degrees F, and the average frost -free period is 80 to 105 days. Typically, the surface layer is very pale brown silty clay loam 2 inches thick. The next layer is light yellowish brown silty clay loam 5 inches thick. The underlying material is yellowish brown silty clay loam about 17 inches thick. Clayey shale is at a depth of about 24 inches. Depth to shale ranges from 20 to 40 inches. The soil is calcareous throughout. Included in this unit are small areas of Moyerson stony clay loam and areas of Badland. Permeability of this Dollard soil is slow. Available water capacity is low. Effective rooting depth is 20 to 40 inches. Runoff is rapid, and the hazard of water erosion is very high. This unit is used for livestock grazing and wildlife habitat. The potential plant community on this unit is mainly western wheatgrass, prairie junegrass, big sagebrush, and low rabbitbrush. Smaller amounts of Indian ricegrass and milkvetch commonly are also present in the potential plant community. The production of forage is limited by slow permeability, rapid runoff, and restricted rooting depth. The average annual production of air-dry vegetation is about 650 pounds per acre. • If the range is overgrazed, the proportion of preferred forage plants decreases and the proportion of less preferred forage plants increases. Therefore, livestock grazing should be managed so that the desired balance of preferred species is maintained in the plant community. Management practices suitable for use on this unit are proper range use, deferred grazing, rotation grazing, and brush management. Seeding is not advisable because of steepness of slope, rapid runoff, and slow permeability. Grazing should be delayed until the soil in this unit is firm