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<br />seeding should meet the seasonal requirements of
<br />livestock or wildlife, or both.
<br />If this unit is used for homesite development, the main
<br />limitations are the potential for shrinking and swelling
<br />and slow permeability. Structures to divert runoff are
<br />needed if buildings and roads are constructed. Buildings
<br />and roads should be designed to offset the limited ability
<br />of the soil in this unit to support a load. The effects of
<br />shrinking and swelling can be minimized by using proper
<br />engineering designs and by backfilling with material that
<br />has low shrink -swell potential.
<br />This map unit is in capability subclass IVe. It is in Deep
<br />Loam range site.
<br />102—Work loam, 8 to 15 percent slopes. This deep,
<br />welldrained soil is on uplands, fans, and terraces. It
<br />formed in eolian and alluvial material. Areas are
<br />elongated and are 20 to 300 acres. The native
<br />vegetation is mainly low shrubs and grasses. Elevation is
<br />6,100 to 7,400 feet. The average annual precipitation is
<br />15 to 18 inches, the average annual air temperature is
<br />39 to 42 degrees F, and the average frost -free period is
<br />80 to 105 days.
<br />Typically, the upper part of the surface layer is brown
<br />loam about 4 inches thick. The lower part is brown loam
<br />about 6 inches thick. The upper 5 inches of the subsoil
<br />is brown clay loam, and the lower 10 inches is light
<br />brown clay loam. The next layer is light brown clay loam
<br />15 inches thick. The upper 20 inches of the substratum
<br />is pink clay loam, and the lower part to a depth of 60
<br />inches or more is pink loam. In some areas below a
<br />depth of 30 inches, this soil is as much as 25 percent
<br />rock fragments. In some areas the surface layer is fine
<br />sandy loam or clay loam.
<br />Included in this unit are small areas of Forelle, Guben,
<br />and Shawa barns and Zoltay clay loam. Included areas
<br />make up about 15 percent of the total acreage. The
<br />percentage varies from one area to another.
<br />Permeability of this Work soil is moderately slow.
<br />Available water capacity is high. Effective rooting depth
<br />is 60 inches or more. Runoff is medium, and the hazard
<br />of water erosion is moderate to high.
<br />This unit is used as nonirrigated cropland and for
<br />livestock grazing and wildlife habitat. Wheat is the main
<br />nonirrigated crop.
<br />If this unit is used for nonirrigated crops, the main
<br />limitations are a short growing season, low precipitation
<br />in summer, slope, and the hazard of water erosion from
<br />snowmelt. The steeper areas are poorly suited to
<br />cultivation.
<br />Compaction and excessive cloddiness occur if the soil
<br />in this unit is cultivated when it is too moist. Tillage
<br />should be kept to a minimum. Returning crop residue to
<br />the soil or regularly adding other organic matter improves
<br />fertility, reduces crusting, and increases the water intake
<br />rate. Maintaining crop residue on or near the surface
<br />also reduces runoff, reduces soil blowing, and helps to
<br />Soil survey
<br />maintain soil tilth and organic matter content, to
<br />conserve moisture, and to reduce erosion. Erosion also
<br />is reduced if fall grain is seeded early, stubble -mulch
<br />tillage is used, and tillage and seeding are on the
<br />contour or across the slope. Also, waterways should be
<br />shaped and seeded to perennial grass.
<br />The potential plant community on this unit is mainly
<br />needleandthread, western wheatgrass, big sagebrush,
<br />muttongrass, bluebunch wheatgrass, and low
<br />rabbitbrush. Smaller amounts of serviceberry and
<br />snowberry commonly are also present in the potential
<br />plant community. The production of forage is limited by a
<br />short growing season and low precipitation in summer.
<br />The average annual production of air-dry vegetation is
<br />about 1,500 pounds per acre.
<br />If the range is overgrazed, the proportion of preferred
<br />forage plants decreases and the proportion of less
<br />preferred forage plants increases. Therefore, livestock
<br />grazing should be managed so that the desired balance
<br />of preferred species is maintained in the plant
<br />community.
<br />Management practices suitable for use on this unit are
<br />proper range use, deferred grazing, rotation grazing, and
<br />brush management. Grazing should be delayed until the
<br />soil in this unit is firm and the more desirable forage
<br />plants have achieved sufficient growth to withstand
<br />grazing pressure.
<br />If the range vegetation is seriously deteriorated,
<br />seeding is needed. The main limitations for seeding are
<br />low precipitation in summer and slow permeability. For
<br />successful seeding, prepare a seedbed and drill in the
<br />seed. The plants selected for seeding should meet the
<br />seasonal requirements of livestock or wildlife, or both.
<br />This map unit is in capability subclass IVe,
<br />nonirrigated. It is in Deep Loam range site.
<br />103—Work loam, 15 to 25 percent slopes. This
<br />deep, well drained soil is on uplands. It formed in eolian
<br />and alluvial material. Areas are irregular in shape and are
<br />20 to 200 acres in size. The native vegetation is mainly
<br />low shrubs and grasses. Elevation is 6,600 to 7,600 feet.
<br />The average annual precipitation is 16 to 20 inches, the
<br />average annual air temperature is 39 to 42 degrees F,
<br />and the average frost -free period is 75 to 100 days.
<br />Typically, the surface layer is grayish brown loam 4
<br />inches thick. The upper 10 inches of the subsoil is
<br />grayish brown clay loam, and the lower 11 inches is
<br />brown clay. The next layer is pale brown clay loam 15
<br />inches thick. The substratum to a depth of 60 inches or
<br />more is pale brown clay loam. In some areas the surface
<br />layer is clay loam or silty clay loam.
<br />Included in this unit are small areas of Abor, Bulkley,
<br />Pinelli, and Zoltay clay loams. Also included are small
<br />areas of soils that are similar to this Work soil but are
<br />moderately deep to bedrock. Included areas make up
<br />about 15 percent of the total acreage. The percentage
<br />varies from one area to another.
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