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Rio Blanco County Area, Colorado •
<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, deterred grazing, rotation grazing, and
<br />brush management. Grazing shoud 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. Livestock grazing should be managed
<br />to protect the soil from excessive erosion.
<br />If this unit is seeded, the main limitations are low
<br />precipitation in summer, alkalinity, and the hazard of
<br />erosion. For successful seeding, prepare a seedbed and
<br />drill in the seed. The plants selected for seeding should
<br />meet the seasonal requirements of livestock or wildlife,
<br />or both. Salt- and alkali-tolerant grasses are best suited
<br />to this unit.
<br />If this unit is used for irrigated hay and pasture, the
<br />main limitations are salinity and alkalinity, slow
<br />permeability, and difficulty of brush removal. For good
<br />establishment of hay and pasture, prepare a seedbed,
<br />drill in the seed, and use supplemental irrigation. Furrow,
<br />border, corrugation, and sprinkler irrigation systems are
<br />suited to this unit. Leveling helps to insure the uniform
<br />application of water. Water needs to be applied at a slow
<br />rate over a long period to insure that the root zone is
<br />properly wetted.
<br />Use of nitrogen and phosphorus fertilizer promotes
<br />good growth of forage plants. Proper stocking rates,
<br />pasture rotation, and restricted grazing during wet
<br />periods help to keep the pasture in good condition and
<br />to protect the soil from erosion.
<br />This map unit is in capability subclasses IVs, irrigated,
<br />and Vlls, nonirrigated. It is in Alkaline Sloes range site.
<br />90-Torrlfluvents, gullied. This map unit is along
<br />narrow valley bottoms, in swales, and on eroded fans.
<br />Slope is 0 to 5 percent. Areas are long and narrow or
<br />irregular in shape and are 40 to 200 acres in size. The
<br />native vegetation is mainly sparse desert shrubs and
<br />annual grasses. Elevation is 5,100 to 7,000 feet. The
<br />average annual precipitation is 8 to i6 inches, the
<br />average annual air temperature is 40 to 50 degrees F,
<br />and the average frost-free period is 75 to 130 days.
<br />This unit is 80 percent Torrifluvents that are
<br />characterized by gullies and headcuts 3 to 35 feet deep
<br />and 5 to 150 feet wide.
<br />Torrifluvents are moderately deep and deep and are
<br />well drained and somewhat excessively drained. They
<br />formed in highly calcareous and gypsiferous, stratified
<br />sandy, loamy, and clayey alluvium derived dominantly
<br />from sandstone and shale.
<br />Included in this unit are small areas of Absher loam,
<br />Billings silty clay loam, Chipeta silty clay loam, Glenton
<br />sandy loam, Havre loam, Tisworth fine sandy loam,
<br />Turley fine sandy loam, and Uffens loam.
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<br />Permeability of the Torrifluvents is moderately rapid to
<br />slow. Available water capacity is moderate to high.
<br />Effective rooting depth is 60 inches or more. Runoff is
<br />rapid, and the hazard of water erosion is very high,
<br />which results in high production of sediment during
<br />rainstorms and periods of snowmelt.
<br />This unit is nearly barren, but a few areas are used for
<br />livestock grazing and wildlife habitat.
<br />This map unit is in capability class VIII.
<br />91-Torriorthents-Rock outcrop complex, 15 to 90
<br />percent slopes. This map unit is in extremely rough and
<br />eroded areas on mountains, hills, ridges, and
<br />canyonsides. Slopes mainly face south. The native
<br />vegetation is mainly sparse shrubs and grasses with
<br />some pinyon and juniper trees. Elevation is 5,100 to
<br />7,500 feet. The average annual precipitation is 8 to 18
<br />inches, the average annual air temperature is 40 to 50
<br />degrees F, and the average frost-free period is 70 to 130
<br />days.
<br />This unit is 50 percent Torriorthents that have slopes
<br />of 15 to 65 percent and 30 percent Rock outcrop that
<br />has slopes of 35 to 90 percent (fig. 6).
<br />Included in this unit are small areas of Barcus
<br />channery loamy sand, Glendive fine sandy loam, Havre
<br />loam, Moyerson stony clay loam, Nihill channery sandy
<br />loam, Patent loam, Redcreek sandy loam, Rentsac
<br />channery loam, Sinkson gravelly sandy loam, and
<br />Blazon, Castner, and Clifterson channery loams.
<br />Torriorthents are very shallow to moderately deep and
<br />are well drained and somewhat excessively drained.
<br />They formed in residuum and colluvium derived
<br />dominantly from sandstone, shale, limestone, and
<br />siltstone. Torriorthents are highly variable. No single
<br />profile of Torriorthents is typical, but one commonly
<br />observed in the survey area has a surface layer of pale
<br />brown channery loam about 3 inches thick. The
<br />underlying material is very pale brown channery loam,
<br />very channery loam, or fine sandy loam about 13 inches
<br />thick. Shale or sandstone is at a depth of 16 inches.
<br />Torriorthents are calcareous throughout. In some areas
<br />the surface layer is stony or flaggy.
<br />Permeability of the Torriorthents is moderate. Available
<br />water capacity is very low. Effective rooting depth is 10
<br />to 20 inches. Runoff is very rapid, and the hazard of
<br />water erosion is very high.
<br />Rock outcrop consists of barren escarpments, ridge
<br />caps, and points of sandstone, shale, limestone, or
<br />siltstone. The escarpments are 3 to 50 feet thick and 25
<br />to 2,500 feet long.
<br />Most areas of this unit are used for wildlife habitat and
<br />livestock grazing.
<br />The potential plant community on this unit is mainly
<br />some pinyon and juniper trees with Indian ricegrass,
<br />beardless wheatgrass, prairie junegrass, low rabbitbrush,
<br />and some fortis. Many areas have sparse stands of
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