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Weld County, Colorado, Northern Part
<br />grayish brown gravelly sandy loam 3 inches thick. The
<br />next layer is calcareous very gravelly loamy coarse sand
<br />21 inches thick. Below this to a depth of 60 inches or
<br />more is calcareous very gravelly loamy coarse sand.
<br />Included in this unit are small areas of soils, on
<br />backslopes, shoulders, and crests of upland ridges and
<br />breaks, that have fine-grained sandstone or siltstone at a
<br />depth of 20 to 40 inches; Rack outcrop on shoulders
<br />and crests of upland ridges and breaks; and Otero sandy
<br />loam and Stoneham fine sandy loam on the lower parts
<br />of backslopes and on upland ridges and breaks.
<br />Included areas make up about 25 percent of the total
<br />acreage. The percentage varies from one area to
<br />another.
<br />Permeability of this Cascajo soil is moderately rapid to
<br />a depth of 3 inches and rapid below this depth. Available
<br />water capacity is moderate. Effective rooting depth is 60
<br />inches or more. Runoff is medium, and the hazard of
<br />water erosion is moderate to very high. The hazard of
<br />soil blowing is slight.
<br />Most areas of this unit are used as rangeland. A few
<br />areas are used as a source of gravel.
<br />The potential plant community on this unit is mainly
<br />blue grama, little bluestem, sideoats grama, and prairie
<br />sandreed. The average annual production of air-dry
<br />vegetation ranges from 500 to 1,200 pounds.
<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 />Areas that are heavily infested with undesirable plants
<br />can be improved by proper grazing management.
<br />Management practices that are suitable for use on this
<br />unit are proper range use, deferred grazing, and rotation
<br />grazing. Mechanical treatment is not practical because of
<br />the stony surtace and the steepness of slope. If the
<br />plant cover is disturbed, protection from erosion is
<br />needed. Loss of the surface layer results in a severe
<br />decrease in productivity and in the potential of the soil iri
<br />this unit to produce plants suitable for grazing. Slope
<br />limits access by livestock and results in overgrazing of
<br />the less sloping areas.
<br />This unit is poorly suited to windbreaks and
<br />environmental plantings. The main limitations are the
<br />large accumulations of lime and moderate available
<br />water capacity. Supplemental irrigation may be needed
<br />when planting and during dry periods. Summer fallow,
<br />cultivation for weed control, and selection of adapted
<br />plants are needed to insure establishment and survival
<br />of seedlings. ~,
<br />This map unit is in capability subclass Vlls,
<br />nonirrigated, and in Gravel Breaks range site.
<br />21-Cushman fine sandy loam, 0 to 6 percent
<br />slopes. This moderately deep, well drained soil is on
<br />slightly dissected to moderately dissected plains. It
<br />21
<br />formed in calcareous loamy residuum derived from
<br />interbedded sandstone and shale.
<br />Typically, the surtace layer is brown fine sandy loam 6
<br />inches thick. The upper 4 inches of the subsoil is fine
<br />sandy loam, and the lower 11 inches is clay loam. The
<br />substratum is calcareous clay loam 8 inches thick.
<br />Interbedded, calcareous sandstone and shale are at a
<br />depth of 29 inches. Depth to sandstone and shale
<br />ranges from 20 to 40 inches.
<br />Included in this unit are small areas of Midway clay
<br />loam, Renohill fine sandy loam, and Shingle clay loam.
<br />Also included are some areas of Rock outcrop.
<br />Permeability of this Cushman soil is moderate.
<br />Available water capacity is moderate. Effective rooting
<br />depth is 20 to 40 inches. Runoff is medium, and the
<br />hazard of water erosion is slight to moderate. The
<br />hazard of soil blowing is slight.
<br />This unit is used as rangeland and nonirrigated
<br />cropland. Winter wheat is the main crop.
<br />The potential plant community on this unit is mainly
<br />blue grama, western wheatgrass, sedges, and
<br />buffalograss. The average annual production of air-dry
<br />vegetation ranges from 500 to 1,500 pounds.
<br />If the range is overgrazed, the proportion of preferred
<br />forage plants decreases and the proportion of less
<br />preferced 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 />Range seeding is suitable if the range is in poor
<br />condition. The plants selected for seeding should meet
<br />the seasonal requirements of livestock or wildlife, or
<br />both. Other manag@ment practices that are suitable for
<br />use on this unit are proper range use, deferred grazing,
<br />and rotation grazing. If the plant cover is disturbed,
<br />protection from erosion is needed. Loss of the surface
<br />layer results in a severe decrease in productivity and in
<br />the potential of the soil to produce plants suitable for
<br />grazing.
<br />This unit is suited to winter wheat, barley, oats, and
<br />sorghum. Because precipitation is not sufficient for
<br />annual cropping, a cropping system that includes small
<br />grain and summer fallow is most suitable. Precipitation
<br />usually is too low for crops on this unit to make efficient
<br />use of fertilizer.
<br />Maintaining-crop residue on or near the surface
<br />reduces erosion and helps to maintain soil filth and
<br />organic matter content. Stubble-mulch farming,
<br />stripcropping, and minimum tillage help to control erosion
<br />and conserve moisture. Terraces reduce runoff and the
<br />risk of erosion and help to conserve moisture.
<br />This unit is well suited to windbreaks and
<br />environmental plantings. The main limitations are the
<br />moderate available water capacity and restricted rooting
<br />depth. Supplemental irrigation may be needed when
<br />planting and during dry periods.
<br />This map unit is in capability subclass IVe,
<br />nonirrigated, and in Loamy Plains range site.
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