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PHILLIPS COUNTY, COLORADO
<br />Ap-0 to 5 inches, grayish-brown (lOYR 5/2) loam, very dark
<br />grayish brown (lOYR 3/2) when moist; weak, thin to
<br />very thick, platy structure that breaks to weak, fine
<br />granular; hard when dry, friable when moist; non-
<br />calcareous; abrupt, smooth boundary,
<br />Bl-5 to 9 inches, dnrk grayish-brown (lOYR 4/2) loam, very
<br />dark grayish brown (lOYR 3/2) when moist; moder-
<br />ate, coarse, subangular blocky structure that breaks
<br />to moderate, medium, subangular; slightly bard when
<br />dry, firm when moist; noncalcareous; about 2 percent
<br />fine gravel; clear, smooth boundary.
<br />B21t-9 to 14 inches, dark grayish-brown (lOYR 4/2) clay
<br />loam, very dark grayish brown (lOYR 3/2) when
<br />moist; moderate, medium, prismatic structure that
<br />breaks to moderate, fine, subangular blocky; hard
<br />when dry, friable when moist; noncnlcareous; very
<br />thin, patchy clay films; clear, smooth boundary.
<br />B22tb-14 to 23 inches, dark-gray (lOYR 4/1) silty clay loam,
<br />very dark brown (lOYR 2/2) when moist; strong,
<br />medium, prismatic structure that breaks to strong,
<br />fine, subangular blocky; hard when dry, firm when
<br />moist; noncalcareous; thick, nearly continuous clay
<br />films; gradual, smooth boundary.
<br />B3cab-23 to 26 inches, pale-brown (lOYR 6/3) silty clay
<br />loam, dark brown (lOYR 4/3) when moist; moderate,
<br />medium, prismatic structure .that breaks to moderate,
<br />medium, subangular blocky; slightly hard when dry,
<br />friable when moist; strongly calcareous; visible lime
<br />along cleavage lines; about 5 percent of the horizon
<br />is very dark grayish brown (lOYR 3/2) when moist;
<br />dear, wavy boundary.
<br />Clca-2G to 43 inches, very pale brown (lOYR 8/3) loam, pale
<br />brown (lOYR 6/3) when moist; moderate, medium,
<br />prismatic structure that breaks to moderate, medium,
<br />subangular blocky; slightly hard when dry, very fri-
<br />able when moist; eery strongly calcareous; lime prom-
<br />inent, but lower part of horizon contnins less lime than
<br />upper part; about 2 percent fine gravel; clear, wavy
<br />boundary.
<br />C2-43 to GO inches, very pale brown (lOYR 8/3) silt loam,
<br />eery pale brown (lOYR 7/3) when moist; massive
<br />(structureless) ; hard when dry, friable when moist;
<br />very strongly calcareous.
<br />The A horizon ranges Prom 5 to 8 inches in thickness, and the
<br />B2t horizon ranges from 10 to 20 inches in thickness. When
<br />moist the B22tb horizon is black to very dark brown. Depth
<br />to lime ranges from 22 to 38 inches. In some areas a gravel bed
<br />underlies the loess at a depth of 40 inches or more.
<br />Aago soils are associated with the %uma and Richfield soils.
<br />In contrast to Richfield soils, Rago soils have a black to dark-
<br />brown layer in the subsoil and are deeper to the limy sub-
<br />stratum. Rago soils have a more clayey B2t horizon than the
<br />%uma soils.
<br />Rago and Kuma loamy (0 to 3 percent slopes) IRa) are
<br />in broad areas of the uplands. These soils are so similar
<br />that it is not practical to map them separately. This map-
<br />ping unit is the most extensive one m Phillips County.
<br />Areas generally extend in a southeast direction and range
<br />from 40 to 400 acres in size. About 70 percent of the unit is
<br />Rago soil, and 30 percent is Iiuma sml, but some fields are
<br />all Rago soil, and others are all Kuma soil.
<br />Included in mapping were small areas of Platner, Rich-
<br />field, and Dawes soils. The Platner soil is in the western
<br />part of the county, the Richfield soil is in the eastern part,
<br />and the Dawes soil is in both the central and western parts.
<br />Also included were areas of a soil that is similar to Rago
<br />loam, except that gravelly material is at a depth of about
<br />24 inches. Many small intermittent lakes or potholes are
<br />within mapped areas and are shown on the soil map by a
<br />symbol.
<br />Rago and Kuma loamy absorb water at a moderate to
<br />slow rate, and runoff causes erosion during some storms.
<br />These soils have high available moisture capacity.
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<br />Almost all the acreage is cultivated. The soils in this s
<br />group are well suited to winter wheat, barley, sorghums,
<br />and corn that are dryfarmed. T1iQyi also are suited to many
<br />kinds of irrigated crops. In dryfarmed fields, the practice
<br />of following small gram or sorghum with summer fallow
<br />helps in maintaining soil moisture and fertility. Stubble
<br />mulching and working crop residue into the soil are prac-
<br />tices needed for controlling erosion.
<br />In irrigated fields the soils cair be leveled so that the
<br />water spreads uniformly. The cro~is respond well if fer-
<br />tilizer is added. Working crop residue into the soil helps
<br />to control erosion and to maintain fertility and tilth. Blue
<br />grams, western wheatgrass, and similar grasses grow well
<br />where these soils are used as range. Capability amts IIo-l
<br />(dryland) and IIe-2 (irrigatel~) ; Loamy Plains range
<br />site; windbreak suitabilify,gronp 1.
<br />Richfield Series
<br />The Richfield series consists of deep, well-drained,
<br />loamy soils of the uplands. These soils occur mainly in the
<br />northeastern part of the county and are nearly level to
<br />moderately sloping.
<br />In a typical profile the surface layer is grayish-brown
<br />loam about 6 inches thick. it is easily worked.
<br />The subsoil, about 14 inches thick, is noncalcareous. It is
<br />grayish-brown, hard clay loam in the upper part, slightly
<br />hard, dark grayish-brown clay loam in the middle part,
<br />and slightly hard, light brownish-gray loam in the lower
<br />part.
<br />Underlying the subsoil is very pale brown loam or very
<br />fine sandy loam that was deposited by wind and then re-
<br />worked locally by wind and water. The underlying mate-
<br />rial is very strongly calcareous or strongly enlcareous. It
<br />contains much accumulated lime.
<br />Runoff is medium where slopes are nearly level, but it is
<br />rapid where they are gently sloping or moderately sloping.
<br />The available water holding capacity and natural fertility
<br />are high.
<br />Most of the acreage of Richfield soils is cultivated. These
<br />soils are suited to winter wheat and sorghums. The native
<br />vegetation consists mostly of western wheatgrass and blue
<br />grams, but some buffalograss grows in depressional areas
<br />where more clay has accumulated in the subsoil. Snake-
<br />weed is a common perennial weed where the native grasses
<br />have been overgrazed.
<br />Typical profile of Richfield loam, 0 to 3 percent slopes,
<br />in a cultivated wheatfield (530 feet east, 2,540 feet north of
<br />the southwest corner of section 23, T. 9 N., R: 43 W.)
<br />Ap-0 to 6 inches, grayish-brown (lOYR 5/2) loam, very dark
<br />grayish brown (lOYR 3/2) when moist; weak, fine,
<br />granular structure; soft when dry, very friable when
<br />moist; noncalcareous; clear, smooth boundary.
<br />Bl-6 to 10 inches, grayish-brown (lOYR 5/2) clay loam, very
<br />dark grayish brown (lOYR 3/2) when moist; weak,
<br />mnrse, prismatic structure that breaks to weak, coarse,
<br />subangular blocky; hard when dry, firm when moist;
<br />very thin, patchy clay films on vertical and horizontal
<br />faces of peds; noncalcareous; clear, smooth boundary.
<br />B2t-10 to 15 inches, dark grayish-brown (IOYR 4/2) day
<br />loam, very dark grayish brown (lOYR 3/2) when
<br />moist; moderate, medium, prismatic structure that
<br />breaks to moderate, medium and fine, subangular
<br />blocky; slightly hard when dry, firm when moist;
<br />thick, continuous clay films on vertical and horizontal
<br />faces of peds; noncalcareous; Clear, smooth boundary.
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