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PHILLIPS COUNTY, COLORADO
<br />Ap-0 to a' inches, grayish -brown (10YR 5/2) loam, very dark
<br />grayish brown (10YR 3/2) when moist; weak, thin to
<br />very thick, platy structure that breaks to weak, flue
<br />granular; hard when dry, friable when moist; non -
<br />calcareous; abrupt, smooth boundary.
<br />131-5 to 0 inches, dark grayish -brown (10YR 4/2) loam, very
<br />dark grayish brown (10YR 3/2) when moist; moder-
<br />ate, coarse, subangular blocky structure that breaks
<br />to moderate, medium, subangular; slightly hard 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 (10YR 4/2) clay
<br />loam, very dark grayish brown (10YR 3/2) when
<br />moist; moderate, medium, prismatic structure that
<br />breaks to moderate, fine, subangular blocky; hard
<br />when dry, friable when moist; noncalcareous ; very
<br />thin, patchy clay films; clear, smooth boundary.
<br />B22tb-14 to 23 inches, dark -gray (10YR 4/1) silty clay loam,
<br />very dark brown (10YR 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 />133cab-23 to 26 inches, pale -brown (10YR 6/3) silty clay
<br />loam, dark brown (10YR 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 (10YR 3/2) when moist;
<br />clear, wavy boundary.
<br />Clea -26 to 43 inches, very pale brown (10YR 8/3) loam, pale
<br />brown (10YR 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; very strongly calcareous; lime prom-
<br />inent, but lower part of horizon contains less lime than
<br />upper part; about 2 percent fine gravel; clear, wavy
<br />boundary.
<br />C2-43 to 60 inches, very pale brown (10YR 8/3) silt loam,
<br />very pale brown (10YR 7/3) when moist; massive
<br />(structureless) ; hard when dry, friable when moist;
<br />very strongly calcareous.
<br />The A horizon ranges from 5 to 8 inches in thickness, and the
<br />132t 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 />Rago soils are associated with the Kuma 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 132t horizon than the
<br />Iiuma soils.
<br />Rago and Kuma loams (0 to 3 percent slopes) (Ra) 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 />pin ; unit is the most extensive one in Phillips County.
<br />Areas generally extend in a southeast direction and range
<br />froni 40 to 400 acres in size. About 70 percent of the unit is
<br />Rago soil, incl 30 percent is Kuma soil, but some fields are
<br />all Rago soil, and others are all Duma 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 />loans, except that gravelly material is at a depth of about
<br />24 inclies. Many small intermittent lakes or potholes are
<br />within mapped areas and are shown on the soil map by a
<br />synibol.
<br />Rago and Kuma loans 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
<br />group are well suited to winter wheat, barley, sorghums,
<br />and corn that are dryfarmed. They also are suited to many
<br />kinds of irrigated crops. In dryf armed fields, the practice
<br />of following small grain or sorghum with summer fall')w
<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 can be leveled so that the
<br />water spreads uniformly. The crops 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 />grama, western wheatgrass, and similar grasses grow well
<br />where these soils are used as range. Capability units IIc-1
<br />(dryland) and IIe-2 (irrigated) ; Loamy Plains range
<br />site; windbreak suitability group 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 calcareous. 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 />grama, 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 (IOYR 5/2) loam, very dark
<br />grayish brown (10YR 3/2) when moist; weak, fine,
<br />granular structure; soft when dry, very friable when
<br />moist; noncalcareous ; clear, smooth boundary.
<br />B1-6 to 10 inches, grayish -brown (10YR 5/2) clay loam, very
<br />(lark grayish brown (10YR 3/2) when moist; weak,
<br />coarse, 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 (10YR 4/2) clay
<br />loam, very dark grayish brown (10YR 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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