LOCATION RICHFIELD KS+CO MT NE OK SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Argiustolls
TYPICAL PEDON: Richfield silt loam, in a cultivated field. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 15 centimeters (0 to 6 inches); grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, friable; slightly sticky and slightly plastic; neutral; clear smooth boundary. Horizon thickness ranges from 10 to 20 centimeters (4 to 8 inches).
Bt--15 to 41 centimeters (6 to 16 inches); dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, firm; sticky and plastic; common fine faint clay films; slightly alkaline; gradual smooth boundary. Horizon thickness ranges from 20 to 36 centimeters (8 to 14 inches).
BCk1--41 to 51 centimeters (16 to 20 inches); grayish brown (10YR 5/2) silty clay loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; hard, firm; few soft accumulations of carbonate; strong effervescence; moderately alkaline; clear smooth boundary.
BCk2--51 to 76 centimeters (20 to 30 inches); light gray (10YR 7/2) silty clay loam, grayish brown (10YR 5/2) moist; weak granular structure; slightly hard, friable; few soft accumulations of carbonate; strong effervescence; moderately alkaline; gradual smooth boundary. Combined thickness for BCk horizons ranges from 46 to 127 centimeters (18 to 50 inches).
C--76 to 152 centimeters (30 to 60 inches); very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; massive; slightly hard, friable; porous; strong effervescence; strongly alkaline.
TYPE LOCATION: Grant County, Kansas; about 14.5 kilometers (9 miles) east and 4.8 kilometers (3 miles) north of Ulysses; located about 304 meters (1,000 feet) west and 30.4 meters (100 feet) south of the northeast corner, sec. 12, T. 28 S., R. 36 W. Hickok NW USGS quad; lat. 37 degrees 38 minutes 2.4 seconds N. and long. 101 degrees 12 minutes 11.4 seconds W., NAD83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 8 to 14 degrees C (46 to 57 degrees F)
Depth to secondary calcium carbonate: 25 to 61 centimeters (10 to 24 inches)
Thickness of the mollic epipedon: 23 to 49 centimeters (9 to 19 inches)
CEC/clay ratios are less than 90 me/100g in the solum
Particle-size control section (weighted average):
Clay content: 35 to 42 percent
An eroded and dry phase is recognized
Ap horizon
Hue: 10YR
Value: 4 or 5 and 2 or 3 moist
Chroma: 2 or 3
Texture: silt loam, silty clay loam, clay loam, loam, very fine sandy loam, and fine sandy loam
Reaction: neutral or slightly alkaline
Some pedons have a thin transitional horizon between the A and Bt horizons
Bt horizon
Hue: 10YR
Value: 4 or 5 and 3 or 4 moist
Chroma: 2 or 3
Texture: silty clay loam or silty clay
Clay content: 35 to 42 percent
Reaction: neutral to moderately alkaline
Bk, BCk horizon
Hue: 10YR
Value: 5 to 7 and 4 to 6 moist
Chroma: 2 or 3
Texture: silty clay loam or silt loam
Clay content: 20 to 32 percent
Reaction: slightly alkaline or moderately alkaline
Identifiable secondary carbonates: 1 to 10 percent
C horizon
Hue: 10YR
Value: 6 to 8 and 4 to 6 moist
Chroma: 2 to 4
Texture: silty clay loam, clay loam, or silt loam
Clay content: 10 to 32 percent
Calcium carbonate equivalent: 10 to 15 percent
Reaction: moderately alkaline or strongly alkaline
This horizon is usually calcareous loess, but in some pedons when the loess mantle is thin, contrasting material is between depths of 102 and 152 centimeters (40 and 60 inches). In some pedons the substratum contains buried horizons.
COMPETING SERIES:
Ashfork soils are moderately deep to a lithic contact.
Bethune soils are moderately deep to a paralithic contact of weakly cemented soft calcareous sandstone.
Blackpipe soils are moderately deep to a paralithic contact.
Boneek soils are deep to a paralithic contact.
Boquillas soils are moderately deep to a paralithic contact.
Chapin soils are moderately deep to a lithic contact.
Collbran soils contain more rock fragments.
Emigrant soils are moderately deep to a lithic contact.
Huggins soils are moderately deep to a lithic contact.
Kube soils have a higher CEC/clay ratio in the solum and are deep to a lithic contact.
Loma soils have carbonates throughout.
Nuncho soils contain more than 15 percent fine sand or coarser in the series control section.
Nunn soils contain more than 15 percent fine sand or coarser in the series control section.
Querc soils are moderately deep to a paralithic contact.
Raku soils are deep to a calcic horizon.
Rednun soils contain more than 15 percent fine sand or coarser in the series control section.
Ryus soils have identifiable secondary carbonates within 15 centimeters (6 inches) of mineral soil surface.
Savo soils have cooler soil temperatures.
Standley soils contain more than 15 percent coarse fragments in the solum.
Weld soils have cooler soil temperatures.
Wormser soils weathered from sandstone and are moderately deep to a lithic contact.
GEOGRAPHIC SETTING:
Parent material: derived from loess ranging from 1 meter (3 feet) to more than 3 meters (10 feet) in thickness
Landform: tablelands that commonly have a plane surface, but the surface ranges from slightly concave to slightly convex
Slopes: 0 to 6 percent
Elevation: 793 to 1402 meters (2600 to 4600 feet)
Mean annual air temperature: 7 to 14 degrees C (45 to 57 degrees F)
Mean annual precipitation: 33 to 56 centimeters (13 to 22 inches)
Precipitation pattern: peak periods of precipitation in the spring and early summer months
Frost-free period: 140 to 201 days.
Thornthwaites Annual P-E Index: 24 to 34
GEOGRAPHICALLY ASSOCIATED SOILS:
These are the
Keith,
Satanta,
Colby,
Ulysses,
Goshen,
Ryus, and
Ness, soils. Keith soils are fine-silty and are on similar positions. Satanta soils are fine-loamy and are on similar positions. The Colby soils are fine-silty and occupy steeper slope positions. Ulysses soils are fine-silty and are on upland hillslopes. Goshen soils have a thicker mollic epipedon and are on lower positions. Ryus soils are on lower positions. Ness soils are more clayey and are in upland depressions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: well drained
Saturated hydraulic conductivity: moderately high
Runoff: low or medium
USE AND VEGETATION: Most of the Richfield soils are cultivated to winter wheat and sorghum. Native vegetation is mainly short and mid grasses.
DISTRIBUTION AND EXTENT: Western Kansas and Nebraska, eastern Colorado, southwestern South Dakota and the Oklahoma Panhandle. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Reconnaissance Soil Survey of Western Kansas, 1910.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: the zone from the surface to 41 centimeters (16 inches) (A and Bt horizons)
Argillic horizon: the zone from 15 to 41 centimeters (6 to 16 inches) (Bt horizon)
Three sets of lab data support a borderline fine and fine-silty family, but range of characteristics presents a fine family soil.