LOCATION WILKERSON CO
Established Series
Rev. LC/TWH
02/2012
WILKERSON SERIES
The Wilkerson series consists of very deep, moderately well drained soils that formed in alluvium. Wilkerson soils are on stream terraces. Slopes range from 0 to 4 percent. Mean annual precipitation is about 305 mm (12 inches) and the mean annual temperature is about 2.8 degrees C (37 degrees F).
TAXONOMIC CLASS: Fine-loamy, gypsic Oxyaquic Calcicryepts
TYPICAL PEDON: Wilkerson fine gypsum material, 0.5 percent slope in grassland at an elevation of 2804 meters. (Colors are for dry soil unless otherwise noted. Reaction, carbonate content, and gypsum content are from lab data.) Described on June 26, 2008.
Akyz--0 to 13 cm (0 to 5 inches); very pale brown (10YR 8/2) fine gypsum material, pale brown (10YR 6/3) moist; apparent field texture is clay loam; weak very fine granular structure; soft, very friable, slightly sticky, slightly plastic; many fine roots; few fine carbonate masses in the matrix; strongly effervescent; 22 percent calcium carbonate equivalent; 43 percent gypsum content; moderately alkaline (pH 8.1); gradual wavy boundary. (13 to 20 cm thick)
Bkyz1--13 to 25 cm (5 to 10 inches); light gray (10YR 7/2) fine gypsum material, pale brown (10YR 6/3) moist; apparent field texture is clay; weak very fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; many fine roots; few fine carbonate masses in the matrix; strongly effervescent; 13 percent calcium carbonate equivalent; 62 percent gypsum content; strongly alkaline (pH 8.6); gradual wavy boundary.
Bkyz2--25 to 51 cm (10 to 20 inches); light gray (10YR 7/2) fine gypsum material, grayish brown (10YR 5/2) moist; apparent field texture is clay; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; common fine roots; few fine carbonate masses in the matrix; strongly effervescent; 13 percent calcium carbonate equivalent; 62 percent gypsum content; strongly alkaline (pH 8.6); gradual wavy boundary. (combined thickness of the Bkyz horizons is 25 to 51 cm)
Bkz1--51 to 66 cm (20 to 26 inches); light brownish gray (10YR 6/2) clay, dark gray (10YR 4/1) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; common fine roots; few fine carbonate masses in the matrix; strongly effervescent; 33 percent calcium carbonate equivalent; moderately alkaline (pH 8.4); gradual wavy boundary.
Bkz2--66 to 76 cm (26 to 30 inches); gray (10YR 6/1) clay, dark gray (10YR 4/1) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; common fine roots; few fine carbonate masses in the matrix; violently effervescent; 33 percent calcium carbonate equivalent; moderately alkaline (pH 8.4); gradual wavy boundary. (combined thickness of the Bkz horizons is 20 to 38 cm)
2Bkz3--76 to 152 cm (30 to 60 inches); light gray (10YR 7/2) very gravelly sandy clay loam, light brownish gray (10YR 6/2) moist; massive; soft, very friable, slightly sticky, slightly plastic; common fine roots; few fine carbonate masses in the matrix; few fine yellowish brown (10YR5/6) redoximorphic concentrations; 37 percent gravel; violently effervescent; 19 percent calcium carbonate equivalent; moderately alkaline (pH 8.1).
TYPE LOCATION: Park County, Colorado; about 16 kilometers (10 miles) northwest of Hartsel; located about 1200 feet north and 5 feet east of the southwest corner of section 24, T. 11 S., R. 77 W., Garo USGS quad; lat. 39 degrees 04 minutes 19 seconds N. and long. 105 degrees 57 minutes 29 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is usually dry in late spring and early summer, moist in some part in late July and August, and intermittently dry in fall; ustic regime bordering on aridic.
Mean annual soil temperature: 2.8 to 5.0 degrees C (37 to 41 degrees F.)
Mean summer soil temperature: 10.6 to 14.4 degrees C (51 to 58 degrees F.)
Thickness of the ochric epipedon: 13 to 20 cm (5 to 8 inches)
Depth to gypsic horizon: 0 to 13 cm (0 to 5 inches)
Depth to salt accumulations: 0 to 13 cm (0 to 5 inches)
Depth to secondary calcium carbonate: 0 to 25 cm (0 to 10 inches)
Depth to calcic horizon: 51 to 76 cm (20 to 30 inches)
Depth to lithologic discontinuity: 71 to 102 cm (28 to 40 inches)
Depth to redox concentrations and seasonal endosaturation: 74 to 100 cm (29 to 39 inches) in April through August
Particle-size control section (weighted averages):
Noncarbonate clay content: 18 to 25 percent
Rock fragment content: 5 to 15 percent
Gypsum content: 15 to 30 percent
Akyz horizon
Value: 7 or 8 dry; 5 or 6 moist
Chroma: 2 or 3 dry; 2 or 3 moist
Texture: fine gypsum material, gypsiferous clay loam
Clay content: 27 to 35 percent
Carbonate clay content: 15 to 20 percent
Gravel content: 0 to 5 percent, indurated
Calcium carbonate equivalent: 15 to 25 percent
Gypsum content: 35 to 45 percent
Electrical conductivity: 4 to 16 mmhos/cm
Sodium adsorption ratio: 1 to 4
Organic matter content: 3 to 6 percent
Bkyz horizons
Value: 6 or 7 dry; 4 to 6 moist
Chroma: 1 to 3 dry; 1 to 3 moist
Texture: fine gypsum material, gypsiferous clay, gypsiferous clay loam
Clay content: 35 to 50 percent
Carbonate clay content: 15 to 25 percent
Gravel content: 0 to 5 percent, indurated
Calcium carbonate equivalent: 10 to 35 percent
Gypsum content: 35 to 65 percent
Electrical conductivity: 4 to 16 mmhos/cm
Sodium adsorption ratio: 1 to 4
Reaction: moderately alkaline or strongly alkaline (pH 7.9 to 9.0)
Organic matter content: 1 to 4 percent
Bkz horizons
Value: 6 or 7 dry; 4 to 6 moist
Chroma: 1 to 3 dry; 1 to 3 moist
Texture: clay, clay loam
Clay content: 35 to 50 percent
Carbonate clay content: 15 to 20 percent
Gravel content: 0 to 5 percent, indurated
Calcium carbonate equivalent: 15 to 35 percent
Gypsum content: 0 to 5 percent
Electrical conductivity: 4 to 16 mmhos/cm
Sodium adsorption ratio: 1 to 4
2Bkz horizon
Value: 6 or 7 dry; 4 to 6 moist
Chroma: 1 to 3 dry; 1 to 3 moist
Texture: very gravelly clay loam, very gravelly sandy clay loam
Clay content: 20 to 35 percent
Carbonate clay content: 1 to 12 percent
Gravel content: 35 to 45 percent, indurated
Calcium carbonate equivalent: 15 to 25 percent
Gypsum content: 0 to 5 percent
Electrical conductivity: 2 to 8 mmhos/cm
Sodium adsorption ratio: 0 to 2
COMPETING SERIES: There are currently no competing series in this family. A similar series in a closely related family is the
Hartsel series. Hartsel soils do not have gypsum accumulations.
GEOGRAPHIC SETTING:
Parent material: alluvium
Landform: stream terraces
Slopes: 0 to 4 percent
Elevation: 2713 to 2926 meters (8900 to 9600 feet)
Mean annual temperature: 1.7 to 3.9 degrees C (35 to 39 degrees F)
Mean annual precipitation: 254 to 356 mm (10 to 14 inches)
Precipitation pattern: Monthly precipitation is lowest in winter and greatest in July and August.
Frost-free period: 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the
Platdon series. The Platdon soils have an aquic moisture regime and are on drainageways and flood plains.
DRAINAGE AND PERMEABILITY: Moderately well drained, slow permeability. These soils have a seasonal high water table from April through August.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Native vegetation consists mainly of western wheatgrass, needleandthread, slender wheatgrass, inland saltgrass, mat muhly, and Wheeler bluegrass.
DISTRIBUTION AND EXTENT: Central Colorado; LRR E, MLRA 48B; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Park County, Colorado, Teller-Park soil survey area, Colorado, 2010. The name is taken from Wilkerson Pass in eastern Park County.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 0 to 152 cm.
Particle-size control section: The zone from 25 to 100 cm. (Bkyz2, Bkz1, Bkz2, part of the 2Bkz3 horizons)
Ochric epipedon: from 0 to 13 cm. (Akyz horizon)
Calcic horizon: from 51 to 152 cm. (Bkz1, Bkz2, 2Bkz3 horizons)
Salt accumulations: from 0 to 152 cm. (all horizons)
Gypsic horizon: from 0 to 51 cm. (Akyz, Bkyz1, Bkyz2 horizons)
Redoximorphic concentrations: from 76 to 152 cm. (2Bkz3 horizon)
Endosaturation: at 76 to 152 cm. and below (2Bkz3 horizon)
Lithologic discontinuity: At the upper boundary of the 2Bkz3 horizon.
Taxonomic Version: Classified according to Keys to Soil Taxonomy, 11th Edition, 2010.
ADDITIONAL DATA: A pedon located a few feet away from this typical pedon was sampled for the NSSL, soil survey lab sample number 08CO093002.
National Cooperative Soil Survey
U.S.A.