LOCATION WHETSOON           WY
Established Series
Rev. RVS/MCS
03/2006

WHETSOON SERIES


The Whetsoon series consists of very deep, somewhat poorly drained soils formed in alluvium derived from mixed sources. Whetsoon soils are on floodplains and seeps on terraces. Slopes are 0 to 3 percent. The mean annual precipitation is about 38 centimeters (15 inches) and the mean annual temperature is about 8 degrees C. (47 degrees F.) at the type location.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aquic Argiustolls

TYPICAL PEDON: Whetsoon fine sandy loam, on a south facing slope of two percent, in an irrigated pasture. (Colors are for a dry soil unless otherwise stated.)

A--0 to 18 centimeters (0 to 7) inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure parting to weak fine granular and very fine subangular blocky; hard, friable, slightly sticky and slightly plastic; many very fine, common fine and few medium roots; few very fine and fine discontinuous random irregularly shaped pores; slight effervescence, calcium carbonate disseminated; moderately alkaline (pH 8.3); abrupt wavy boundary. (13 to 38 centimeters (5 to 15 inches) thick)

Bt1--18 to 33 centimeters (7 to 13 inches); brown (10YR 5/3) loam, dark grayish brown (10YR 4/2) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; hard, firm, sticky and slightly plastic; many very fine and few fine roots; many very fine and common fine continuous random irregularly shaped pores; common distinct clay films on faces of peds; strongly effervescent, calcium carbonate disseminated; moderately alkaline (pH 8.3); abrupt wavy boundary.

Bt2--33 to 53 centimeters (13 to 21 inches); pale brown (10YR 6/3) sandy clay loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine discontinuous random irregularly shaped pores; few faint clay films on faces of peds; strongly effervescent, calcium carbonate disseminated; strongly alkaline (pH 8.5); gradual wavy boundary. (Combined thickness of the Bt horizon 25 to 51 centimeters (10 to 20 inches)

Bk1--53 to 84 centimeters (21 to 33 inches); pale brown (10YR 6/3) loam, brown (10YR 5/3) moist; few fine prominent reddish yellow (7.5YR 6/6) redox concentrations; weak medium subangular blocky structure parting to weak fine subangular blocky; hard, friable, sticky and plastic; common very fine roots; common fine and few very fine continuous tubular pores; strong effervescence, calcium carbonate disseminated and as common distinct irregular soft concretions; strongly alkaline (pH 8.5); clear wavy boundary.

Bk2--84 to 152 centimeters (33 to 60 inches); very pale brown (10YR 7/3) loam, pale brown (10YR 6/3) moist; common fine prominent reddish yellow (7.5YR 6/6) redox concentrations and few fine distinct light gray (10YR 7/2) redox depletions; massive; hard, very friable, slightly sticky and slightly plastic; strong effervescence, calcium carbonate disseminated and as few distinct irregular soft concretions; moderately alkaline (pH 8.3).

TYPE LOCATION: Platte County, Wyoming; 10 kilometers (6 miles) west of Wheatland, about 137 meters (450 feet) south and 228 meters (750 feet) east of the northwest corner of Section 13, T. 24 N., R. 69 W. Hightower Quadrangle. 42 degrees 3 minutes 34 seconds north latitude and 105 degrees 4 minutes 35 seconds west longitude.

RANGE IN CHARACTERISTICS:
Mollic epipedon: 18 to 51 centimeters (7 to 20 inches) thick
Seasonal high water table: 46 to 91 centimeters (18 to 36 inches)
Particle size control section:
Clay content: 20 to 30 percent
Fine sand or coarser: 15 to 30 percent

A horizon:
Hue: 10YR
Value: 4 or 5
Chroma: 2 or 3
Texture: very fine sandy loam, fine sandy loam or loam
Reaction: slightly alkaline or moderately alkaline

An AB horizon may be present in some pedons.

Bt horizon:
Hue: 10YR
Value: 5 or 6, 3 to 5 moist
Chroma: 2 or 3
Texture: loam, sandy clay loam, or clay loam
Reaction: slightly alkaline or moderately alkaline

Bk horizon and C horizon(if present):
Value: 6 or 7, 5 or 6 moist
Chroma: 2 or 3
Redoximorphic features: present in this horizon
Colors: vary widely, 2 chroma depletions occur above 102 centimeters (40 inches)
Texture: commonly loam, but includes very fine sandy loam, clay loam, fine sandy loam or sandy clay loam
Reaction: slightly alkaline to strongly alkaline

COMPETING SERIES: There are currently no competing series in this family.

GEOGRAPHIC SETTING:
Landform: floodplains and in seep areas on terraces
Parent material: alluvium derived dominantly from mixed sources
Slopes: 0 to 3 percent
Elevations: 1372 to 1676 meters (4500 to 5500 feet)
Mean annual precipitation: 30 to 38 centimeters (12 to 15 inches)
Mean annual temperature: 8 to 9 degrees C. (46 to 48 degrees F.)
Frost-free season: 110 to 130 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anvil, Clarkelen, Forkwood and Manter soils.
Anvil, Clarkelen, and Forkwood soils do not have mollic epipedons.
The Manter soil has a coarse-loamy particle-size control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: somewhat poorly drained
Runoff: low
Saturated hydraulic conductivity: moderately high
Water table: irrigation induced water table

USE AND VEGETATION: These soils are utilized for grazing by domestic livestock, wildlife habitat, and for irrigated hayland and pastures.
The native vegetation is basin wildrye, big bluestem, little bluestem, prairie cordgrass, slender wheatgrass and switchgrass.

DISTRIBUTION AND EXTENT: Whetsoon soils occur in eastern Wyoming. The series is of limited extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado

SERIES ESTABLISHED: Platte County, Wyoming, 1989.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 18 centimeters (0 to 7 inches) (A)
Argillic horizon: 18 to 53 centimeters (7 to 21 inches) (Bt1,Bt2)

MLRR- G
SIR - WY1035

Modified format by LRM in 2/2006 to include metric conversion and change permeability to saturated hydraulic conductivity.


National Cooperative Soil Survey
U.S.A.