LOCATION WHEELON UT+IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Calcixerepts
TYPICAL PEDON: Wheelon silt loam--cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 6 inches; light brownish gray (2.5Y 6/2) silt loam, light olive brown (2.5Y 5/3) moist; weak medium subangular blocky structure mixed with weak fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine roots; few fine pores; strongly effervescent; 15 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); abrupt smooth boundary. (4 to 13 inches thick.)
AB--6 to 12 inches; light gray (2.5Y 7/2) silt loam, grayish brown (10YR 5/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; few fine pores; strongly effervescent; 17 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); gradual wavy boundary. (0 to 6 inches thick.)
Bk1--12 to 23 inches; pale yellow (2.5Y 8/2) silt loam, light brownish gray (2.5Y 6/2) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine and coarse roots; violently effervescent; 31 percent calcium carbonate equivalent; moderately alkaline (pH 7.9); gradual wavy boundary. (10 to 15 inches thick.)
Bk2--23 to 43 inches; pale yellow (2.5Y 8/2) silt loam, light gray (2.5Y 7/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; few medium and few fine pores; violently effervescent; 34 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); gradual wavy boundary. (10 to 25 inches thick.)
C--43 to 66 inches; pale yellow (5Y 8/2) silt loam, light olive gray (5Y 6/2) moist; massive; slightly hard, friable, slightly sticky and nonplastic; common medium prominent brownish yellow (10YR 6/6) relict masses of iron accumulation; violently effervescent; 29 percent calcium carbonate equivalent; moderately alkaline (pH 8.3).
TYPE LOCATION: Cache County, Utah; about one mile north and 2 miles west of Newton; approximately 200 feet north and 3,000 feet west of the southeast corner of section 11, T. 13 N., R. 2 W.; USGS Cutler Dam 7.5 minute topographic quadrangle; 41 degrees 52 minutes 26 seconds north latitude and 112 degrees 02 minutes 27 seconds west longitude, NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in winter and spring, dry in summer and fall; the soils are dry in all parts of the moisture control section for more than 60 consecutive days following the summer solstice; Xeric moisture regime that borders on aridic.
Mean annual soil temperature - 47 to 52 degrees F.
Mean summer soil temperature - 65 to 68 degrees F.
Depth to calcic horizon - 10 to 16 inches.
Particle-size control section - Clay content: Averages 24 to 34 percent.
A or Ap horizons
Hue: 2.5Y or 10YR.
Value: 6 or 7 dry, 3 through 7 moist.
Chroma: 1 through 3, dry or moist.
Structure: Weak, very fine to medium granular or subangular blocky.
Reaction: Slightly alkaline or moderately alkaline.
Effervescence: Strong or violent.
Calcium carbonate equivalent: 12 to 25 percent.
Bk horizons
Hue: 10YR or 2.5Y.
Value: 7 or 8 dry, 5 through 7 moist.
Chroma: 2 or 3, dry or moist.
Texture: Silt loam or silty clay loam.
Reaction: Moderately alkaline or strongly alkaline.
Calcium carbonate equivalent: 15 to 35 percent.
Volcanic glass content: 5 to 27 percent in coarse silt through fine sand fractions.
Oxalate extractable aluminum plus one-half iron content: 0.08 to 0.20 percent.
Other features: Some pedons have relict redoximorphic features.
C horizon
Hue: 10YR through 5Y.
Value: 7 or 8 dry, 5 through 7 moist.
Chroma: 2 or 3, dry or moist.
Texture: Silt loam or silty clay loam.
Reaction: Moderately alkaline or strongly alkaline.
Calcium carbonate equivalent: 10 to 30 percent.
Volcanic glass content: 5 to 27 percent in coarse silt through fine sand fractions.
Oxalate extractable aluminum plus one-half iron content: 0.08 to 0.20 percent.
Other features: Some pedons have relict redoximorphic features.
COMPETING SERIES: This is Taylorsville series. Taylorsville soils are not influenced by volcanic ash in the parent material and have less than 5 percent volcanic glass.
GEOGRAPHIC SETTING: Wheelon soils are on high and medium-level lake terraces. They typically occur on backslope and footslope positions. These soils formed in lacustrine deposits derived from conglomerate, tuffaceous sandstone, and limestone. There is a loess influence in some places. Slopes are 4 to 60 percent. Elevations range from 4,500 to 5,500 feet. The mean annual precipitation is 14 to 17 inches, the mean annual temperature is 45 to 48 degrees F., and the mean summer temperature is 65 to 68 degrees F. The frost-free period is 110 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Avon, Barfuss, Collinston, LaPlatta, Leatham, and Mendon soils. All of these soils have mollic epipedons. In addition Avon, Barfuss, LaPlatta, and Mendon soils have argillic horizons. Leatham soils contain more than 40 percent carbonates.
DRAINAGE AND PERMEABILITY: Well drained; medium or high surface runoff; moderate or moderately slow permeability (moderately high or high saturated hydraulic conductivity)
USE AND VEGETATION: Wheelon soils are used for dry cropland and rangeland. Crops are small grains and alfalfa. The native vegetation is mainly bluebunch wheatgrass, Indian ricegrass, prairie junegrass, balsamroot, and big sagebrush.
DISTRIBUTION AND EXTENT: Northern Utah and southeastern Idaho. These soils are moderately extensive. MLRA 28A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Northern Utah SCD, 1941.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 12 inches (Ap and AB horizons).
Calcic horizon - The zone from 12 to 43 inches (Bk1 and Bk2 horizons).
Particle-size control section - The zone from 10 to 40 inches (Bk1 horizon and parts of the AB and Bk2 horizons).
The superactive cation exchange activity class is based on NSSL data. The calcic horizon is based on a CCE increase in the Ck1 and Ck2 noted in NSSL data.
The series range was narrowed in October 1993. A statement in the range of characteristics allowing, "partially consolidated tuffaceous limestone and sandstone ... below 24 inches" was removed. It is inappropriate for one series to encompass interpretations for bedrock from 24 inches to greater than 60 inches. The range for the A-horizon will no longer allow a value of 5. This will prevent soils from meeting the range of Wheelon and also classifying as mollisols.
ADDITIONAL DATA: The typical pedon at the series type location has partial characterization data by the Soils Laboratory from Utah State University (USU) Logan, UT and is published on pages 184-185, Table 7 of the Soil Survey of Cache Valley Area, Utah, Parts of Cache and Box Elder Counties. The pH values in the typical pedon are from saturated paste.
Other pedons are sampled for partial or full characterization by the Soil Survey Laboratory (SSL), Lincoln, NE, as soil survey sample numbers S89ID-041-001 (pedon # 89P0802), S91UT-005-001 (pedon # 92P0114), S91UT-005-002 (pedon # 92P0115), S91UT-005-003 (pedon # 92P0113), S91UT-005-004 (pedon # 92P0116), S91UT-003-001 (pedon # 92P0117), and S91UT-003-002 (pedon # 92P0118).
Some of the pedons have fine particle size classes based on the rule in Soil Taxonomy to calculate clay content (2.5 times 15-bar water). It is unclear what impact the glass content of the soil has on the validity of the calculation. The Soil Survey Laboratory Methods Manual suggests caution in applying the factor to soils with amorphous or glassy materials. Wheelon will remain in the fine-silty family based on field determinations and lab results that place some pedons in the fine-silty family and some in the fine family.
More study is needed to determine whether this series should be reclassified into the subgroup of Vitrandic Calcixerepts. Only two laboratory pedons have glass count data or oxalate extraction data to test this possibility.