LOCATION SKUMPAH UT+COEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Typic Natrargids
TYPICAL PEDON: Skumpah silt loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 3 cm; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; weak thick platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many fine and very fine vesicular pores; strongly effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (1 to 5 cm thick)
A2--3 to 8 cm; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; weak medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many fine and very fine vesicular pores; strongly effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (3 to 8 cm thick)
Btn1--8 to 18 cm; light brown (7.5YR 6/3) silty clay loam, brown (7.5YR 4/3) moist; weak medium prismatic structure that parts to strong fine and very fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; few very fine pores; common distinct clay films on faces of peds; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (8 to 15 cm thick)
Btn2--18 to 33 cm; light brown (7.5YR 6/3) silty clay loam, brown (7.5YR 4/3) moist; weak coarse prismatic structure that parts to moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine and few fine roots; few very fine pores; few faint clay films on faces of peds; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (8 to 15 cm thick)
Cy1--33 to 69 cm; light brown (7.5YR 6/3) silt loam, brown (7.5YR 4/3) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine pores; many fine veins and crystals of gypsum; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (25 to 38 cm thick)
Cy2--69 to 99 cm; pinkish gray (7.5YR 7/2) silt loam, brown (7.5YR 4/3) moist; weak medium and thick platy structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine pores; common veins and flakes of gypsum; strongly effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (25 to 38 cm thick)
Cy3--99 to 114 cm; light brown (7.5YR 6/3) silt loam, brown (7.5YR 4/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine pores; few veins and threads of gypsum; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (15 to 20 cm thick)
Cy4--114 to 152 cm; light brown (7.5YR 6/3) silt loam, brown (7.5YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine pores; common veins and threads of gypsum; strongly effervescent; moderately alkaline. (pH 8.0)
TYPE LOCATION: Sanpete County, Utah; 2 miles south of the Axtell junction, 660 feet west of U. S. Highway 89, along the Redmond airport fence; about 1,800 feet north and 660 feet east of the southwest corner of section 29, T. 20 S., R. 1 E.; USGS Redmond 7.5 minute quadrangle; latitude 39 degrees 2 minutes 17 seconds N and longitude 111 degrees 49 minutes 55 seconds W; NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry; intermittently moist in winter and spring and for brief periods in late summer due to convection storms; typic aridic soil moisture regime.
Mean annual soil temperature: 8.9 to 12.0 degrees C.
Depth to base of natric horizon: 25 to 43 cm.
Organic carbon content: Less than .58 where the sand/clay ratio is 1 or less
Calcium carbonate equivalent: 5 to 40 percent; slight accumulations of carbonates occur in some pedons
Other features: Some pedons have thin E horizons.
Particle-size control section -Clay content: 27 to 35 percent
Sand content: less than 15 percent coarser than very fine sand
A horizon
Hue: 10YR or 7.5YR.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Moderately alkaline or strongly alkaline.
Sodicity (SAR): 3 to 30.
Btn horizon
Hue: 7.5YR or 10YR.
Value: 5 to 7 dry, 4 or 5 moist.
Chroma: 2 to 6, dry or moist.
Texture: Clay loam or silty clay loam.
Structure: Weak medium to coarse prismatic structure that parts to strong fine or medium or coarse angular blocky or subangular blocky structure.
Reaction: Moderately alkaline to very strongly alkaline.
Salinity (EC): 0 to 32 mmhos/cm.
Sodicity (SAR): 13 to 90.
Calcium carbonate equivalent: 5 to 40 percent.
Other features: Few faint or common distinct clay films.
Cy horizon
Hue: 7.5YR through 2.5Y.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 through 6, dry or moist.
Texture: Silty clay loam to very fine sandy loam.
Salinity (EC): 4 to 32 mmhos/cm.
Sodicity (SAR): 5 to 90.
Gypsum content: 1 to 5 percent.
Secondary gypsum: Few to many veins, filaments, and clusters of crystals.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Skumpah soils are on alluvial flats, lake plains, lake terraces and alluvial fans. They formed in alluvium derived from shale, limestone, siltstone, sandstone, and some igneous rocks. Slopes are 0 to 5 percent. Elevations range from 1,372 to 1,840 m. The climate is arid with cool, moist winters and warm, intermittently dry summers. The mean annual precipitation is 100 to 300 mm, the mean annual temperature is 7 to 12 degrees C., and the frost-free period is 100 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Billings, Genola, Mayfield, Ravola, and Woodrow soils. None of these soils have natric horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium or high surface runoff; moderately slow or slow permeability; moderately high or moderately low saturated hydraulic conductivity.
USE AND VEGETATION: Skumpah soils are used mainly as rangeland. Some small areas are used for irrigated alfalfa, small grains, and pasture. The principal native vegetation is shadscale, black greasewood, yellowbrush, halogeton, lichens, and mosses. These soils are correlated to alkali flat, alkali bottom and desert ecological sites in Utah.
DISTRIBUTION AND EXTENT: West-central and central Utah and western Colorado. These soils are not extensive. The series concept and main acreage is in MLRA 28A, while other acreage occurs in MLRAs 34 and 47.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Richfield Area, Utah, 1947.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 8 cm (A1 and A2 horizons).
Natric horizon - The zone from 8 to 33 cm (Btn1 and Btn2 horizons).
Particle-size control section - The zone from 8 to 33 cm (Btn1 and Btn2 horizons).
The active cation exchange activity class was added to the taxonomic classification in December 2002 based on soil property data.
ADDITIONAL DATA: Previous authors and editors include: VLP-RSJ-MJD.