LOCATION POBER UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, mesic Calcic Petrocalcids
TYPICAL PEDON: Pober fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; brown (10YR 5/3) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure parting to weak very fine granular; soft, friable, slightly sticky and slightly plastic; few very fine roots; slightly effervescent; carbonates are disseminated; strongly alkaline (pH 8.5); abrupt smooth boundary. (3 to 5 inches thick)
A2--4 to 13 inches; brown (10YR 5/3) gravelly loam, brown (10YR 4/3) moist; moderate medium granular structure; soft, friable, slightly sticky and slightly plastic; few very fine and fine roots; common fine pores; 20 percent pebbles; strongly effervescent; carbonates are disseminated; strongly alkaline (pH 8.6); clear smooth boundary. (4 to 9 inches thick)
Bk1--13 to 18 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; very hard, friable, moderately sticky and slightly plastic; few very fine roots; few fine pores; 25 percent pebbles and 10 percent cobbles; strongly effervescent; carbonates are disseminated and coated on rock fragments; strongly alkaline (pH 8.6); gradual smooth boundary. (5 to 7 inches thick)
Bk2--18 to 26 inches; light gray (10YR 7/2) very gravelly loam, pale brown (10YR 6/3) moist; massive; very hard, friable, slightly sticky and slightly plastic; few very fine roots; 40 percent pebbles and hardpan fragments and 10 percent cobbles; strongly effervescent; secondary carbonates are disseminated and segregated as coats on rock fragments; strongly alkaline (pH 8.8); abrupt smooth boundary. (8 to 19 inches thick)
Bkm--26 to 32 inches; cemented material; indurated by secondary calcium carbonate; upper surface of horizon has a trowelled appearance and very pale brown (10YR 7/3) laminae 2 mm to 10 mm thick; roots are matted on the surface; subhorizons are very pale brown (10YR 8/2) moist and are less cemented than indurated.
TYPE LOCATION: Juab County, Utah; about 5 miles south and 4 miles west of Mills in the NW 1/4, NE 1/4, NW 1/4 of section 20, T. 16 S., R. 2 W.
RANGE IN CHARACTERISTICS:
Soil moisture - These soils are dry in all parts of the moisture control section 50 to 55 percent of the time that the soil temperature is above 41 degrees F. at depths of 20 inches in 7 out of 10 years; aridic moisture regime that borders on xeric.
Mean annual soil temperature - 48 to 51 degrees F.
Depth to petrocalcic horizon - 20 to 40 inches.
Particle-size control section - Clay content: Averages 8 to 27 percent; Rock fragments: 25 to 70 percent, but averages more than 35 percent between depths of 10 inches and the petrocalcic horizon.
A horizons - Hue: 10YR or 7.5YR.
Value: 4 through 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Fine sandy loam, gravelly loam, stony loam, very cobbly loam, or loamy fine sand.
Calcium carbonate equivalent: 1 to 15 percent.
Reaction: Moderately alkaline or strongly alkaline.
Bk horizons - Hue: 10YR or 7.5YR.
Value: 5 through 8 dry, 5 through 7 moist.
Chroma: 2 through 4, dry or moist.
Texture: Gravelly loam, very gravelly loam, gravelly sandy loam, very gravelly sandy loam, very cobbly loam, extremely cobbly loamy sand, or very cobbly fine sandy loam.
Calcium carbonate equivalent: 15 to 40 percent.
Bkm horizon - Value: 7 or 8 dry, 6 through 8 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Strongly alkaline or very strongly alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Pober soils are on fan remnants. These soils formed in alluvium derived from quartzite, sandstone, limestone, and some basic igneous rocks. Slopes are 2 to 15 percent. Elevations range from 4,700 to 5,700 feet. The climate is semiarid. The mean annual precipitation is 8 to 12 inches. The mean annual temperature is 46 to 55 degrees F. and the mean summer temperature is 66 to 70 degrees F. The frost-free period is 120 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Genola and Medburn soils. Genola and Medburn soils do not have petrocalcic horizons.
DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; moderate permeability.
USE AND VEGETATION: Pober soils are used mainly for rangeland. The potential vegetation is Wyoming big sagebrush, Indian ricegrass, bluebunch wheatgrass, antelope bitterbrush, and Sandberg's bluegrass.
DISTRIBUTION AND EXTENT: Western Utah. These soils are not extensive with about 9,600 acres of the series mapped to date. MLRA 28A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Juab County (Fairfield-Nephi Area), Utah, 1980.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 13 inches (A1 and A2 horizons).
Calcic horizon - The zone from 13 to 26 inches (Bk1 and Bk2 horizons).
Petrocalcic horizon - The zone from 26 to 32 inches (Bkm horizon).
Particle-size control section - The zone from 10 to 26 inches (Bk1 and Bk2 horizons and part of the A2 horizon).
The active cation exchange activity class was added to the taxonomic classification in December 2002 based on soil property data.
The taxonomic classification was changed from Xerollic Paleorthids to Calcic Petrocalcids in September 1994.