LOCATION KOOSHAREM UT+ID

Established Series
Rev: RLT/VLP/MJD
07/2014

KOOSHAREM SERIES

The Koosharem series consists of very deep, well drained, moderately permeable soils formed in alluvium derived from basic and intermediate igneous rocks. Koosharem soils are on alluvial fans and valley fill. Slopes range from 0 to 5 percent. The average annual precipitation is about 12 inches and the mean annual air temperature is about 43 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Cumulic Haploxerolls

TYPICAL PEDON: Koosharem silt loam--rangeland. (Colors are for air-dry soil unless otherwise stated.)

A1--0 to 2 inches; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure parting to weak fine granular; soft, friable, slightly sticky and slightly plastic; few fine roots; few fine tubular pores; noncalcareous; mildly alkaline (pH 7.8); clear smooth boundary. (2 to 11 inches thick)

A2--2 to 14 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; few fine roots; few fine tubular pores; noncalcareous; moderately alkaline (pH 8.2); gradual wavy boundary. (0 to 12 inches thick)

A3--14 to 23 inches: dark grayish brown (10YR 4/2) loam very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; few fine and medium roots; few fine tubular pores; slightly calcareous with lime in veins; strongly alkaline (pH 8.6); gradual wavy boundary. (9 to 24 inches thick)

A4--23 to 34 inches; dark grayish brown (10YR 4/2) heavy loam, very dark brown (10YR 2/2) moist; moderate medium angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; few fine tubular pores; noncalcareous; moderately alkaline (pH 8.4); gradual wavy boundary. (5 to 12 inches thick)

A5--34 to 49 inches; brown (7.5YR 4/3) loam, dark brown (7.5YR 3/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; few very fine and fine pores; noncalcareous; moderately alkaline (pH 8.4); abrupt wavy boundary. (10 to 16 inches thick)

2C--49 to 56 inches; brown (7.5YR 4/3) gravelly sand, brown (7.5YR 3/2) moist; single grain; loose; 30 percent gravel; noncalcareous; moderately alkaline (pH 8.4); abrupt wavy boundary. (0 to 7 inches thick)

3C--56 to 60 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; massive; soft, friable, slightly sticky and slightly plastic; few fine pores; noncalcareous; moderately alkaline (pH 8.4).

TYPE LOCATION: Sevier County, Utah; 0.5 mile northwest of Koosharem; 1,300 feet west and 900 feet north of the southeast corner of sec. 27, T. 26 S., R. 1 W., SLBM.

RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 43 to 47 degrees F. The mollic epipedon is 20 or more inches thick. The particle size control section averages 18 to 27 percent clay and has 15 percent or more fine sand or coarser. They are continually moist in all parts of the moisture control section for 60 to 75 days out of the 120 days following the winter solstice and are dry 60 to 80 consecutive days in more than 7 out of 10 years in all parts of the moisture control section within the 3 month period following the summer solstice.

The A horizon has a hue of 7.5YR or 10YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. Textures are a silt loam or loam. It is neutral to moderately alkaline and is 10 to 50 inches thick. It is noncalcareous to slightly calcareous.

The C horizon has hue of 10YR or 7.5YR, value of 4 to 6 dry, 2 to 4 moist, and chroma of 2 to 4. It is typically loam or silt loam with the range including stratified lenses of loamy sand or gravelly sand below depth of 40 inches. It is noncalcareous or slightly calcareous and is neutral to moderately alkaline.

COMPETING SERIES: These are the Toehead and Zola (ID) series. Toehead and Zola soils have more than 27 percent clay in the particle size control section.

GEOGRAPHIC SETTING: The Koosharem soils are at elevations of 5,600 to 7,000 feet. Slopes are 0 to 5 percent. The soils are on alluvial fans, stream terraces and valley fill and formed in alluvium derived from basic and intermediate igneous rocks. The climate is semiarid, the average annual precipitation is about 10 to 14 inches. The mean annual air temperature is 41 to 45 degrees and the freeze-free period is 80 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Eldgin, Krueger, and Raftriver soils. Eldgin and Krueger soils have an argillic horizon and the mollic epipedon is less than 20 inches thick. Raftriver soils are non-mollic, average less than 18 percent clay in the particle size control section and are moderately deep to a duripan.

DRAINAGE AND PERMEABILITY: Well drained; very slow, slow, or medium runoff; moderate permeability.

USE AND VEGETATION: These soils are used for irrigated cropland and for rangeland. Native vegetation is basin big sagebrush, basin wildrye, western wheatgrass and bluebunch wheatgrass. The irrigated crops are pasture, alfalfa, barley and oats.

DISTRIBUTION AND EXTENT: Central and Northwestern Utah; Grass Valley, Sevier and Piute Counties, UT; southern Idaho in Cassia Co, ID. This series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: DAVIS, CALIFORNIA

SERIES ESTABLISHED: Box Elder County, Utah (Western Part) 1985.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - the zone from 0 to 49 inches (A1, A2, A3, A4, A5 horizons).

Particle size control section - the zone from 10 to 40 inches.

The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.

National Cooperative Soil Survey
U.S.A.