LOCATION HYRUM UT+IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Pachic Argixerolls
TYPICAL PEDON: Hyrum gravelly loam-cultivated. (Colors are for air-dry soil unless otherwise stated.)
A1--0 to 8 inches; very dark grayish brown (10YR 3/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate medium and fine granular structure; hard, friable, slightly sticky, plastic; many fine roots; many fine pores; neutral (pH 6.9); clear smooth boundary. (8 to 10 inches thick.)
B1--8 to 17 inches; very dark grayish brown (10YR 3/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure parting to moderate fine granular structure; hard, friable, sticky, plastic; few thin clay films; common fine roots; many fine, medium and large pores; neutral (pH 6.8) diffuse smooth boundary. (4 to 11 inches thick.)
B21t--17 to 31 inches; dark grayish brown (10YR 4/2) very cobbly clay loam, very dark grayish brown (10YR 2/2) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky structure; very hard, firm, sticky, plastic; common fine roots; many fine and medium pores; thin continuous clay films on ped faces; neutral (pH 7.1); clear smooth boundary. (9 to 16 inches thick.)
B22t--31 to 42 inches; grayish brown (10YR 5/2) very cobbly clay loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, plastic, few fine roots; many medium and fine pores; few thin clay films on some ped faces; neutral (ph 7.1); diffuse wavy boundary. (7 to 12 inches thick.)
C1--42 to 57 inches; pale brown (10YR 6/3) very cobbly loam, brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky, slightly plastic; mildly alkaline (pH 7.4).
TYPE LOCATION: Cache County, Utah; 1/2 mile west of the northeast corner of sec. 7, T. 11 N., R.1W.
RANGE IN CHARACTERISTICS: The solum ranges from 30 to 45 inches in thickness. Coarse fragments are mainly cobblestones and pebbles of slightly rounded and angular sandstone and quartzite and some limestone. They range from 20 to 40 percent by volume in the A1 horizon, and from 35 to 80 percent in the B and C horizons. The mean annual soil temperature ranges from 47 degrees to 52 degrees F., and the mean summer soil temperature from 63 degrees to 68 degrees F. The soils are usually moist but are dry for 60 consecutive days in 8 to 24 inches depth during summer in more than 7 out of 10 years. The mollic epipedon ranges from 20 to 45 inches in thickness and includes the A horizon and much of the B horizon. The A1 horizon has hue of 10YR, value of 3 through 5 dry and 2 or 3 moist, and chroma between 1 and 2. It has weak to moderate fine to medium granular structure and some subangular blocky structure in the lower part. It is neutral in reaction. It contains from 3 to 7 percent organic matter. The B2t
horizon has hue of 10YR, value of 4 or 5 dry and 2 or 3 moist, and chroma of 2 or 3. It is very cobbly clay loam or very cobbly heavy loam. It has weak to moderate medium and fine subangular blocky or angular blocky structure. It is neutral in reaction. Clay films are few to continuous. The C horizon has hue of 10YR, value of 5 or 6 dry and 4 or 5 moist, and chroma of 2 or 3. It is very cobbly loam or very cobbly heavy very fine sandy loam. It is mildly alkaline to neutral. Some pedons have calcareous lake sediments at depths below 36 inches.
COMPETING SERIES: Related and similar soils are the Bingham, Crowshaw, Hibner, and Smarts series. Bingham soils have less than 35 percent coarse fragments in the upper parts, and they have calcic horizons. Crowshaw soils have gravelly loam series control sections that contain less than 35 percent coarse fragments. Hibner soils have extremely stony clay argillic horizons. Smarts soils have A horizons that range from 20 to 40 inches in thickness, and mean annual temperature of less than 47 degrees F.
GEOGRAPHIC SETTING: Hyrum soils are on high and medium lake terraces at elevations of 4,600 to 5,000 feet. Slopes are 3 to 25 percent. The soil formed in alluvium and modified lake sediments from sandstone, quartzite, and some limestone. The climate is moist subhumid. Mean annual temperature is 45 to 47 F., the mean summer temperature is 65 to 70 F., and the mean annual precipitation ranges from 16 to 18 inches. Frost-free period ranges from 130 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Crowshaw and Hibner soils, and Hendricks, Menddon, Nebecker, and Ricks soils. Hendricks, Mendon, and Nebecker soils are essentially free of gravel and cobblestones in the argillic horizon. Mendon soils have horizons of calcium carbonate accumulation. Nebecker soils have argillic horizons that contain more than 35 percent clay. Ricks soils have gravelly and cobbly loam series control sections, the soil contain less than 35 percent coarse fragments, the IIC horizons are very gravely and cobbly sand, and the soils have calcic horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate to slow permeability.
USE AND VEGETATION: These soils are used principally for dry cropland for growing small grains and alfalfa. Potential vegetation consists of sagebrush, slender wheatgrass, Western wheatgrass, and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Northern Utah. This series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cache County (Cache Valley Area Soil Survey) Utah, 1913.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Last updated by state 10/69.
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.