LOCATION HOWCREE ID

Established Series
Rev. DL/CLM
01/2019

HOWCREE SERIES

The Howcree series consists of soils that are well drained and very deep, that formed in alluvium from welded tuff and volcanic ash. They are on terraces. Slopes range from 2 to 6 percent. The average annual precipitation is about 360 mm and the average annual temperature is about 6.1 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Ultic Argixerolls

TYPICAL PEDON: Howcree loam - on a 2 percent slope under rangeland vegetation at 1,760 meters elevation. When described on August 4, 1982, the soil was dry throughout. (Colors are for dry soil unless otherwise noted.)

A--0 to 10 cm; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine to medium roots; many fine and very fine tubular pores; slightly acid (pH 6.3); clear smooth boundary. (8 to 23 cm thick)

Bt1--10 to 28 cm; grayish brown (10YR 5/2) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine to medium roots; many fine and very fine tubular pores; few faint clay films on faces of peds and in pores; 30 percent gravel; slightly acid (pH 6.3); gradual wavy boundary. (13 to 25 cm thick)

Bt2--28 to 48 cm, brown (10YR 5/3) very gravelly clay, dark brown (10YR 3/3) moist; strong fine angular blocky structure; hard, firm, very sticky and very plastic; common very fine to medium roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 35 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (20 to 53 cm thick)

Bt3--48 to 76 cm; pale brown (10YR 6/3) very gravelly clay, brown (10YR 4/3) moist; strong fine angular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots; few very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 55 percent gravel; neutral (pH 6.6); gradual wavy boundary. (25 to 51 cm thick)

Bq--76 to 152 cm; light yellowish brown (10YR 6/4) extremely gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; strong fine angular blocky structure; very hard, firm, slightly sticky and slightly plastic; few very fine to medium roots; few very fine tubular pores; 80 percent gravel; neutral (pH 7.0).

TYPE LOCATION: Twin Falls County, about 22 miles southwest of Rogerson, Idaho; about 980 feet south and 1,660 feet east of the northwest corner section 11, T. 15 S., R. 12 E.; USGS Grassy Hills 7.5 minute topographic quadrangle; latitude 42 degrees 08 minutes 26 seconds N and longitude 115 degrees 01 minutes 23 seconds W; WGS84 Decimal Degrees 42.1405556 latitude, -115.0230556 longitude.

RANGE IN CHARACTERISTICS:

Average annual soil temperature - 6.1 to 7.2 degreesC.
Soil Moisture: This soil is usually moist, but is dry for 45 to 70 consecutive days during the late summer and autumn. Typic xeric moisture regime.
Depth to bedrock - 150 cm or more
Mollic epipedon thickness - 12 to 20 inches
Base saturation upper 30 inches - 60 to 70 percent
Average clay percent in control section - 35 to 45 percent
Coarse fragments in the control section - 35 to 55 percent

A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 through 3 dry or moist

Bt1 and Bt2 horizons
Value - 5 or 6 dry, 3 or 4 moist
Hue - 10YR or 7.5 YR
Chroma - 2 through 4 dry or moist
Structure - angular blocky or subangular blocky
Texture - GR-CL, GR-C, GRV-C or C
Clay - 35 to 45 percent
Gravel - 25 to 50 percent
Reaction - Slightly acid or neutral

Bt3 horizon
Value - 5 or 6 dry
Hue - 10YR or 7.5 YR
Chroma - 3 or 4 dry or moist
Structure - angular blocky or subangular blocky
Texture - GRV-C or GRV-SC
Clay - 45 to 55 Gravel - 40 to 55 percent
Cobbles - 0 to 5 percent
Reaction - slightly acid or neutral

COMPETING SERIES: These are the Cavanaugh and Elksel series. Cavanaugh soils are 50 to 100 cm deep to bedrock. Elksel soils are cobbly in the argillic horizon and lack silica cementation above 100 cm.

GEOGRAPHIC SETTING: Howcree soils are on terraces. The slope ranges from 2 to 6 percent. The soils formed in alluvium from welded tuff and volcanic ash. Elevations are 1,525 to 1,830 meters. The average annual precipitation ranges from 300 to 380 mm. The average annual temperature is 5.0 to 7.8 degrees C. The frost free season is 90 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Budlewis, Chayson, Eep, and Tanner soils. Budlewis, Chayson, and Tanner soils occur on lower terraces, and are moderately deep to a hardpan. Eep soils occur on breaks and scarp faces, are ashy-skeletal, and moderately deep to volcanic ash.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, slow runoff; slow saturated hydraulic conductivity.

USE AND VEGETATION: Howcree soils are used for rangeland. Native vegetation is mountain big sagebrush, antelope bitterbrush, Idaho fescue, and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Howcree soils are of small extent in south central Idaho. MLRA 25.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Twin Falls County, Idaho, 1992.

REMARKS: Clay percent by hydrometer: 0 to 10 cm - 20 percent; 10 to 28 cm - 28 percent; 28 to 48 cm - 40 percent; 48 to 76 cm - 42 percent.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 48 cm (A, Bt1, and Bt2 horizons).
Argillic horizon - 10 to 76 cm (Bt1, Bt2 and the Bt3 horizon)

Particle-size control section - The zone from 10 to 60 cm (The Bt1, Bt2 and part of the Bt3 horizons).

National Cooperative Soil Survey
U.S.A.