LOCATION SEARLA ID+UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Calcic Argixerolls
TYPICAL PEDON: Searla gravelly loam--rangeland. Colors are for dry soil unless otherwise noted.
A--0 to 13 cm; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial pores; 10 percent cobbles and 20 percent gravel; neutral (pH 7.3); clear smooth boundary. (13 to 36 cm thick)
Bt1--13 to 30 cm; dark grayish brown (10YR 4/2) very gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and common fine tubular pores; common faint clay films on faces of peds; 10 percent cobbles and 30 percent gravel; neutral (pH 7.3); clear smooth boundary. (10 to 25 cm thick)
Bt2--30 to 48 cm; brown (10YR 5/3) very gravelly sandy clay loam, dark grayish brown (10YR 4/2) moist; moderate fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; common faint clay bridging between sand grains; 5 percent cobbles and 35 percent gravel; neutral (pH 7.3); gradual smooth boundary. (13 to 36 cm thick)
Btk--48 to 81 cm; brown (10YR 5/3) very cobbly sandy clay loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; few fine tubular pores; strongly effervescent; common faint clay bridging between sand grains; 20 percent cobbles and 25 percent gravel; neutral (pH 7.3); clear wavy boundary. (13 to 64 cm thick)
Bk1--81 to 99 cm; light yellowish brown (10YR 6/4) very cobbly sandy clay loam, brown (10YR 5/3) moist; massive; hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few fine tubular pores; strongly effervescent, carbonate coats on bottom of rock fragments; 25 percent cobbles and 30 percent gravel; neutral (pH 7.3); gradual wavy boundary. (13 to 38 cm thick)
Bk2--99 to 152 cm; light yellowish brown (10YR 6/4) very cobbly sandy loam, brown (10YR 4/3) moist; massive; hard, very friable, slightly sticky and slightly plastic; few fine roots; few fine tubular pores; strongly effervescent; 25 percent cobbles and 30 percent gravel; moderately alkaline (pH 8.0).
TYPE LOCATION: Cassia County, Idaho; about 33 kilometers (20.5 miles) southeast of Malta; located about 3,170 feet west and 200 feet north of the southeast corner of sec. 25, T. 14 S., R. 29 E.; Sweetzer Canyon USGS quad; latitude 42 degrees 10 minutes 14 seconds N and longitude 113 degrees 00 minutes 48 seconds W; NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture: the soils are dry from 45 to 60 consecutive days in the four months following the summer solstice; xeric soil moisture regime.
Average annual soil temperature: 4.4 to 8.0 degrees C.
Average summer soil temperature: 15.5 to 17.8 degrees C.
Depth to bedrock: greater than 100 cm.
Thickness of the mollic epipedon: 23 to 41 cm.
Depth to secondary carbonates: 41 to 99 cm.
Particle-size control section - Clay content: 27 to 35 percent.
Rock fragment content: 35 to 80 percent.
A horizon
Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Reaction: slightly acid to slightly alkaline.
Bt and Btk horizons
Hue: 10YR or 7.5YR.
Value: 4 to 7 dry, 3 to 5 moist.
Chroma: 2 to 4, dry or moist.
Texture: Clay loam, silty clay loam, or sandy clay loam; some pedons have thin strata of silt loam or loam.
Clay content: 27 to 35 percent.
Rock fragment content: 35 to 80 percent, mostly angular or subangular gravel and cobbles.
Reaction: Neutral through moderately alkaline.
Bk horizon
Hue: 10YR, 7.5YR, or 2.5Y.
Value: 5 to 8 dry, 4 to 7 moist.
Chroma: 2 to 4, dry or moist.
Texture: Silt loam, loamy sand, sandy loam or sandy clay loam.
Clay content: 5 to 27 percent.
Rock fragment content: 30 to 70 percent, mostly gravel and cobbles.
Reaction: Slightly alkaline to strongly alkaline.
COMPETING SERIES: These are the Amelar, Broad, Custco, Drage, Rawnjay, Remount, Scalfar, Sheep Creek, Small and Swampydraw series.
Amelar sois have secondary carbonates at 25 to 38 cm. Broad, Sheep Creek and Small soils have bedrock at 50 to 100 cm and have a calcic horizon. Custco soils have 18 to 27 percent clay in the particle-size control section and have a calcic horizon. Drage soils have 35 to 60 percent rock fragments in the particle-size control section and do not have Btk horizons. Rawnjay soils have a calcic horizon and do not have Btk horizons. Remount soils are dry in the moisture control section for more than 60 consecutive days and have greater than 75 percent rock fragments in the Bk horizon. Scalfar soils have a calcic horizon and do not have Btk horizons. Swampydraw soils have a calcic horizon, have 15 to 21 percent carbonates in the particle-size control section, are influenced by loess in the A horizons and are dry in the moisture control section for more than 60 consecutive days.
GEOGRAPHIC SETTING:
Parent material: alluvium, slope alluvium, residuum, and colluvium dominantly from igneous or sedimentary rocks
Landform: fan remnants, alluvial fans, hillslopes and mountain slopes
Slopes: 4 to 60 percent
Elevation: 1,524 to 2,580 meters
Mean annual air temperature: 3.3 to 7.2 degrees C
Mean annual precipitation: 300 to 460 mm; the climate is semiarid to subhumid
Frost-free period: 50 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bullrey and Sourdough soils. Bullrey soils have mollic epipedons thicker than 50 cm and are noneffervescent throughout. Sourdough soils have bedrock at depths of less than 100 cm. Bullrey soils are on fan terraces, foothills, and mountainsides. Sourdough soils are on mountainsides.
DRAINAGE AND PERMEABILITY: Well drained; medium to very high runoff; moderately slow permeability; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Used mostly for livestock grazing. Vegetation is principally arbuscula sagebrush, mountain big sagebrush, bluebunch wheatgrass, cheatgrass, Sandberg bluegrass, squirreltail grass, beardless wheatgrass, lupine, wild buckwheat, and skeleton weed. Ecological sites: Idaho - Gravelly Loam 16-22 ARTRV/PSSP6; Utah - Mountain Gravelly Loam (Oak), Upland Stony Loam (Black Sagebrush), Upland Stony Loam (Pinyon-Utah Juniper).
DISTRIBUTION AND EXTENT: Southern Idaho, Utah, and north-central Nevada. The soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Owyhee County, Idaho, 1975.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 30 cm (A and Bt1 horizons).
Argillic horizon - The zone from 13 to 81 cm (Bt1, Bt2 and Btk horizons).
Secondary carbonate accumulation - The zone from 61 to 152 cm (Btk, Bk1, and Bk2 horizons).
Particle-size control section - The zone from 13 to 63 cm. (Bt1, Bt2 and part of Btk horizons).
An earlier revision moved the type location from Owyhee County to Cassia County.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.