LOCATION SEARLA ID+UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Calcic Argixerolls
TYPICAL PEDON: Searla very gravelly loam, rangeland. Colors are for dry soil unless otherwise noted.
A--0 to 5 inches; 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. (5 to 14 inches thick)
Bt1--5 to 12 inches; 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. (4 to 10 inches thick)
Bt2--12 to 19 inches; 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. (5 to 14 inches thick)
Btk--19 to 32 inches; brown (10YR 5/3) very gravelly 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 grain; 20 percent cobbles and 25 percent gravel; neutral (pH 7.3); clear wavy boundary. (5 to 25 inches thick)
Bk1--32 to 39 inches; light yellowish brown (10YR 6/4) very gravelly 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 with line coatings on underside of gravel and cobbles; 25 percent cobbles and 30 percent gravel; neutral (pH 7.3); gradual wavy boundary. (5 to 15 inches thick)
Bk2--39 to 60 inches; light yellowish brown (10YR 6/4) very gravelly 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 3,170 feet west and 200 feet north of the southeast corner of sec. 25, T. 14S., R. 29E; lat. 42 degrees 10 minutes 14.9 seconds N and long. 113 degrees 0 minutes 46.7 seconds W, NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture - the soils are dry from 45 to 60 consecutive days in the four months following the summer solstice.
Depth to bedrock - greater than 40 inches
Average annual soil temperature - 40 to 47 degrees F.
Average summer soil temperature - 60 to 64 degrees F.
Mollic epipedon thickness - 9 to 16 inches
Depth to secondary carbonates - 12 to 35 inches
Particle-size control section - averages 35 to 80 percent rock fragments
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 through 7 dry, 3 through 5 moist
Chroma - 2 through 4 dry or moist
Clay content - 27 to 35 percent
Rock fragment content - 35 to 80 percent, mostly angular or subangular fragments
Reaction - neutral through moderately alkaline
Texture - very gravelly clay loam, very gravelly sandy clay loam, extremely gravelly clay loam
Bk horizon
Hue - 10YR, 7.5YR, or 2.5Y
Value - 5 through 8 dry, 4 through 7 moist
Chroma - 2 through 4, dry or moist
Rock fragment content - 30 to 70 percent
Texture - extremely gravelly sandy loam, very gravelly sandy loam
COMPETING SERIES:
Amelar (NV) soils have carbonates at 10 to 15 inches and the depth to the base of the argillic is 15 to 20 inches.
Broad (UT) soils have bedrock at 20 to 40 inches.
Custco (T ID) soils have less than 27 percent clay in the particle-size control section.
Drage (ID) soils don't have Btk horizons.
Remount (MT) 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 (NV) soils don't have Btk horizons.
Sheep Creek (UT) soils have bedrock at 20 to 40 inches.
Small (T ID) soils have bedrock at 20 to 40 inches.
Swampydraw (T ID) soils have a calcic horizon and are dry in the moisture control section for more than 60 consecutive days.
GEOGRAPHIC SETTING: Searla soils are on level to steep fan remnants, alluvial fans and colluvial slopes, with gradients of 0 to 60 percent, dominantly 0 to 25 percent. Elevations range from about 5,000 to 7,700 feet. The soils formed in alluvium, residuum, and colluvium dominantly from rhyolitic or sedimentary rocks. The climate is semiarid to subhumid with annual precipitation of about 14 to 18 inches. The average annual temperature is about 38 to 45 degrees F. The frost-free season is about 50 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bullrey and Sourdough soils. Bullrey soils have mollic epipedons thicker than 20 inches and are noncalcareous throughout. Sourdough soils have bedrock at depths of less than 40 inches. Bullrey soils are on fan terraces, foothills, and mountainsides. Sourdough soils are on mountainsides.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used mostly for range. 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).
DISTRIBUTION AND EXTENT: Southern Idaho, Utah, and north-central Nevada. The soils are moderately extensive.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Owyhee County, Idaho, 1975.
REMARKS: This revision moves the type location from Owyhee County to Cassia County. Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to 12 inches (A, and Bt1 horizons)
Argillic horizon - the zone from 5 to 32 inches (Bt1, Bt2 and Btk horizons)
Secondary lime accumulation - the zone from 24 to 60 inches (Btk1, Btk2, and Bk horizons)
The classification is based on the "Keys to Soil Taxonomy, Eighth Edition, 1998". Superactive cation exchange activity class is and estimate based on CEC-7 and clay values in NASIS.