LOCATION OREJANO AZEstablished Series
TAXONOMIC CLASS: Clayey-skeletal over sandy or sandy-skeletal, mixed, superactive, mesic Aridic Argiustolls
TYPICAL PEDON: Orejano gravelly sandy loam, 4 to 35 percent slopes - rangeland. (Colors are for dry soil unless otherwise noted).
A--0 to 2 inches; brown (7.5YR 4/3) very gravelly sandy loam, dark brown (7.5YR 3/2) moist; weak fine granular structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine roots; many very fine irregular pores; 55 percent gravel; noneffervescent; neutral (pH 6.8); abrupt smooth boundary. (1 to 3 inches thick)
Bt1--2 to 7 inches; brown (7.5YR 4/4) gravelly clay, dark brown (7.5YR 3/2) moist; strong fine and medium subangular blocky structure; hard, firm, very sticky and very plastic; many fine and medium roots; common very fine tubular pores; 25 percent gravel; few faint clay films lining pores and on faces of peds; noneffervescent; neutral (pH 7.0); clear wavy boundary.
Bt2--7 to 12 inches; brown (7.5YR 4/4) very gravelly sandy clay, brown (7.5YR 4/3) moist; strong very fine subangular blocky structure; hard, firm, very sticky and very plastic; common fine and medium roots; common very fine tubular pores; 50 percent gravel; few faint clay films lining pores and on faces of peds; noneffervescent; neutral (pH 7.2); clear wavy boundary. (The combined thickness of the argillic horizon is 8 to 34 inches thick)
BC--12 to 18 inches; brown (7.5YR 4/4) very gravelly sandy clay loam, brown (7.5YR 4/3) moist; weak fine subangular blocky structure; hard, firm, very sticky and very plastic; common fine and medium roots; common very fine tubular pores; 50 percent gravel; few faint clay films lining pores and on faces of peds; noneffervescent; neutral (pH 7.2); clear wavy boundary. (0 to 10 inches thick)
2C1--18 to 28 inches; brown (7.5YR 5/3) extremely gravelly coarse sandy loam, brown (7.5YR 4/3) moist; massive; hard, very friable, nonsticky and nonplastic; few fine, medium and coarse roots; many very fine irregular pores; discontinuously weakly cemented; 80 percent gravel; noneffervescent; neutral (pH 7.2); abrupt smooth boundary. (0 to 12 inches thick)
2C2--28 to 60 inches; brown (7.5YR 5/3) very gravelly loamy coarse sand, brown (7.5YR 4/3) moist; massive; hard, very friable, nonsticky and nonplastic; few fine, medium and coarse roots; many very fine irregular pores; weakly cemented; 55 percent gravel; noneffervescent; neutral (pH 7.2). (20 to 35 inches thick)
TYPE LOCATION: Mohave County, Arizona; 35 degrees, 13 minutes, 17 seconds north latitude and 113 degrees, 27 minutes, 38 seconds west longitude; about 1,200 feet south and 1,450 feet west of the northeast corner of section 8, T. 21 N., R. 11 W.
RANGE IN CHARACTERISTICS:
Soil Moisture: Moist in some part of the moisture control section for 45 to 90 days cumulative during July to September and December to February. Driest during May and June. Aridic ustic soil moisture regime.
Soil temperature: 50 to 59 degrees F.
Rock Fragments: 35 to 75 percent in the particle-size control section
Clay content: averages 35 to 55 percent in the argillic and less than 10 percent below the argillic
A horizon
Hue: 7.5YR, 10YR
Value: 3 or 4, dry or moist
Chroma: 2 or 3, dry or moist
Bt horizons
Hue: 7.5YR, 10YR
Value: 3 to 5 dry, 3 or 4 moist
Chroma: 3 or 4 dry, 2 to 4 moist
Texture: clay, sandy clay, sandy clay loam
C horizons
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 3 to 5 moist
Chroma: 3 or 4 dry, 2 to 4 moist
Texture: loamy sand, loamy coarse sand
Cementation: weak to strong, occurring as discontinuous lenses in one or more horizons
Some pedons may not have coarse sandy loam textures.
BC horizons are not present in all pedons
COMPETING SERIES: There are no competing series
GEOGRAPHIC SETTING: Orejano soils are on plateaus at elevations of 4,700 to 5,400 feet. They formed in alluvium from volcanic rock. Slopes range from 4 to 35 percent. The mean annual precipitation is 14 to 18 inches. The mean annual air temperature is about 48 to 57 degrees F. The frost-free period is 135 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cabezon, Thunderbird, Valena and Thimble soils. Cabezon, Valena and Thimble soils are less than 20 inches to bedrock. Thunderbird soils are 20 to 40 inches to bedrock. .
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Orejano soils are used mainly for livestock grazing, wildlife habitat and recreation. Vegetation is banana yucca, desert ceanothus, desert needlegrass, flattop buckwheat, singleleaf pinyon and turbinella oak.
DISTRIBUTION AND EXTENT: Northwestern Arizona. MLRA 38. These soils are of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Mohave County, Arizona; Soil survey of Mohave County, AZ, Central Part; 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 7 inches (A & Bt1 horizons)
Argillic horizon - The zone from 2 to 12 inches (Bt1, Bt2 horizons)
Lithologic discontinuity - The boundary at 18 inches.
A strongly contrasting particle-size class is within a depth of 40 inches.
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.