LOCATION SASCO AZEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, hyperthermic Typic Haplocambids
TYPICAL PEDON: Sasco silt loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; dark yellowish brown (10YR 4/4) silt loam, dark brown (10YR 3/3) moist; moderate very fine granular structure; soft, friable, slightly sticky and slightly plastic; few very fine roots; many fine vesicular pores; slightly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 3 inches thick)
Bw1--2 to 6 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium prismatic structure parting to moderate medium subangular blocky; soft, friable, slightly sticky and plastic; common very fine roots; common fine vesicular pores; very few faint patchy organic stains lining pores; strongly effervescent; moderately alkaline (pH 8.4) clear smooth boundary. (3 to 6 inches thick)
Bw2--6 to 26 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium prismatic structure parting to weak medium subangular blocky; soft, friable, slightly sticky and slightly plastic; few very fine roots; many fine vesicular pores; very few faint patchy organic stains lining pores; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (6 to 24 inches thick)
Bk--26 to 33 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak coarse subangular blocky structure; soft, friable, slightly sticky and slightly plastic; few very fine roots; many fine vesicular pores; few faint patchy organic stains lining pores; secondary calcium carbonate in some root channels; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (5 to 10 inches thick)
C--33 to 47 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; few very fine roots; many very fine tubular pores; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (10 to 15 inches thick)
Bb--47 to 60 inches; brown (7.5YR 5/4) clay loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; hard, firm, sticky and plastic; few fine roots; few very fine tubular pores; very few distinct clay films on faces of peds; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Pinal County, Arizona; 400 feet east and 2300 feet south of the northwest corner of section 2, T.8 E., R.10 S.
RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of the soil moisture control section during July-September and December-February. Driest during May and June. Typic aridic soil moisture regime.
Soil temperature - 74 to 77 degrees F.
Rock fragments - Less than 5 percent fine gravel in the control section
Reaction - Mildly or moderately alkaline
Organic matter content - Less than 1 percent
Salinity- None to very slight
Particle-size - Less than 18 percent clay; 50 to 85 percent silt; 15 to 35 percent very fine sand
A horizon
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 3, 4, 5, or 6 moist
Chroma: 2, 3, 4, or 6, dry or moist
B and C horizons
Hue: 7.5YR, 10YR
Value: 5, 6, or 7 dry, 3, 4, 5, or 6 moist
Chroma: 2, 3, 4, or 6, dry or moist
Texture: Silt loam, silt (4 to 18 percent clay)
The buried soil, when present, is at depths of 40 to 60 inches or more.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Sasco soils are on stream terraces. Slopes are 0 to 1 percent. The soils formed in silty textured alluvium of Holocene Age. The alluvium is derived from acid and basic igneous rocks which are mainly granite, schist, rhyolite, andesite, and quartzite. Elevations are 1100 to 2000 feet. The mean annual precipitation is 4 to 10 inches. The mean annual air temperature is 72 to 75 degrees F. Frost-free period is about 240 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gadsden, Gilman, Glenbar, and Marana soils. Gadsden, Gilman and Glenbar soils do not have cambic horizons. Marana soils are fine-silty.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: Used for livestock grazing following seasonal rains. When irrigated, is used for growing cultivated crops such as alfalfa, cotton and small grains. Native vegetation is mesquite, creosotebush, desertbroom, annual weeds and grasses.
DISTRIBUTION AND EXTENT: Southern Arizona. MLRA is 40. This series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Pinal County Area, Western Part, Arizona; 1984.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 2 inches (A horizon)
Cambic horizon - The zone from 2 to 26 inches (Bw1, Bw2 horizons)
Classified according to Soil Taxonomy Second Edition, 1999
Additional Data: Laboratory data are available, NSSL Number S84 021 011