LOCATION ARAVE UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Aquic Natrixeralfs
TYPICAL PEDON: Arave silt loam--pastureland. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 inches; light brownish gray (2.5Y 6/2) silt loam, dark grayish brown (2.5Y 4/2) moist; weak medium platy structure; soft, friable, slightly sticky and nonplastic; many medium roots; common medium pores; slightly effervescent; 2 percent calcium carbonate equivalent; strongly alkaline (pH 8.6); clear smooth boundary. (6 to 10 inches thick)
Btkn1--8 to 12 inches; light gray (10YR 7/2) loam, grayish brown (2.5Y 5/2) moist; weak medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; many medium roots; common medium pores; few faint clay films on faces of peds and lining pores; violently effervescent; 30 percent calcium carbonate equivalent; strongly alkaline (pH 8.7); clear smooth boundary. (3 to 5 inches thick)
Btkn2--12 to 18 inches; pale yellow (2.5Y 8/2) clay loam, light olive brown (2.5Y 5/4) moist; moderate medium prismatic structure; very hard, firm, moderately sticky and moderately plastic; few medium roots; common medium pores; few faint clay films on faces of peds and lining pores; violently effervescent; 26 percent calcium carbonate equivalent; strongly alkaline (pH 8.9); clear smooth boundary. (5 to 9 inches thick.)
C1--18 to 36 inches; light gray (5Y 7/2) silty clay loam, light olive brown (2.5Y 5/4) moist; massive; very hard, firm, slightly sticky and slightly plastic; few fine and medium roots; common fine pores; common fine distinct yellowish brown (10YR 5/6) masses of iron accumulation; violently effervescent; 21 percent calcium carbonate equivalent; very strongly alkaline (pH 9.1); clear wavy boundary. (9to 21 inches thick)
C2--36 to 42 inches; pale yellow (2.5Y 7/4) silt loam, light olive brown (2.5Y 5/4) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; few fine roots; common fine pores; common coarse prominent yellowish brown (10YR 5/8) masses of iron accumulation; violently effervescent; 19 percent calcium carbonate equivalent; strongly alkaline (pH 8.9); clear wavy boundary. (8 to 16 inches thick)
C3--42 to 60 inches; pale yellow (2.5Y 7/4) silty clay loam, light olive brown (2.5Y 5/4) moist; massive; hard, firm, slightly sticky and slightly plastic; few fine roots; common fine pores; common coarse prominent yellowish brown (10YR 5/8) masses of iron accumulation; violently effervescent; 18 percent calcium carbonate equivalent; strongly alkaline (pH 8.8).
TYPE LOCATION: Weber County, Utah; about 1.5 miles north and 0.5 miles west of Hooper School; in the northwest one quarter of section 12, T. 5 N., R. 3 W.; USGS Ogden Bay topographic quadrangle; 41 degrees 11 minutes 15 seconds north latitude and 112 degrees 08 minutes 11 seconds west longitude, NAD27; UTM zone 12N 404637E, 4560203N, NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture - Typically moist in the moisture control section in winter and spring, dry in summer and fall; dry in all parts of the moisture control section for more than 60 consecutive days following the summer solstice; Xeric moisture regime that borders on aridic.
Mean annual soil temperature - 48 to 54 degrees F.
Particle-size control section - Clay content: 20 to 35 percent.
Other features - The calcic horizon is commonly just below the A horizon in the Btkn horizons.
A horizon - Hue: 2.5Y or 10YR.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 1 or 2, dry or moist.
Texture: Silt loam or silty clay loam.
Salinity (EC): 8 to 32 mmhos/cm.
Sodicity (SAR): 13 to 30.
Exchangeable sodium: 15 to 60 percent.
Effervescence: Slightly effervescent or strongly effervescent.
Calcium carbonate equivalent: 0 to 5 percent.
Btkn horizons - Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 5 or 6 moist.
Chroma: 2 through 4, dry or moist.
Texture: Loam, silt loam, clay loam, or silty clay loam.
Clay content: 20 to 35 percent.
Structure: Weak or moderate prismatic.
Calcium carbonate equivalent: 15 to 40 percent.
Salinity (EC): 8 to 32 mmhos/cm.
Sodicity (SAR): 13 to 100.
Exchangeable sodium: 25 to 75 percent.
C horizons - Hue: 2.5Y or 5Y.
Value: 7 or 8 dry, 5 or 6 moist.
Chroma: 2 through 4, dry or moist.
Texture: Silt loam or silty clay loam; some pedons have loamy very fine sand below a depth of 40 inches.
Redoximorphic features: Redox concentrations of iron are found at upper depths between 20 and 30 inches and become more prominent with increasing depth; Redox depletions are interpreted to be the horizon matrix color when chroma is 2 and high-chroma redox concentrations are present.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Arave soils are on lake plains and low lake terraces. These soils formed in lacustrine deposits derived mainly from limestone, shale, sandstone, and quartzite. Slopes are 0 to 1 percent. The climate is dry subhumid. The mean annual precipitation is 12 to 18 inches. The mean annual temperature is 45 to 51 degrees F. and the mean summer temperature is 68 to 72 degrees F. The frost-free period is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Saltair and Warm Springs soils. Saltair soils have salic horizons and do not have natric horizons. Warm Springs soils have mollic epipedons and do not have natric horizons.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; medium surface runoff; slow permeability (moderately low or moderately high saturated hydraulic conductivity); Endosaturation is present with an apparent seasonal high water table between 1.7 and 3.3 feet (moderately deep free water occurrence class) between April and September. Cumulative annual duration class is Common.
USE AND VEGETATION: Arave soils are used for rangeland and wildlife habitat. The native vegetation is mainly inland saltgrass, alkali sacaton, black greasewood, and foxtail barley.
DISTRIBUTION AND EXTENT: Northwestern Utah. These soils are not extensive with about 9,300 acres of the series mapped to date. MLRA 28A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Weber County (Davis-Weber Area), Utah, 1967.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 8 inches (A horizon).
Natric horizon - The zone from 8 to 18 inches (Btkn1 and Btkn2 horizons).
Calcic horizon - The zone from 8 to 18 inches (Btkn1 and Btkn2 horizons).
Aquic conditions - The conditions of endosaturation, reduction, and redoximorphic features between 20 and 40 inches at certain times during normal years (parts of the C1 and C2 horizons).
Particle-size control section - The zone from 8 to 18 inches (Btkn1 and Btkn2 horizons).
The revision of October 2005 updated the taxonomic class from Aquic Natrustalfs to Aquic Natrixeralfs based on the assumed moisture regime being xeric instead of ustic.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. Later review of laboratory data places the typical pedon in the active class.
ADDITIONAL DATA: The typical pedon at the series type location has partial characterization data by the Soils Laboratory from Utah State University (USU) Logan, UT and is published on pages 136-137, Table 11 of the Soil Survey of Davis-Weber Area, Utah. The pH values in the typical pedon are from saturated paste.