LOCATION ADELMANN IDTentative Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Aridic Argixerolls
TYPICAL PEDON: Adelmann cobbly sandy loam -- on a 16 percent convex south-southeast facing slope at 3,270 feet elevation in rangeland. When described on October 2, 1995, the soil was moist throughout. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; grayish brown (10YR 5/2) cobbly sandy loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; many very fine and fine, few medium tubular pores; about 10 percent cobbles and 10 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (2 to 10 inches thick)
AB--3 to 10 inches; grayish brown (10YR 5/2) cobbly sandy loam, dark brown (10YR 3/3) moist; moderate fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; many very fine and fine, few medium tubular pores; about 10 percent cobbles and 10 percent gravel; neutral (pH 6.8); clear wavy boundary. (2 to 13 inches thick)
Bt1--10 to 13 inches; yellowish brown (10YR 5/4) very gravelly sandy clay, dark yellowish brown (10YR 3/4) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and moderately plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; common distinct clay films on faces of peds, in pores and bridging sand grains; about 10 percent cobbles and 40 percent gravel; neutral (pH 6.8); clear wavy boundary.
Bt2--13 to 22 inches; light yellowish brown (10YR 6/4) very gravelly clay loam, dark yellowish brown (10YR 4/4) moist; strong fine and medium subangular blocky structure; very hard, friable, very sticky and very plastic; few very fine, fine and medium roots; few very fine and fine tubular pores; common prominent clay films on faces of peds, in pores and bridging sand grains; about 10 percent cobbles and 45 percent gravel; neutral (pH 7.1); clear smooth boundary.
Bt3--22 to 31 inches; light yellowish brown (10YR 6/4) very gravelly sandy clay, dark yellowish brown (10YR 4/4) moist; strong fine and medium subangular blocky structure; very hard, friable, very sticky and very plastic; few very fine and fine roots; few very fine and fine tubular pores; common distinct clay films on faces of peds, in pores and bridging sand grains; about 10 percent cobbles and 45 percent gravel; neutral (pH 7.1); gradual wavy boundary. (combined thickness of Bt1, Bt2, and Bt3 horizons is 15 to 49 inches)
Bt4--31 to 46 inches; light yellowish brown (10YR 6/4) extremely gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and fine tubular pores; common distinct clay films on faces of peds, in pores and bridging sand grains; about 15 percent cobbles and 60 percent gravel; neutral (pH 7.2); clear wavy boundary. (7 to 24 inches thick)
Bt5--46 to 60 inches; very pale brown (10YR 7/4) extremely gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and fine tubular pores; few distinct clay films on faces of peds, in pores and bridging sand grains; about 20 percent cobbles and 60 percent gravel; neutral (pH 7.2).
TYPE LOCATION: Ada County, Idaho; about 1.25 miles north and 1.25 miles west of Lucky Peak Dam; about 1,000 feet south and 75 feet east of the northwest corner of section 2, T. 2 N., R. 3 E.; USGS Lucky Peak Quadrangle; (Latitude - 43 degrees, 32 minutes, 49 seconds N. and Longitude - 116 degrees, 04 minutes, 37 seconds W.)
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 52 to 54 degrees F.
Thickness of mollic epipedon - 10 to 20 inches
Depth to bedrock - 60 inches or more
Moisture control section - moist less than 90 consecutive days when the soil temperature is greater than 47 degrees F.
A and AB horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 15 to 25 percent
Rock fragments - 10 to 20 percent cobbles
5 to 10 percent gravel
5 to 15 percent stones (in some pedons)
15 to 35 percent total
Reaction - neutral or slightly acid
Bt1, Bt2 and Bt3 horizons
Hue - 7.5YR or 10YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Texture - CL, SC or C
Clay content - 35 to 55 percent
Rock fragments - 5 to 20 percent cobbles
30 to 50 percent gravel
50 to 60 percent stones (in some pedons)
35 to 70 percent total
Reaction - neutral or slightly acid
Bt4 and Bt5 horizons
Hue - 7.5YR or 10YR
Value - 5 through 7 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Texture - CL or SCL
Clay content - 20 to 35 percent
Rock fragments - 10 to 25 percent cobbles
50 to 65 percent gravel
60 to 90 percent stones (in some pedons)
60 to 90 percent total
Reaction - neutral or slightly acid
COMPETING SERIES: These are the Cassiro, Cochran (T), Eglirim, Fivesprings (T), Nammoth, Pickup and Ruclick series. Fivesprinqs, Nammoth and Ruclick soils are 20 to 40 inches deep to a lithic contact. Cassiro soils are 40 to 60 inches deep to a paralithic contact and have average annual soil temperatures of 47 to 52 degrees F Cochran soils have average annual soil temperatures of 47 to 50 degrees F and are 30 to 50 inches to the base of the argillic horizon. Eglirim soils have average annual soil temperatures of 49 to 52 degrees F and are 20 to 40 inches deep to the base of the argillic horizon.
GEOGRAPHIC SETTING: Adelmann soils are on hill backslopes and footslopes, fan remnants, butte escarpments, structural benches and landslides and have slopes of 4 to 50 percent. The soils formed in slope alluvium and colluvium from mixed sediments. The elevation ranges from 2,900 to 4,000 feet. The average annual precipitation is 13 to 16 inches and the average annual temperature is 50 to 52 degrees F. The frost-free period is 135 to 155 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barbermill and Cranegulch soils. Barbermill soils are shallow and have less than 35 percent rock fragments in the particle-size control section. Cranegulch soils have less than 35 percent rock fragments in the particle-size control section. These soils occur on the same landform as the Adelmann soils.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; slow permeability.
USE AND VEGETATION: Adelmann soils are used mainly for rangeland. Natural vegetation is basin big sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Ada County, Idaho. MLRA 10. The soils are of limited extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Boise Front Project, Ada County, Idaho, 1996
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - zone from the surface to 10 inches (A and AB horizons)
Argillic horizon - zone from 10 to 60 inches (Bt1, Bt2, Bt3, Bt4 and Bt5 horizons)
Particle-size control section - zone from 10 to 30 inches Soil moisture regime - aridic bordering on xeric
Linear extensibility - 4.0 to 6.0 cm (assumed) from 0 to 40 inches.
These soils are drier than other Xerolls in the region under similar precipitation due to early runoff and extended period of high evapotranspiration.