LOCATION VAN DUSEN IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Argixerolls
TYPICAL PEDON: Van Dusen loam -- on a 55 percent north-facing slope in rangeland. (Colors are for air-dry soil unless otherwise noted.)
Al--0 to 8 inches; dark gray (10YR 4/1) loam, very dark brown (10YR 2/2) moist; weak thin platy structure parting to moderate very fine granular; slightly hard, very friable slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine pores; neutral (pH 6.6); clear smooth boundary. (2 to 10 inches thick)
A2--8 to 15 inches; dark gray (10YR 4/1) loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure parting to moderate very fine and fine granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine pores; neutral (pH 6.8); clear smooth boundary. (4 to 11 inches thick)
Bt1--15 to 24 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; common very fine roots; many very fine tubular pores; few faint clay films on faces of peds; neutral (pH 6.9); clear smooth boundary. (6 to 22 inches thick)
Bt2--24 to 29 inches; grayish brown (10YR 5/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine roots; common very fine tubular pores; many faint clay films on faces of peds; neutral (pH 7.0); clear wavy boundary. (5 to 21 inches thick)
Bt3--29 to 34 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; common very fine roots; common very fine tubular pores; few faint clay films on faces of peds; neutral (pH 6.9); clear wavy boundary. (0 to 27 inches thick)
BC--34 to 42 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; few very fine roots; common very fine tubular pores; neutral (pH 6.9); abrupt smooth boundary. (0 to 10 inches thick)
C1--42 to 50 inches; brown (10YR 5/3) coarse sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; common very fine tubular pores; neutral (pH 6.9); gradual smooth boundary.
C2--50 to 60 inches; stratified sandy lacustrine materials.
TYPE LOCATION: Gem County, Idaho; about 6 miles north of Emmett; 400 feet north and 1,800 feet east of the southwest corner of section 5, T.7 N., R.1 W.; USGS Northeast Emmett Quadrangle; (Latitude - 43 degrees, 58 minutes, 01 second N. and Longitude - 116 degrees, 29 minutes, 13 seconds W.)
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 20 to 60 inches
Depth to bedrock - greater than 60 inches
Depth to stratified lacustrine materials - 40 to 60 inches or more
Depth to calcium carbonates - greater than 44 inches
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 47 to 52 degrees F.
A horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 through 3 dry or moist
Rock fragments - 0 to 35 percent stones, 0 to 5 percent cobbles, 0 to 15 percent gravel
Reaction - slightly acid through slightly alkaline
Bt horizon
Hue - 7.5YR or 10YR
Value - 4 through 6 dry, 3 through 5 moist
Chroma - 2 through 4 dry or moist
Texture - CL, SCL or L (with greater than 15 percent coarse and very coarse sands)
Clay content - 18 to 30 percent
Rock fragments - 0 to 5 percent cobbles,0 to 25 percent gravel and 0 to 35 percent total
Reaction - moderately acid through slightly alkaline
C horizon (when present)
Hue - 10YR or 2.5Y
Value - 5 through 7 dry, 4 through 6 moist
Chroma - 2 through 4 dry or moist
Texture - COS, LCOS, COSL or SL
Clay content - 3 to 15 percent
Rock fragments - 0 to 5 percent cobbles,0 to 35 percent gravel and 0 to 35 percent total
Calcium carbonate equivalent - 0 to 5 percent
Reaction - slightly acid through slightly alkaline
Thin lamellae occur in the lower part of some pedons
COMPETING SERIES: These are the Adieux, Banning, Blockhouse, Coolbrith, Deadpan (T), Dotta, Drews, Gorman, Harriman, Haysum, Henhill, Lonkey, Piercepark, Pumphouse (T), Rankor (T), Robinette, Starboard, Supan, Waha, Wapinitia, and Yaxon series. Banning soils do not have a designated family activity class and are somewhat poorly drained with a high water table at a depth of 1 to 3 feet. Coolbrith soils are somewhat poorly drained with a high water table at a depth of 25 to 40 inches. Deadpan soils are not currently in the database and cannot be competed. Dotta and Drews soils have less than 15 percent coarse and very coarse sand in the argillic horizon. Gorman soils have a mean annual soil temperature of about 57 degrees F. and are strongly acid in the lower Bt and C horizons. Harriman soils have considerable influence from diatomaceous material, are dry 80 to 120 days following the summer solstice and typically have a paralithic contact (2Crk) at 40 to 60 inches. Haysum soils have an average annual soil temperature of 53 to 59 degrees F. Lonkey soils have bedrock at 20 to 40 inches and are dry 120 to 130 days following the summer solstice. Pumphouse soils have less than 15 percent sand coarser than very fine sand in the particle-size control section. Piercepark soils have an aridic bordering on xeric soil moisture regime. Rankor soils have an average annual soil temperature of 52 to 58 degrees F., are dry 140 to 160 consecutive days, and are 40 to 60 inches deep to a paralithic contact. Robinette soils have basalt bedrock at 40 to 60 inches and more than 60 percent rock fragments in the lower part of the argillic (2Bt) horizon. Starboard soils are 20 to 40 inches to a paralithic contact and have a MAST of 54 to 59 degrees F. Supan soils are 30 to 48 inches deep to a lithic contact. Waha soils have basalt bedrock at 20 to 40 inches and silt loam or silty clay loam textures in the upper argillic (Bt) horizon. Wapinita soils have basalt bedrock at 40 to 60 inches. Yaxon soils have hard nodules in the Bt horizon, lack micaceous material in and below the argillic horizon, and are dry for 90 to 120 consecutive days.
GEOGRAPHIC SETTING: Van Dusen soils are mainly on north-facing hill backslopes and gulch slopes at elevations of 2,400 to 5,000 feet. These soils formed in alluvium and colluvium from mixed lacustrine sediments. Slopes dominantly range from 30 to 75 percent, but range down to 2 percent in one mapping unit on terraces in Elmore County, Idaho. Stony phases are below ledges of rock outcrop. The average annual precipitation is 12 to 20 inches. The average annual temperature is 45 to 50 degrees F. The frost-free period is 90 to 145 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Haw, Payette, Picketpin and Rainey soils. These soils have mollic epipedons less than 20 inches thick. Payette soils are on north aspects at lower elevations. Haw and Rainey soils occur on south aspects. Picketpin soils occur on similar geographic positions.
DRAINAGE AND PERMEABILITY: Well drained; very slow to very rapid runoff; moderate permeability.
USE AND VEGETATION: Van Dusen soils are used mainly for rangeland. Native vegetation is xeric big sagebrush, bluebunch wheatgrass and Idaho fescue.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10. Van Dusen soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Gem County, Idaho, 1962.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - zone from the soil surface to 42 inches (Al, A2, Bt1, Bt2, Bt3, and BC horizons)
Argillic horizon - zone from 15 to 34 inches (Bt1, Bt2 and Bt3 horizons)
Particle-size control section - zone from 15 to 34 inches
Mica is a significant mineral throughout the pedon
Soil moisture regime - xeric
Series pedon revisions 4/04 reflect the soil color as described at the type location and documented in the series file. The mollic epipedon is thickened by 13 inches as result.