LOCATION STARHOPE IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Ultic Argixerolls
TYPICAL PEDON: Starhope loam, on a 10 percent south slope, at an elevation of 6,250 feet in rangeland. When described on November 7, 1979, the profile was moist above 10 inches. (Colors are for dry soil unless otherwise noted)
A1--0 to 4 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine roots; many very fine irregular pores; neutral (pH 6.6); abrupt wavy boundary.
A2--4 to 7 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and plastic; many very fine and fine roots; many very fine irregular and tubular pores; slightly acid (pH 6.4); abrupt smooth boundary. (Combined thickness of the A horizon is 7 to ll inches thick)
BA--7 to 10 inches; yellowish brown (10YR 5/4) clay loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and fine roots; common very fine tubular pores; few faint clay films on faces of peds; slightly acid (pH 6.4); abrupt smooth boundary. (0 to 6 inches thick)
Bt1--10 to 17 inches; light yellowish brown (10YR 6/4) clay loam, dark yellowish brown (10YR 4/4) moist; weak fine angular blocky structure; very hard, very firm, sticky and plastic; few very fine roots; common very fine tubular pores; many distinct clay films on faces of peds and lining pores; few faint bleached sand and silt grains on ped faces; about 5 percent fine pebbles; neutral (pH 6.6); clear smooth boundary. (6 to 16 inches thick)
Bt2--17 to 26 inches; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 4/4) moist; weak fine prismatic structure; very hard, very firm, sticky and plastic; few very fine roots; many prominent clay films on faces of peds; neutral (pH 6.8); clear wavy boundary. (3 to 17 inches thick)
Bt3--26 to 30 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; hard, firm, sticky and plastic; few very fine roots; common distinct clay films on faces of peds and lining pores; about 10 percent cobbles; neutral (pH 6.8); abrupt wavy boundary. (0 to 9 inches thick)
R--30 inches; welded tuffaceous bedrock.
TYPE LOCATION: Blaine County, Idaho about 1/2 mile north of Little Fishcreek Reservoir; 900 feet south and 1,800 feet east of the northwest corner of section 2, T. 1 N R. 21 E.
RANGE IN CHARACTERISTICS:
Depth to andesite, latite, or welded tuff bedrock - 20 to 40 inches Average annual soil temperature - 41 to 47 degrees F.
Reaction - neutral to strongly acid
Thickness of mollic epipedon - 7 to 18 inches
Base saturation - 50 to 75 percent between 25 and 75 cm
BA horizons - may be lacking in some pedons
Btb horizons - present in some pedons
A Horizon
Value - 4 or 5 dry
Chroma - 2 or 3 dry or moist
Bt1 and Bt2 Horizons
Hue - 5Y, 5YR, 7.5YR, 10YR
Value - 4 through 6 dry, 3 to 5 moist
Chroma - 3 or 4 dry or moist
Texture - CL, CB-C, or GR-CL, SICL, SIC
Clay content - 35 to 60 percent
Rock fragments - 0 to 30 percent
Bt3 or Btb horizon
Hue - 7.5YR or 10YR
Value - 5 or 6 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - CL, GR-CL, SICL, SIC
Clay content - 35 to 60 percent
Rock fragments - 0 to 20 percent
COMPETING SERIES: These are the Donner, Lemonex, and Uptmor series. Donner soils have a paralithic contact at a moderate depth. Lemonex soils have an O horizon and have an annual precipitation of more than 16 inches. Uptmor soils have O horizons and are deeper than 40 inches to bedrock.
GEOGRAPHIC SETTING: Starhope soils are on basalt plains, foothills and mountainsides. Slopes range from 1 to 60 percent. Elevation ranges from 5,000 to 7,500 feet. The soil formed in loess and residuum from andesite, basalt, latite, and welded tuff. The average annual precipitation is 12 to 16 inches, most of which falls as snow and early spring rains. The mean annual air temperature is 39 to 45 degrees F. The frost free season is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: They are the Goodington, and Friedman series, and the Peevywell, Elksel, and Winridge series. Goodington soils have Bk subsurface horizons and occur on basalt plains. Friedman soils have more than 35 percent coarse fragments in the control section and occur on north and east-facing mountainsides. Peevywell soils have a duripan and occur on fan terraces. Elksel soils have more than 35 percent rock fragments in the control section. Elksel soils occur on south and west-facing mountainsides. Winridge soils have mean summer soil temperatures of 59 degrees F or less, and occur on ridges or convex positions on north and east-facing mountainsides.
DRAINAGE AND PERMEABILITY: Well drained. Medium to very rapid runoff. Permeability is slow.
USE AND VEGETATION: Mainly used for rangeland. Vegetation is Mountain big sagebrush, low sage, bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Moderate extent in south central Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Blaine County, Idaho, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon is the zone from the soil surface to approximately 10 inches (A1, A2, and BA horizons).
Argillic horizon is the zone from approximately 10 to 30 inches (Bt1, Bt2, and Bt3 horizons).
ADDITIONAL DATA: Laboratory data No. (S-81ID-013-001).