LOCATION BREADLOAF IDEstablished Series
The Breadloaf series consists of moderately deep, well drained soils with very slow permeability that formed in colluvium and residuum from lacustrine deposits. Slopes range from 4 to 50 percent in foothills. The average annual precipitation is about 17 inches and the average annual temperature is about 48 degrees F.
TAXONOMIC CLASS: Fine, smectitic, mesic Leptic Haploxererts
TYPICAL PEDON: Breadloaf clay loam -- on a 15 percent slightly convex southwest-facing slope at 4,220 feet elevation in rangeland. When described on July 11, 1994, the soil was dry to 11 inches and slightly moist below. (Colors are for air-dry soil unless otherwise noted.)
A--0 to 2 inches; grayish brown (10YR 5/2) clay loam, brown (10YR 4/3) moist; weak medium and coarse subangular blocky structure parting to strong fine granular; very hard, friable, moderately sticky and moderately plastic; common very fine and fine few medium and coarse roots; many very fine and fine tubular pores; cracks 5mm to 5cm wide; neutral (pH 7.1); abrupt smooth boundary. (2 to 6 inches thick)
Bt--2 to 6 inches; brown (10YR 5/3) clay, dark yellowish brown (10YR 4/4) moist; moderate medium prismatic structure; extremely hard, very firm, very sticky and very plastic; few very fine, fine, medium and coarse roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; cracks 5mm to 5cm wide; neutral (pH 6.6); abrupt wavy boundary. (2 to 11 inches thick)
Btss1--6 to 12 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; strong medium and coarse prismatic structure; extremely hard, very firm, very sticky and very plastic; few very fine, fine, medium and coarse roots; common very fine and fine tubular pores; common prominent clay films on faces of peds and in pores; common intersecting slickensides; cracks 5mm to 5cm wide; neutral (pH 6.7); clear smooth boundary. (4 to 13 inches thick)
Btss2--12 to 17 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; strong medium and coarse prismatic structure; extremely hard, very firm, very sticky and very plastic; few very fine, fine, medium and coarse roots; common very fine and fine tubular pores; many prominent clay films on faces of peds and in pores; many intersecting slickensides; common wedge shaped aggregates oriented at 40 to 50 degrees from horizontal at lower part of horizon; 1 percent fine black (10YR 2/1) dry, manganese concretions; cracks 5mm to 5cm wide; neutral (pH 6.9); gradual wavy boundary. (4 to 10 inches thick)
Btss3--17 to 23 inches; very pale brown (10YR 7/3) paragravelly clay, brown (10YR 5/3) moist; moderate fine and medium prismatic structure parting to strong fine and medium angular blocky; extremely hard, very firm, very sticky and very plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; few intersecting slickensides; 20 percent siltstone paragravel; cracks 1mm to 2cm wide; neutral (pH 7.0); abrupt wavy boundary. (2 to 9 inches thick)
Crk--23 to 33 inches; stratified silty lacustrine deposits that have less than 5 percent calcium carbonate on horizontal and vertical bedding faces and in pockets.
TYPE LOCATION: Boise County, Idaho; about 5.5 miles south and 2 miles west of Horseshoe Bend; 1,800 feet south and 2,650 feet east of the northwest corner of section 20, T.6 N., R.2 E.; USGS Cartwright Canyon Quadrangle; Latitude - 43 degrees, 50 minutes, 42 seconds N. and Longitude - 116 degrees, 14 minutes, 43 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Depth to paralithic contact - 20 to 40 inches
Surface cracks - 1mm to 10cm wide; open from July through November in most years
Particle-size control section - 35 to 60 percent clay; 0 to 5 percent rock fragments
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 47 to 53 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 27 to 35 percent
Rock fragments - 0 to 5 percent cobbles
Reaction - slightly acid or neutral
Bt horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Texture - SIC or C
Clay content - 40 to 60 percent
Rock fragments - 0 to 5 percent gravel
Reaction - slightly acid or neutral
Btss horizon
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - SICL, SIC or C
Clay content - 35 to 60 percent
Rock fragments - 0 to 5 percent gravel
Pararock fragments - 0 to 25 percent paragravel
Reaction - neutral or slightly alkaline
Slickensides - few or common intersecting
Wedge shaped aggregates - few or common (oriented 30 to 60 degrees from horizontal)
COMPETING SERIES: These are the Aikman, Karcal, Lassen and Shafer series. Aikman, Karcal and Lassen soils are moderately deep to a lithic contact. Shafer soils are moderately deep to a lithic contact.
GEOGRAPHIC SETTING: Breadloaf soils are on hill footslopes and backslopes, and landslides at elevations of 2,600 to 4,650 feet. Slopes range from 4 to 50 percent. The soils formed in colluvium and residuum from lacustrine deposits. The average annual precipitation is 14 to 20 inches. The average annual temperature is 45 to 51 degrees F. The frost-free period is 90 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Doubledia and Hann soils. Doubledia soils are deep to a paralithic contact. Hann soils are very deep and have mollic epipedons. These soils occur on similar geomorphic positions.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; very slow permeability.
USE AND VEGETATION: Breadloaf soils are used mainly for rangeland. Native vegetation is xeric big sagebrush, biscuitroot, bluebunch wheatgrass and Sandburg bluegrass.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10. Breadloaf soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Boise County Area, Idaho, Parts of Ada and Boise Counties, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - zone from the surface to 2 inches (A horizon)
Particle-size control section - zone from 10 to 23 inches
Paralithic contact - at 23 inches (Crk horizon)
Cracks - 1mm to 5cm wide; extending from the soil surface to the paralithic contact
Soil moisture regime - xeric
ADDITIONAL DATA: Characterization sample no. S95ID-015-009 (NSSL pedon 95P935).