LOCATION CROSSBOW IDEstablished Series
The Crossbow series consists of very deep, somewhat poorly drained soils with moderately rapid permeability that formed in alluvium from igneous rocks and fine pyroclastic materials. Slopes range from 0 to 3 percent in mountain valleys and canyons. The average annual precipitation is about 22 inches and the average annual temperature is about 46 degrees F.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Aquic Cumulic Haploxerolls
TYPICAL PEDON: Crossbow fine sandy loam -- on a nearly level flood-plain step at 3,030 feet elevation in semi-wet meadow pasture. When described on September 3, 1997, the soil was dry to 42 inches and moist below. (Colors are for air-dry soil unless otherwise noted.)
A1--0 to 4 inches; dark grayish brown (10YR 4/2) fine sandy loam, very dark brown (10YR 2/2) moist; moderate medium and coarse granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine and medium, few coarse roots; many very fine and fine irregular pores; slightly acid (pH 6.1); clear smooth boundary.
A2--4 to 11 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; many very fine and fine irregular pores; common distinct (10YR 5/3 dry and 10YR 3/3 moist) relict Fe concentrations in pores and on faces of peds; slightly acid (pH 6.2); gradual wavy boundary.
A3--11 to 21 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; many very fine and fine irregular pores; common distinct (10YR 5/3 dry and 10YR 3/3 moist) relict Fe concentrations in pores and on faces of peds; moderately acid (pH 5.8); gradual wavy boundary.
A4--21 to 36 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; many very fine and fine irregular pores; common distinct (10YR 5/4 dry and 10YR 3/4 moist) Fe concentrations in pores and on faces of peds, few faint (10YR 5/1 dry and 10YR 3/1 moist) depletions; slightly acid (pH 6.3); clear smooth boundary. (combined A horizon - 20 to 40 inches thick)
C1--36 to 42 inches; light gray (10YR 7/2) loamy fine sand, grayish brown (10YR 5/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine irregular pores; common distinct (10YR 5/4 dry and 10YR 3/4 moist) Fe concentrations in lenses; moderately acid (pH 5.6); abrupt smooth boundary. (6 to 15 inches thick)
C2--42 to 60 inches; light gray (10YR 7/2) gravelly coarse sand, grayish brown (10YR 5/2) moist; single grain; loose, nonsticky and nonplastic; few very fine and fine roots; many very fine, fine, medium and coarse irregular pores; common distinct (10YR 5/4 dry and 10YR 3/4 moist) Fe concentrations in lenses; 30 percent gravel; moderately acid (pH 5.6).
TYPE LOCATION: Boise County, Idaho; about 2.5 miles north of Crouch; 2,400 feet north and 2,500 feet east of the southwest corner of section 3, T.9 N., R.4 E.; USGS Pyle Creek Quadrangle; Latitude - 44 degrees, 08 minutes, 26 seconds N. and Longitude - 115 degrees, 58 minutes, 04 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 20 to 40 inches
Depth to redoximorphic features - 20 to 30 inches
Depth to bedrock - 60 inches or more
Reaction - moderately acid or slightly acid
Particle-size control section - 5 to 18 percent clay; 0 to 10 percent rock fragments
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 47 to 50 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 or 2 dry or moist
Clay content - 8 to 18 percent
Rock fragments - 0 to 5 percent gravel
Redoximorphic features (lower part) - common or many, distinct or prominent Fe concentrations; few or common faint depletions (relict redoximorphic features commonly occur above 20 inches)
C1 horizon
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 1 or 2 dry or moist
Texture - LFS or LS
Clay content - 3 to 8 percent
Rock fragments - 0 to 10 percent gravel
Redoximorphic features - common or many, distinct or prominent Fe concentrations in lenses
C2 horizon
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 1 or 2 dry or moist
Texture - COS or S
Clay content - 0 to 5 percent
Rock fragments - 15 to 30 percent gravel, 0 to 5 percent cobbles and 15 to 35 percent total
Redoximorphic features - common or many, distinct or prominent Fe concentrations in lenses
COMPETING SERIES: There are no competing series. Chewelah and Dressler soils are similar, but have mollic epipedons less than 20 inches thick. Kernfork soils are similar, but are thermic.
GEOGRAPHIC SETTING: Crossbow soils are on flood-plain steps of rivers and streams at elevations of 3,000 to 3,500 feet. Slopes range from 0 to 3 percent. The soils formed in alluvium from igneous rocks (dominantly granodiorite) and fine pyroclastic materials. The average annual precipitation is 20 to 26 inches. The average annual temperature is 45 to 48 degrees F. The frost-free period is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Foxlane, Pay and Ralsen soils. Foxlane soils are sandy-skeletal and moderately well drained. Pay soils are sandy, do not have mollic epipedons and are poorly drained. Ralsen soils are coarse-loamy and poorly drained. These soils occur on adjacent flood-plain steps.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained with a high water table at 20 and 30 inches below the surface during April and May; very slow runoff; moderately rapid permeability. Crossbow soils are subject to occasional flooding for brief periods in December through June.
USE AND VEGETATION: Crossbow soils are used mainly for wildlife habitat and mountain semi-wet meadow pastureland. Native vegetation is slender wheatgrass and mountain brome.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 44. Crossbow 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:
Mollic epipedon with irregular decrease in organic carbon - zone from 0 to 36 inches (A1, A2, A3 and A4 horizons)
Redoximorphic features - zone from 21 to 60 inches (A4, C1 and C2 horizons)
Particle-size control section - zone from 10 to 40 inches
Soil moisture regime xeric