LOCATION LESBOIS                 ID

Established Series
Rev: JCB/ALH
07/2012

LESBOIS SERIES

The LesBois series consists of very deep, somewhat poorly drained soils with high saturated hydraulic conductivity that formed in alluvium from granitic rocks. Slopes range from 0 to 1 percent in valleys. The average annual precipitation is about 292 mm and the average annual temperature is about 10.6 degrees C.

TAXONOMIC CLASS: Sandy, mixed, mesic Oxyaquic Torrifluvents

TYPICAL PEDON: LesBois loamy sand -- on a nearly level floodplain-step under riparian woodland at 750 meters elevation. When described on October 5, 2006, the soil was dry to 61 cm, slightly moist to 105 cm, moist to 163 cm and wet below. (Colors are for air-dry soil unless otherwise noted.)

A1--0 to 3 cm; grayish brown (10YR 5/2) loamy sand, very dark grayish brown (10YR 3/2) moist; moderate thin and medium platy structure; moderately hard, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine and fine, few medium vesicular pores; neutral (pH 6.7); abrupt smooth boundary.

A2--3 to 17 cm; pale brown (10YR 6/3) fine sandy loam, brown (10YR 4/3) moist; weak coarse platy structure parting to single grain; slightly hard, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine and fine vesicular, few very fine and fine tubular pores; neutral (pH 6.8); abrupt wavy boundary. (combined A horizon - 10 to 45 cm thick)

C1--17 to 46 cm; very pale brown (10YR 7/4) loamy sand, yellowish brown (10YR 5/4) moist; single grain; loose, nonsticky and nonplastic; few very fine and fine roots; common very fine and fine vesicular pores; common medium faint dark yellowish brown (10YR 4/4) moist redox concentrations; neutral (pH 6.9); clear smooth boundary.

C2--46 to 64 cm; pale brown (10YR 6/3) fine sandy loam, brown (10YR 5/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; many very fine, fine and medium roots; many very fine and fine, few medium vesicular, common very fine and fine tubular pores; many medium and coarse distinct dark yellowish brown (10YR 4/4) moist redox concentrations and common medium faint pale brown (10YR 6/3) moist redox depletions; neutral (pH 6.8); abrupt smooth boundary.

C3--64 to 86 cm; very pale brown (10YR 7/4) sand, yellowish brown (10YR 5/4) moist; single grain; loose, nonsticky and nonplastic; few very fine and fine roots; common very fine and fine vesicular pores; few fine and medium distinct dark yellowish brown (10YR 4/4) moist redox concentrations; neutral (pH 7.1); abrupt wavy boundary.

C4--86 to 107 cm; pale brown (10YR 6/3) fine sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine and fine, few medium and coarse roots; common very fine and fine vesicular and tubular pores; many medium distinct dark yellowish brown (10YR 4/6) moist redox concentrations and common medium faint pale brown (10YR 6/3) moist redox depletions; neutral (pH 6.9); abrupt smooth boundary.

Ab--107 to 112 cm; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine vesicular and tubular pores; many medium distinct dark yellowish brown (10YR 4/6) moist redox concentrations and common medium faint pale brown (10YR 6/3) moist redox depletions; neutral (pH 7.0); abrupt smooth boundary. (0 to 18 cm thick)

2C5--112 to 168 cm; multi-colored very gravelly coarse sand; single grain; loose, nonsticky and nonplastic; 45 percent gravel, 5 percent cobbles; neutral (pH 7.2).

TYPE LOCATION: Ada County, Idaho; about one-half mile southeast of Star; 1,830 feet north and 3,000 feet west of the southeast corner of section 17, T.4 N., R.1 W.; USGS Star Quadrangle; Latitude - 43 degrees, 40 minutes, 56 seconds N. and Longitude - 116 degrees, 29 minutes, 06 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Depth to discontinuity (sand and gravel) - 63 to 152 cm or more
Depth to bedrock - greater than 180 cm
Particle-size control section - 2 to 10 percent clay; 0 to 35 percent rock fragments
Moisture control section - moist less than 90 consecutive days when the soil temperature is greater than 8.3 degrees C.
Average annual soil temperature - 11.1 to 12.2 degrees C.

A horizon
Value - 5 through 7 dry, 3 through 5 moist
Chroma - 2 or 3 dry and moist
Texture - FSL, SL or LS
Clay content - 2 to 12 percent
Rock fragments - 0 to 5 percent gravel
Redoximorphic features - none to common, faint or distinct Fe concentrations

C horizon
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 2 through 4 dry and moist
Texture (stratified) - FSL, LFS, LS, S or COS
Clay content - 0 to 10 percent
Rock fragments - 0 to 20 percent gravel
Redoximorphic features - common or many, distinct or prominent Fe concentrations; none through common faint depletions; occasionally gleyed below 100 cm

2C horizon
Texture (stratified) - LS, S or COS
Clay content - 0 to 5 percent
Rock fragments - 0 to 60 percent gravel, 0 to 10 percent cobbles and 0 to 60 percent total

COMPETING SERIES: These are the Bebeevar, Bowington, Carwalker, Escawetter, Labyrinth and Sagouspe series. Bebeevar, Bowington, Carwalker, Escawetter, Labyrinth and Sagouspe soils are moderately well drained. Bebeevar soil has seasonal high saturation of 105 to 150 cm. Bowington, Carwalker and Escawetter soils have seasonal high saturation of 100 to 150 cm. Labyrinth and Sagouspe soils have seasonal high saturation of 90 to 150 cm.

GEOGRAPHIC SETTING: The LesBois soils are on low floodplain-steps at elevations of 748 to 860 meters. Slopes range from 0 to 1 percent. These soils formed in alluvium from granitic rocks with minor influence of other igneous materials. The average annual precipitation is 254 to 330 mm. The average annual temperature is 10 to 11 degrees C. The frost-free period is 145 to 155 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Notus and Eagle soils. Eagle soils are moderately well drained, are less than 50 cm deep to sand and gravel with more than 35 percent rock fragments in the control section and on higher geomorphic positions. Notus soils are less than 50 cm deep to sand and gravel with more than 35 percent rock fragments in the control section and on similar geomorphic positions.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained with normal seasonal high saturation between depths of 50 and 100 cm; occasional flooding where not protected; slow runoff; high over very high saturated hydraulic conductivity.

USE AND VEGETATION: LesBois soils are used mainly for irrigated hayland/pasture and wildlife habitat. Urbanized river corridors are used for recreation. Native vegetation is black cottonwood and willows.

DISTRIBUTION AND EXTENT: Southwestern Idaho. MLRA 11. LesBois soils are of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Ada County, Idaho, 2012

REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - 0 to 17 cm
Lithologic discontinuity - at 111 cm
Redoximorphic features - zone from 17 to 111 cm
Particle-size control section - zone from 25 to 100 cm
Soil moisture regime - aridic bordering xeric

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National Cooperative Soil Survey
U.S.A.