LOCATION BREQUITO                ID

Established Series
Rev. BLR/BDG/RJS
02/2016

BREQUITO SERIES

The Brequito series consists of very deep, well drained soils formed in loess over colluvium and residuum from granitic or low mica metamorphic rock with a thin mantle of volcanic ash. They are on mountain slopes, ridges, structural benches and summits. Saturated hydraulic conductivity is moderately slow and slopes range from 5 to 75 percent. The average annual precipitation is about 1,000 mm and the average annual air temperature is about 5.5 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Andic Hapludalfs

TYPICAL PEDON: Brequito ashy silt loam, forested, on a 15 percent slope at 1,035 meters elevation. Aspect is north. When described on November 11, 1991, the soil was saturated to 430 mm and moist below to 168 cm. (Colors are for dry soil unless otherwise stated).

Oi--0 to 3 cm; fresh and partially decomposed needles, twigs, moss, and leaves.

Oe--3 to 8 cm; decomposed needles, twigs, moss, leaves, and roots.

A--8 to 13 cm; dark grayish brown (10YR 4/2) ashy silt loam, dark brown (7.5YR 3/3) moist; weak very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine irregular pores; 1 percent fine rounded iron-manganese concretions; neutral (pH 6.7); abrupt wavy boundary. (5 to 13 cm thick)

Bw--13 to 28 cm; light yellowish brown (10YR 6/4) ashy silt loam, dark brown (7.5YR 3/4) moist; weak fine and medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine irregular pores; 3 percent fine rounded iron-manganese concretions; neutral (pH 6.7); abrupt wavy boundary. (8 to 28 cm thick)

2Bt/E1--28 to 38 cm; B - yellowish brown (10YR 5/4) silt loam, brown (10YR 4/3) moist; E - pale brown (10YR 6/3), yellowish brown (10YR 5/4) moist; moderate medium to coarse subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; many very fine and fine and few coarse roots; common very fine and fine irregular and few very fine and fine tubular pores; common faint clay films on faces of peds; common distinct skeletans on faces of peds and in pores; 1 percent fine charcoal; 3 inch wide krotovina filled with volcanic ash; 1 percent fine mica flakes; neutral (pH 6.8); clear wavy boundary.

2Bt/E2--38 to 50 cm inches; B - light yellowish brown (10YR 6/4) silt loam, brown (10YR 5/3) moist; E - very pale brown (10YR 7/4), yellowish brown (10YR 5/4) moist; weak medium and coarse prismatic structure parting to moderate fine and medium subangular blocky; hard, firm, slightly sticky and slightly plastic; common fine and medium roots throughout and common coarse roots along ped faces; common very fine and fine irregular and tubular pores; common faint clay films on faces of peds; common distinct skeletans on faces of peds and in pores; 1 percent fine mica flakes; slightly acid (pH 6.3); gradual wavy boundary. (Combined thickness of 2Bt/E1 & 2Bt/E2 horizons is 0 to 41 cm)

2Bt1--50 to 70 cm; light yellowish brown (10YR 6/4) silty clay loam, yellowish brown (10YR 5/4) moist; moderate very coarse prismatic structure parting to moderate medium and coarse subangular blocky; very hard, firm, sticky and plastic; common very fine and fine and few medium and coarse roots along ped faces and few very fine and fine roots in interior of peds; common very fine and fine irregular and tubular pores; common, distinct clay films on faces of peds and in pores; 1 percent fine mica flakes; slightly acid (pH 6.1); gradual smooth boundary.

2Bt2--70 to 93 cm; very pale brown (10YR 7/4) silty clay loam, yellowish brown (10YR 5/4) moist; moderate very coarse prismatic structure parting to strong and coarse subangular blocky; very hard, firm, sticky and plastic; common fine and medium roots along ped faces and few very fine roots in interior of peds; few very fine and fine irregular and tubular pores; many distinct clay films on faces of peds and in pores; 2 percent fine mica flakes; 2 percent rounded quartz gravel; moderately acid (pH 5.6); clear irregular boundary.

2Bt3--93 to 120 cm; very pale brown (10YR 7/4) clay loam, yellowish brown (10YR 5/4) moist; weak very coarse prismatic structure parting to moderate medium and coarse subangular blocky; very hard, firm, sticky and plastic; common very fine and fine roots along ped faces; common very fine and fine irregular and tubular pores; common distinct clay films on faces of peds; 2 percent fine mica flakes; 2 percent rounded quartz gravel; moderately acid (pH 5.6); clear smooth boundary. (Combined thickness of 2Bt1, 2Bt2 & 2Bt3 horizons is 18 to 109 cm)

3BCt--120 to 155 cm; very pale brown (10YR 8/4) loam, light yellowish brown (10YR 6/4) moist; weak very coarse prismatic structure parting to moderate medium and coarse subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and fine irregular and few very fine tubular pores; 0.5 to 1 inch thick clay bands 2 to 3 inches apart, dark yellowish brown (10YR 4/4) loam with common distinct clay films; 5 percent fine mica flakes; 5 percent gravel; strongly acid (pH 5.4); clear smooth boundary.

3C--155 to 168 cm; yellow (10YR 8/6) loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine roots; common very fine and fine irregular pores; 3 to 6 mm thick clay bands in horizontal and vertical cracks, strong brown (7.5YR 4/6) loam; 5 percent gravel; strongly acid (pH 5.3).

TYPE LOCATION: Clearwater County, Idaho; about 4 miles east of Weippe, Idaho, about 400 feet north and 1,600 feet east of the southwest corner of sec. 9. T. 35 N., R. 5 E.; Latitude - 46 degrees, 23 minutes, 03 seconds North; Longitude - 115 degrees, 50 minutes, 27 seconds West. USGS Pierce, Idaho Qudrangle.

RANGE IN CHARACTERISTICS:
Average annual soil temperature - 3.9 to 7.8 degrees C.
Temperature regime - frigid
Moisture regime - udic
Soil moisture - usually moist year around and not dry for 45 consecutive days during June to October
Thickness of volcanic ash - 18 to 33 cm
Volcanic glass content - 25 to 35 percent

A horizon
Hue - 7.5YR, 10YR
Value - 4 to 6 dry, 2.5, 3 moist
Chroma - 2 to 4 dry or moist
Texture - ashy silt loam
Clay content - 8 to 12 percent
Rock fragments - 0 to 10 percent gravel
Reaction - 5.4 to 6.8
Bulk density - 0.65 to 0.90 g/cc
Ammonium oxalate extractable Al plus 1/2 Fe - 1.2 to 2.25

Bw horizon
Hue - 7.5YR, 10YR
Value - 5, 6 dry, 3, 4 moist
Chroma - 3, 4 moist
Texture - ashy silt loam, ashy loam
Clay content - 8 to 12 percent
Rock fragments - 0 to 5 percent gravel
Reaction - 5.4 to 6.8
Bulk density - 0.70 to 1.20 g/cc
Ammonium oxalate extractable Al plus 1/2 Fe - 1.0 to 2.35

2Bw horizon (present in some pedons)
Hue - 7.5YR, 10YR moist
Value - 5, 6 dry, 4 moist
Chroma - 3, 4 dry or moist
Texture - loam, silt loam
Clay content - 17 to 20 percent
Rock fragments - 0 to 5 percent gravel
Reaction - 5.6 to 6.5

2EBt, 2BtE horizons (present in some pedons)
Hue - 10YR dry, 7.5YR, 10YR moist
Value - 3 to 5 moist
Chroma - 3, 4 moist
Clay content - 15 to 21 percent
Rock fragments - 0 to 5 percent gravel
Reaction - 5.2 to 6.3

2Bt/E1, 2Bt/E2 horizons
B part:
Hue - 7.5YR or 10YR
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 3 or 4 dry, 3 to 6 moist
Texture - silt loam, loam, sandy clay loam
Clay content - 18 to 27 percent
E part:
Hue - 7.5YR, 10YR
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 3, 4 dry, 3 to 8 moist
Texture - loam, silt loam
Clay Content - 15 to 20 percent
Rock fragments - 0 to 15 percent gravel, 0 to 5 percent cobbles, 0 to 20 percent total rock fragment content
Reaction - 5.1 to 6.5

2Bt1, 2Bt2, 2Bt3 horizons
Hue - 7.5YR, 10YR
Value - 4 to 7 dry, 3 to 6 moist
Chroma - 2 to 6 dry or moist
Texture - loam, silt loam, silty clay loam
Clay Content - 18 to 30 percent
Rock fragments - 0 to 15 percent gravel, 0 to 5 percent cobbles, 0 to 20 percent total rock fragments
Reaction - 5.1 to 6.4

3Bt horizons (present in some pedons)
Hue - 5YR to 10YR
Value - 4 to 7 dry, 3 to 5 moist
Chroma - 2 to 6 dry, 3 to 6 moist
Texture - loam, silt loam
Clay Content - 16 to 26 percent
Rock fragments - 0 to 20 percent gravel, 0 to 15 percent cobbles, 0 to 25 percent total rock fragments
Reaction - 5.1 to 5.8

3BCt horizon (absent in some pedons)
Hue - 7.5YR or 10YR dry, 2.5YR to 10YR moist
Value - 6 to 8 dry, 4 to 6 moist
Chroma - 4 to 6 moist
Texture - loam, sandy loam, sandy clay loam
Clay Content - 10 to 23 percent
Coarse fragments - 2 to 35 percent gravel, 0 to 15 percent cobbles, 2 to 35 percent total rock fragments
Reaction - 5.1 to 5.8

3C horizon (absent in some pedons)
Hue - 7.5YR, 10YR moist
Value - 5 to 8 dry, 4 to 6 moist
Chroma - 4 to 6 dry, 3 to 6 moist
Texture - loam, sandy loam, loamy sand
Clay Content - 5 to 18 percent
Rock fragments - 5 to 45 percent gravel
Reaction - 5.1 to 5.8

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Landforms - mountain slopes, ridges, structural benches and summits
Elevations - 475 to 1,325 meters
Slopes - 5 to 75 percent
Parent material - formed in loess over colluvium and residuum from granitic and low mica metamorphic rock with a thin mantle of volcanic ash
Mean annual precipitation - 625 to 1,450 mm
Mean annual air temperature - 3.3 to 7.8 degrees C.
Frost-free season - 50 to 120 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brodeer, Mushel, and Lado series. Brodeer soils are on steep concave mountain side slopes, have thick volcanic ash mantles, and do not have a discrete loess layer. Mushel soils are on convex mountain side slopes, have thin volcanic ash mantles, and do not have a discrete loess layer. Lado soils are on concave mountain side slopes, have thick volcanic ash mantles and have a discrete loess layer.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, medium to very rapid runoff, moderately high saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for timber production, livestock grazing, wildlife habitat, watershed, and recreation. Potential natural vegetation is western red cedar, grand fir, western larch, western white pine, Douglas-fir, and ponderosa pine with an understory of queencup beadlily, coolwort foamflower, princes pine, western goldthread, and bunchberry dogwood.

DISTRIBUTION AND EXTENT: North Central Idaho. Brequito soils are moderately extensive. MLRA 43A.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Clearwater County, Idaho, 2003.

REMARKS: Diagnostic horizons and other features recognized in this pedon are:
Ochric epipedon - from 0 to 13 cm (Oi, Oe, A horizons)
Andic soil properties - from 8 to 28 cm (A, Bw horizons)
Cambic horizon - from 13 to 28 cm (Bw horizon)
Argillic horizon - from 28 to 120 cm (2Bt/E1, 2Bt/E2, 2Bt1, 2Bt2, 2Bt3 horizons)
Lithologic discontinuities - one at 28 cm and a second at 120 cm
Particle size control section - from 28 to 78 cm (2Bt/E1, 2Bt/E2, 2Bt1, part of 2Bt2 horizons).

ADDITIONAL DATA: Laboratory data is available for this series: Soil survey sample no. S92ID-035-030 (project no. 92P 181, pedon no. 92P968) (this pedon) from Clearwater County Idaho by NSSL, Lincoln, NE.

Additional information: Particle size class changed from fine-silty to fine-loamy 6/2013 based on a preponderance of available data.

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National Cooperative Soil Survey
U.S.A.