LOCATION SLY                     ID

Established Series
Rev. CJW-BDG-EMM
07/2013

SLY SERIES

The Sly series consists of very deep, well drained soils on dissected terraces and structural benches in canyons. They formed in loess deposits with minor amounts of volcanic ash overlying basalt. Permeability is moderately slow. Slopes are 3 to 50 percent. The average annual temperature is about 43 degrees F. and the average annual precipitation is 32 inches.

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

TYPICAL PEDON: Sly ashy silt loam, forest, on a 5 percent slope at 3,000 feet elevation. When described on April 14, 1983, the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)

0i--0 to 0.75 inches; slightly decomposed needles, leaves, and twigs.

0e--0.75 to 1.5 inches; decomposed organic matter mixed with Mt. St. Helen's volcanic ash. (0 to 4 inches thick)

A--1.5 to 5 inches; brown (10YR 5/3) ashy silt loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure parting to weak very fine and fine granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, and common medium and coarse roots; many very fine, common fine, and few medium tubular pores; slightly acid (pH 6.5); clear wavy boundary. (1 to 7 inches thick)

Bw--5 to 11 inches; pale brown (10YR 6/3) ashy silt loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, and few medium and coarse roots; many very fine, common fine, and few medium tubular pores; slightly acid (pH 6.3); clear wavy boundary. (4 to 16 inches thick)

Bt1--11 to 22 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; moderate medium and coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine, few fine and medium roots; many very fine, common fine, and few medium tubular pores; common faint and few distinct clay films on faces of peds and lining pores; moderately acid (pH 5.8); clear wavy boundary. (5 to 13 inches thick)

Bt2--22 to 38 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; moderate coarse and very coarse angular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and few fine roots; many very fine and fine, and few medium tubular pores; many faint and common distinct clay films on faces of peds and lining pores; strongly acid (pH 5.5); clear wavy boundary. (0 to 22 inches thick)

Bt3--38 to 62 inches; mixed pale brown (10YR 6/3) and brown (10YR 5/3) silty clay loam, brown (10YR 4/3) and dark brown (10YR 3/3) moist; moderate coarse and very coarse angular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; many very fine, fine, and few medium tubular pores; common distinct and few prominent clay films on faces of peds and lining pores; 10 percent gravel; strongly acid (pH 5.5).

TYPE LOCATION: Benewah County, Idaho; about 1 miles east of St. Maries, about 3,100 feet south and 1,100 feet west of the northeast corner of Section 24, T. 46 N., R. 2 W.; Latitude - 47 degrees, 19 minutes, 07 seconds North; Longitude - 116 degrees, 31 minutes, 34 seconds West; NAD 83; USGS St. Maries Quadrangle.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry for 30 to 40 consecutive days, moist in mid-September through July, dry August to September.
Udic moisture regime
Average annual soil temperature - 39 to 46 degrees F
Average summer soil temperature - 44 to 52 degrees F with an 0 horizon
Frigid temperature regime
Depth to bedrock - greater than 60 inches
Solum thickness - 40 to more than 60 inches

Volcanic ash influence -7 to 20 inches thick; surface layers
Volcanic glass content - 5 to 20 percent
Acid Oxalate extractable Al + Fe - 0.4 to 1.0 percent
Moist bulk density - 1.0 to 1.2 grams per cubic centimeter (estimated)
Phosphate retention - 25 to 55 percent

A horizon
Hue - 10YR or 7.5YR dry or moist
Value - 3 to 5 dry, 2 or 3 moist
Chroma - 1 to 4, dry or moist
Texture - ashy-loam or ashy-silt loam
Clay content - 8 to 25 percent
Rock fragments - 0 to 10 percent gravel
Reaction - moderately acid to neutral

Bw horizon (and AB or BA horizons when present)
Hue - 10YR or 7.5YR dry or moist
Value - 4 to 6 dry, 3 to 5 moist
Chroma - 3 or 4 dry or moist
Texture - ashy silt loam, ashy loam or ashy sitly clay loam
Clay content - 8 to 30 percent
Rock fragments - 0 to 10 percent
Reaction - strongly acid to neutral

E/B, B/E, 2E/B, or 2B/E horizons (when present)
Hue - 10YR or 7.5YR dry or moist
Value - 5 to 8 dry, 3 to 6 moist
Chroma - 1 to 4 dry, 2 to 4 moist
Texture - silt loam or silty clay loam
Clay content - 18 to 30 percent
Rock fragments - 0 to 10 percent gravel
Reaction - extremely acid to neutral

Bt horizons
Hue - 10YR to 5YR dry, 2.5Y to 5YR moist
Value - 4 to 8 dry, 3 to 7 moist
Chroma - 2 to 6 dry or moist
Texture - silt loam, loam, silty clay loam, or clay loam
Clay content - 18 to 34 percent in the upper part, 25 to 38 in the lower part
Rock fragments - 0 to 25 percent gravel, 0 to 5 percent cobbles, 0 to 25 percent total
Base saturation (sum of cations) - 50 to 70 percent
Reaction - extremely acid to neutral

C horizon - present in some pedons
Hue - 2.5Y to 7.5YR moist
Value - 5 to 8 dry, 4 to 6 moist
Chroma - 1 to 6 dry, 2 to 6 moist
Texture - silt loam, loam, or clay loam
Clay content - 20 to 35 percent
Rock fragments - 0 to 25 percent gravel, 0 to 15 percent cobbles, 0 to 30 percent total
Reaction - strongly acid to slightly acid

COMPETING SERIES:

Bechtel - are 40 to 60 inches to a paralithic contact
Christoff - have 2Bt horizons
Keeler - have 2Bt horizons with sandy loam or sandy clay loam textures and are dominated by rock fragments of granitic or metamorphic origin

GEOGRAPHIC SETTING: Sly soils are on dissected terraces and structural benches in canyons. Slopes range from 3 to 50 percent. These soils formed in loess deposits overlying basalt at elevations of 1,100 to 3,400 feet. The average annual air temperature ranges from 38 to 46 degrees F with an average annual precipitation of 25 to 40 inches. The frost free period is from 50 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Agatha, Bobbitt, Helmer, Hugus, Santa and Tigley soils. Agatha soils are on northeast and northwest-facing terrace escarpments and canyonsides and have bedrock at depths of 20 to 40 inches. Bobbitt soils on south-facing canyon slopes are mesic and xeric. Helmer and Santa soils are on dissected terraces, have fragipans and are moderately well drained. Hugus soils are on north-facing toeslopes and dissected terraces and are loamy-skeletal. Tigley soils are on south-facing toeslopes and dissected terraces and are loamy-skeletal.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability.

USE AND VEGETATION: These soils are used for timber production, livestock grazing, hay and pasture, homesites, recreation, and wildlife habitat. Potential natural vegetation is western hemlock, western redcedar, grand fir, western larch, Douglas-fir, western white pine, and lodgepole pine with an understory of queencup beadlily, myrtle pachystima, bunchberry dogwood, goldthread, violet, common prince's pine, longtube twinflower, sedge, starry false-Solomon's seal, western rattlesnake plantain, American trailplant, and shinyleaf spirea.

DISTRIBUTION AND EXTENT: Northern Idaho. MLRA 43A. This soil is not extensive.

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

SERIES ESTABLISHED: St. Joe Area, Shoshone County, Idaho, 1993.

REMARKS: Diagnostic horizons and other features recognized in this pedon:

Ochric epipedon - the zone from 0 to 5 inches (Oi, Oe and A horizons).

Argillic horizon - the zone from 11 to 62 inches (Bt horizons).

Volcanic ash influence - the zone from 1.5 to 11 inches (A and Bw horizons)

Particle-size control section - the zone from 11 to 31 inches (Bt1 and part of the Bt2 horizon)

ADDITIONAL DATA: Partial laboratory data available for Soil Survey Sample Numbers: 91ID009-005, NSSL Pedon Number: 92P0278 and S03ID-009-008, Pedon Number: 04N0226, Benewah County, Idaho.

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National Cooperative Soil Survey
U.S.A.