LOCATION STIEN ID+WA

Established Series
Rev. JCC-RWL-RJS
10/2016

STIEN SERIES

The Stien series consists of very deep, well drained soils on glacial moraines and outwash terraces. They formed in glacial outwash and drift with a thick mantle of volcanic ash. Permeability is moderate in the upper part and very rapid below. Slope ranges from 0 to 20 percent. The average annual precipitation is about 28 inches and average annual air temperature is about 43 degrees F.

TAXONOMIC CLASS: Ashy-skeletal over loamy-skeletal, aniso, glassy over isotic, frigid Typic Vitrixerands

TYPICAL PEDON: Stien gravelly ashy silt loam, forested; on a 3 percent slope at 2,800 feet elevation. When described on October 25, 1972, the soil was moist. Pedon was redescribed on August 14, 1994. (Colors are for dry soil unless otherwise stated.)

0i--0 to 1 inch; needles, leaves, and twigs. (0 to 1.5 inches thick)

0e--1 to 2 inches; partly decomposed needles, leaves, and twigs. (0.5 to 1 inch thick)

A--2 to 3 inches; dark grayish brown (10YR 4/2) gravelly ashy silt loam, very dark brown (10YR 2/2) moist; weak very fine and fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine pores; 20 percent gravel; slightly acid (pH 6.2); abrupt wavy boundary. (1 to 3 inches thick)

Bw1--3 to 6 inches; light yellowish brown (10YR 6/4) gravelly ashy silt loam, dark brown (7.5YR 3/4) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many fine and medium roots; many very fine pores; 25 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (3 to 6 inches thick)

Bw2--6 to 17 inches; light yellowish brown (10YR 6/4) very gravelly ashy silt loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common fine and medium roots; many very fine pores; 55 percent gravel, 5 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (Combined thickness of the Bw horizon is 13 to 21 inches)

2BC--17 to 27 inches; very pale brown (10YR 7/4) extremely cobbly sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; loose, nonsticky and nonplastic; few fine roots; many fine pores; 35 percent gravel, 50 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (7 to 17 inches thick)

3C--27 to 60 inches; very pale brown (10YR 7/3) extremely cobbly coarse sand, yellowish brown (10YR 5/4) moist; single grain; loose, nonsticky and nonplastic; very porous; 40 percent gravel, 30 percent cobbles; slightly acid (pH 6.5).

TYPE LOCATION: Boundary County, Idaho; near Robinson Lake, about 900 feet north of the center of section 21, T. 65 N., R. 2 E.; Latitude - 48 degrees, 58 minutes, 24 seconds North; Longitude - 116 degrees, 12 minutes, 34 seconds West; USGS Eastport Quadrangle.

RANGE IN CHARACTERISTICS:
Moisture control section - dry 45 to 60 days (August to September), moist October through July
Average annual soil temperature - 43 to 46 degrees F.
Average summer soil temperature - 54 to 56 degrees F. with an O horizon
Surface cobbles - 0 to 3 percent
Very thin volcanic ash layer - present in most undisturbed pedons between the organic and upper mineral layer
Volcanic ash mantle - 14 to 24 inches thick
Volcanic glass content - 30 to 65 percent
Acid-oxalate extractable Al + 1/2 Fe - 1.0 to 3.0 percent
Phosphate retention - 55 to 90 percent
15 bar water (air dried) - 7 to 12 percent

A horizon
Value - 4 to 6 dry, 2 to 4 moist
Chroma - 2 or 3 dry or moist
Texture - GR-Ashy-SIL, CB-ASHY-SIL, ASHY-SIL
Clay content - 3 to 10 percent
Rock fragments - 0 to 30 percent
Bulk density - 0.65 to 0.85 g/cc
Reaction - slightly acid or neutral

Bw horizons
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 4 or 6 dry or moist
Texture - GR-ASHY-SIL, CB-ASHY-SIL, ASHY-SIL, ASHY-VFSL upper part, GRV-ASHY-SIL, CBV-ASHY-SIL, STV -ASHY SIL, GRX-ASHY-SIL lower part
Clay content - 3 to 10 percent
Rock fragments - 10 to 30 percent upper part, 35 to 65 percent lower part, averages greater than 35 percent
Bulk density - 0.65 to 0.85 g/cc
Reaction - slightly acid or neutral

A 2Bw horizon is present in some pedons

2BC horizon
Hue - 10YR or 2.5Y
Value - 5 to 7 dry, 3 to 6 moist
Chroma - 3 to 6 dry or moist
Texture - CBX-SL, CBV-SL, GRV-SL, GRX-SL, GRV-LS, STV-LS, STX-LS
Clay content - 3 to 8 percent
Rock fragments - 45 to 85 percent
Reaction - strongly acid to slightly acid

3C horizon
Hue - 10YR, 2.5Y or variegated
Value - 6 or 7 dry, 4 to 6 moist
Chroma - 3 or 4 dry or moist
Texture - GRX-COS, CBX-S, CBX-LS, GRX-LS, CBX-COS
Clay content - 0 to 3 percent
Rock fragments - 65 to 80 percent
Reaction - strongly acid to slightly acid

COMPETING SERIES: There are no competing series. Series with a similar ashy-skeletal family include the Doe (T), Grenet, Kusu, Natkin (T), Pettijohn (T), Roundknoll, Stices, Twelvemile, and Yallani series. Doe soils have coarse sandy loam textures in the A and Bw horizons. Natkin soils have 2Bw horizons and have sandy loam textures in the 2C horizon. Pettijohn, and Twelvemile soils have fine sandy loam textures in the A and Bw horizons. Grenet soils have a paralithic contact at 20 to 40 inches. Kusu soils have a lithic contact at 40 to 60 inches. Roundknoll soils have loamy sand textures in the A and Bw horizons. Stices and Yallani soils have loam textures in the A and Bw horizons.

GEOGRAPHIC SETTING: Stien soils are on glacial moraines and outwash terraces and outwash plains. Slopes range from 0 to 30 percent. These soils formed in glacial outwash and drift with a thick mantle of volcanic ash. Elevations range from 1,700 to 2,800 feet. The climate is subhumid with cold wet winters and warm dry summers. The average annual precipitation is 22 to 32 inches and average annual air temperature is 42 to 45 degrees F. The average frost-free period is 90 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pend Oreille and Seelovers soils. Pend Oreille soils are on glaciated foothills and are ashy over loamy. Seelovers soils are on low stream terraces and valley bottoms, and have mollic epipedons and are poorly drained.

DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability in the upper part and very rapid below.

USE AND VEGETATION: These soils are used mainly for woodland, wildlife habitat, and recreation. Some areas are used for the production of wheat, barley, oats, hay and pasture. Natural vegetation is mainly Douglas-fir, ponderosa pine, lodgepole pine, and western larch, with an understory of pine reedgrass, white spirea, baldhip rose, common snowberry, Saskatoon serviceberry, low Oregongrape, strawberry, and Oregon fairybells. Moist phases have a grand fir-twinflower plant community.

DISTRIBUTION AND EXTENT: Northern Idaho, northeastern Washington, and possibly northwestern Montana. The series is not extensive.

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

SERIES ESTABLISHED: Boundary County, Idaho, 1974.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 7 inches (Oi, Oe, A, Bw1 and part of Bw2 horizons)
Cambic horizon - the zone from 3 to 17 inches (Bw1 and Bw2 horizons)
Volcanic ash mantle - the zone from the mineral soil surface to 17 inches (A, Bw1 and Bw2 horizons)
Particle-size control section - the zone from 2 to 42 inches (A, Bw1, Bw2, 2BC and part of the 3C horizon) with the zone from 2 to 6 inches qualifying as ashy, from 6 to 17 inches qualifying as ashy-skeletal, from 17 to 27 inches qualifying as loamy-skeletal, and from 27 to 42 inches qualifying as sandy or sandy-skeletal.

Classification change 03/2000 from medial-skeletal, frigid Typic Vitrandepts to ashy-skeletal, mixed, frigid Typic Vitrixerands.
Classification revised 3/04 from Ashy-skeletal, glassy, frigid Typic Vitrixerands to Ashy-skeletal over loamy-skeletal, glassy over isotic, aniso, frigid Typic Vitrixerands based on the 9th edition of Keys to Taxonomy.

National Cooperative Soil Survey
U.S.A.