LOCATION VASSAR ID+WA

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

VASSAR SERIES

The Vassar series consists of deep, well-drained soils that formed in volcanic ash overlying material weathered from granitic bedrock. Vassar soils are on mountains and have slopes of 5 to 75 percent. Saturated hydraulic conductivity is moderately high to 26 inches and high below this depth. The average annual precipitation is about 35 inches and the average annual air temperature is about 42 degrees F.

TAXONOMIC CLASS: Ashy over loamy, amorphic over isotic, frigid Typic Udivitrands

TYPICAL PEDON: Vassar ashy silt loam, forested, on a north-facing 55 percent slope at 3,500 feet elevation. (Colors are for dry soil unless otherwise noted.)

0i--0 to 1 inch; undecomposed coniferous needles and twigs.

0e--1 to 2 inches; dark gray (10YR 4/1) decomposed organic material, very dark brown (10YR 2/2) moist; common gray (10YR 6/1) splotches. (0 to 1.5 inches thick)

A--2 to 8 inches; yellowish brown (10YR 5/4) ashy silt loam, dark yellowish brown (10YR 3/4) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium roots; many very fine continuous tubular pores; few fine yellowish brown concretions; few pieces of charcoal; neutral (pH 6.6); clear smooth boundary. (0 to 6 inches thick)

Bw1--8 to 20 inches; light yellowish brown (10YR 6/4) ashy silt loam, brown (7.5YR 4/4) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium roots; many very fine continuous tubular pores; few fine yellowish brown concretions; few pieces of charcoal; neutral (pH 6.6); clear smooth boundary.

Bw2--20 to 26 inches; light yellowish brown (10YR 6/4) ashy silt loam, brown (7.5YR 4/4) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium roots; many very fine continuous tubular pores; many pieces of charcoal; slightly acid (pH 6.4); abrupt wavy boundary. (combined thickness of Bw horizons is 13 to 30 inches thick)

2C1--26 to 41 inches; pale brown (10YR 6/3) coarse sandy loam, brown (7.5YR 4/3) moist; massive; slightly hard; friable, slightly sticky and nonplastic; few very fine and fine roots; many fine continuous tubular pores; few pieces of charcoal; moderately acid (pH 5.8); abrupt irregular boundary. (10 to 20 inches thick)

2C2--41 to 55 inches; very pale brown (10YR 7/3) loamy coarse sand, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; few fine roots; many very fine continuous tubular pores; slightly acid (pH 6.4); abrupt wavy boundary. (10 to 20 inches thick)

2Cr--55 inches; weathered granite.

TYPE LOCATION: Latah County, Idaho; 540 feet east and 1,240 feet north of the southwest corner, sec. 13, T. 40 N., R. 4 W.; Latitude - 46 degrees, 48 minutes, 19 seconds North; Longitude - 116 degrees, 47 minutes, 24 seconds West; USGS Moscow Mountain Quadrangle.

RANGE IN CHARACTERISTICS:
Volcanic ash mantle - 14 to 36 inches thick
Thirty percent or more by weight is between 0.02 and 2.0 mm and the volcanic glass in the 0.02 to 2.0 mm fraction - 30 to 60 percent
Acid-oxalate extractable Al plus 1/2 Fe - 1.0 to 3.0 percent
Phosphate retention - 25 to 90 percent
15-bar water retention on air dried samples - 9 to 12 percent
Average annual soil temperature - 38 to 46 degrees F.
Frigid temperature regime.
Soil moisture regime - not dry for 45 consecutive days during 4 months that follow summer solstice.
Udic moisture regime.
Depth to paralithic contact - 40 to 60 inches

A horizon
Hue - 7.5YR or 10YR
Value - 3 to 5 dry, 2 or 3 moist
Chroma - 2 to 4, dry or moist
Rock fragments - 0 to 15 percent gravel
Texture - ashy silt loam, ashy loam, or ashy very fine sandy loam
Clay content - 6 to 10 percent
Reaction - 5.6 to 7.3
Bulk density - 0.60 to 0.90 g/cc

E horizon - present in some pedons

Bw horizon
Hue - 7.5YR or 10YR
Value - 3 to 7 dry, 3 or 4 moist
Chroma - 2 to 4 dry, 3 to 6 moist
Rock fragments - 0 to 15 percent gravel
Texture - ashy silt loam, ashy loam, or ashy very fine sandy loam
Clay content - 4 to 15 percent
Reaction - 5.0 to 7.3
Bulk density - 0.59 to 1.24 g/cc

2Bw horizons (present in some pedons)
Hue - 7.5YR or 10YR
Value - 5 to 8 dry, 3 to 6 moist
Chroma - 3 or 4 dry, 3 to 6 moist
Textures - loam, fine sandy loam, sandy loam or coarse sandy loam
Clay content - 8 to 25 percent
Rock fragments - 0 to 30 percent gravel, 0 to 10 percent cobbles, 0 to 30 percent total rock fragments
Reaction - 5.0 to 6.3

2BC horizon (present in some pedons)
Hue - 7.5YR or 10YR
Value - 5 to 8 dry, 4 or 5 moist
Chroma - 4 to 6 dry, 3 to 6 moist
Textures - sandy loam, coarse sandy loam or loamy sand
Clay content - 5 to 12 percent
Coarse fragments - 10 to 25 percent gravel
Reaction - 5.0 to 6.3

2C horizon
Hue - 7.5YR to 2.5Y
Value - 5 to 8 dry, 4 to 6 moist
Chroma - 2 to 4 dry, 2 to 6 moist
Coarse fragments - 0 to 50 percent gravel, 0 to 15 percent cobbles, 0 to 10 percent stones, 0 to 50 percent total rock fragments
Reaction - 5.1 to 6.3

COMPETING SERIES: These are the Dullaxe, Flewsie and Gorhamgulch series.

Flewsie (ID) - are very deep
Dullaxe (ID) - are very deep to a paralithic contact
Gorhamgulch (OR) - have an ash mantle with more than 60 percent volcanic glass and have 2Eb horizons

GEOGRAPHIC SETTING: Vassar soils are on mountains and have slopes of 5 to 65 percent. Elevations range from 1,600 to 5,200 feet. They occur on northerly aspects at lower elevations. The soils formed in loess and volcanic ash overlying material weathered from granite, gneiss, or schist. The average annual precipitation is 30 to 45 inches and the average annual air temperature is 38 to 45 degrees F. The frost-free season is 50 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ardenvoir, Threebear, Moscow, and Vay soils. Ardenvoir and Vay soils have more than 35 percent coarse fragments in the lower part. Threebear soils have a fragipan. Moscow soils are 20 to 40 inches to bedrock.

DRAINAGE AND PERMEABILITY: Well-drained; rapid to very rapid runoff; Saturated hydraulic conductivity is moderately high to 26 inches and high below this depth.

USE AND VEGETATION: Used mainly for timber production, watershed, wildlife habitat, and recreation. A few areas are used for limited livestock grazing. The principal vegetation is western redcedar, western white pine, grand fir, western larch, Douglas-fir, with an understory of myrtle pachystima, northern twinflower, goldthread, and queenscup beadlily.

DISTRIBUTION AND EXTENT: Northern Idaho and eastern Washington. The soils are extensive. MLRA 43A.

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

SERIES ESTABLISHED: Latah County, Idaho, 1939.

REMARKS: Revision of 10/2002 changed the classification from Ashy over loamy, mixed Typic Vitricryands to Ashy over loamy, amorphic over isotic Typic Vitricryands.

Revision of 10/2012 changes the classification from Ashy over loamy, amorphic over isotic Typic Vitricryands to Ashy over loamy, amorphic over isotic, frigid Typic Udivitrands after an investigation of Vassar across its extent. Depth class also changed from deep and very deep to deep. Areas of Vassar that are very deep (primarily in Kootenai County) should be investigated further to determine proper series assignment and parent material (parent material in ID606 is metamorphic).

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 8 inches (Oi, Oe and A horizons)
Cambic horizon - the zone from 8 to 26 inches (Bw1 and Bw2 horizons)
Particle-size control section - 2 to 42 inches (A, Bw1, Bw2, 2C1, and part of the 2C2 horizons)
Andic soil properties - the zone from 2 to 26 inches (A, Bw1 and Bw2 horizons)
Paralithic contact - the zone below 55 inches (2Cr horizon)

Additional Data: Laboraory data are available for this series: NSSL pedon ID S08ID057003, Pedon No. 09N0077, from Latah County, Idaho, and NSSL pedon ID S04ID057008, Pedon No. 05N0161 from Latah County, Idaho.

National Cooperative Soil Survey
U.S.A.