LOCATION DIGIT                   OR

Established Series
Rev. RJO/DAL
10/2012

DIGIT SERIES

The Digit series consists of very deep, well drained soils on alluvial terraces and in swales on valleys of mountains and dissected plateaus. Digit soils are formed in volcanic ash overlying alluvium from basalt. Slopes are 0 to 30 percent. The mean annual precipitation is about 38 inches and the mean annual temperature is about 40 degrees F.

TAXONOMIC CLASS: Ashy over loamy, amorphic over isotic Typic Vitricryands

TYPICAL PEDON: Digit ashy silt loam, woodland, on a 0 percent slope at an elevation of 5340 feet. (Colors are for moist soil unless otherwise noted.)

Oi--0 to 1 inches; needles and twigs.

A--1 to 7 inches; very dark brown (7.5YR 2.5/2) ashy silt loam, brown (7.5YR 4/3) dry; moderate fine granular structure; hard, very friable, slightly sticky and slightly plastic; many fine, common medium and few coarse roots; common fine and few medium irregular pores; moderately acid (pH 6.0); clear smooth boundary. (1 to 8 inches thick)

Bw1--7 to 16 inches; dark brown (7.5YR 3/4) ashy silt loam, brown (7.5YR 5/4) dry; weak fine and very fine subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common fine and coarse, and many medium roots; few fine tubular pores; slightly acid (pH 6.5); abrupt wavy boundary. (9 to 19 inches thick)

Bw2--16 to 22 inches; brown (7.5YR 4/4) ashy silt loam, light brown (7.5YR 6/4) dry; moderate fine and medium angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and few medium roots; common fine tubular pores; neutral (pH 6.7); abrupt wavy boundary. (0 to 9 inches thick)

2Eb--22 to 35 inches; dark brown (7.5YR 3/4) silt loam, brown (7.5YR 5/4) dry; weak fine and very fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few fine and medium roots; common fine and few medium tubular pores; neutral (pH 6.6); clear wavy boundary. (4 to 13 inches thick)

2Bwb--35 to 46 inches; dark brown (7.5YR 3/3) sandy clay loam, brown (7.5YR 4/4) dry; weak very fine subangular blocky structure; slightly hard, firm, moderately sticky and slightly plastic; few fine roots; few fine irregular and few fine tubular pores; slightly acid (pH 6.4); gradual smooth boundary. (9 to 21 inches thick)

2BC--46 to 62 inches; dark brown (7.5YR 3/3) sandy clay loam, dark brown (7.5YR 3/4) dry; massive; slightly hard, firm, moderately sticky and slightly plastic; few fine tubular pores; slightly acid (pH 6.4).

TYPE LOCATION: Wallowa County, Oregon, Section 35, T. 4 S., R. 46 E.UTM: zone 11, Northing: 5001836; Easting: 497206
Latitude: 45 degrees, 10 minutes, 12 seconds N
Longitude: 117 degrees, 02 minutes, 08 seconds W
USGS Quadrangle: Lick Creek

RANGE IN CHARACTERISTICS:

Soil Temperature: cryic regime
Mean Annual Soil Temperature: 39 to 44 degrees F
Mean Summer Soil Temperature: 42 to 47 degrees F
Mean Winter Soil Temperature: 32 to 37 degrees F
Soil Moisture: udic regime, dry 30 to 45 days in summer

Particle-size Control Section: mineral soil surface to 40 inches below the mineral surface
Upper part (ashy): 18 to 28 inches thick
Clay content: 6 to 9 percent
Rock fragment content: 0 to 20 percent
Lower part (loamy): 12 to 22 inches thick
Clay content: 10 to 24 percent
Rock fragment content: 0 to 30 percent
Rock fragment shape: subrounded or rounded

Diagnostic Horizons and Features:
andic soil properties: upper boundary at the mineral soil surface; 18 to 28 inches thick
Al+1/2Fe(aox): 1.5 to 3.0 percent
bulk density: 0.65 to 1.00 g/cc
P retention: 60 to 90 percent
0.02-2.0 mm fraction: 50 to 70 percent of fine earth
glass content in the 0.02-2.0 mm fraction: 60 to 90 percent
water content at 1500 kPa tension (air dried): 5 to 12 percent
8Si + 2Fe(aox): 5 to 12 percent
8Si - 2Fe(aox): 4 to 8 percent
ochric epipedon: 1 to 8 inches thick
cambic horizon (upper): 17 to 24 inches thick
cambic horizon (buried): 9 to 21 inches thick
lithic contact depth: more than 60 inches

Major Horizons:
A horizon
color, moist: 7.5YR 2.5/1, 2.5/2, 3/2; 10YR 2/1, 2/2
color, dry: 7.5YR 4/3; 10YR 4/2, 5/2, 5/3
texture: ASHY-SIL
clay content: 6 to 12 percent
rock fragment content: 0 to 15 percent
gravel: 0 to 15 percent
reaction: moderately acid or slightly acid; pH: 5.6 to 6.5
base saturation (sum of bases): 25 to 50 percent
organic carbon: 1 to 6 percent

Bw1 horizon
color, moist: 7.5YR 3/3, 3/4; 10YR 3/4, 4/2, 4/4
color, dry: 7.5YR 5/4; 10YR 5/3, 5/4, 6/3, 6/4
texture: ASHY-SIL, GR-ASHY-SIL
clay content: 6 to 8 percent
rock fragment content: 0 to 20 percent
gravel: 0 to 20 percent
reaction: moderately acid to slightly acid, pH: 5.6 to 6.5
base saturation (sum of bases): 15 to 35 percent
organic carbon: 0.6 to 1.7 percent

Bw2 horizon
color, moist: 7.5YR 4/4; 10YR 5/4, 5/6
color, dry: 7.5YR 6/4; 10YR 7/3, 7/4
texture: ASHY-SIL
clay content: 5 to 8 percent
rock fragment content: 0 to 5 percent
gravel: 0 to 5 percent
reaction: slightly acid or neutral, pH: 6.1 to 7.3
base saturation (sum of bases): 15 to 35 percent
organic carbon: 0.6 to 1.7 percent

2Eb horizon (2Ab in some pedons)
color, moist: 7.5YR 3/2, 3/3, 3/4, 4/3; 10YR 3/3, 4/2
color, dry: 7.5YR 5/3, 5/4; 10YR 5/2, 5/3, 6/2
texture: L, SIL, SL, GR-SIL
clay content: 6 to 22 percent
rock fragment content: 0 to 25 percent
gravel: 0 to 20 percent
cobbles: 0 to 5 percent
reaction: slightly acid or neutral, pH: 6.1 to 7.3
base saturation (sum of bases): 60 to 80 percent

2Bwb horizon
color, moist: 7.5YR 3/2, 3/3, 4/3; 10YR 4/4
color, dry: 7.5YR 4/4, 5/3; 10YR 5/3, 5/4, 6/2, 6/4
texture: GR-SIL, SCL, SIL, CL, GR-L
clay content: 12 to 30 percent
rock fragment content: 0 to 35 percent
gravel: 0 to 30 percent
cobbles: 0 to 10 percent
stones: 0 to 5 percent
reaction: slightly acid or neutral, pH: 6.1 to 7.3
base saturation (sum of bases): 70 to 90 percent

2BC horizon (2C in some pedons)
color, moist: 7.5YR 3/3, 3/4, 4/4; 10YR 3/3, 3/4
color, dry: 7.5YR 3/4, 4/3, 5/4; 10YR 5/4, 6/4
texture: L, CL, SCL, GR-CL, CBV-SIL, CBX-L, CBX-SL
clay content: 8 to 34 percent
rock fragment content: 0 to 70 percent
gravel: 0 to 35 percent
cobbles: 0 to 25 percent
stones: 0 to 20 percent
reaction: slightly acid to neutral; pH: 6.1 to 7.3
base saturation (sum of bases): 70 to 90 percent

COMPETING SERIES:

Hoffer - deep and very deep (40 to 80 inches) to a paralithic contact of weathered bedrock; ashy part of the pscs is ashy silt loam with 0 to 10 percent gravel and cobbles, has 1.5 to 3.0 percent ammonium oxalate extractable Al plus Fe, 60 to 90 percent glass and 60 to 90 percent phosphate retention; loamy part of pscs averages 2 to 8 percent clay, and 0 to 25 percent subrounded gravel; formed in ash over colluvium and residuum from granite or granodiorite
Spexarth - moderately deep (24 to 40 inches) to a paralithic contact of soft sandstone; ashy part of pscs is ashy sandy loam with 20 to 70 percent soft sandstone pararock in Bw horizons; loamy part of pscs is sandy loam or loam averages 5 to 15 percent clay with 0 to 20 percent gravel, 50 to 60 percent paragravel and 0 to 10 percent paracobble; formed in ash mixed with colluvium and residuum from sandstone and siltstone.
Spukwush - very deep, (60 inches or more) to a paralithic contact of highly weathered tuff; texture of the ash mantle is ashy loamy sand with 5 to 30 percent pumice and cinders; has spodic Bs horizons and glassy family mineralogy; lower part of particle-size control section averages 18 to 27 percent clay; formed in ash, pumice and cinders over weathered tuffaceous material.
Tusip - deep (40 to 60 inches) to a paralithic contact of weathered sandstone; ashy part of the pscs is ashy sandy loam or ashy loamy sand with 5 to 10 percent hard cinders; has spodic Bs horizons and glassy family mineralogy; loamy part of pscs is gravelly sandy loam or gravelly fine sandy loam, and averages 10 to 18 percent clay and 15 to 30 percent gravel; formed in ash, pumice and cinders over colluvium and residuum from sandstone.
Vassar - deep and very deep (> 40 inches) to a paralithic contact of weathered bedrock; ashy part of the pscs is ashy silt loam, has 0.4 to 1.0 percent ammonium oxalate extractable Al plus Fe, 40 to 70 percent glass and 25 to 50 percent phosphate retention; loamy part of pscs averages 2 to 10 percent clay and 0 to 35 percent angular rock fragments; formed in ash over colluvium and residuum from granite, gneiss or schist

GEOGRAPHIC SETTING:
Landform: alluvial terraces and shallow depressions, on valley floors, in mountains and on dissected plateaus
Slope gradient: 0 to 30 percent
Parent material: volcanic ash overlying mostly alluvium and some colluvium from basalt
Lithology: basalt
Elevation: 4,500 to 6,000 feet
Climate: cold, wet winters and warm, dry summers
Mean annual precipitation: 35 to 40 inches
Mean annual temperature: 37 to 42 degrees F.
Frost-free period: 30 to 75 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Pachic Haplocryolls-associated with open meadows with a mollic surface;
Typic Cryaquents-in association with channels and flood plains without an ash mantle;
Bucketlake-on terrace positions with loamy-skeletal materials below the ash mantle
Typic Cryaqolls-on adjacent flood plains with non-forest herbaceous cover, coarse-loamy without an ash mantle.

DRAINAGE AND PERMEABILITY:
Drainage: well drained
Permeability: moderate

USE AND VEGETATION:
Use: watershed, wildlife habitat, timber production, and recreation
Native vegetation: subalpine fir, Englemann spruce, western larch, grand fir, lodgepole pine, longtube twinflower, thinleaf huckleberry, grouse whortleberry, Utah honeysuckle, roundleaf violet, skunkleaved polemonium, bluebells and pinegrass
Ecological site: ABLA/LIBOL2 but may include PICO(ABLA)/VASC/POPU3 or ABLA/VAME.

DISTRIBUTION AND EXTENT:
Distribution: MLRA 43C; Blue and Seven Devils Mountains
Extent: small

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

SERIES ESTABLISHED: Wallowa-Whitman National Forests, Oregon, 2012

REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon 1 to 7 inches A
cambic horizon 7 to 22 inches Bw1, Bw2
particle-size control section
ashy part 1 to 22 inches A, Bw1, Bw2
loamy part 22 to 41inches 2Eb, 2Bw

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National Cooperative Soil Survey
U.S.A.