LOCATION YELM                    WA

Established Series
Rev: BAL/MPR/TDT
05/2012

YELM SERIES

The Yelm series consists of very deep, moderately well drained soils formed in glacial outwash. They are in relict glacial lacustrine lakes and drainageways on terraces. Slopes are 0 to 30 percent. The mean annual precipitation is about 1,150 millimeters and the mean annual air temperature is about 9.4 degrees C.

TAXONOMIC CLASS: Coarse-loamy, isotic, mesic Aquic Dystroxerepts

TYPICAL PEDON: Yelm very fine sandy loam, forest. (Colors are for dry soil unless otherwise stated.)

Oi--0 to 5 cm; slightly decomposed plant material; abrupt smooth boundary. (0 to 15 cm thick)

A--5 to 17 cm; brown (7.5YR 5/3) very fine sandy loam, dark brown (7.5YR 3/2) moist; moderate fine and medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; many very fine to medium and few coarse roots; common very fine and fine irregular pores; very strongly acid ( pH 5.0); clear wavy boundary. (5 to 20 cm thick)

Bw1--17 to 34 cm; brown (7.5YR 4/4) very fine sandy loam, dark brown (7.5YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky, nonplastic; many very fine to medium and few coarse roots; common very fine interstitial pores; moderately acid (pH 5.7); clear wavy boundary.

Bw2--34 to 58 cm; light brownish gray (2.5Y 6/2) very fine sandy loam, grayish brown (2.5Y 5/2) moist; massive; soft, very friable; nonsticky, nonplastic; common fine and few medium and coarse roots; common very fine interstitial pores; moderately acid (pH 5.9); clear wavy boundary. (Combined thickness of Bw horizons is 40 to 80 cm thick)

Bg--58 to 110 cm; light yellowish brown (2.5Y 6/4) very fine sandy loam, light olive brown (2.5Y 5/4) moist; massive; slightly hard, very friable, nonsticky, nonplastic; few fine and medium roots; common very fine interstitial pores; 10 percent fine irregular strong brown (7.5YR 5/6), and strong brown (7.5YR 4/6), moist, iron-manganese masses and 20 percent fine light gray (2.5Y 7/1), and dark grayish brown (2.5Y 4/2), moist, iron depletions; moderately acid, (pH 5.7); gradual wavy boundary. (75 to 100 cm thick)

Cg--110 to 150 cm; light yellowish brown (2.5Y 6/4) very fine sandy loam, light olive brown (2.5Y 5/4) moist; massive; soft, very friable, nonsticky, nonplastic; common very fine and few fine and medium roots; common very fine interstitial pores; 20 percent fine light gray (2.5Y 7/1), and dark grayish brown (2.5Y 4/2), moist, iron depletions; moderately acid (pH 5.6).

TYPE LOCATION: Thurston County, Washington, about 6 km south of Dupont, Joint Base Lewis-McChord; Yelm Prairie, Washington USGS quadrangle; 46 degrees, 55 minutes, 9.80 seconds north latitude and 122 degrees, 40 minutes, 7.90 seconds west longitude; UTM 525181 meters E, 5203669 meters N, zone 10 NAD83.

RANGE IN CHARACTERISTICS:

Mean annual soil temperature - 8.9 to 10 degrees C
Moisture control section - dry 45 to 60 days following the summer solstice
Depth to redoximorphic features - 50 to 100 cm
Reaction - very strongly acid to slightly acid
Particle size control section:
Clay content - 1 to 17 percent
Rock fragments -0 to 10 percent gravel

A horizon
Hue - 7.5YR or 10YR
Value - 3 or 5 moist or dry
Chroma - 2 or 4 moist and dry
Texture - very fine sandy loam of fine sandy loam
Rock fragment content - 0 to 10 percent gravel

Bw horizon (upper part)
Hue -10YR or 7.5YR
Value - 3 to 5 moist and 4 through 7 dry
Chroma - 2 to 4 moist and dry
Structure: weak fine subangular blocky or stronger
Texture - very fine sandy loam, fine sandy loam, loamy sand or sandy loam
Rock fragment content - 0 to 10 percent gravel

Bw horizon (lower part)
Hue - 2.5Y, 10YR, or 7.5YR
Value - 3 to 5 moist and 4 through 7 dry
Chroma - 2 to 4 moist and dry
Texture - very fine sandy loam, fine sandy loam, loamy sand or sandy loam
Rock fragment content - 0 to 10 percent gravel

Bg horizon
Hue - 2.5Y or 10YR,
Value - 3 to 5 moist and 4 through 7 dry
Chroma - 2 to 4 moist and dry
Texture - very fine sandy loam, fine sandy loam, loamy sand or sandy loam
Rock fragment content - 0 to 10 percent gravel

Cg horizon
Hue - 5Yor 2.5Y
Value - 4 to 7 moist and dry
Chroma - 2 to 4 moist and dry
Texture - stratified very fine sandy loam, fine sandy loam, loamy sand, sandy loam, fine sand or silt loam
Rock fragment content - 0 to 5 percent gravel

COMPETING SERIES: These are the Elwha and Roche series. The Elwha soils have a densic horizon between 50 and 100 cm and are dry in the moisture control section for 60 to 75 days following. Roche soils have a densic horizon between 50 and 100 cm and are dry in the moisture control section for 60 to 90 days following.

GEOGRAPHIC SETTING: Yelm soils are on glacial outwash terraces at elevations of 10 to 100 meters. Slopes are 0 to 30 percent. These soils formed in sandy glacial outwash. Yelm soils are in a marine climate with cool, dry summers and mild, wet winters. The mean annual precipitation is 1,067 to 1,219 mm. Mean January temperature is 2 degrees C; mean July temperature is 24 degrees C. Mean annual air temperature is about 9.4 degrees C. The frost-free season is 170 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Steilacoom, Everett, and McChord series. The Everett and McChord series are on convex glacial features such as kames, eskers, and till plains. Everett soils are sandy-skeletal. and McChord soils are loamy-skeletal. Steilacoom soils are in concave areas of relict glacial lakes and drainageways and are coarse-silty.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained; slow to medium runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Used mostly for woodland and wildlife habitat. Native vegetation consisted of Douglas-fir, red alder, western redcedar and bigleaf maple with an understory of salal, Oregon-grape, trailing blackberry, red huckleberry, western brackenfern, western swordfern, salmonberry and vine maple.

DISTRIBUTION AND EXTENT: Western Washington; MLRA 2. The series is of small extent.

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

SERIES ESTABLISHED: Thurston County, Washington, 1982.

REMARKS: Typical pedon moved and classification changed in 10/2011 from Ashy, amorphic, acid, mesic Typic Vitraquands to Coarse-loamy, isotic, mesic Aquic Dystroxerepts based on insufficient glass percentages and chemical data to support andic properties.

Diagnostic horizons and features include:
Ochric epipedon
Cambic horizon -17 to 34 cm
Aquic feature -58 to 150 cm.

ADDITIONAL DATA: NSSL pedon S09WA067061

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National Cooperative Soil Survey
U.S.A.