LOCATION ENSON              WA
Established Series
Rev. BJD/TDT
07/2005

ENSON SERIES


The Enson series consists of moderately deep to a densic contact, well drained soils formed in till from granitic rock with a component of volcanic ash in the upper part. These soils are on footslopes and backslopes of glaciated mountains. Slopes are 15 to 35 percent. The average annual precipitation is about 22 inches and the average annual temperature is about 42 degrees F.

TAXONOMIC CLASS: Coarse-loamy, isotic, frigid Vitrandic Haploxerepts

TYPICAL PEDON: Enson ashy sandy loam, on a southeast facing 15 percent slope at an elevation of 3,690 feet in a Douglas-fir, ponderosa pine forest. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)

Oe--0 to 2 inches; moderately decomposed needles, leaves, and twigs; abrupt smooth boundary. (1 to 2 inches thick)

A--2 to 5 inches; light brownish gray (10YR 6/2) ashy sandy loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium and coarse roots; common very fine and fine tubular pores; 5 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (3 to 5 inches thick)

Bw1--5 to 8 inches; pale brown (10YR 6/3) ashy sandy loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and few medium and coarse roots; common very fine and fine tubular pores; 5 percent gravel; slightly acid (pH 6.2); clear wavy boundary.

Bw2--8 to 17 inches; pale brown (10YR 6/3) ashy sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and few medium and coarse roots; common very fine and fine tubular pores; 5 percent gravel; slightly acid (pH 6.2); clear smooth boundary. (combined Bw horizon thickness is 9 to 13 inches)

2C--17 to 35 inches; light gray (10YR 7/2) gravelly sandy loam, light brownish gray (10YR 6/2) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine and few medium roots; common very fine and fine irregular pores; common medium and coarse masses of dark yellowish brown (10YR 4/4) moist volcanic ash; 15 percent gravel and 3 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (14 to 18 inches thick)

2Cd1--35 to 46 inches; light gray (10YR 7/2) gravelly loamy sand, light brownish gray (10YR 6/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few fine roots; few very fine irregular pores; 25 percent gravel and 3 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (9 to 13 inches thick)

2Cd2--46 to 62 inches; light yellowish brown (10YR 6/4) very gravelly loamy sand, yellowish brown (10YR 5/4) moist; massive; hard, very friable, nonsticky and nonplastic; few very fine roots; thin layers of yellowish brown (10YR 5/6) moist stains; 30 percent grvel and 5 percent cobbles; slightly acid (pH 6.4).

TYPE LOCATION: Okanogan County, Washington, about 15 miles west of Okanogan, WA; 500 feet east and 2,300 feet south of the northwest corner of section 24, T. 33 N., R. 23 E. (Latitude 48 degrees, 20 minutes, 43 seconds N., Longitude 119 degrees, 54 minutes, 19 seconds W.)

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 42 to 45 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 60 to 75 consecutive days following the summer solstice. Thickness of the volcanic ash influence is 12 to 16 inches, and has an estimated moist bulk density of 1.10 to 1.30 g/cc, volcanic glass content of 5 to 20 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.4 to 1.0 percent, and 15 bar water retention of 5 to 10 percent for air dried samples. The particle-size control section averages 15 to 35 percent rock fragments and 3 to 8 percent clay. Depth to the densic contact is 20 to 40 inches. Reaction is slightly acid to neutral throughout.

The A horizon has values of 3 or 4 moist, and chromas of 2 or 3 dry or moist.

The Bw horizon has values of 3 or 4 moist, and chromas of 3 or 4 dry or moist. It is ashy sandy loam or gravelly ashy sandy loam. It has 5 to 20 percent gravel.

The 2C horizon has values of 6 or 7 dry, 5 or 6 moist, and chromas of 2 or 3 dry or moist. It has 15 to 25 percent gravel and 0 to 5 percent cobbles.

The 2C horizon has values of 6 or 7 dry, 5 or 6 moist, and chromas of 2 or 3 dry or moist. It is gravelly sandy loam or gravelly loamy sand. It has 15 to 30 percent gravel and 0 to 5 percent cobbles.

The 2Cd horizon has hues of 10YR or 2.5Y, values of 6 or 7 dry, 5 or 6 moist, and chromas of 2 to 4 dry or moist. It is very gravelly loamy sand or gravelly loamy sand. It has 15 to 30 percent gravel and 0 to 5 percent cobbles.

COMPETING SERIES: These are the Ardenmont, Labuck, and Stapaloop series. Stapaloop soils have fine sandy loam and very fine sandy loam textures throughout. Yocridge soils are 20 to 40 inches to a lithic contact. Ardenmont soils are deep to a paralithic contact. Labuck soils are moderately deep to a paralithic contact. Stapaloop soils lack the densic contact.

GEOGRAPHIC SETTING: Enson soils are on footslopes and backslopes of glaciated mountains. Elevations range from 2,400 to 4,000 feet. Slopes are 15 to 35 percent. These soils formed in till from granitic rock with a component of volcanic ash in the upper part. The climate is characterized by warm, dry summers and cool, wet winters. The average annual precipitation ranges from 20 to 24 inches. The average January temperature ranges from 22 to 26 degrees F; the average July temperature ranges from 62 to 67 degrees F; and the average annual air temperature ranges from 40 to 44 degrees F. The frost-free season is 90 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Merkel, Pebcreek, and Watony series. Merkel soils are on footslopes and backslopes and are loamy-skeletal. Pebcreek soils are on more northerly aspects and are sandy-skeletal. Watony soils are on southerly aspects, with little volcanic ash influence.

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

USE AND VEGETATION: Timber production, wildlife habitat, watershed, recreation, and livestock grazing. Native vegetation is Douglas-fir and ponderosa pine, with an understory of pinegrass, silky lupine, heartleaf arnica, and shinyleaf spirea.

DISTRIBUTION AND EXTENT: Northcentral Washington; MLRA 6. The series is of small extent.

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

SERIES ESTABLISHED: Okanogan National Forest, Okanogan County, Washington, 2005.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Cambic horizon - 3 to 15 inches (Bw horizon)
PSCS - zone from 10 to 35 inches (part of the Bw2 and the 2C horizons.)
Vitrandic properties from 0 to 15 inches.
Densic contact at 35 inches

ADDITIONAL DATA: S97WA-047-004 for type location.


National Cooperative Soil Survey
U.S.A.