LOCATION DISAPPOINT              AK

Established Series
Rev. JPM-MHC
02/2022

DISAPPOINT SERIES

The Disappoint series consists of very deep, poorly drained soils formed in a thin silty loess mantle over coarse and medium textured glacial till. Disappoint soils are in depressions on glacial till plains and toeslopes. Slopes range from 0 to 12 percent. Mean annual precipitation is about 21 inches and the mean annual temperature is about 34 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid Humic Cryaquepts

TYPICAL PEDON: Disappoint very cobbly mucky silt loam -- at 500 feet elevation under paper birch and white spruce forest. (soil was saturated when described)

Oi--4 inches to 3 inches; dark reddish brown (5YR 3/3) fibrous undecomposed twigs, roots, moss and grass fibers. (1 to 3 inches thick)

Oe--3 inches to 0; dark reddish brown (5YR 2.5/2) partially decomposed twigs, moss and grass. (1 to 3 inches thick)

A1--0 to 4 inches; black (10YR 2/1) very cobbly mucky silt loam; weak fine granular structure; very friable, nonsticky and nonplastic; many roots of all sizes; 30 percent cobble, 5 percent gravel and 5 percent stone; strongly acid (pH 5.2); clear smooth boundary. (3 to 9 inches thick)

A2--4 to 13 inches; very dark grayish brown (10YR 3/2) very cobbly silt loam; weak medium subangular blocky structure; slightly sticky and slightly plastic; few fine distinct dark yellowish brown (10YR 4/4) mottles; very fine, fine, and medium roots; 30 percent cobble, 5 percent gravel and 5 percent stones; strongly acid (pH 5.4); abrupt smooth boundary. (0 to 12 inches thick)

2Bg--13 to 27 inches; very dark grayish brown (2.5Y 3/2) gravelly silt loam; occasional pockets and lenses of sandy loam material; moderate thick platy structure; firm, slightly sticky and slightly plastic; common medium distinct brown (7.5YR 4/4) mottles; few very fine and fine roots; 10 percent gravel and 5 percent cobble; moderately acid (pH 5.6); gradual irregular boundary. (12 to 30 inches thick)

2C1--27 to 41 inches; olive (5Y 4/4 and 5Y 4/3) gravelly silt loam stratified with sandy loam; moderate thick platy structure; firm, slightly sticky and slightly plastic; 20 percent gravel, few cobbles; moderately acid (pH 6.0); diffuse irregular boundary. (10 to 34 inches thick)

2C2--41 to 60 inches; olive (5Y 4/4 and 5Y 4/3) very gravelly sandy loam; massive; firm, slightly sticky and slightly plastic; 35 percent gravel and few cobbles; moderately acid (pH 6.0).

TYPE LOCATION: Matanuska-Susitna Area, Alaska; about 5 miles east of Palmer; the NE1/4 of the NE1/4 of section 27, T.18N., R.2E., Seward Meridian.

RANGE IN CHARACTERISTICS: The organic mat ranges from 2 to 5 inches thick. The organic carbon content of the surface mineral layer ranges from 8 to 12 percent. Rock fragment content of the control section ranges from 10 to 30 percent. Reaction throughout the control section ranges from very strongly acid to moderately acid, but the pH does not range below 5.5 throughout the control section.

The A1 horizon has hue from 5YR through 10YR, value from 2 through 4, and chroma of 1 or 2. Coarse fragment content ranges from 15 to 60 percent and includes 10 to 40 percent cobbles and 5 to 20 percent gravel.

The A2 horizon, when present, has hue from 5YR to 10YR, value from 2 to 4, and chroma of 1 or 2. Texture is silt loam or loam. Coarse fragment content ranges from 15 to 60 percent and includes 10 to 40 percent cobbles and 5 to 20 percent gravel.

The 2Bg horizon is gleyed with hue moist of 5GY, 2.5Y or 5Y; value moist from 2 through 5; chroma moist from 1 through 4. Texture includes sandy loam, loam or silt loam. Occasional pockets and strata of silty clay loam and sandy clay loam materials occur in this horizon. Coarse fragment content ranges from 5 to 15 percent gravel and 5 to 15 percent cobble.

The 2C horizons have hue moist of 2.5Y or 5Y and chroma moist from 1 through 4. Texture is loam or silt loam with occasional pockets and strata of silty clay loam, sandy clay loam and sandy loam. Coarse fragment content ranges from 5 to 15 percent cobble and 20 to 35 percent gravel.

COMPETING SERIES: There are no competing series in the same family. The Coal Creek series in an adjacent family has pH less than 5.5 (H2O,1:1) throughout the control section.

GEOGRAPHIC SETTING: The Disappoint soils are in depressions on glacial till plains and toeslope positions on hills. They formed in a thin loess mantle over coarse and medium textured glacial till deposits. The climate is transitional maritime-continental with the average annual precipitation ranging from 16 to 28 inches. Mean annual temperature ranges from 33 to 36 degrees F.

DRAINAGE AND PERMEABILITY: Poorly drained. Slow to rapid runoff. Moderate permeability in the upper layers and moderately slow in the substratum.

USE AND VEGETATION: Used for wildlife habitat and recreation. Mostly in native vegetation of alder, willows, paper birch, and a dense ground cover of grasses, horsetail, and other forbs and shrubs. In many cases, trees are absent, and the vegetation consists mainly of tussocks of grass.

DISTRIBUTION AND EXTENT: Southcentral Alaska. The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA

SERIES ESTABLISHED: Matanuska-Susitna Soil Survey Area, Alaska, 1996.

REMARKS: Diagnostic horizons and features recognized in this profile include: an umbric epipedon from 0 to 13 inches; mottling and matrix chromas of 2 or less from 4 to 27 inches; pH greater 5.5 (H2O,1:1) from 13 to 40 inches; coarse-loamy particle size from 13 to 41 inches; cryic temperature regime.

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National Cooperative Soil Survey
U.S.A.