LOCATION KASHWITNA               AK

Established Series
Rev. KMO/DM
05/2022

KASHWITNA SERIES

Depth class: very deep
Drainage class: well drained
Parent material: ash influenced loess overlying gravelly outwash
Landform: outwash plains, moraines, and hills
Slopes: 0 to 85 percent
Mean annual precipitation: 14 to 32 inches.
Mean annual temperature: 32 to 36 degrees F.

TAXONOMIC CLASS: Medial over sandy or sandy-skeletal, amorphic over mixed Andic Haplocryods

TYPICAL PEDON: Kashwitna silt loam - on a 2 percent west facing slope under forest vegetation at 150 feet elevation. (All colors are for moist soil)

Oi--0 to 3 inches; very dark brown (10YR 2/2) slightly decomposed plant material, moss, mycelia, and fine roots; very strongly acid (pH 4.5); abrupt wavy boundary. (2 to 5 inches thick)

E--3 to 5 inches; gray (10YR 5/1) silt loam; weak fine granular structure; very friable, nonsticky and nonplastic; many medium and coarse roots; very strongly acid (pH 4.7); abrupt smooth boundary. (1 to 3 inches thick)

Bs1--5 to 7 inches; dark reddish brown (5YR 3/4) silt loam, weak fine subangular blocky structure; very friable, slightly smeary, nonsticky and nonplastic; many medium and coarse roots; few fine concretions; very strongly acid (pH 4.8); abrupt wavy boundary. (1 to 4 inches thick)

Bs2--7 to 10 inches; strong brown (7.5YR 4/6) silt loam; weak fine granular structure; very friable, slightly smeary, nonsticky and nonplastic; many medium and coarse roots; very strongly acid (pH 5.0); abrupt smooth boundary. (2 to 6 inches thick)

Eb--10 to 12 inches; very dark grayish brown (10YR 3/2) silt loam; weak fine granular structure; very friable, slightly smeary, nonsticky and nonplastic; many medium and coarse roots; very strongly acid (pH 5.0); abrupt smooth boundary. (0 to 3 inches thick)

Bsb--12 to 18 inches; brown (7.5YR 4/4) silt loam; weak fine subangular blocky structure; very friable, slightly smeary, nonsticky and nonplastic; common coarse roots; strongly acid (pH 5.2); clear wavy boundary. (3 to 6 inches thick)

BC--18 to 21 inches; dark yellowish brown (10YR 3/4) silt loam; weak fine subangular blocky structure; very friable, slightly smeary, nonsticky and nonplastic; 10 percent coarse gravel; strongly acid (pH 5.3); clear smooth boundary. (3 to 8 inches thick)

2C--21 to 60 inches; olive brown (2.5Y 4/4) very gravelly sand; single grain; loose; 45 percent gravel; strongly acid (pH 5.4).

TYPE LOCATION: Yentna Area, Alaska; in the SW quarter of the NW quarter of section 36, T.12N., R.11W., Seward Meridian.

RANGE IN CHARACTERISTICS:
Some pedons lack bisequal sola
Depth to gravelly outwash: 14 to 21 inches
Ash influenced loess mantle: 10 to 21 inches thick
Solum: formed ash influenced loess, in some pedons it extends into the underlying material
Exchange complex of the solum: dominated by amorphous material
Small pockets of ash: occur in the loess mantle in some pedons
Reaction ranges from extremely acid to moderately acid.

O horizon:
Matrix color: hue of 7.5YR or 10YR; value of 2 to 4; chroma of 1 to 4
Texture: slight decomposed plant material, moderately decomposed plant material
Reaction class: extremely acid to strongly acid

E and Eb horizons:
Matrix color: hue of 5YR to 10YR; value of 2 to 6; chroma of 1 to 3; colors may be darkened by large quantities of charcoal
Texture: silt loam, very fine sandy loam, fine sandy loam
Reaction class: extremely acid to strongly acid

Bs and Bsb horizons:
Matrix color: hue of 2.5YR to 7.5YR; value of 3 to 5; and chroma of 3 to 6. Texture is silt loam, very fine sandy loam.
Reaction class: very strongly acid or strongly acid

BC or 2BC horizons: (where present)
Matrix color: hue of 10YR or 2.5Y; value of 3 to 5; chroma of 2 to 6
Texture: sandy loam, fine sandy loam, very fine sandy loam, silt loam modified by 0 to 40 percent gravel and 0 to 10 percent cobbles
Reaction class: very strongly acid to strongly acid

2C horizon:
Matrix color: variegated
Texture: is sand, loamy sand modified by 35 to 70 percent gravel, 0 to 30 percent cobbles, and 0 to 3 percent stones. Thin layers of fine sand or sandy loam may be present in the upper part.

COMPETING SERIES: These are the Benka, Chulitna, Shoestring, and Soldotna series. Benka series have less than 35 percent coarse fragments in the substratum. Chulitna soils have loess mantles greater than 30 inches thick, Shoestring soils have pumice coarse fragments. Soldotna soils have moderately acid or slightly acid substratums.

GEOGRAPHIC SETTING:
Drainage class: well drained
Parent material: ash influenced loess overlying gravelly outwash
Landform: outwash plains, moraines, and hills
Slopes: 0 to 85 percent
Mean annual temperature: 32 to 36 degrees F.
Mean annual precipitation: 14 to 32 inches.

GEOGRAPHICALLY ASSOCIATED SOILS:

DRAINAGE AND PERMEABILITY: Well drained, very low to very high runoff. Saturated hydraulic conductivity is high is the solum and high to very high in the substratum.

USE AND VEGETATION: Mostly forested. Paper birch, white spruce, Lutz spruce, and aspen are the dominant trees. Areas are cleared and used for crop production and homesite development.

DISTRIBUTION AND EXTENT: MLRA 224Cook Inlet Lowlands, South-central Alaska. The series is extensive.

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

SERIES ESTABLISHED: Susitna Valley Area, Alaska, 1979.

REMARKS: Diagnostic horizons and features recognized in this profile include: Albic horizons from 3 to 5 inches and 10 to 12 inches
Spodic horizons from 5 to 18 inches
Amorphous material: 3 to 21 inches
Sandy-skeletal material: 21 to 60 inches.
Temperature regime: cryic
Moisture regime: udic

Kashwitna series incorporates the concept of the Rabideux (T) series, shallow phase, as mapped in the Susitna Valley Area, Alaska.

ADDITIONAL DATA: Soil characterization sample from pedon 89AK170005 from Matanuska-Susitna Valley Area, Alaska, June 1989.

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National Cooperative Soil Survey
U.S.A.