LOCATION ISLAND                  AK

Established Series
Rev. RBH/SR/DLM
05/2022

ISLAND SERIES

Depth class: very deep
Drainage class: well drained
Parent material: ash influenced loess over loamy till
Landform: till plains and hillslopes on till plains
Slopes: 0 to 45 percent
Mean annual precipitation: 18 to 28 inches
Mean annual temperature: 33 to 36 degrees F.

TAXONOMIC CLASS: Medial over loamy, amorphic over mixed, superactive Pachic Fulvicryands

TYPICAL PEDON: Island silt loam on a 17 percent slopes, native grass (All colors are for moist soil)

Oi--0 to 1 inch; very dark brown (10YR 2/2) slightly decomposed plant material; many very fine, fine, and medium roots; extremely acid (pH 4.3) abrupt smooth boundary. (1/2 to 4 inches thick)

A--1 to 13 inches; very dark brown (10YR 2/2) silt loam; moderate very fine granular structure; friable, nonsticky and nonplastic; many very fine, fine, and medium roots; smeary; strongly acid (pH 5.2) clear wavy boundary. (12 to 33 inches thick)

Bw--13 to 24 inches; dark yellowish brown (10YR 4/4) silt loam; moderate very fine granular structure; friable, nonsticky and nonplastic; many very fine, fine, and few medium roots; smeary; strongly acid (pH 5.4); abrupt wavy boundary. (8 to 18 inches thick)

BC--24 to 33 inches; dark olive brown (2.5Y 3/3) silt loam; massive; common very fine and fine roots; smeary; moderately acid (pH 5.8); abrupt wavy boundary. (6 to 15 inches thick)

2C--33 to 60 inches; dark grayish brown (2.5Y 4/2) gravelly silt loam; massive; few very fine and fine roots; nonsmeary; 15 percent gravel; moderately acid (pH 5.8).

TYPE LOCATION: Western Kenai Peninsula Area, Alaska; about 1 mile northwest of Ninilchik in the SW 1/4 of the SE 1/4, section 27, T. 1 S, R. 14 W; Kenai A5 SE 1:25,000 quad; Seward Meridian, UTM north 6658160 and UTM east 574700, zone 5.

RANGE IN CHARACTERISTICS:
Depth to substratum: 25 to 60 inches
Coarse fragments: may occur in the substratum
Soil surface: commonly irregular, with earth hummocks about 18 inches high and a few feet in diameter
Profile characteristics: similar in hummocks and in low areas between them
Thin lenses of white sand size ash: may occur in the upper 2 feet of the profile

O horizon:
Matrix color: hue of 7.5YR or 10YR; value of 2 to 4; chroma of 2 to 4
Reaction class: extremely acid or very strongly acid

A horizon:
Matrix color: hue of 7.5YR or 10YR; value of 2 or 3; chroma of 1 to 3
Texture: silt loam, very fine sandy loam

Bw horizon: hue of 7.5YR or 2.5Y; value of 3 to 5; chroma of 2 to 6
Texture: silt loam, very fine sandy loam

BC horizon:
Matrix color: hue of 10YR or 2.5Y; value of 3 to 5; chroma of 2 to 4
Texture: silt loam, very fine sandy loam
Reaction class: moderately acid or slightly acid

2C horizon:
Matrix color: hue of 10YR to 5Y; value of 3 to 6; chroma of 2 to 6
Texture: sandy loam, silt loam, fine sandy loam, very fine sandy loam modified by 0 to 30 percent total coarse fragments; 0 to 30 percent grave; 0 to 5 percent cobbles

COMPETING SERIES: There are no completing series in this classification.

GEOGRAPHIC SETTING:
Depth class: very deep
Drainage class: well drained
Parent material: ash influenced loess over loamy till
Landform: till plains and hillslopes on till plains
Slopes: 0 to 45 percent
Climate: cool summers and long moderately cold winters
Mean annual temperature: 33 to 36 degrees F.
Mean annual precipitation: 18 to 28 inches

GEOGRAPHICALLY ASSOCIATED SOILS: These include Cohoe, Mutnala, Soldotna, Salamatof, and Nikolai soils. The Cohoe, Mutnala and Soldotna soils have a thin gray E horizon, a reddish B horizon and occur on similar landscapes. The Salamatof and Nikolai soils are organic soils that occur in depressions.

DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is low to medium depending on slope. Saturated hydraulic conductivity is moderately high to high in the solum and high to very high in the substratum.

USE AND VEGETATION: The native vegetation consists of grasses and associated low growing plants. Spruce is invading most areas. A few areas are used for gardens, potatoes, hay, and small grain.

DISTRIBUTION AND EXTENT: MLRA 224 Cook Inlet Lowlands South-central Alaska. The series is of small extent.

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

SERIES ESTABLISHED: Kenai-Kasilof Area, Alaska, 1960.

REMARKS: Diagnostic features and horizons recongized in the profile include:
Andic properties: 1 to 33 inches
Total carbon: weighted average greater than 6 percent and greater than 4 percent from 1 to 24 inches
Pachic epipedon: 1 to 24 inches
Temperature regime: cryic

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National Cooperative Soil Survey
U.S.A.