LOCATION NUKA                    AK

Established Series
Rev. DVP-JDW
05/2022

NUKA SERIES

The Nuka series consists of very deep, very poorly drained soils that formed in accumulations of partially decomposed mosses, sedges, and woody material over glacial till. Nuka soils are on slopes affected by seepage and in depressions between glacial moraines. Slopes range from 0 to 25 percent. Mean annual temperature is about 38 degrees F. and the mean annual precipitation is about 70 inches.

TAXONOMIC CLASS: Loamy-skeletal, mixed, euic Terric Cryohemists

TYPICAL PEDON: Nuka peat, on 1 percent slope under sphagnum moss, sedge, and dwarf shrubs, at 100 feet elevation. (Colors are for moist soil unless otherwise stated. When described, the soil was moist throughout).

Oi1--0 to 3 inches; dark brown (7.5YR 3/2 and 7.5YR 3/4, broken face, rubbed and pressed) peat; 95 percent fiber, 80 percent rubbed; dominantly moss fibers; many very fine, fine, and medium roots; 5 percent mineral content; very strongly acid (pH 5.0); clear smooth boundary. (2 to 7 inches thick)

Oi2--3 to 9 inches; strong brown (7.5YR 5/8, broken face) reddish yellow (7.5YR 6/6, rubbed and pressed) peat; 95 percent fiber, 80 percent rubbed; dominantly moss fibers; many very fine, fine, medium, and coarse roots; 5 percent mineral content; strongly acid (pH 5.2); clear smooth boundary. (6 to 8 inches thick)

Oe1--9 to 26 inches; dark brown (7.5YR 3/2, broken face, rubbed) dark brown (7.5YR 4/4 pressed) mucky peat; 50 percent fiber, 30 percent rubbed; weak thick platy structure; admixture of sedge and moss fibers; many very fine and fine roots; 5 percent mineral content; very strongly acid (pH 5.0); clear smooth boundary.

Oe2--26 to 47 inches; dark brown (7.5YR 3/3, broken face, rubbed and pressed) mucky peat; 75 percent fiber, 35 percent rubbed; weak thick platy structure; admixture of sedge and moss fibers; few very fine and fine roots; 5 percent mineral content; thin discontinuous strata of volcanic ash; very strongly acid (pH 5.0); abrupt smooth boundary.

C--47 to 60 inches; dark grayish brown (2.5Y 4/2) very gravelly loam; massive; friable, nonsticky, nonplastic; 35 percent gravel, 5 percent cobble.

TYPE LOCATION: Kenai Peninsula Area, Alaska; about 3 miles southeast of Port Graham, 2550 feet west of the NE corner of section 11, T. 10S., R. 15W., Seward Meridian; USGS Seldovia B-5 quadrangle; lat. 59 degrees 19 minutes 52 seconds N. and long. 151 degrees 45 minutes 20 seconds W.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 38 to 40 degrees F. The subsurface tier is composed dominantly of hemic material but includes thin layers of fibric and sapric material. Thickness of the organic material ranges from 16 to 51 inches.

The Oi horizon is comprised dominantly of sphagnum moss fibers and woody debris that are relatively undecomposed. Thickness of the Oi horizon ranges from 2 to 21 inches. Thin discontinuous strata of volcanic ash are common.

The Oe horizon is comprised dominantly of moss and sedge fibers that are in an intermediate stage of decomposition. The pH ranges from 4.2 to 5.7. Thin discontinuous strata of volcanic ash are common.

The C horizon has hue of 2.5Y or 5Y, value of 2 to 5, and chroma of 2 to 4. It is very gravelly loam or very gravelly sandy loam. Rock fragments range from 35 to 45 percent with 25 to 35 percent gravel and 5 to 15 percent cobble.

COMPETING SERIES: There are no competing series in this family. Doroshin(AK) and Hewitt(AK) series are in the same subgroup but have less that 35 percent rock fragments in the mineral substratum.

GEOGRAPHIC SETTING: Nuka soils are formed in partially decomposed mosses, sedges, and woody material, that are always saturated, over compact glacial till. Nuka soils are on slopes affected by seepage and in depressions between glacial moraines. Slopes range from 0 to 25 percent. Elevations are 10 to 1000 feet.

The climate is maritime with mild winters and cool summers. Mean annual precipitation ranges from 65 to 75 inches and the mean annual snowfall is 70 to 120 inches. Mean January temperature is 25 degrees F., mean July temperature is 54 degrees F., and the mean annual temperature ranges from 37 to 39 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Kasitsna and Koyuktolik soils. Kasitsna soils are well drained mineral soils that occur on glacial moraines in complex with Nuka soils. Koyuktolik soils do not have the mineral layers within the control section and occur in deeper depressions than Nuka soils.

DRAINAGE AND PERMEABILITY: Very poorly drained. Runoff is very slow to ponded. Permeability is rapid in the organic material and slow in the glacial till.

USE AND VEGETATION: These soils are used for subsistence, recreation, and wildlife habitat. Nuka soils have native vegetation of stunted Sitka spruce, labrador tea, bog blueberry, willow, sedge, and sphagnum moss.

DISTRIBUTION AND EXTENT: Kenai Peninsula, Alaska. The series is of small extent.

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

SERIES ESTABLISHED: Lower Kenai Peninsula Area, Alaska. 1998.

REMARKS: Diagnostic horizons and features recognized in this profile include:

Dominantly hemic soil material in the subsurface tier 12 to 35 inches (Oe1 and Oe2).
Thickness of organic material less than 51 inches (130 cm).
Assumed pH is greater than 4.5(in 0.01 M CaCl2) in one or more layers of organic soil materials within the control section.
Assumed cryic temperature regime; freeze below a depth of 2 inches (5cm) from the surface.

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National Cooperative Soil Survey
U.S.A.