LOCATION NICKOLNA                AK

Established Series
Rev. MHC/JPM/DLM
05/2022

NICKOLNA SERIES

The Nickolna series consists of very deep, well drained soils formed in a thin mantle of loess overlying loamy lacustrine deposits on lacustrine terraces and hills. Slopes range from 4 to 16 percent. The mean annual temperature is about 26 degrees F. and the mean annual precipitation is about 16 inches.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Humicryepts

TYPICAL PEDON: Nickolna silt loam=on an 14 percent slope under open white spruce forest and glandular birch scrub at 2650 feet elevation. (All colors are for moist soil)

Oi--2 inch to 0 (5 centimeters to 0); peat; fibrous moss and forest litter; clear wavy boundary. (1 to 4 inches thick)

A--0 to 8 inch (0 to 20 centimeters); very dark brown (10YR 2/2) silt loam; moderate coarse granular structure; friable, slightly sticky and slightly plastic; many roots of all sizes; moderately acid (pH 5.6); gradual wavy boundary. (1 to 8 inches thick)

2C1--8 to 11 inches (20 to 28 centimeters); dark grayish brown (2.5Y 4/2) loam; moderate coarse granular structure; friable, sticky and plastic; 5 percent subangular and subrounded gravel; common very fine and fine roots: moderately acid (pH 5.8); diffuse irregular boundary. (3 to 18 inches thick)

2C2--11 to 44 inches (28 to 112 centimeters); dark grayish brown (2.5Y 4/2) clay loam; moderate medium subangular blocky structure; friable, sticky and plastic; 5 percent gravel and 5 percent cobble; moderately acid (pH 6.0); gradual wavy boundary. (20 to 33 inches thick)

2C3--44 to 60 inches (112 to 152 centimeters); dark grayish brown (2.5Y 4/2) cobbly clay loam; moderate medium subangular blocky structure; friable, sticky and plastic; 10 percent subrounded and subangular gravel and 10 percent subangular and subrounded cobble; neutral (pH 6.6).

TYPE LOCATION: Gulkana River Area, Alaska; about 19 miles north of Sourdough; the NE1/4 of the NW1/4 of section 20, T.11N., R.2W., Copper River Meridian.

RANGE IN CHARACTERISTICS: Thickness of the silty loess mantle ranges from 1 to 8 inches. There is more than 18 percent clay and more than 15 percent fine sand or coarser in the control section. Reaction ranges from strongly acid or moderately acid in the solum and moderately acid to neutral in the substratum.

The A or 2A horizons have value moist of 2 or 3; chroma moist of 1 through 3. Texture is silt loam, loam or clay loam. Rock fragments range from 0 to 5 percent and include gravel and cobble.

The 2C horizons have hue of 10YR, 2.5Y or 5Y; value moist of 3 or 4; chroma moist of 1 or 2. Texture is loam, clay loam or silty clay loam. Rock fragments range from 0 to 25 percent and include 0 to 25 percent gravel and 0 to 15 percent cobble.

COMPETING SERIES: These include the Archabal, Domo, and Packtrail series. Archabal soils have sands and gravel below 40 inches. Domo soils lack lithological discontinuities. Packtrail soils have bedrock between 20 and 40 inches.

GEOGRAPHIC SETTING: The Nickolna soils are on lacustrine terraces and hills. Slopes range from 4 to 16 percent. The soils formed in a thin loess mantle over loamy lacustrine sediments. The climate is subarctic continental with a mean annual temperature of about 26 degrees F. Mean annual precipitation is about 16 inches.

GEOGRAPHICALLY ASSOCIATED SOILS:

DRAINAGE AND PERMEABILITY: Well drained. Medium to rapid runoff. Moderate permeability.

USE AND VEGETATION: Primary use is as wildlife habitat. Native vegetation is open white spruce forest and mixed glandular birch and willow shrub.

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

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

SERIES ESTABLISHED: Gulkana River Area, Alaska, 1999.

REMARKS: Diagnostic features and horizons recognized in this profile include: an umbric epipedon from 0 to 8 inches; a loess mantle with a coarse-silty particle-size from 0 to 6 inches; fine-loamy particle-size from 8 to 60 inches; cryic temperature regime. Formerly classified as Entic Cryumbrepts

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National Cooperative Soil Survey
U.S.A.