LOCATION WILLOWCREEK AK
Established Series
MPS/SAS/TJR
02/2022
WILLOWCREEK SERIES
Landscape--plains, hills
Landform--drainageways
Slope--2 to 10 percent
Parent material--herbaceous organic material over alluvium
Mean annual precipitation--about 330 mm
Mean annual air temperature--about -3 degrees C
Depth class--very deep
Drainage class--poorly drained
Soil moisture regime--aquic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid Fluvaquentic Cryaquepts
TYPICAL PEDON: Willowcreek silt loam on a north by northwest facing linear, linear drainageway on a hill, on a stope of 5 percent at an elevation of 99 m (The soil was moist throughout when described on June 19, 2016.)
Oi--0 to 18 cm; peat, dark gray (10YR 4/1) dry, black (10YR 2/1) moist; nonsticky, nonplastic; many very fine and common medium, fine, and coarse roots; slightly acid (pH 6.5); clear smooth boundary
Bg--18 to 47 cm; silt loam, 50 percent gray (5Y 5/1) dry, very dark gray (5Y 3/1) moist, 40 percent pale yellow (2.5Y 7/4) dry, light olive brown (2.5Y 5/4) moist, 10 percent dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; weak medium granular structure; friable, nonsticky, nonplastic; many very fine and common fine and medium roots; common fine irregular pores; neutral (pH 6.7); gradual irregular boundary, buried woody debris
C/Ag--47 to 63 cm; silt loam, 70 percent gray (2.5Y 5/1) dry, very dark gray (2.5Y 3/1) moist, 20 percent pale yellow (2.5Y 7/4) dry, light olive brown (2.5Y 5/4) moist, 10 percent light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; weak medium subangular blocky structure; very friable, nonsticky, nonplastic; many very fine and common fine and medium roots; few fine irregular pores; 3 percent medium lenticular yellowish red (5YR 4/6) masses of oxidized iron with sharp boundaries lining pores; 0.12 ms of EC; neutral (pH 6.8); clear wavy boundary
Cg1--63 to 85 cm; silt loam, gray (10YR 5/1) dry, very dark gray (10YR 3/1) moist; massive; very friable, nonsticky, nonplastic; common very fine roots; few fine irregular and few fine tubular pores; 1 percent medium lenticular yellowish red (5YR 4/6) masses of oxidized iron with sharp boundaries lining pores; neutral (pH 6.7); clear wavy boundary, sand lenses
Cg2--85 to 150 cm; stratified silt loam gray (2.5Y 5/1) dry, very dark gray (2.5Y 3/1) moist; massive; friable, nonsticky, slightly plastic; 3 percent coarse irregular (n 4/) masses of reduced iron with sharp boundaries in matrix and 3 percent coarse irregular dark reddish brown (5YR 3/4) masses of oxidized iron with sharp boundaries in matrix; 2 percent by volume; slightly acid (pH 6.3)
TYPE LOCATION: Nome Census Area County, Alaska, latitude 63.8295760, longitude -160.4921840 degrees, datum WGS84 (Coordinates determined with a GPS unit)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--1 to 2.5 degrees C
Soil moisture control section--saturated throughout during the growing season (aquic moisture regime)
Thickness of ochric epipedon--4 to 18 cm
Depth to reduced matrix--4 to 18 cm
Depth to redoximorphic iron concentrations--25 to 75 cm
Particle Size Control Section:
*Clay--10 to 18 percent gravels or channers
*Total fragments--0 to 25 percent gravels or channers
Oi horizon
Thickness--4 to 18 cm
Bg (or Ag) horizon
Hue--10YR, 2.5Y, or 5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 3
Clay--5 to 12 percen t
Sand--15 to 40 percent
Organic carbon--3 to 7 percent
Reaction--5.6 to 7.1
Thickness--2 to 25 cm
C/Ag (or B/Ag) horizon
Hue--10YR, 2.5Y, or 5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 or 2
Fine-earth texture--silt, silt loam, very fine sandy loam
Clay--5 to 15 percent
Sand--15 to 60 percent
Organic carbon--3 to 7 percent
Total fragments--0 to 13 percent gravels
Reaction--5.8 to 7.1
Thickness--2 to 30 cm
Cg1 or Cg2 horizon
Hue--2.5Y, 5Y, or N
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 2
Fine-earth texture--silt loam, sandy loam, very fine sandy loam
Clay--10 to 22 percent
Sand--15 to 70 percent
Organic carbon--0.2 to 2 percent
Total fragments--0 to 15 percent gravels
Reaction--5.9 to 7.1
COMPETING SERIES:
Lamplugh--no coarse fragments, pH ranges to 7.2, outwash parent material, water table within 25 cm of soil surface in April through December (poorly drained)
Rabbit--coarse fragments range 25 to 50 percent in the lower part of the profile; floodplains
GEOGRAPHIC SETTING:
*Elevation--0 to 350 m
*Climate--warm, moist summers; cold, dry winters
*Mean annual precipitation--350 to 600 mm
*Mean annual air temperature-- -5 to -1 degrees C
*Frost-free period--55 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
*
Apun--aquic conditions between 0 and 25 cm (poorly drained), drainageways
*
Nikaat--histic epipedon, plains and toeslopes of hills
*Piak--aquic conditions below 25 cm (somewhat poorly drained), mounds on hillslopes
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
*Drainage class--poorly drained
*Saturation during normal years--saturated at the soil surface for at least two weeks during the growing season and saturated at a depth of 0 to 50 cm throughout the remainder of the growing season
*Flooding--frequent, brief
*Ponding--none
*Saturated hydraulic conductivity (Ksat)--moderately high or high throughout
USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential native vegetation--reedgrass, field horsetail, tealeaf willow, Richardson's willow, purple marshlocks, moss, feltleaf willow, beauverd spirea
DISTRIBUTION AND EXTENT: Nulato Hills-Southern Seward Peninsula Highlands, Alaska; MLRA 240; large extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Nulato Hills BLM area, Nome Census Area, Alaska; 2021
REMARKS:
Diagnostic horizons and features recognized in this pedon
*Particle-size control section--zone from 43 to 118 cm
*Ochric epipedon--zone from 0 to 18 cm
*Reduced matrix--zones from 18 to 47 cm and 63 to 150 cm
*Aquic conditions--zone from 0 to 150 cm
*Redoximorphic iron concentrations--zone from 47 to 150cm
National Cooperative Soil Survey
U.S.A.