LOCATION UKPIK AK
Established Series
SAS/TJR
02/2022
UKPIK SERIES
Landscape--plains
Landform--swales
Slope--0 to 5 percent
Parent material--grassy organic material over loess
Mean annual precipitation--about 500 mm
Mean annual air temperature--about -3 degrees C
Depth class--very deep
Drainage class--somewhat poorly drained
Soil moisture regime--aquic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, acid Fluvaquentic Cryaquepts
TYPICAL PEDON: Ukpik highly organic silt on an east by southeast facing concave, concave swale on a plain, on a slope of 2 percent at an elevation of 318 m (The soil was moist to 26 cm, wet from 26 to 62 cm, and moist from 62 to 150 cm when described on June 13, 2017.)
Oi--0 to 5 cm; slightly decomposed plant material, 90 percent light yellowish brown (10YR 6/4) dry and dark yellowish brown (10YR 4/4) moist, and 10 percent dark gray (10YR 4/1) dry and black (10YR 2/1) moist; nonsticky, nonplastic; many very fine and fine, and common medium and coarse roots throughout; very strongly acid (pH 4.5); clear smooth boundary
Oe/Ajj--5 to 26 cm; moderately decomposed plant material, 80 percent brown (7.5YR 4/2) dry and very dark brown (7.5YR 2.5/2) moist, and 20 percent brown (7.5YR 4/3) dry and very dark brown (7.5YR 2.5/3) moist; nonsticky, nonplastic; many very fine and common medium and fine roots; extremely acid (pH 4.3); clear irregular boundary
Ajj--26 to 46 cm; highly organic silt, 80 percent brown (7.5YR 4/2) dry and very dark brown (7.5YR 2.5/2) moist, and 20 percent brown (7.5YR 5/3) dry and dark brown (7.5YR 3/3) moist; weak fine granular structure; friable, nonsticky, nonplastic; many very fine and common fine roots throughout; few fine irregular pores; very strongly acid (pH 5.0); abrupt irregular boundary
C/Ajjg1--46 to 62 cm; silt, 80 percent light brownish gray (10YR 6/2) dry and dark grayish brown (10YR 4/2) moist, and 20 percent reddish brown (5YR 5/3) dry and dark reddish brown (5YR 3/3) moist; moderate thin platy structure; friable, nonsticky, nonplastic; common very fine roots throughout; few fine irregular pores; 3 percent lenticular extremely weakly cemented black (5YR 2.5/1) manganese masses with diffuse boundaries in matrix and 5 percent coarse irregular strong brown (7.5YR 4/6) masses of oxidized iron with clear boundaries in matrix; strongly acid (pH 5.1); abrupt irregular boundary
C/Ajjg2--62 to 78 cm; silt loam, 90 percent light brownish gray (10YR 6/2) dry and dark grayish brown (10YR 4/2) moist, and 10 percent brown (7.5YR 4/3) dry and very dark brown (7.5YR 2.5/3) moist; weak thin platy structure; friable, nonsticky, nonplastic; common very fine roots throughout; 5 percent coarse irregular strong brown (7.5YR 4/6) masses of oxidized iron with diffuse boundaries in matrix; 1 gravel; very strongly acid (pH 5.0); clear irregular boundary
Cg1--78 to 125 cm; silt loam, light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist; massive; friable, nonsticky, slightly plastic; common very fine roots; 2 percent coarse irregular dark reddish brown (5YR 3/4) manganese masses with diffuse boundaries around rock fragments and 2 percent medium extremely weakly cemented strong brown (7.5YR 4/6) ironstone nodules and 30 percent medium dark reddish brown (5YR 2.5/2) masses of oxidized iron; 5 percent gravel; very strongly acid (pH 4.5); clear smooth boundary
Cg2--125 to 150 cm; silt loam, gray (5Y 6/1) dry, dark gray (5Y 4/1) moist; massive; friable, nonsticky, moderately plastic; 50 percent coarse irregular strong brown(7.5YR 4/6) masses of oxidized iron with diffuse boundaries in matrix; strongly acid (pH 5.2)
TYPE LOCATION: Nome Census Area County, Alaska, latitude 63.2986036, longitude -161.3471027 degrees, datum WGS84 (Coordinates determined with a GPS unit)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature-- -1 to 3 degrees C
Soil moisture control section--saturated between 25 and 50 cm for at least two weeks during the growing season (aquic moisture regime)
Thickness of folistic epipedon--15 to 30 cm
Depth to redoximorphic features--25 to 50 cm
Depth to aquic conditions--25 to 50 cm
Depth to reduced matrix--25 to 50 cm
Particle Size Control Section:
*Clay--10 to 18 percent
*Total fragments--0 to 30 percent
*Total gravel--0 to 30 percent
*Total cobbles--0 to 20 percent
*Total stones--0 to 20 percent
Oi horizon
Hue--10YR or 7.5YR
Value--2 to 5 moist, 4 to 7 dry
Chroma--1 to 6
Thickness--2 to 10 cm
Oe/Ajj horizon
Hue--10YR or 7.5YR
Value--2.5 to 4 moist, 5 to 6 dry
Chroma--1 to 3
Thickness--5 to 28 cm
Ajj horizon
Hue--10YR or 7.5YR
Value--2 to 3 moist, 4 to 5 dry
Chroma--1 to 4
Fine-earth texture--silt, silt loam, very fine sandy loam
Clay--5 to 12 percent
Sand--10 to 50 percent
Organic carbon--5 to 10 percent
Reaction--4.7 to 5.8
Thickness--5 to 20 cm
C/Ajjg1 or C/Ajjg2 horizon
Hue--2.5Y, 5Y, 10YR, 7.5YR, or 5YR
Value--2.5 to 5 moist, 4 to 7 dry
Chroma--1 to 3
Fine-earth texture--silt loam, silt
Clay--8 to 15 percent
Sand--10 to 35 percent
Organic carbon--2 to 5 percent
Total fragments--0 to 5 percent gravels
Reaction--5.0 to 5.4
Combined thickness--15 to 40 cm
Cg1 or Cg2 horizon
Hue--2.5Y, 5Y, or N
Value--4 to 5 moist, 6 to 7 dry
Chroma--1 or 2
Fine-earth texture--silt loam, loam, silt
Clay--10 to 22 percent
Sand--10 to 45 percent
Organic matter--0.1 to 1 percent
Total fragments--0 to 30 percent
Total gravel--0 to 30 percent
Total cobbles--0 to 20 percent
Total stones--0 to 20 percent
Reaction--4.5 to 6.4
COMPETING SERIES:
Bidart-depth to aquic conditions is at the soil surface (very poorly drained), soil temperature ranges 5 to 6 degrees C, pH ranges to 6 in all horizons, alluvial parent material
GEOGRAPHIC SETTING:
*Elevation--0 to 500 m
*Climate--warm, moist summers; cold, dry winters
*Mean annual precipitation--350 to 650 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
*
Sikinik--histic epipedon, plains and toeslopes of hills
*
Akpik--aquic conditions above 25 cm (poorly drained), plains
*
Ugruk--aquic conditions at the surface (very poorly drained), organic surface layers greater than 40 cm thick, depressions on plains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
*Drainage class--somewhat poorly drained
*Saturation during normal years--saturated between 25 and 50 cm for at least two weeks during the growing season
*Ponding--frequent, brief
*Saturated hydraulic conductivity (Ksat)--very high in the surface organic layers and moderately high or high throughout the rest of the profile
USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential native vegetation--bluejoint, tealeaf willow, Alaska wild rhubarb
DISTRIBUTION AND EXTENT: Nulato Hills-Southern Seward Peninsula Highlands, Alaska; MLRA 240; moderate 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 51 to 126 cm
*Particle-size control section--pH is less than 5.5
*Particle-size control section--clay ranges from 10 to 18 percent
*Folistic epipedon--zone from 0 to 26 cm
*Cryoturbation-zone from 5 to 78 cm
*Cambic horizon--zone from 26 to 46 cm
*Reduced matrix--zone from 46 to 150 cm
*Aquic conditions--zone from 46 to 150 cm
*Redoximorphic iron concentrations--zones from 46 to 78 cm and 125 to 150 cm
*Manganese masses--zones from 46 to 62 cm and 78 to 125 cm
________________________________________
National Cooperative Soil Survey
U.S.A.