LOCATION EKWOK AK
Established Series
SAS/TJR/MPR
02/2022
EKWOK SERIES
Landscape--plains
Landform--rises
Slope--0 to 70 percent
Parent material--volcanic ash over loess
Mean annual precipitation--about 800 mm
Mean annual air temperature--about 0 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Coarse-loamy, isotic Typic Haplocryods
TYPICAL PEDON: Ekwok silt loam on a rise of a plain, on a 3-percent slope at an elevation of 31 m (The soil was moist throughout when described on July 31, 2006.)
Oi--0 to 3 cm; slightly decomposed plant material; many very fine, fine, and medium and few coarse roots; moderately acid (pH 5.8); clear smooth boundary
E/A--3 to 7 cm; ashy silt loam, matrix color 60 percent light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist, and 40 percent brown (10YR 5/3) dry, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine, common medium, and few coarse roots; extremely acid (pH 4.4); clear smooth boundary
Bhs--7 to 15 cm; medial silt loam, reddish brown (5YR 5/4) dry, dark reddish brown (5YR 3/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, and medium and few coarse roots; very strongly acid (pH 4.8); abrupt wavy boundary
2Bs--15 to 50 cm; silt loam, matrix color 75 percent light brown (7.5YR 6/4) dry, brown (7.5YR 4/4) moist, and 25 percent brown (7.5YR 5/2) dry, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine and few medium and coarse roots; moderately acid (pH 5.6); clear wavy boundary
2C--50 to 180 cm; sandy loam, light brown (7.5YR 6/4) dry, brown (7.5YR 4/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine, fine, and medium and few coarse roots; 5 percent fine masses of oxidized iron, strong brown (7.5YR 4/6) moist, diffuse boundaries; 25 percent mottles, light gray (2.5Y 7/2) dry, grayish brown (2.5Y 5/2) moist; moderately acid (pH 5.6)
TYPE LOCATION: Dillingham Census Area, Alaska, village of Ekwok, on the Nushagak River; about 70 km northeast of Dillingham, Alaska; latitude 59.358611 degrees north, longitude 157.473889 degrees west, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0 to 2 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October (udic moisture regime)
Particle-size control section
*Clay content--1 to 10 percent
*Sand content--20 to 70 percent
*Sodium fluoride pH--8.4 to 11.6
*Ratio of 1500 kPa water to measured clay--0.6 to 6.0
Oi horizon
Thickness--3 to 18 cm
E/A, A, or E horizon
Hue--7.5YR, 10YR
Value--4 or 5 moist, 6 or 7 dry (E part); 2 to 3 moist, 4 or 5 dry (A part)
Chroma--1 to 2 moist (E part); 1 to 3 moist (A part)
Fine-earth texture--ashy silt loam, ashy very fine sandy loam
Clay content--4 to 8 percent
Reaction--3.7 to 5.6
Thickness--2 to 15 cm
Bulk density--0.45 to 0.90 g/cm3
Phosphorous retention--20 to 50 percent
Ammonium oxalate Al plus 1/2 Fe--0.2 to 0.4 percent
Volcanic glass content--20 to 30 percent
Bhs horizon
Hue--5YR, 7.5YR
Value--2.5 to 4 moist, 4 to 6 dry
Chroma--1 to 6
Clay content--4 to 10 percent
Reaction--3.7 to 5.6
Thickness--3 to 9 cm
Bulk density--0.45 to 0.9 g/cm3
Phosphorous retention--85 to 100 percent
Ammonium oxalate Al plus 1/2 Fe--2 to 4 percent
Volcanic glass content--5 to 30 percent
2Bs horizon
Hue--7.5YR, 10YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 4 moist
Fine-earth texture--silt loam, very fine sandy loam, fine sandy loam
Clay content--0 to 10 percent
Reaction--4.8 to 6.0
Sodium fluoride pH--8.4 to 11.6
Ratio of 1500 kPa water to measured clay--0.6 to 6.0
Thickness--5 to 65 cm
2C horizon
Hue--10YR, 2.5Y
Value--4 or 5 moist, 6 or 7 dry
Chroma--2 to 6 moist
Fine-earth texture--sandy loam, silt loam, very fine sandy loam
Clay content--0 to 10 percent
Reaction--5.0 to 6.3
Sodium fluoride pH--8.4 to 11.6
Ratio of 1500 kPa water to measured clay--0.6 to 6.0
Thickness--more than 20 cm
COMPETING SERIES:
Barlow--no andic soil properties in the spodic horizon; mean annual soil temperature of 4.4 to 8.0 degrees C
Timberly--no andic soil properties in the spodic horizon
GEOGRAPHIC SETTING:
Elevation--3 to 300 m
Climate--warm, moist summers; cold, moist winters
Mean annual precipitation--600 to 1400 mm
Mean annual air temperature-- -2 to 1 degree C
Frost-free period--85 to 140 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Ekvik--coarse fragments in C material; steep slopes of bluffs
Kemuk--no spodic horizon; aquic conditions; talfs of plains
Klutuk--no spodic horizon; similar landform positions
Kumla--no spodic horizon; aquic conditions; permafrost; talfs of plains
Pellernarquq--no spodic horizon; aquic conditions; dips and talfs of plains
Unguiq--aquic conditions; no spodic horizon; drainageways
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high or high
USE AND VEGETATION:
Use--community development, wildlife habitat
Potential natural vegetation--white spruce, paper birch, lingonberry, dwarf blueberry, crowberry, Labrador tea, feather moss, lichens
DISTRIBUTION AND EXTENT: Bristol Bay Lowlands, Alaska; MLRA 236; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Bristol Bay-Northern Alaska Peninsula, North and Bordering Areas, Alaska; 2016
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 28 to 103 cm
*Ochric epipedon
*Spodic horizons--Bhs and Bs horizons
*Albic material--E or E/A horizon
*Andic soil properties--Bhs horizon
Laboratory pedon number 06N1043
National Cooperative Soil Survey
U.S.A.