LOCATION ALEKNAGIK               AK

Established Series
SAS/TJR/SJN
02/2022

ALEKNAGIK SERIES

The Aleknagik series consists of very deep, well drained soils formed in volcanic ash over glacial drift on rises and of plains and on hills. Slopes range from 0 to 25 percent. The mean annual precipitation is about 775 millimeters and the mean annual air temperature is about 0.5 degrees C.

TAXONOMIC CLASS: Medial over loamy-skeletal, amorphic over mixed, superactive Andic Humicryods

TYPICAL PEDON: Aleknagik silt loam, located on a rise on a plain with a slope of 4 percent and elevation of 53 meters; when described on July 14th, 2011 the soil was moist throughout (Colors are for moist soil unless otherwise noted)

Oe--0 to 9 centimeters; moderately decomposed plant material; common fine roots, common medium roots, common coarse roots, and many very fine roots; ultra acid, pH 3.4; clear smooth boundary

E/A--9 to 14 centimeters; 90 percent brown (7.5YR 4/2) and 10 percent black (10YR 2/1) silt loam; 30 percent sand; 63 percent silt; 7 percent clay; weak medium granular structure; very friable, nonsticky, nonplastic; common fine roots, common medium roots, common coarse roots, and many very fine roots; 10 percent nonflat 2 to 75 millimeter fragments; extremely acid, pH 3.5; abrupt irregular boundary

Bhs--14 to 27 centimeters; 35 percent very dark brown (7.5YR 2/3) and 65 percent black (5YR 2.5/1) medial silt loam; 25 percent sand; 70 percent silt; 5 percent clay; moderate medium subangular blocky structure; very friable, nonsticky, nonplastic; common fine roots and common very fine roots; 10 percent nonflat 2 to 75 millimeter fragments; very strongly acid, pH 4.5; clear smooth boundary

BC1--27 to 45 centimeters; dark yellowish brown (10YR 3/4) medial gravelly silt loam; 25 percent sand; 69 percent silt; 6 percent clay; weak fine subangular blocky structure; friable, nonsticky, nonplastic; common fine roots and common very fine roots; 5 percent fine dark brown (7.5YR 3/4) masses of oxidized iron; 15 percent nonflat 2 to 75 millimeter fragments; strongly acid, pH 5.2; clear wavy boundary

2BC2--45 to 183 centimeters; brown (10YR 4/3) extremely gravelly sandy loam; 65 percent sand; 27 percent silt; 8 percent clay; weak fine granular structure; friable, nonsticky, nonplastic; 1 percent fine dark brown (7.5YR 3/4) masses of oxidized iron; 65 percent nonflat 2 to 75 millimeter fragments; strongly acid, pH 5.3

TYPE LOCATION: Dillingham Census Area, Alaska; 4 kilometers southwest of the Village of Aleknagik; 59.2450000 degrees north latitude and 158.6627778 degrees west longitude.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 0.5 to 1.7 degrees C (cryic soil temperature regime)
Soil moisture control section - Dry less than 45 consecutive days from June to October (udic soil moisture regime)
Thickness of ochric epipedon - 8 to 25 cm
Thickness of albic horizon - 3 to 12 cm
Thickness of spodic horizon - 12 to 24 cm
Thickness of andic soil properties - 31 to 40 cm

All mineral horizons-
Reaction - 3.4 to 6.1
Volcanic glass content - 0 to 21 percent
Ammonium oxalate extractable Al + Fe - 0.25 to 3.57
Moist bulk density - 0.60 to 1.65 g/cc

Particle-size control section-
Clay content - 5 to 8 percent
Rock fragments - 0 to 65 percent

Oe horizon
Thickness - 5 to 13 cm

E/A horizon
Hue - 7.5YR or 10YR
Value - 2 to 5
Chroma - 1 to 3
Fine earth texture - silt loam or highly silt
Clay content - 5 to 9 percent
Reaction - 3.4 to 5.2
Rock fragments - 0 to 11 percent subangular gravels
Thickness - 3 to 12 cm

Bhs horizon
Hue - 5YR or 7.5YR
Value - 2 to 3
Chroma - 1 to 3
Fine earth texture - Medial silt loam
Clay content - 3 to 7 percent
Reaction - 4.5 to 5.9
Rock fragments - 0 to 11 percent subangular gravels
Thickness - 12 to 24 cm

BC1 (or BC) horizon
Hue - 10YR or 7.5YR
Value - 2 to 4
Chroma - 2 to 6
Fine earth texture - Medial silt loam or medial sandy loam
Clay content - 5 to 8 percent
Reaction - 5.2 to 5.8
Rock fragments - 0 to 47 percent subangular gravels
Thickness - 18 to 28 cm

2BC2 (or 2C) horizon
Hue - 10YR or 2.5Y
Value - 3 or 4
Chroma - 1 to 4
Fine earth texture - Silt loam, sandy loam, or stratified sandy loam
Clay content - 5 to 8
Reaction - 5.3 to 6.1
Rock fragments - 40 to 65 percent subrounded gravels
Thickness - 106 to 138 cm

COMPETING SERIES:
Hurdygurdy - Found on mountains and on slopes up to 70 percent
Talkeetna - Cobbles present in glacial till, slopes range up to 85 percent

GEOGRAPHIC SETTING:
Parent material - Herbaceous organic material over coarse-loamy volcanic ash over gravelly glacial drift
Landform - Rises on plains, hills
Slope - 0 to 25 percent
Elevation - 10 to 184 meters
Climate - Cool summers; cold winters, August and September are the wettest months
Mean annual precipitation - 614 to 934 mm
Mean annual air temperature - -0.5 to 0.7 degrees C
Frost free duration - 85 to 140 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Damcreek - Aquic conditions within 60 cm, drainageways on plains
Wearyriver - Aquic conditions at surface, dips on plains
Ciimaq - Shallow (22 cm below the mineral soil surface) to lithic contact, summits and shoulders on hills
Terlak - No albic horizon present, medial over sandy or sandy skeletal, swales on plains

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: (Ksat)
Drainage class - Well drained
Saturation in normal years - None
Flooding - None
Ponding - None
Ksat - Moderately high in the E/A and Bhs horizons and moderately high to high in the BC1 and 2BC2 horizons

USE AND VEGETATION:
Use - Community development, wildlife habitat, recreation, berry picking, and forestry resources
Potential natural vegetation - Boreal forest composed of white spruce, paper birch, spirea, grass, and ferns

DISTRIBUTION AND EXTENT: Bristol Bay Lowlands; MLRA 236; moderate extent

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

SERIES ESTABLISHED: Nushagak-Mulchatna Watershed Soil Survey, Dillingham Census Area, Alaska, 2015

REMARKS:
Particle-size control section - 34 to 109 cm
Ochric epipedon
Soil moisture regime - Udic
Andic soil properties - Bhs and BC1 (or BC) horizons
Spodic Horizon - Bhs horizon
Albic Horizon - E/A horizon

Type location was moved during initial mapping of Nushagak-Mulchatna Watershed Soil Survey, classification updated to reflect documentation. The series was proposed in the 1964 Dillingham Area, Alaska, Soil Survey. Established during the final correlation of the Togiak, AK Soil Survey where it is also used. The tentative series Snagpoint was correlated to Aleknagik, which had previously not been established. Previous classification was coarse-loamy, mixed, superactive Spodic Dystrocryepts.

---

National Cooperative Soil Survey
U.S.A.