LOCATION TERLAK AK
Established Series
SAS/TJR/SJN
02/2022
TERLAK SERIES
The Terlak series consists of very deep, somewhat poorly drained soils formed in volcanic ash over slope alluvium on swales on plains. Slopes range from 0 to 6 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 sandy or sandy-skeletal, amorphic over mixed Oxyaquic Haplocryands
TYPICAL PEDON: Terlak highly organic silt loam, located on a rise on a plain with a slope of 4 percent and elevation of 16 meters; when described on July 20th, 2011 the soil was moist throughout (Colors are for moist soil unless otherwise noted)
Oe--0 to 3 centimeters; moderately decomposed plant material; common fine roots, common medium roots, and many very fine roots; extremely acid, pH 4.3
AE--3 to 9 centimeters; 30 percent black (10YR 2/1) and 70 percent very dark gray (7.5YR 3/1) stratified highly organic silt loam; 20 percent sand; 73 percent silt; 7 percent clay; weak medium granular structure; friable, nonsticky, nonplastic; common fine roots, common medium roots, and common very fine roots; 10 percent nonflat 2 to 75 millimeter fragments; extremely acid, pH 4.2; abrupt wavy boundary
Bhs--9 to 29 centimeters; black (5YR 2.5/1) medial highly organic silt loam; 23 percent sand; 71 percent silt; 6 percent clay; weak medium subangular blocky structure; very friable, nonsticky, nonplastic; common fine roots, common medium roots, common coarse roots, and common very fine roots; 10 percent nonflat 2 to 75 millimeter fragments; very strongly acid, pH 4.7; clear smooth boundary
BC--29 to 50 centimeters; 20 percent dark brown (10YR 3/3) and 70 percent dark brown (7.5YR 3/2) medial gravelly silt loam; 27 percent sand; 67 percent silt; 6 percent clay; weak coarse subangular blocky structure; friable, nonsticky, nonplastic; common fine roots, common medium roots, common coarse roots, and common very fine roots; 10 percent coarse prominent irregular dark brown (7.5YR 3/4) masses of oxidized iron with clear boundaries in matrix; 1 percent nonflat 76 to 250 millimeter fragments and 30 percent nonflat 2 to 75 millimeter fragments; very strongly acid, pH 5.0; clear smooth boundary
2C1--50 to 77 centimeters; 30 percent brown (10YR 4/3) and 70 percent very dark gray (10YR 3/1) stratified very gravelly loamy sand; 80 percent sand; 14 percent silt; 6 percent clay; massive; friable; common very fine roots; 50 percent nonflat 2 to 75 millimeter fragments; strongly acid, pH 5.1; clear wavy boundary
3C2--77 to 183 centimeters; brown (10YR 4/3) stratified very gravelly sandy clay loam; 50 percent sand; 27 percent silt; 23 percent clay; massive; friable; 55 percent nonflat 2 to 75 millimeter fragments; strongly acid, pH 5.1; clear smooth boundary
TYPE LOCATION: Dillingham Census Area, Alaska; 2 kilometers southeast of the Village of Aleknagik; 59.2669444 degrees north latitude and 158.5919444 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 umbric epipedon - 26 to 47 cm
Thickness of spodic horizon - 7 to 20 cm
Thickness of andic soil properties - 33 to 88 cm
All mineral horizons-
Reaction - 4.2 to 5.2
Volcanic glass content - 0 to 21 percent
Ammonium oxalate extractable Al + 1/2 Fe - 0.25 to 3.57
Moist bulk density - 0.60 to 1.65 g/cc
Particle-size control section-
Clay content - 4 to 23 percent
Rock fragments - 0 to 55 percent
Oe horizon
Thickness - 2 to 15 cm
AE horizon
Hue - 7.5YR or 10YR
Value - 2 to 4
Chroma - 1 or 2
Fine earth texture - Stratified highly organic silt loam or stratified highly organic sandy loam
Clay content - 5 to 9 percent
Reaction - 4.2 to 4.4
Rock fragments - 0 to 10 percent subangular gravels
Thickness - 2 to 26 cm
Bhs horizon
Hue - 5YR or 7.5YR
Value - 2.5 to 3
Chroma - 1 to 4
Fine earth texture - Medial highly organic silt loam
Clay content - 4 to 8 percent
Reaction - 4.4 to 4.7
Rock fragments - 0 to 10 percent subangular gravels
Thickness - 13 to 20 cm
BC horizon
Hue - 10YR or 7.5YR
Value - 2 or 3
Chroma - 1 to 3
Fine earth texture - Medial silt loam or stratified medial silt loam
Clay content - 4 to 8 percent
Reaction - 4.8 to 5.1
Rock fragments - 25 to 31 percent total; 25 to 30 percent subangular gravels and 0 to 1 percent subangular cobbles
Thickness - 6 to 52 cm
2C1 horizon (where present)
Hue - 10YR
Value - 3 or 4
Chroma - 1 to 3
Fine earth texture - Stratified loamy sand
Clay content - 4 to 8 percent
Reaction - 5.1
Rock fragments - 15 to 50 percent subrounded gravels
Thickness - 10 to 27 cm
3C2 or 2C horizon
Hue - 10YR
Value - 4
Chroma - 3 or 4
Fine earth texture - Silt loam or stratified sandy clay loam
Clay content - 14 to 23
Reaction - 5.1 to 5.2
Rock fragments - 25 to 55 percent subrounded gravels
Thickness - 93 to 106 cm
COMPETING SERIES: There are no competing series
GEOGRAPHIC SETTING:
Parent material - Organic material over coarse-loamy volcanic ash over sandy and gravelly slope alluvium
Landform - Swales on plains
Slope - 0 to 6 percent
Elevation - 10 to 184 meters
Climate - Cool summers; cold winters, August and September are the wettest months
Mean annual precipitation - 628 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
Snagpoint - No slope alluvium present, rises on plains and hills
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: (Ksat)
Drainage class - Somewhat poorly drained
Saturation in normal years - Within 36 cm less than one month of the growing season
Flooding - None
Ponding - Occasional and very brief
Ksat - Moderately high to high in the volcanic ash parent material, high in the 2C1, and moderately low to high in the 3C2
USE AND VEGETATION:
Use - Wildlife habitat and forestry resources
Potential natural vegetation - Boreal forest composed of white spruce, paper birch with and understory of spirea, grass, and ferns
DISTRIBUTION AND EXTENT: Bristol Bay Lowlands; MLRA 236; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Nushagak-Mulchatna Watershed Soil Survey, Dillingham Census Area, Alaska, 2019
REMARKS:
Particle-size control section - 3 to 103 cm
Umbric epipedon - AE, Bhs, and BC horizons
Soil moisture regime - Udic
Andic soil properties - Bhs and BC horizons
Spodic Horizon - Bhs horizon
Redox concentrations - BC horizon
National Cooperative Soil Survey
U.S.A.