LOCATION NUNACHUAK AK
Established Series
SAS/SJN
05/2022
NUNACHUAK SERIES
The Nunachuak series consists of very deep, very poorly drained soils formed in organic material over silty and loamy alluvium on flood plains. Slopes are 0 to 3 percent. The mean annual precipitation is about 630 millimeters and the mean annual air temperature is about 0.6 degrees C.
TAXONOMIC CLASS: Coarse-loamy, isotic, acid Typic Cryaquents
TYPICAL PEDON: Nunachuak mucky silt, located on a flood plain with a slope of 1 percent and elevation of 10 meters; when described on August 30th, 2009 the soil was saturated from 50 to 183 cm (Colors are for moist soil unless otherwise noted)
Oi--0 to 9 cm; peat; nonsticky, nonplastic; many fine roots, many medium roots, and few coarse roots; very strongly acid (pH 4.6); clear smooth boundary
A--9 to 18 cm; very dark grayish brown (10YR 3/2) mucky silt; 13 percent sand; 82 percent silt; 5 percent clay; weak medium granular structure; friable, nonsticky, nonplastic; common fine roots, many medium roots, and few coarse roots; very strongly acid (pH 4.9); gradual smooth boundary
Cg1--18 to 41 cm; dark grayish brown (2.5Y 4/2) silt; 13 percent sand; 82 percent silt; 5 percent clay; massive; firm, slightly sticky, nonplastic; common fine roots, few medium roots, and few coarse roots; 15 percent medium brown (7.5YR 4/4) masses of oxidized iron with clear boundaries; strongly acid (pH 5.1); clear smooth boundary
2Cg2--41 to 110 cm; gray (5Y 5/1) stratified silt loam; 40 percent sand; 50 percent silt; 10 percent clay; massive; firm, slightly sticky, nonplastic; few fine roots, few medium roots, and few coarse roots; 10 percent medium brown (7.5YR 4/4) masses of oxidized iron with clear boundaries; 5 percent nonflat 2 to 75 millimeter fragments; strongly acid (pH 5.5); clear smooth boundary
3Cg3--110 to 183 cm; dark greenish gray (10Y 4/1) sandy loam; massive; 5 percent medium dark brown (7.5YR 3/3) masses of oxidized iron with clear boundaries; moderately acid (pH 5.8)
TYPE LOCATION: Dillingham Census Area, Alaska; 4 kilometers northwest of the Village of Portage Creek; 58.9388889 degrees north latitude and 157.6919444 degrees west longitude.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 0.9 to 2.5 degrees C (cryic soil temperature regime)
Soil moisture control section - Soil is saturated within 25 cm of the soil surface for much of the growing season in most years (aquic soil moisture regime)
Depth to reduced matrix - 10 to 20 cm
Depth to aquic conditions - 0 - 26 cm
All mineral horizons-
Reaction - 4.9 to 5.9
Particle-size control section-
Clay content - 1 to 10 percent
Rock fragments - 0 to 5 percent
Oi horizon
Thickness - 5 to 15
Reaction - 4.6 to 5.5
A horizon
Hue - 10YR or 7.5YR
Value - 3
Chroma - 2 to 4
Fine earth texture - Mucky silt, stratified mucky silt loam, or very fine sandy loam
Clay content - 4 to 8 percent
Reaction - 4.9 to 5.5
Rock fragments - 0 percent
Thickness - 7 to 10 cm
Cg1 horizon
Hue - 10YR to 5Y
Value - 4
Chroma - 1 or 2
Fine earth texture - Silt or stratified silt loam
Clay content - 2 to 8 percent
Reaction - 5.1 to 5.7
Rock fragments - 0 percent
Thickness - 23 to 70 cm
2Cg2 horizon
Hue - 5Y
Value - 5
Chroma - 1
Fine earth texture - Stratified silt loam or silt
Clay content - 1 to 10 percent
Reaction - 5.5 to 5.9
Rock fragments - 2 to 5 percent total; 1 to 5 percent rounded gravels and 1 to 3 percent rounded cobbles
Thickness - 50 to 75 cm
3Cg3 horizon
Hue - 10YR or 5Y
Value - 4
Chroma - 1 or 2
Fine earth texture - Sandy loam, stratified silt loam, or silt loam
Clay content - 1 to 9 percent
Reaction - 5.8 to 5.9
Rock fragments - 0 percent
Thickness - 43 to 73 cm
COMPETING SERIES: There are no competing series
GEOGRAPHIC SETTING:
Parent material - Grassy organic material over coarse-silty alluvium over coarse-loamy alluvium
Landform - Flood plains
Slope - 0 to 2 percent
Elevation - 8 to 43 meters
Climate - Cool summers; cold winters, August and September are the wettest months
Mean annual precipitation - 608 to 726 mm
Mean annual air temperature - 0.5 to 0.7 degrees C
Frost free duration - 85 to 140 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Lewispoint - Moderately well drained; loamy alluvium; flood plains
Kokwok - Well drained; loamy, sandy and gravelly alluvium; similar landform position
Halfmoon - Very poorly drained; organic parent material; low flood plains
Ekwok - Well drained; loamy eolian deposits; plains
Klutuk - Well drained; volcanic ash and loamy eolian deposits; plains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: (Ksat)
Drainage class - Very poorly drained
Saturation in normal years - Occurs within 25 cm of the soil surface for much of the growing season
Flooding - Frequent and brief
Ponding - Occasional and long
Ksat - Moderately high to high throughout the soil profile, except moderately high in the Cg1 and 2Cg2 horizons
USE AND VEGETATION:
Use - Wildlife habitat
Potential natural vegetation - Western maritime scrubland composed of feltleaf willow, tealeaf willow, bluejoint grass, and horsetails
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 - 34 to 109 cm
Soil moisture regime - Aquic
Ochric epipedon
Reduced matrix - All Cg horizons
Aquic soil conditions - All horizons
National Cooperative Soil Survey
U.S.A.