LOCATION USTIUGOF                AK

Established Series
SAS/TJR/SJN
02/2022

USTIUGOF SERIES

The Ustiugof series consists of very deep, very poorly drained soils formed in silty, sandy, and gravelly marine deposits on coastal plains. Slopes are 0 to 3 percent. The mean annual precipitation is about 610 millimeters and the mean annual air temperature is about 0.6 degrees C.

TAXONOMIC CLASS: Sandy-skeletal, mixed Typic Cryaquents

TYPICAL PEDON: Ustiugof silt loam, located on a coastal plain talf with a slope of 1 percent and elevation of 5 meters; when described on September 17th, 2007 the soil was wet from 32 to 183 cm (Colors are for moist soil unless otherwise noted)

A--0 to 20 cm; dark grayish brown (10YR 4/2) silt loam; 15 percent sand; 78 percent silt; 7 percent clay; massive; friable, nonsticky, nonplastic; many very fine and fine roots, many medium roots, and common coarse roots; noneffervescent; neutral (pH 6.6); clear wavy boundary

Cg1--20 to 32 cm; dark gray (2.5Y 4/1) silt loam; 35 percent sand; 61 percent silt; 4 percent clay; massive; friable, nonsticky, nonplastic; common very fine and fine roots, common medium roots, and few coarse roots; noneffervescent; neutral (pH 6.6); abrupt smooth boundary

2Cg2--32 to 183 cm; very dark gray (10YR 3/1) extremely gravelly sand; 95 percent sand; 3 percent silt; 2 percent clay; single grain; loose, nonsticky, nonplastic; few very fine and fine roots, few medium roots, and few coarse roots; 68 percent nonflat 5 to 75 millimeter fragments, 2 percent nonflat 2 to 5 millimeter fragments; noneffervescent; moderately acid (pH 6.0)

TYPE LOCATION: Dillingham Census Area, Alaska; Located in the Village of Ekuk; 58.802222 degrees north latitude and 158.5536111 degrees west longitude.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 1.5 to 3.5 degrees C (cryic soil temperature regime)
Soil moisture control section - Soil is wet within 25 centimeters of the soil surface for much of the growing season in most years (aquic soil moisture regime)
Depth to reduced matrix - 11 to 20 cm
Depth to aquic conditions - 11 to 20 cm

All mineral horizons-
Reaction - 6.0 to 7.5

Particle-size control section-
Clay content - 1 to 6 percent
Rock fragments - 0 to 70 percent

A horizon
Hue - 10YR to 5Y
Value - 2.5 to 4
Chroma - 2
Fine earth texture - Silt loam or silt
Clay content - 5 to 9 percent
Reaction - 6.5 to 7.2
Rock fragments - 0 percent
Thickness - 11 to 20 cm

Cg1 horizon
Hue - 10YR to 10Y
Value - 2.5 to 5
Chroma - 1 or 2
Fine earth texture - Stratified loamy coarse sand, coarse sand, or silt loam
Clay content - 1 to 6 percent
Reaction - 6.6 to 7.5
Rock fragments - 0 to 10 percent subrounded gravels
Thickness - 4 to 46 cm

2Cg2 horizon
Hue - 10YR
Value - 3
Chroma - 1
Fine earth texture - Coarse sand or sand
Clay content - 1 to 3 percent
Reaction - 6.0 to 7.3
Rock fragments - 35 to 70 percent total; 35 to 70 percent rounded medium and coarse gravels, and 0 to 3 percent rounded fine gravels
Thickness - 121 to 168 cm

COMPETING SERIES: Anan, Eachuston, and Jurvannah. Anan soils have mean annual precipitation of 2780 mm and mean annual temperature of 5 degrees C. Eachuston soils have mean annual precipitation of 250 mm and the lower part ranges to slightly alkaline. Jurvannah soils have a water table that fluctuates between 45 and 90 cm.

GEOGRAPHIC SETTING:
Parent material - Coarse-silty marine deposits over sandy and gravelly marine deposits
Landform - Coastal plains, talfs
Slope - 0 percent
Elevation - 0 to 10 meters
Climate - Cool summers; cold winters, August and September are the wettest months
Mean annual precipitation - 607 to 615 mm
Mean annual air temperature - 0.3 to 0.7 degrees C
Frost free duration - 85 to 140 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Ekuk - No aquic conditions, formed in sandy and gravelly fluviomarine deposits, coastal plains
Sheepisland - Aquic conditions within 25 cm, formed in organic parent material, coastal plains
Mudie - Aquic conditions within 25 cm, formed in silty marine deposits, coastal plains
Flounder - Aquic conditions within 25 cm, formed in colluvium and glacial till, bluffs

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: (Ksat)
Drainage class - Very poorly drained
Saturation in normal years - Within 25 cm of the soil surface for all months
Flooding - Rare
Ponding - None
Ksat - Moderately high in the A horizon, moderately high to high in the Cg1 horizon, and high in the 2Cg2 horizon

USE AND VEGETATION:
Use - Wildlife habitat
Potential natural vegetation - Western maritime grassland composed of bluejoint grass, American dunegrass, beach pea, and Scottish licorice-root

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 - 25 to 100 cm
Soil moisture regime - Aquic
Ochric epipedon
Aquic soil conditions - All Cg horizons
Reduced matrix - All Cg horizons

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National Cooperative Soil Survey
U.S.A.