LOCATION AWBRIG                  OR

Established Series
Rev. WRP/JGM/EED
12/2017

AWBRIG SERIES

Landscape--Willamette Valley
Landform--depressions and drainageways of stream terraces
Slope--0 to 2 percent
Parent material--mixed alluvium derived from volcanic and sedimentary rock over glaciolacustrine deposits from the Missoula Floods
Mean annual precipitation--about 1150 mm
Mean annual air temperature--about 11 degrees C
Depth class--very deep
Drainage class--poorly drained
Soil moisture regime--aquic
Soil temperature regime--mesic
Soil moisture subclass--typic

TAXONOMIC CLASS: Fine, smectitic, mesic Chromic Vertic Albaqualfs

TYPICAL PEDON: Awbrig silty clay loam in an area of pasture

Ap1--0 to 5 cm; silty clay loam, light brownish gray (10YR 6/2) dry, very dark grayish brown (10YR 3/2) moist; moderate very fine subangular blocky and fine granular structure; hard, friable, moderately sticky and moderately plastic; many very fine roots; many fine irregular pores; 1 percent fine prominent yellowish brown (10YR 5/6) masses of oxidized iron on surfaces along root channels; strongly acid (pH 5.4); clear smooth boundary

Ap2--5 to 18 cm; silty clay loam, light brownish gray (10YR 6/2) dry, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine and common fine roots; many very fine tubular and irregular pores; 10 percent fine faint and distinct brown (10YR 4/3) and dark yellowish brown (10YR 4/4) masses of iron accumulation and 3 percent fine spherical black (10YR 2/1) iron-manganese concretions throughout; slightly acid (pH 6.5); abrupt irregular boundary

2Btssg1--18 to 46 cm; clay, gray (10YR 5/1) dry, very dark gray (10YR 3/1) moist; weak coarse prismatic structure with vertical cracks 1 cm wide or more when dry, but appears massive when wet; extremely hard, very firm, very sticky and very plastic; few very fine and fine roots; few very fine tubular pores; common distinct slickensides (pedogenic) and pressure faces and common faint clay films on faces of peds; 1 percent fine yellowish brown (10YR 5/6) masses of oxidized iron on surfaces along pores and 1 percent fine spherical black (10YR 2/1) iron-manganese concretions throughout; slightly acid (pH 6.3); clear wavy boundary

2Btssg2--46 to 74 cm; silty clay, dark grayish brown (10YR 4/2) dry, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse prismatic structure parting to weak medium and fine subangular blocky; extremely hard, firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; few faint slickensides (pedogenic), many pressure faces, and 75 percent faint and distinct clay films on all faces of peds; 40 percent medium distinct irregular yellowish brown (10YR 5/4) masses of oxidized iron on faces of peds; slightly acid (pH 6.5); gradual irregular boundary

2Btg--74 to 122 cm; silty clay loam, pale brown (10YR 6/3) dry, grayish brown (10YR 5/2) moist; weak medium prismatic structure; hard, firm, moderately sticky and moderately plastic; many very fine tubular pores; 60 percent distinct very dark grayish brown (10YR 3/2) clay films on faces of peds and on surfaces along pores; 40 percent fine prominent irregular yellowish brown (10YR 5/6) and brown (7.5YR 4/4) masses of oxidized iron on faces of peds and 20 percent fine distinct irregular light gray (10YR 7/2) iron depletions on faces of peds; 3 percent gravel; neutral (pH 6.6); abrupt smooth boundary

2Cg--122 to 152 cm; clay loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; massive; hard, firm, moderately sticky and moderately plastic; common very fine tubular pores; 20 percent fine distinct irregular dark gray (10YR 4/1) iron depletions on faces of peds; neutral (pH 7.0)

TYPE LOCATION: Lane County, Oregon, about 12 km northwest of Eugene; about 12 m north and 640 m west of the southeast corner of section 32, T. 16 S. R. 4 W.; latitude 44.1280531, longitude -123.1955537, datum WGS 84 (coordinates estimated from PLSS details)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--11 to 13 degrees C
Moisture control section--seasonal high water table within 15 to 30 cm of soil surface during the growing season
Depth to top of argillic horizon--13 to 30 cm
Depth to slickensides--13 to 30 cm
Depth to bottom of cracks when dry--more than 50 cm

Particle-size control section
*Clay content--50 to 60 percent
*Total fragment content--0 to 5 percent

Ap horizon
Hue--7.5YR to 2.5Y
Value--3 or 5 moist, 6 or 7 dry
Chroma--2 or less moist or dry
Clay content--27 to 30 percent
Sand content--5 to 20 percent
Total fragment content--0 to 5 percent
Reaction--5.1 to 6.5
Thickness--13 to 30 cm

2Btssg horizon
Hue--7.5YR to 2.5Y
Value--3 or 4 moist, 5 or 6 dry
Chroma--1 or 2 moist or dry
Fine-earth texture--clay, silty clay
Clay content--50 to 60 percent
Sand content--2 to 15 percent
Total fragment content--0 to 5 percent
Reaction--6.1 to 7.3
Thickness--20 to 100 cm

2Btg horizon
Hue--10YR, 2.5Y
Value--4 or 5 moist, 6 dry
Chroma--1 to 4 moist and dry
Fine-earth texture--clay loam, silty clay loam
Clay content--27 to 40 percent
Sand content--2 to 25 percent
Total fragment content--0 to 5 percent
Reaction--6.6 to 7.3
Thickness--0 to 56 cm

2C horizon
Hue--10YR, 2.5Y
Value--4 or 5 moist, 6 dry
Chroma--1 to 4 moist or dry
Fine-earth texture--clay loam, silty clay loam
Clay content--27 to 40 percent
Sand content--2 to 25 percent
Total fragment content--0 to 5 percent
Reaction--6.6 to 7.3

COMPETING SERIES:
Beckwith--less than 10 percent sand throughout profile, including the particle-size control section; only hue of 10YR in A or Ap horizon
Floraville--less than 7 percent sand and 35 to 48 percent clay in particle-size control section; mean annual soil temperature 13 to 15 degrees C; only hue of 10YR in A or Ap horizon
Mariosa--brittleness (fragipan) from 50 to 100 cm; only hue of 10YR in A or Ap horizon
Okaw--less than 15 percent sand throughout profile, including particle-size control section; only hue of 10YR in A or Ap horizon

GEOGRAPHIC SETTING:
Elevation--55 to 185 m
Climate--warm, dry summers; cool, moist winters
Mean annual precipitation--1000 to 1300 mm
Mean annual air temperature--10 to 12 degrees C
Mean January air temperature--4 to 5 degrees C
Mean July air temperature--18 to 19 degrees C
Frost-free period--165 to 210 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Bashaw--no abrupt textural change; in similar positions
Clackamas--fine-loamy; somewhat poorly drained; in convex positions
Coburg--mollic epipedon; moderately well drained; in linear positions
Conser--no abrupt textural change; in similar positions
Courtney--very gravelly or extremely gravelly C horizon within a depth of 100 cm; in similar positions

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--poorly drained
Saturation in normal years--apparent water table at a depth of 15 cm above the surface to a depth of 45 cm below the surface in December through April
Flooding--rare
Ponding--frequent, long periods in December through April
Saturated hydraulic conductivity (Ksat)--low

USE AND VEGETATION:
Use--production of spring grain, grass seed, hay, and pasture
Potential natural vegetation--grasses, sedges, rushes, hawthorn, rose, Oregon ash

DISTRIBUTION AND EXTENT: Willamette Valley, Oregon; MLRA 2; moderate extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Lane County Area, Oregon; 1981

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 18 to 68 cm
*Ochric epipedon
*Argillic horizon--zone from 18 to 122 cm
*Aquic conditions--zone from 5 to 152 cm
*Depth to abrupt textural change--18 cm
*Depth to lithologic discontinuity--18 cm
*Slickensides--zone from 18 to 74 cm

The Awbrig soils are on the Winkle geomorphic surface in the Willamette Valley of Oregon. The lithologic discontinuity represents a change in parent material from alluvium deposited by the Willamette River and its tributaries to Missoula Flood sediment.

8/2017--This official series description was updated according to SSR01 Technical Note 11--Content and Format of Official Series Descriptions (revised 11/2017). Most of the changes were in formatting. The competing series were updated, and the classification was updated from Vertic Albaqualfs to Chromic Vertic Albaqualfs. The high value of the Ap horizon when dry meets the criteria for Chromic Vertic Albaqualfs in the twelfth edition of the Keys to Soil Taxonomy.

ADDITIONAL DATA:
Characterization data--pedon number S65-Oreg-20-1, Oregon State University, unpublished; soil survey sample number S99OR-043-004, Kellogg Soil Survey Laboratory

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National Cooperative Soil Survey
U.S.A.