LOCATION COURTNEY OR
Established Series
Rev. AON/JGM/EED
12/2017
COURTNEY SERIES
Landscape--Willamette Valley
Landform--depressions and drainageways of stream terraces
Slope--0 to 3 percent
Parent material--mixed alluvium
Mean annual precipitation--about 1300 mm
Mean annual air temperature--about 11 degrees C
Depth class--very deep
Drainage class--poorly drained
Soil moisture regime--aquic
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Fine, smectitic, mesic Abruptic Argiaquolls
TYPICAL PEDON: Courtney gravelly silty clay loam, cultivated
A1--0 to 20 cm; gravelly silty clay loam, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine roots; few fine tubular pores; 1 percent fine distinct yellowish brown (10YR 5/6) masses of oxidized iron; 20 percent gravel; moderately acid (pH 5.6); clear smooth boundary
A2--20 to 43 cm; gravelly silty clay loam, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many fine roots; few fine tubular pores; 6 percent medium distinct yellowish brown (10YR 5/6) masses of oxidized iron; 25 percent gravel; moderately acid (pH 5.8); abrupt smooth boundary
2Btg1--43 to 60 cm; gravelly clay, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; strong medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many fine roots; few fine tubular pores; 15 percent clay films on all faces of peds; 1 percent medium distinct yellowish brown (10YR 5/6) masses of oxidized iron; 25 percent gravel; moderately acid (pH 5.8); abrupt smooth boundary
2Btg2--60 to 84 cm; gravelly clay, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, firm, very sticky and very plastic; few fine roots; many fine tubular pores; 25 percent clay films on all faces of peds; 1 percent medium distinct yellowish brown (10YR 5/6) masses of oxidized iron; 30 percent indurated mixed gravel; moderately acid (pH 5.8); clear smooth boundary
3Cg--84 to 122 cm; very gravelly clay loam, brown (7.5YR 5/4) dry, brown (7.5YR 4/4) moist; massive; hard, firm, moderately sticky and moderately plastic; many coarse tubular pores; 1 percent medium distinct yellowish brown (10YR 5/6) masses of oxidized iron; 50 percent gravel and 5 percent cobbles; moderately acid (pH 5.8); clear smooth boundary
4C--122 to 150 cm; extremely gravelly sand, brown (7.5YR 5/4) dry, brown (7.5YR 4/4) moist; massive; soft, friable, nonsticky and nonplastic; many fine irregular pores; 70 percent indurated mixed gravel and 10 percent indurated mixed cobbles; moderately acid (pH 5.8)
TYPE LOCATION: Linn County, Oregon, about 8 km east of Albany; about 100 m north and 60 m east of the southwest corner of section 6, T. 11 S., R. 2 W.; latitude 44.6363870, longitude -122.9870215, 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 at the soil surface more than 30 consecutive days
Depth to aquic conditions--0 to 30 cm
Thickness of mollic epipedon--25 to 49 cm
Thickness of argillic horizon--25 to 70 cm
Particle-size control section
Clay content--50 to 60 percent
Total fragment content--15 to 35 percent
A horizon
Hue--10YR, neutral
Value--2 or 3 moist, 4 or 5 dry
Chroma--0 to 2 moist or dry
Fine-earth texture--silty clay loam, clay loam
Clay content--27 to 35 percent
Sand content--10 to 30 percent
Total fragment content--15 to 30 percent
Gravel content--15 to 30 percent
Cobble content--0 to 3 percent
Reaction--5.1 to 6.0
Thickness--25 to 49 cm
2Btg horizon
Hue--10YR, neutral
Value--3 or 4 moist, 5 or 6 dry
Chroma--0 to 2 moist or dry
Fine-earth texture--clay, silty clay
Clay content--50 to 60 percent
Sand content--5 to 25 percent
Total fragment content--15 to 35 percent
Gravel content--15 to 35 percent
Cobble content--0 to 3 percent
Reaction--5.6 to 6.5
Thickness--25 to 70 cm
3Cg horizon
Hue--7.5YR, 10YR
Value--4 or 5 moist, 5 to 7 dry
Chroma--4 to 6 moist or dry
Fine-earth texture--clay loam, sandy clay loam
Clay content--27 to 35 percent
Sand content--30 to 50 percent
Total fragment content--35 to 60 percent
Gravel content--32 to 55 percent
Cobble content--3 to 6 percent
Reaction--5.6 to 6.5
4C horizon
Hue--7.5YR, 10YR
Value--4 or 5 moist, 5 to 7 dry
Chroma--4 to 6 moist or dry
Fine-earth texture--sand, coarse sand
Clay content--0 to 5 percent
Sand content--85 to 100 percent
Total fragment content--50 to 85 percent
Gravel content--45 to 80 percent
Cobble content--0 to 10 percent
Reaction--5.6 to 7.3
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--50 to 245 m
Climate--dry, warm summers; wet, cool winters
Mean annual precipitation--1000 to 1500 mm
Mean annual air temperature--10 to 12 degrees C
Mean July air temperature--19 degrees C
Mean January air temperature--4 degrees C
Frost-free period--165 to 210 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Awbrig--cracks on the surface in summer; in similar positions
Bashaw--cracks on the surface in summer; slickensides; in similar positions
Clackamas--less than 35 percent clay in particle-size control section; in similar positions
Conser--cracks on the surface in summer; in similar positions
Salem--well drained; less than 35 percent clay in particle-size control section; in convex 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 November through May
Flooding--none
Ponding--frequent, long periods in November through May
Saturated hydraulic conductivity (Ksat)--low
USE AND VEGETATION:
Use--production of spring grain and grass seed; production of hay and pasture in artificially drained areas
Potential natural vegetation--annual and perennial grasses, wild rose brush, Oregon ash
DISTRIBUTION AND EXTENT: Willamette Valley, Oregon; MLRA 2; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Linn County, Oregon; 1924
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 43 to 84 cm
*Aquic conditions-zone from the surface to a depth of 150 cm
*Mollic epipedon--zone from the surface to a depth of 43 cm
*Argillic horizon--zone from 43 to 84 cm
The Courtney soils are on the Winkle geomorphic surface in the Willamette Valley of Oregon.
7/2017--The type location of this official series description was changed from Marion County, Oregon, in the NW1/4SE1/4 of section 6, T. 8 S., R. 2 W., to reflect more recent data and a more geographically central location. The competing series were updated also. The 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. No major technical changes were made.
National Cooperative Soil Survey
U.S.A.