LOCATION EILERTSEN OREstablished Series
TAXONOMIC CLASS: Fine-silty, isotic, mesic Ultic Hapludalfs
TYPICAL PEDON: Eilertsen silt loam, woodland. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; leaves, twigs, moss and woody materials.
A1--1 to 8 inches; very dark brown (10YR 2/2) silt loam, grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; slightly acid (pH 6.2); clear smooth boundary.
A2--8 to 18 inches; very dark grayish brown (10YR 3/2) silt loam, brown (10YR 5/3) dry; strong fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; strongly acid (pH 5.2); clear wavy boundary. (Combined thickness of the A horizon is 10 to 19 inches)
Bt1--18 to 26 inches; brown (10YR 4/3) silty clay loam, yellowish brown (10YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots; many very fine tubular pores; common prominent very dark grayish brown (10YR 3/2) clay films on faces of peds and in pores; very strongly acid (pH 5.0); gradual wavy boundary.
Bt2--26 to 38 inches; dark yellowish brown (10YR 4/4) silt loam, light yellowish brown (10YR 6/4) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine tubular pores; common distinct very dark grayish brown (10YR 3/2) clay films on faces of peds and in pores; very strongly acid (pH 5.0); clear smooth boundary. (Combined thickness of the Bt horizon is 15 to 31 inches)
2BC--38 to 50 inches; brown (10YR 4/3) loam, light yellowish brown (10YR 6/4) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; very strongly acid (pH 4.9); gradual wavy boundary. (0 to 15 inches thick)
2C--50 to 61 inches; brown (10YR 4/3) fine sandy loam, light yellowish brown (10YR 6/4) dry; massive; slightly hard, very friable, slightly sticky and nonplastic; few fine roots; many very fine tubular pores; common fine distinct grayish brown (10YR 5/2) iron depletions and brown (7.5YR 4/4) masses of iron accumulation; very strongly acid (pH 4.7).
TYPE LOCATION: Columbia County, Oregon; 100 yards west of logging road in SE1/4 SW1/4 NW1/4 section 23, T. 5 N., R. 4 W.; Pittsburgh, OR USGS 7.5 minute quadrangle; NAD 1927.
RANGE IN CHARACTERISTICS: The soil is usually moist but is dry for a short period of less than 45 consecutive days between depths of 4 to 12 inches in the four month period following the summer solstice in most years. The mean annual soil temperature is 49 to 55 degrees F. The umbric epipedon ranges from 10 to 20 inches thick. Depth to bedrock is over 60 inches. Hue is 10YR, 7.5YR, or 2.5Y. The particle-size control section has 18 to 35 percent clay content and less than 15 percent coarser than very fine sand.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It is silt loam with 12 to 20 percent clay. Soil reaction is very strongly acid to slightly acid.
The Bt horizon has value of 4 or 5 moist, 5 through 7 dry, and chroma of 3 through 6 moist and dry. Redox concentrations are below 40 inches in some pedons and are distinct grayish brown or dark brown. It is silt loam, loam, clay loam, or silty clay loam with 18 to 35 percent clay and has less than 15 percent coarser than very fine sand. It has few or common clay films. Soil reaction is very strongly acid to strongly acid.
The 2C horizon has value of 4 or 5 moist, 5 or 6 dry, and chroma of 3 or 4 dry and moist. It is fine sandy loam, loam or silt loam with 10 to 25 percent clay. Redox features are few to common, and distinct or prominent. Soil reaction is extremely acid to strongly acid.
COMPETING SERIES: This is the Vernonia series. Vernonia soils have ochric epipedons and are 40 to 60 inches deep to a paralithic contact.
GEOGRAPHIC SETTING: Eilertsen soils occur on low stream terraces along major drainages in mountainous areas of the Coast Range. Elevations are 15 to 800 feet. Slopes are 0 to 7 percent. These soils formed in mixed silty alluvium derived from sedimentary and volcanic rock types. The climate is characterized by warm wet winters and hot moist summers. The mean annual temperature is 47 to 53 degrees F. The mean annual precipitation is 60 to 100 inches. The frost-free period is 110 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kauppi, Kirkendall, McNulty, Meda, Nekoma, Quosantana, Treharne, and Zyzzug soils. All of these soils lack an argillic horizon and are on flood plains except Treharne soils which are moderately well drained and Zyzzug soils which are poorly drained. Both of these soils occur on low stream terraces. Meda soils are fine-loamy and occur on alluvial fans.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: These soils are used for hay, pasture, timber production, recreation, homesite development, and wildlife habitat. Native vegetation is Douglas fir, western hemlock, western redcedar, red alder, cascade Oregongrape, common snowberry, red huckleberry, swordfern and forbs. In addition, tanoak, California laurel, and Pacific rhododendron occur in the more southern reaches of the Coast Range in Curry County, Oregon.
DISTRIBUTION AND EXTENT: Along river valley low stream terraces of the Coast Range Mountains in western Oregon; MLRA 1. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lane County Area, Oregon, 1981. The source of the name is Eilertsen Creek in Columbia County, Oregon.
REMARKS: Diagnostic horizons and features included in this pedon are:
Umbric epipedon - from 1 to 18 inches (A1, A2 horizons).
Argillic horizon - from 18 to 38 inches (Bt1, Bt2 horizons).
Particle-size control section - from 18 to 38 inches
Depth to diagnostic horizons and features is measured from the top of the first mineral horizon.
Classification revised 08/2002 from mixed mineralogy to isotic mineralogy based on lab data and geographically associated soils.
ADDITIONAL DATA: Characterization data on the typical pedon (S78-OR-09-03-1 through 6) completed by OSU lab at Corvallis, Oregon.