LOCATION LATOURELL OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ultic Haploxeralfs
TYPICAL PEDON: Latourell loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap1--0 to 9 inches; dark brown (10YR 3/3) loam, brown (10YR 5/3) dry; strong very fine granular structure; slighty hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine pores; strongly acid (pH 5.3); abrupt smooth boundary. (6 to 9 inches thick)
Ap2--9 to 16 inches; brown (10YR 4/3) loam, pale brown (10YR 6/3) dry; weak thick platy structure; hard, firm, slightly sticky and slightly plastic; common very fine roots; many very fine pores; slightly acid (pH 6.1); clear smooth boundary. (0 to 8 inches thick)
B21t--16 to 25 inches; dark yellowish brown (10YR 4/4) loam, light yellowish brown (10YR 6/4) dry; weak medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine roots; many very fine pores; few moderately thick clay films; medium acid (pH 6.0); gradual wavy boundary. (6 to 12 inches thick)
B22t--25 to 37 inches; dark yellowish brown (10YR 4/4) heavy loam, light yellowish brown (10YR 6/4) dry; weak medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine roots; many very fine pores; common moderately thick clay films in pores and faces of peds; medium acid (pH 6.0); gradual wavy boundary. (8 to 15 inches thick)
B3--37 to 45 inches; dark yellowish brown (10YR 4/4) loam; light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few moderately thick clay films in pores; few 10YR 5/2 and 5/6 streaks along root channels with 5YR 5/6 stainings on the margins of the channels; medium acid (pH 5.9); gradual wavy boundary. (0 to 10 inches thick)
C1--45 to 56 inches; dark yellowish brown (10YR 4/4) loam, light yellowish brown (10YR 6/4) dry; massive; hard, firm, slightly sticky and slightly plastic; many very fine pores; few moderately thick clay films in pores; medium acid (pH 5.9); abrupt wavy boundary. (10 to 24 inches thick)
IIC2--56 to 66 inches; dark yellowish brown (10YR 4/4) very gravelly sandy loam, yellowish brown (10YR 5/4) dry; massive; firm, nonsticky and nonplastic; many very fine pores; slightly acid (pH 6.2).
TYPE LOCATION: Multnomah County, Oregon; 1,000 feet east of road, 300 feet south of Douglas-fir stand, NW1/4 NE1/4 SW1/4 section 35, T. 1 N., R. 3 E.
RANGE IN CHARACTERISTICS: The soil is usually moist but is dry between depths of 4 and 12 inches for 45 to 80 consecutive days during the 120-day period following the summer solstice. The mean annual soil temperature ranges from 54 degrees to 56 degrees F. Depth to bedrock is over 60 inches. Thickness of the solum ranges from 30 to 50 inches. The solum is slightly to strongly acid.
The A horizon has value of 3 or 4 moist, 5 or 6 dry and chroma of 3 or 4 moist and dry. It is loam or silt loam.
The Bt horizon has value of 4 or 5 moist and chroma of 3 or 4 moist and dry. It is loam with 18 to 22 percent clay based on values of 15-bar water and has more than 15 percent coarser than very fine sand. It has weak or moderate structure. Clay films range from few to common and thin to moderately thick.
At depths of 40 to 60 inches the IIC2 horizon is sandy loam with 25 to 60 percent pebbles and a few embedded stones or cobbles.
COMPETING SERIES: These are the Boomer, Centralia, Cherryhill, Cle Elum, Cohasset, Crozier, Fives, Holland, Hood, Hotaw, Kalama, Musick, Rosehaven, Speaker, Underwood, Wilkeson, and Varelum series. Boomer, Centralia, Cohasset, Fives, Holland, Kalama, Musick and Varelum soils have more than 22 percent clay in the B2t horizon. Also, Boomer, Cohasset, Holland and Musick soils have hue redder than 10YR in the B2t horizon. Cherryhill soils have an umbric epipedon. Cle Elum, Crozier, Hotaw and Speaker soils are 20 to 40 inches deep to a paralithic contact. Hood soils have argillic horizons with coatings of clean sand grains on faces of peds and are brittle and firm in the lower part. Underwood soils have a hue of 7.5YR or redder in the control section. Wilkeson has more than 15 percent rock fragments on the control section.
GEOGRAPHIC SETTING: Latourell soils are on broad terraces at elevations of 50 to 400 feet. Slopes are mainly 0 to 8 percent, but some slopes on terrace fronts and along drainageways are as much as 30 percent.
The soils formed in medium textured mixed alluvium. The climate is humid temperature. Mean annual precipitation is 40 to 60 inches. The mean annual temperature is 52 degrees to 54 degrees F. The average January temperature is 39 degrees F. and the average July temperature is 67 degrees F. The frost-free season is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Burlington,
Multnomah, and
Powell soils. Burlington soils are somewhat excessively drained and sandy. Multnomah soils have contrasting textures within depth of 40 inches. Powell soils are somewhat poorly drained, have fragipans and lack argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used mainly for vegetable crops, nursery stock, fruit production, pasture and homesites. Native vegetation is Douglas-fir, Oregon white oak, bigleaf maple, western redcedar, vine maple, western hazel, common snowberry, rose, grasses and forbs.
DISTRIBUTION AND EXTENT: These soils are primarily along the Columbia River in Multnomah and Columbia Counties, Oregon. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Multnomah County, Oregon, 1977.
ADDITIONAL DATA: Characterization data on two profiles (S70 Ore-26-10) reported in Riverside Soil Survey Laboratory computer printout for soils sampled in Multnomah County, Oregon, 1970.