LOCATION ROSE VALLEY WAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aquic Palexeralfs
TYPICAL PEDON: Rose Valley silt loam, 0 to 8 percent slopes.
Ap--0 to 4 inches; very dark grayish brown (10YR 3/2) silt loam, dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common coarse roots; few fine tubular pores; strongly acid (pH 4.6); clear smooth boundary. (4 to 10 inches thick)
A--4 to 11 inches; very dark grayish brown (10YR 3/2) silt loam, brown (10YR 5/3) dry; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; few fine tubular pores; very strongly acid (pH 4.6); gradual wavy boundary. (0 to 8 inches thick)
Bt/E1--11 to 18 inches; (B part 85 percent of horizon) dark brown (10YR 4/3) silt loam, brown (10YR 5/3) dry; (E part 15 percent of horizon) light gray (10YR 7/2) silt loam, white (10YR 8/2) dry; few fine faint yellowish brown (10YR 5/6) mottles; weak fine subangular blocky structure; hard, friable, sticky and slightly plastic; common fine roots; few fine tubular pores; very strongly acid (pH 4.6); gradual wavy boundary.
Bt/E2--18 to 23 inches; B part 70 percent of horizon strong brown (7.5YR 5/6) silty clay loam, reddish yellow (7.5YR 6/6) dry, E part 30 percent of horizon brown (10YR 5/3) silt loam, very pale brown (10YR 7/3) dry; weak fine angular blocky structure; hard, firm, sticky and plastic; few fine roots; common fine continuous pores; few patchy strong brown (7.5YR 5/6) iron-manganese coats on faces of peds; very strongly acid (pH 4.9); gradual wavy boundary.
Bt/E3--23 to 38 inches; B part 70 percent of horizon grayish brown (10YR 5/2) silty clay loam, gray (10YR 6/2) dry; E part of horizon white (2.5Y 8/2) silt loam, white (2.5Y 8/1) dry coating on prism faces,; common medium prominent strong brown (7.5YR 5/6) mottles, strong brown (7.5YR 5/6) dry; weak fine angular blocky structure; hard, firm, sticky and plastic; few fine roots; very few to few fine tubular pores; few discontinuous strong brown (7.5YR 5/6) iron-manganese coats throughout; strongly acid (pH 5.3); gradual wavy boundary.
Bt/E4--38 to 51 inches; B part of horizon 60 percent grayish brown (10YR 5/4) silty clay loam, light yellowish brown (10YR 6/4) dry; E part of horizon 40 percent white (10YR 8/1) silt loam, white (10YR 8/1) dry coatings on ped faces; moderate medium angular blocky structure; very hard, firm, sticky and plastic; few fine roots in cracks; very few to few tubular pores; few discontinuous black (5Y 2/2) iron-manganese coats throughout; moderately acid (pH 5.7); gradual wavy boundary. (combined thickness of the B/E horizon is 30 to 50 inches)
Btg1--51 to 65 inches; gray (5Y 5/1) clay, light gray (5Y 7/1) dry; many large distinct strong brown (7.5YR 5/6) mottles reddish yellow (7.5YR 7/6) dry; strong medium angular blocky structure; very hard, firm, sticky and plastic; no roots; very few to few fine tubular pores; common discontinuous black (5Y 2/2) iron-manganese coats throughout; moderately acid (pH 5.8); clear wavy boundary.
Btg2--65 to 75 inches; gray (5Y 5/1) clay, light gray (5Y 7/1) dry; massive; extremely hard, very firm, very sticky and very plastic; no roots; few very fine tubular pores; few patchy prominent black (5Y 2/2) iron-manganese coats throughout; strongly acid (pH 5.2).
TYPE LOCATION: Cowlitz County, Washington; about 5 miles southeast of Kelso in Rose Valley, 2,300 feet east and 500 feet north of the southwest corner of sec. 8, T. 7 N., R. 1 W.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry for 45 to 60 consecutive days following summer solstice. The mean annual temperature is 52 to 54 degrees F.
The A horizon has value of 3 or 5 when moist or dry, chroma of 2 through 4 when moist or dry. Reaction is very strongly acid through moderately acid.
The Bt part of the B/E horizons has hue of 7.5YR or 10YR, value of 4 or 5 when moist and 5 or 6 when dry, and chroma of 2 through 6 when moist or dry. The E part of the Bt/E horizon has hue of 10YR or 2.5Y, value of 5 through 8 when moist and 7 or 8 when dry, chroma of 1 through 3 when moist or dry. The Bt/E horizons are faintly to prominently mottled. Texture is silt loam or silty clay loam. Reaction is very strongly acid to moderately acid.
The Bt horizons have hues of 10YR to 5Y, values of 4 through 6 when moist and 7 or 8 when dry, and chroma of 1 or 2 when moist or dry. The upper part of the Bt horizon is distinctly or prominently mottled with hue of 10YR or 7.5YR, value of 5 through 8 when moist and 7 or 8 when dry, and chroma of 6 through 8 when moist or dry. Texture is silty clay loam, silty clay, or clay. Reaction is strongly acid through moderately acid.
COMPETING SERIES: These are the Galvin and Stella series. Galvin soils do not have albic coatings in the upper part of the argillic horizon. Stella soils have chroma of 4 to 6 throughout the argillic horizon and are moderately well drained.
GEOGRAPHIC SETTING: Rose Valley soils ae on terraces at elevations of 40 to 300 feet. They developed in old alluvium from mostly basic igneous rock. The climate is characterized by warm, dry summers and cool, wet winters. The mean January temperature is 38 degrees F, and in July it is 64 degrees F. The mean annual temperature is about 51 degrees F. The average growing season at 28 degrees F is 220 to 240 days. The average annual precipitation is 45 to 55 inches. The frost-free period is 165 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These include Kelso, Olympic, and Sauvola series. Kelso and Olympic soils lack grayish mottles in the upper part of the argillic horizon. In addition, Olympic soils are in a clayey family. Sauvola soils are in a fine family.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained with slow, to rapid runoff. Permeability is very slow. Perched water table is as high as 1 to 2 feet at times from December to April.
USE AND VEGETATION: Used mostly for timber and pasture production. Principal native vegetation includes Douglas-fir, western redcedar, red alder and bigleaf maple with an understory of vine maple, cascara buckthorn, willow, Douglas spirea, salmonberry, western swordfern, sedges, and evergreen blackberry.
DISTRIBUTION AND EXTENT: Cowlitz County, Washington. Rose Valley soils are small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Cowlitz County, Washington, 1981.
REMARKS: Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 11 inches and an argillic horizon from 11 to 75 inches that has interfingering and tonguing of albic material in the upper 40 inches. Laboratory data are available on this pedon S84WA-015-009.