LOCATION DAROW OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Argixerolls
TYPICAL PEDON: Darow silty clay loam, forested. (Colors are for moist soil unless otherwise noted.)
A1--0 to 5 inches; dark brown (10YR 3/3) silty clay loam, brown
(10YR 5/3) dry; strong medium granular structure; hard, friable, slightly sticky and plastic; many fine roots; many irregular pores; neutral (pH 6.8); abrupt smooth boundary. (4 to 7 inches thick)
A2--5 to 12 inches; dark brown (10YR 3/3) silty clay loam, brown (10YR 5/3) dry; moderate fine subangular blocky structure; hard, friable, sticky and plastic; common fine and few medium roots; many very fine tubular pores; neutral (pH 6.6); clear smooth boundary. (6 to 9 inches thick)
BA--12 to 21 inches; dark brown (10YR 4/3) silty clay, yellowish brown (10YR 5/4) dry; weak coarse subangular blocky structure; very hard, firm, very sticky and plastic; few fine and common medium roots; common very fine tubular pores; slightly acid (pH 6.4); clear smooth boundary. (3 to 10 inches thick)
Bt--21 to 32 inches; dark yellowish brown (10YR 4/4) silty clay, yellowish brown (10YR 5/4) dry; weak coarse prismatic structure; very hard, very firm, very sticky and very plastic; common fine roots; common very fine tubular pores; few moderately thick clay films on peds and in pores; slightly acid (pH 6.4); clear wavy boundary. (7 to 15 inches thick)
Crt--32 inches; weathered siltstone bedrock with thick dark brown (7.5YR 4/4); clay films in fractures.
TYPE LOCATION: Jackson County, Oregon; 4 miles south of Medford, about 850 feet south and 1,750 feet west from the NE corner of sec. 13, T. 38 S., R. 2 W., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 54 to 56 degrees F. The soils are usually moist but, in most years, they are dry between 4 and 12 inches for 80 to 110 consecutive days during the summer. The soils crack to 20 inches or more in the summer months in more than 7 out of 10 years. Depth to a paralithic contact is 20 to 40 inches. It has 0 to 5 percent gravel.
The A horizon has hue of 10YR or 7.5YR, value of 3 moist, 5 dry, and chroma of 2 or 3 moist and 3 or 4 dry.
The Bt horizon has hue of 10YR, 7.5YR, or 2.5Y, value of 4 or 5 moist, 5 or 6 dry, and chroma of 3 or 4 moist and dry. It is a silty clay or clay with 45 to 60 percent clay. Soft gravel fragments range from 0 to 15 percent.
COMPETING SERIES: These are the Forsgren, Kuck, Montour and Ukiah series. Forsgren soils are over 60 inches to bedrock. Kuck soils have a mean annual precipitation of 12 to 20 inches, 5 to 30 percent rock fragments, and value of 2 or 3 dry in the A horizon and 4 or 5 dry in the Bt, chroma of 1 to 3 dry in the A horizon and 1 or 2 dry in the Bt. Montour soils have calcareous C horizons and are deeper than 60 inches to bedrock. Ukiah soils have a mean annual soil temperature of 47 to 51 degrees F.
GEOGRAPHIC SETTING: Darow soils are on hillslopes at elevations of 1,200 to 3,000 feet. Slopes range from 1 to 35 percent. The soils formed in residuum and colluvium weathered from siltstone, shale or tuffaceous sandstone rocks. The mean annual precipitation is 18 to 30 inches. The mean annual temperature is 52 to 54 degrees F. The frost-free period is 120 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brader, Carney, Debenger, Manita, and Selmac soils. Carney soils have intersecting slickensides. Manita soils are well drained and have ochric epipedons. Selmac soils have an ochric epipedon and are fine-loamy over clayey in the control section. Brader soils are less than 20 inches to bedrock. Debenger soils are fine-loamy.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for pasture, hay, pears, grazing and homesites. Native vegetation consists of Oregon white oak, poison oak, birchleaf mountainmahogany, ponderosa pine, Idaho fescue, Junegrass, and other grasses.
DISTRIBUTION AND EXTENT: Southwestern Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Jackson County Area, Oregon, 1988.