LOCATION RICCO OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Fluvaquentic Vertic Endoaquolls
TYPICAL PEDON: Ricco silty clay loam, hayland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 3 inches; black (10YR 2/1) silty clay loam, gray (10YR 5/1) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine pores; many very fine roots; slightly acid (pH 6.2); clear smooth boundary. (2 to 7 inches thick)
A2--3 to 15 inches; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine roots; many very fine, common fine and few medium tubular pores; slightly acid (pH 6.3); gradual smooth boundary. (6 to 18 inches thick)
Bw1--15 to 20 inches; black (10YR 2/1) silty clay loam, gray (10YR 6/1) dry; moderate medium angular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine roots; common very fine and fine continuous tubular pores; neutral (pH 6.7); clear smooth boundary. (3 to 9 inches thick)
Bw2--20 to 30 inches; very dark grayish brown (10YR 3/2) silty clay loam, gray (10YR 6/1) dry; moderate medium and fine angular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine roots; common very fine pores; neutral (pH 6.7); clear smooth boundary. (5 to 15 inches thick)
Cg1--30 to 45 inches; very dark gray (10YR 3/1) silty clay loam, gray (10YR 5/1) dry; massive; hard, friable, moderately sticky and moderately plastic; few very fine roots; common fine and very fine pores; neutral (pH 6.7); clear smooth boundary. (14 to 20 inches thick)
Cg2--45 to 72 inches; dark gray (10YR 4/1) silty clay loam, light gray (10YR 7/1) dry; massive; hard, friable, moderately sticky and moderately plastic; few very fine roots; common fine and very fine pores; neutral (pH 6.7); clear smooth boundary.
TYPE LOCATION: Grant County, Oregon; about 6 miles southeast of Prairie City, Oregon, 1/4 mile west of old Riverside School; 350 feet from the road fence, 40 feet southeast of northeast running field fence; 1,000 feet north and 500 feet east of the SW corner of section 22, T. 13 S., R. 34 E. Latitude 44 degrees, 25 minutes, 08 seconds North and Longitude 118 degrees, 36 minutes, 19 seconds West.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to about 54 degrees F. The soil is saturated with water at some period of the year. The soil is noncalcareous and is slightly acid to neutral. The particle-size control section is silty clay loam, clay loam, silty clay and clay and averages 35 to 45 percent clay. Hue is 10YR or 2.5Y The mollic epipedon is 10 to 20 inches thick. It is slightly acid or neutral.
The A horizon has value of 4 or 5 dry, 1 or 2 moist and chroma of 1 moist and dry. It has 7 to 10 percent organic matter.
The Bw horizon has value of 2 or 3 moist, 5 or 6 dry and chroma of 1 or 2 moist and dry.
The Cg horizon has value of 3 or 4 moist, 5 to 7 dry and chroma of 1 moist and dry.
COMPETING SERIES: These are the Blend, Darwin, Saddlerock, Stillwater and Waldo series. Blend soils have a buried soil at depths of 24 to 36 inches and occur in a udic soil moisture regime environment. Darwin soils occur in a udic soil moisture regime environment. Saddlerock soils are slightly or moderately alkaline and have 2 to 4 percent organic matter. Stillwater soils have a mean annual soil temperature of 53 to 57 degrees F. and contain significant amounts of sodium. Waldo soils are strongly acid to slightly acid and have a mean annual soil temperature of 52 to 56 degrees F.
GEOGRAPHIC SETTING: Ricco soils are on low alluvial fans and floodplains at elevations of 2,400 to 4,000 feet. Slopes range from 0 to 3 percent. The soils formed in mixed alluvium derived largely from fine-textured waterlain sediments weathered from basalt, volcanic tuffs and diatomaceous earth. The climate is subhumid with hot dry summers and cold moist winters. The mean annual precipitation is 11 to 16 inches. The mean July temperature is 66 degrees F., the mean January temperature is 32 degrees F., and the mean annual temperature is 45 to 52 degrees F. The frost-free period is 80 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boyce, Courtrock, Dayville, Hack and Veazie soils. Boyce and Dayville soils are fine-silty over sandy-skeletal. Courtrock and Hack soils are on associated terraces and fans and are well drained. Veazie soils are coarse-loamy over sandy-skeletal and are well drained.
DRAINAGE AND PERMEABILITY: Poorly drained; slow permeability.
USE AND VEGETATION: Principally for hay production. Natural vegetation is mainly sedges, tufted hairgrass, Nevada bluegrass and redtop.
DISTRIBUTION AND EXTENT: East-central Oregon; MLRA 10. These soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grant County, Oregon, 1975.
REMARKS: Diagnostic horizons and other features:
Mollic epipedon 0 to 15 inches
Cambic horizon 15 to 30 inches based on color change and structure.
Assume a LE of greater than 6.0 cm within the upper 100 cm.
Assume an irregular decrease in organic matter.
Pedons need review for the presence of redox concentrations.
ADDITIONAL DATA: S97OR-023-000 data supports fine family and Vertic but the irregular organic matter increase begins at 135 cm. Fluvaquentic requires increase within 125 cm.