LOCATION RIDENBAUGH IDEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Abruptic Xeric Argidurids
TYPICAL PEDON: Ridenbaugh silty clay loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A2--0 to 3 inches; pale brown (10YR 6/3) silt loam, dark brown (10YR 3/3) moist; strong thick platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few medium and common fine roots; common coarse and many fine vesicular pores; mildly alkaline (pH 7.6); abrupt smooth boundary. (2 to 4 inches thick)
B2t--3 to 9 inches; yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 4/4) moist; strong coarse prismatic structure parting to strong medium subangular blocky; hard, firm, very sticky and very plastic; few medium and common fine roots; common very fine and fine tubular pores; continuous thick clay films on faces of peds and in pores; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 7 inches thick)
B3tca--9 to 13 inches; light yellowish brown (10YR 6/4) clay loam; dark yellowish brown (10YR 4/4) moist; strong medium angular blocky structure; hard, firm, sticky and plastic; common fine and very fine roots; few very fine and fine tubular pores; many moderately thick clay films on faces of peds and in pores; few large strongly calcareous lime veins and splotches; moderately alkaline (pH 8.3); clear smooth boundary. (2 to 4 inches thick)
C1ca--13 to 17 inches; very pale brown (10YR 8/3) silt loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, slightly plastic; common very fine and fine roots; common very fine tubular pores; about 20 percent durinodes; strongly calcareous; strongly alkaline (pH 8.5); abrupt smooth boundary. (2 to 5 inches thick)
C2casim--17 to 33 inches; white (10YR 8/2) duripan, very pale brown (10YR 7/4) moist; alternating layers of indurated plate-like laminations 1 to 3 inches thick with a continuous opalized upper surface, and loose soil 0.5 to 2 inches thick; thin root mat covers the upper surface of the pan; strongly calcareous; strongly alkaline (pH 8.6); clear wavy boundary. (10 to 20 inches thick)
IIC3ca--33 to 72 inches; very pale brown (10YR 7/3) sandy loam, pale brown (10YR 6/3) moist; massive; soft, very friable; about 10 percent fine gravel; strongly calcareous; strongly alkaline (pH 8.5).
TYPE LOCATION: Ada County, Idaho; about 8 miles south of Boise; approximately 675 feet north and 210 feet west of the SW corner of the NW1/4 of sec. 8, T. 1 N., R. 2 E.
RANGE IN CHARACTERISTICS: Depth to the duripan ranges from 10 to 20 inches. Mean annual soil temperature is 51 degrees to 54 degrees F. The textural control section averages 38 to 50 percent clay.
The A2 horizon has value of 3 or 4 moist, and chroma of 2 or 3.
The B2t horizon has hue of 7.5YR or 10YR, value of 5 or 6 dry, 3 or 4 moist, and chroma of 3 or 4. It is clay, clay loam or silty clay.
The B3tca horizon has value of 6 or 7 dry and chroma of 3 or 4. It is clay loam, silty clay or clay.
The Cca horizon above the duripan has value of 7 or 8 dry, 5 or 6 moist, and chroma of 3 or 4. It is strongly or very strongly calcareous.
The Ccasim horizon is strongly cemented or indurated. It is strongly or very strongly calcareous.
The C horizon below the pan is sandy loam or loamy sand in the fine earth fraction. Gravel ranges from 5 to 45 percent.
COMPETING SERIES: These are the Kunaton and Puls series. Kunaton soils have bedrock at 20 to 40 inches. Puls soils lack lime in the lower part of the profile.
GEOGRAPHIC SETTING: Ridenbaugh soils are on old alluvial plains and low alluvial terraces. Elevation ranges from 2,700 to 3,200 feet. Slopes are 0 to 4 percent. The soils formed in a veneer of loess or silty alluvium underlain by coarse alluvium. The climate is middle-latitude steppe (Trewartha's modified Koppen system) with cool wet winters and dry summers. Mean annual precipitation ranges from 10 to 12 inches. Mean January temperature is about 32 degrees F.; mean July temperature is 72 degrees F.; the mean annual temperature is 49 degrees to 53 degrees F. Frost-free period is 140 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chilcott, Colthorp, Elijah, Purdam and Sebree soils and the competing Kunaton soils. Chilcott, Elijah, Purdam and Sebree soils have a duripan at a depth of 20 to 40 inches. Colthorp soils have less than 35 percent clay in the textural control section.
DRAINAGE AND PERMEABILITY: Well drained; very slow or slow runoff; slow permeability.
USE AND VEGETATION: Well drained; very slow or slow runoff; slow permeability.
USE AND VEGETATION: These soils are used dominantly for range, with some irrigated cropland. Native vegetation is dominantly big sagebrush, Sandberg bluegrass, bluebunch wheatgrass, burr buttercup, perfoliate-leaved peppergrass and annual brome. Principal crops are alfalfa small grains, corn and permanent pasture.
DISTRIBUTION AND EXTENT: Southwestern Idaho. These soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Ada county, Idaho, 1977.