LOCATION TUTUILLA OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Palexerolls
TYPICAL PEDON: Tutuilla silty clay loam, rangeland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 5 inches; black (10YR 2/1) silty clay loam, dark grayish brown (10YR 4/2) dry; moderate fine granular structure; hard, friable, sticky and plastic; many fine and very fine roots; many very fine irregular pores; 5 percent gravel; neutral (pH 7.0); clear wavy boundary. (4 to 8 inches thick)
A2--5 to 19 inches; black (10YR 2/1) silty clay loam, dark grayish brown (10YR 4/2) dry; strong medium and fine subangular blocky structure; hard, firm, sticky and plastic; common fine and very fine roots; many very fine irregular and tubular pores; 5 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (5 to 15 inches thick)
2Bt1--19 to 35 inches; dark grayish brown (2.5Y 4/2) clay, brown (10YR 4/3) dry; moderate coarse columnar structure; very hard, very firm, very sticky and very plastic; few very fine roots; common fine tubular pores; common moderately thick clay films in pores and on faces of peds; 5 percent cobbles and 10 percent gravel; neutral (pH 7.0); clear wavy boundary. (12 to 25 inches thick)
2Bt2--35 to 50 inches; dark brown (10YR 3/3) clay, dark brown (10YR 4/3) dry; moderate medium angular blocky structure; very hard, firm, very sticky and plastic; common fine tubular pores; common moderately thick clay films in pores and on faces of peds; 5 percent cobbles, 10 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (5 to 15 inches thick)
2Cr--50 inches; partially decomposed sedimentary material.
TYPE LOCATION: Umatilla County, Oregon; SE1/4SW1/4 section 27, T. 3 S., R. 30 E.
RANGE IN CHARACTERISTICS: The soils are usually moist but are dry throughout between depths of 4 and 12 inches for 60 to 80 consecutive days. The mean annual soil temperature is 47 to 50 degrees F. Depth of the paralithic contact is 40 to 60 inches. Thickness of the mollic epipedon and depth to the 2Bt horizon is 14 to 20 inches. The particle-size control section has 0 to 15 percent rock fragments and 50 to 60 percent clay. It is slightly acid or neutral throughout. There is an absolute increase in clay of 20 to 30 percent between the A2 and 2Bt horizons.
The A horizon has value of 3 or 4 dry and chroma of 1 or 2 moist. It has granular or subangular blocky structure and 27 to 35 percent clay.
The 2Bt horizon has hue of 10YR or 2.5Y, value of 2 through 4 moist and dry and chroma of 2 or 3 moist and 3 or 4 dry. Structure is subangular or angular blocky to columnar. It has 0 to 10 percent gravel and 0 to 10 percent cobbles. The upper part is silty clay or clay with 50 to 60 percent clay. The lower part is clay, clay loam or silty clay with 35 to 60 percent clay.
COMPETING SERIES: There are the Coleman, Dry Creek, Pomponio and Pritchard (T) series. The Coleman soils have C horizons within 60 inches and lacks a paralithic contact between 40 and 60 inches. Dry Creek and Pritchard soils are calcareous above 40 inches. Pomponio soils are 20 to 40 inches deep to shale. Pritchard soils are mildly alkaline in the subsoil.
GEOGRAPHIC SETTING: The soils are in basins and on side slopes at elevations of 3,600 to 4,000 feet. Slopes are 1 to 35 percent. The soils formed in residuum weathered from meda-sedimentary material mixed with loess in the upper part. The mean annual precipitation is 24 to 28 inches and the mean annual temperature is 45 to 50 degrees F. The frost-free period is 100 to 125 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bridgecreek, Gurdane and Hankins soils. The Bridgecreek soils are 20 to 40 inches deep to weathered bedrock and are frigid. Gurdane soils are 20 to 40 inches deep to unweathered basalt and are clayey-skeletal. Hankins soils are frigid.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; slow permeability.
USE AND VEGETATION: The soils are used for range, dryland small grain and hay and pasture. Native vegetation is Idaho fescue, bluebunch wheatgrass and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: The series is of small extent in the foothills of the Blue Mountains.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Umatilla County, Oregon, 1985.