LOCATION CONBOY WATentative Series
TAXONOMIC CLASS: Medial over clayey, amorphic over mixed, superactive, nonacid, frigid Thaptic Endoaquands
TYPICAL PEDON: Conboy medial clay loam - pasture, on a 1 percent northeast-facing slope in a managed pasture of reed canarygrass at 1,800 feet elevation. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Ap1--0 to 9 inches; dark brown (7.5YR 3/2) medial clay loam, brown (7.5YR 5/2) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; many very fine and fine roots; many very fine and fine irregular and common fine tubular pores; moderately acid (pH 5.6); clear smooth boundary. (7 to 9 inches thick)
Ap2--9 to 14 inches; very dark grayish brown (10YR 3/2) medial clay loam, gray (10YR 6/1) dry; few fine distinct strong brown (7.5YR 5/6) redox concentrations, strong brown (7.5YR 5/8) dry; moderate medium subangular blocky structure; hard, friable, slightly sticky and nonplastic; many very fine and fine roots; many very fine and fine irregular and common fine tubular pores; moderately acid (pH 5.8); abrupt smooth boundary. (4 to 7 inches thick)
C1--14 to 18 inches; very dark grayish brown (10YR 3/2) medial silty clay loam, light brownish gray (10YR 6/2) dry; few fine distinct strong brown (7.5YR 5/6) redox concentrations, strong brown (7.5YR 5/8) dry; moderate very coarse prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine irregular pores; moderately acid (pH 5.8); abrupt smooth boundary. (3 to 6 inches thick)
C2--18 to 22 inches; dark brown (10YR 3/3) medial loam, very pale brown (10YR 8/2) dry; massive; slightly hard, friable, nonsticky and nonplastic, weakly smeary; common very fine and few fine roots; common very fine and fine irregular pores; fine sand-sized pumice; moderately acid (pH 6.0); abrupt smooth boundary. (3 to 6 inches thick)
C3--22 to 32 inches; very dark grayish brown (10YR 3/2) medial silty clay, light brownish gray (10YR 6/2) dry; moderate very coarse prismatic structure; slightly hard, friable, slightly sticky and nonplastic; many very fine and common fine roots; many very fine and fine irregular pores; moderately acid (pH 5.8); clear smooth boundary. (5 to 12 inches thick)
2Ab1--32 to 42 inches; black (10YR 2/1) silty clay loam, grayish brown (10YR 5/2) dry; massive; slightly hard, friable, slightly sticky and nonplastic; common very fine and few fine roots, many very fine irregular and common very fine tubular pores; moderately acid (pH 5.8); clear smooth boundary. (10 to 12 inches thick)
2Ab2--42 to 48 inches; very dark grayish brown (10YR 3/2) silty clay loam; light brownish gray (10YR 6/2) dry; about 20 percent fiber, less than 5 percent rubbed massive; slightly hard, friable, slightly sticky and nonplastic; common very fine and few fine roots; many fine irregular and few very fine tubular pores; moderately acid (pH 5.8); clear smooth boundary. (6 to 8 inches thick)
3C4--48 to 60 inches; brown (10YR 4/3) sandy loam, pale brown (10YR 6/3) dry; few fine distinct yellowish red (5YR 5/6) redox concentrations, strong brown (7.5YR 5/6) dry; massive; slightly hard, friable, nonsticky and nonplastic, common very fine and few fine roots; many very fine and fine irregular pores; white coarse sand-sized pumice; moderately acid (pH 6.0).
TYPE LOCATION: Klickitat County, Washington; about 4 miles south of Glenwood and 1,500 feet north and 200 feet west of the southeast corner of section 33, T. 6 N., R. 12 E. (Latitude 45 degrees, 57 minutes, 40" seconds N. and Longitude 121 degrees, 18 minutes,10 seconds W. )
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 45 to 47 degrees F. Organic carbon in the control section decreases irregularly with depth and ranges from 0.4 to 11 percent. The upper part of the 0 to 40 inch particle-size control section has an estimated moist bulk density of 0.50 to 0.85 g/cc, volcanic glass content of 30 to 60 percent, acid oxalate extractable aluminum plus one-half iron of 1.0 to 2.0 percent, phosphate retention of 50 to 75 percent, and 15 bar water retention of 15 to 35 percent. The lower part has a moist bulk density of 0.95 to 1.20 g/cc, volcanic glass content of 0 to 5 percent, and clay of 35 to 45 percent.
The A horizon has hue of 7.5YR or 10YR, value of 2 or 3 moist and chroma of 1 or 2 moist and dry. The upper part of the A horizon has a value of 5 dry and the lower part has a value of 6.
The C horizon above 40 inches is stratified with layers having from 18 to 62 percent clay in individual layers and a weighted average of 35 to 50 percent.
The 2Ab horizon has value of 1 to 3 moist, 4 to 6 dry and chroma of 0 to 2.
The 3C horizon has value of 4 or 5 moist, 5 to 7 dry and chroma of 1 to 3. It has few to common distinct redox concentrations.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Conboy soils are in lake basins on slightly depressed topography at elevations of 1,800 to 1,900. Slopes are 0 to 1 percent. The soils formed in alluvium from mixed sources including volcanic ash, diatomite, and basalt. Summers are warm and dry; winters are cold and wet. The mean annual precipitation is 33 to 37 inches. The average January temperature is 27 degrees and the average July temperature is 66 degrees F. The mean annual temperature is 43 to 46 degrees F. The frost-free season is 50 to 90 days, although a damaging frost can occur any month of the year.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fanal, Grayland, Guler, and Segidal soils. Fanal soils are coarse-loamy. Grayland soils have a mollic epipedon, a regular decrease in organic carbon and are fine-loamy. Guler soils are medial- skeletal. Segidal soils have a spodic horizon.
DRAINAGE AND PERMEABILITY: Poorly drained; very slow runoff; moderately slow permeability. A seasonal high water table is at a depth of 1.0 foot above the surface to 1.0 foot below the surface from December to July. Frequent flooding from December to June.
USE AND VEGETATION: These soils are used mainly for pasture and hay production. Principal introduced plants are reed canarygrass and some sedges and rushes. Native vegetation is Baltic rush and barestem lomatium.
DISTRIBUTION AND EXTENT: Southern Glenwood Valley, Klickitat County, Washington; MLRA 6. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Klickitat County, Washington, 1941; Yakima Indian Reservation.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to 14 inches
Particle-size control section - the zone from 0 to 40 inches with 0 to 32 inches qualifying as medial (andic soil properties) and 32 to 40 inches qualifying as clayey .
There is an irregular decrease in organic carbon with depth in the particle-size control section.
Classification revised 9/93 - reflects a change in classification based on amendment 16 from fine, mixed, nonacid, frigid Mollic Fluvaquents to medial over clayey, mixed, frigid Thaptic Endoaquands.
Classification revised 1/98 - Amorphic mineralogy based on associated Guler series NSSL lab data pedon number 87P064.
12/2005 This series originally set up within the Klickitat County soil survey until boundary change with Yakima Indian Reservation soil survey in 2003.
ADDITIONAL DATA: Laboratory data available NSSL pedon number 78P0257.