LOCATION POALL OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Xeric Paleargids
TYPICAL PEDON: Poall very fine sandy loam - on a 20 percent west-facing slope in rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 3 inches; brown (10YR 5/3) very fine sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; mildly alkaline (pH 7.8); abrupt wavy boundary. (2 to 8 inches thick)
A2--3 to 9 inches; pale brown (10YR 6/3) very fine sandy loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common fine roots; many very fine tubular pores; mildly alkaline (pH 7.8); abrupt wavy boundary. (0 to 7 inches thick)
2Bt1--9 to 15 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; strong fine and medium prismatic structure parting to strong fine and medium angular blocky; hard, firm, slightly sticky and plastic; few fine roots; many very fine tubular pores; common thin clay films on ped faces and in pores; moderately alkaline (pH 8.0); gradual wavy boundary. (4 to 9 inches thick)
2Bt2--15 to 25 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine roots; many very fine tubular pores; common thin clay films on ped faces and in pores; moderately alkaline (pH 8.0); gradual wavy boundary. (5 to 16 inches thick)
3Bk1--25 to 41 inches; light yellowish brown (10YR 6/4) very fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; hard, firm, nonplastic and nonsticky; slightly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (10 to 20 inches thick)
3Bk2--41 to 60 inches; very pale brown (10YR 7/4) very fine sandy loam, yellowish brown (10YR 5/4) moist; massive; soft, friable, nonsticky and nonplastic; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Baker County, Oregon; 2 miles south of Huntington; 120 feet east of dirt road, SW1/4NW1/4 sec. 30, T. 14 S., R. 45 E.
RANGE IN CHARACTERISTICS: The soils are usually dry; they are dry for 90 consecutive days or more in all parts between depths of about 4 and 12 inches after the summer solstice but are moist in some part for a continuous period greater than one-fourth of the time that the soil temperature exceeds 41 degrees F. The mean annual soil temperature is 49 to 53 degrees F. The depth to carbonates is 15 to 35 inches. There is an absolute clay increase of 20 to 30 percent between the A and 2Bt horizons. Depth to bedrock is over 60 inches.
The A horizon has value of 3 or 4 moist and 5 or 6 dry, and chroma of 2 or 3 moist and dry. It is mildly or moderately alkaline.
The 2Bt horizon has value of 3 or 4 moist, 5 or 6 dry and chroma of 3 or 4 moist and dry. The texture is clay, clay loam or silty clay loam with 35 to 50 percent clay. Clay loam and silty clay loam texture occur in the lower part. It is mildly or moderately alkaline.
The 3Bk horizon has value of 6 or 7 dry and 4, 5 or 6 moist, and chroma of 3 or 4 moist and dry. It is very fine sandy loam, fine sandy loam, silt loam or clay loam. It is moderately or strongly alkaline.
COMPETING SERIES: These are the Acoma, Borda, Bowns, Brent, Chardoton, Gooding, Locey(T), Mahala, Phing, Reba, Sorf, and Verdico soils. Acoma soils have 15 to 35 percent gravel in the particle-size control section. Borda soils have a solum thickness of 30 or 45 inches and have a lithic contact at 40 to 60 inches. Bowns and Locey soils have a lithic contact at 20 to 40 inches. Brent, Bowns, Chardoton, and Phing soils have an E horizon. Brent soils have a mean annual soil temperature of 50 to 54 degrees F, and Chardoton soils have a mean annual soil temperature of 52 to 56 degrees F. Gooding soils have a hardpan over bedrock at less than 40 inches. Mahala and Verdico soils have a paralithic contact at 20 to 40 inches. Reba soils are slightly acid or medium acid in the surface and slightly acid or neutral in the subsoil. Sorf soils have 20 to 60 percent stones and cobbles in or on the surface and are neutral in the surface and upper part of the Bt horizon.
GEOGRAPHIC SETTING: Poall soils are on hills. They formed in lacustrine sediments. Slope ranges from 2 to 40 percent. Elevation is 2,200 to 4,200 feet. The climate is characterized by cold moist winters and warm dry summers. The mean annual temperature is 45 to 52 degrees F. The mean annual precipitation is 8 to 12 inches. The frost-free period is 80 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kimberly, Lickskillet, Redcliff, Ruckles, and Virtue soils. The Kimberly soils are deep, coarse textured soils formed in recent alluvium. The Lickskillet and Ruckles soils are shallow and skeletal over hard bedrock. The Redcliff soils are moderately deep over hard metavolcanic rock. The Virtue soils are moderately deep to a duripan.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow or medium. Permeability is moderate in the A horizon and slow in the B horizon.
USE AND VEGETATION: Most areas of Poall soils are used for range. The native vegetation is mainly bluebunch wheatgrass, Idaho fescue, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Southeastern Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Baker County Area, Oregon; 1988.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Argillic horizon - the zone from approximately 9 to 25 inches (2Bt1, 2Bt2 horizons).
Paleargid feature - has an argillic horizon that has a clayey particle-size class and an abrupt upper boundary.
Additional features - aridic moisture regime that borders on a xeric regime and an ochric epipedon.
NSTH 17, RECLASSIFICATION ONLY, 3/95