LOCATION HOT LAKE OREstablished Series
TAXONOMIC CLASS: Medial over loamy, mixed over siliceous, superactive, mesic Aquic Haploxerands
TYPICAL PEDON: Hot Lake ashy silt loam, cropland. (Colors are for moist soil unless otherwise noted.)
Ap1--0 to 6 inches; black (10YR 2/1) ashy silt loam, gray (10YR 5/1) dry; weak fine granular structure; slightly hard, friable, slightly sticky plastic; many fine roots; many very fine tubular pores; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (5 to 7 inches thick)
Ap2--6 to 10 inches; black (10YR 2/1) ashy silt loam, gray (10YR 5/1) dry; massive or very weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common medium and fine roots; common very fine tubular pores; slightly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 8 inches thick)
A--10 to 14 inches; very dark brown (10YR 2/2) ashy silt loam, grayish brown (10YR 5/2) dry; weak very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and few medium roots; common very fine tubular pores; slightly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 5 inches thick)
Bk--14 to 19 inches; very dark grayish brown (10YR 3/2) ashy silt loam, light brownish gray (10YR 6/2) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine and few fine pores; strongly calcareous with many fine light gray calcium carbonate accumulations; moderately alkaline (pH 8.4); clear smooth boundary. (0 to 5 inches thick)
C1--19 to 27 inches; dark grayish brown (2.5Y 4/2) ashy coarse silt loam, gray (2.5Y 6/1) dry; common fine brown (7.5YR 4/4) redox concentrations; massive; slightly hard, friable, nonsticky and nonplastic; common fine roots; common very fine and few fine pores; moderately alkaline (pH 8.4); abrupt smooth boundary. (6 to 14 inches thick)
C2--27 to 39 inches; grayish brown (2.5Y 5/2) ashy very fine sandy loam, light gray (10YR 7/2) dry; common fine brown (7.5YR 4/4) redox concentrations; massive; slightly hard, friable, nonsticky and nonplastic; common fine roots; common very fine and few fine pores; moderately alkaline (pH 8.4); abrupt smooth boundary. (6 to 14 inches thick)
2C3--39 to 48 inches; light brownish gray (10YR 6/2) diatomaceoussilt, white (10YR 8/1) dry; common fine brown (7.5YR 4/4) redox concentrations; moderate medium platy structure; hard, firm, nonsticky and nonplastic; few fine roots; few very fine and fine pores; strongly alkaline (pH 8.8); clear smooth boundary. (7 to 12 inches thick)
2C4--48 to 60 inches; light gray (10YR 7/2) diatomaceoussilt, white (10YR 8/1) dry; massive; hard, firm, nonsticky and nonplastic; strongly alkaline (pH 8.6).
TYPE LOCATION: Union County, Oregon; 225 feet south of center of Gekeler Lane, 850 feet west of section line; NE1/4 SE1/4 section 14, T.3S., R.39E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 52 degrees F. The depth to the diatomaceous sediments (2C horizon) ranges from 20 to 40 inches. Redox features with chroma of 2 or less are within 30 inches of the surface. The solum is slightly alkaline or moderately alkaline and the diatomaceous sediments are slightly alkaline to strongly alkaline. The 0.02 to 2.0 mm fraction makes up 50 to 80 percent of the less than 2.0 mm fine-earth fraction throughout the soil. Moist bulk density is 0.90 to 1.0 grams per cubic centimeter.
The A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 1 or 2 moist and dry. It has 15-bar moisture of 15 to 25 percent based on an air-dried sample and has an estimated phosphate retention of more than 25 percent and acid oxalate extractable aluminum plus one-half iron of more than 0.4 percent.
The Bk and C horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry, 3 through 5 moist and chroma of 1 or 2 moist and dry. It is silt loam and averages 5 to 17 percent clay.
The 2C horizon has hue of 10YR or 2.5Y, value of 6 or 7 moist and chroma of 1 or 2 moist. It is platy or massive and is weakly calcareous or noncalcareous. It is diatomaceous silt and averages more than 70 percent silt and 3 to 10 percent clay.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Hot Lake soils are on old lake basins and valley floors. Slope is 0 to 2 percent. Elevation is 2,600 to 2,800 feet. These soils formed from volcanic ash, loess and mixed lacustrine materials in the upper part over mixed volcanic ash and diatomaceous sediments. The climate is characterized by cool wet winters and hot dry summers. The mean annual precipitation is 13 to 20 inches. The mean annual temperature is 45 to 50 degrees F. The frost-free period is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Catherine, Conley, Hooly, Hoopal and La Grande soils Catherine and La Grande soils are fine-silty and have a mollic epipedon thicker than 20 inches. Conley soils have a fine textured argillic horizon. Hooly soils have redox features with chroma of 2 or less within 10 to 20 inches of the surface and are 14 to 20 inches to the 2C diatomaceous sediments. Hoopal soils have a duripan.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderate permeability in the upper part and moderately slow permeability in the lower part. A seasonal high water table is at a depth of 1.5 to 2.5 feet from December to April.
USE AND VEGETATION: These soils are used for irrigated and nonirrigated wheat and alfalfa production. The natural vegetation is grasses, sedges, and rushes.
DISTRIBUTION AND EXTENT: Grande Ronde Valley in eastern Oregon; MLRA 9. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Union County, Oregon, 1978.
REMARKS: This draft reflects a change in classification from coarse-silty, mixed, mesic Aquic Haploxerolls based on the Andisol Order.
Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - from 0 to 14 inches (Ap1, Ap2, and A horizons)
Cambic horizon - from 14 to 19 inches (Bk horizon)
Andic properties - from 0 to 39 inches (Ap1, Ap2, A, Bk, C1, C2 horizon)
Particle-size control section - from 0 to 40 inches with 0 to 27 inches meeting Medial family criteria, 27 to 39 inches meeting ashy family criteria based on 15-bar moisture of less than 12 percent (air-dried), and 39 to 40 inches meeting coarse-silty family criteria. The Medial family class is based on weighted average of the control section.
Redox features with chroma of 2 or less - from 19 to 39 inches
ADDITIONAL DATA: Characterization data on two profiles (S60-OR-31-10 and 31-11) reported in the Riverside Soil Survey Laboratory report for the soils sampled in Union County, Oregon.