LOCATION HOOLY OREstablished Series
TAXONOMIC CLASS: Medial over loamy, mixed over siliceous, superactive, nonacid, mesic Typic Endoaquands
TYPICAL PEDON: Hooly ashy silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 3 inches; very dark grayish brown (10YR 3/2) ashy silt loam, gray (10YR 5/1) dry; weak thin platy structure; soft, friable, slightly sticky and slightly plastic; many fine roots; many fine tubular pores; slightly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (5 to 7 inches thick)
A--3 to 11 inches; very dark grayish brown (10YR 3/2) ashy silt loam, gray (10YR 6/1) dry; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; common fine and few coarse roots; common fine tubular pores; slightly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (0 to 9 inches thick)
AC--11 to 17 inches; dark grayish brown (10YR 4/2) ashy silt loam, gray (10YR 6/1) dry; few fine distinct of grayish brown (10YR 5/2) and dark yellowish brown (10YR 4/6) redox features along root channels; weak fine granular structure; soft, friable, nonsticky and nonplastic; common fine and few coarse roots; common fine tubular pores; few krotovinas; slightly effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary. (3 to 7 inches thick)
2C1--17 to 21 inches; light brownish gray (10YR 6/2) diatomaceous silt, light gray (10YR 7/1) dry; massive; soft, friable, nonsticky and nonplastic; few fine roots; few fine tubular pores; slightly alkaline (pH 7.4); abrupt wavy boundary. (3 to 6 inches thick)
2C2--21 to 36 inches; pale brown (10YR 6/3) diatomaceous silt, white (10YR 8/1) dry; massive; slightly hard, firm, nonsticky and nonplastic; few medium vesicular pores; slightly alkaline (pH 7.4); clear wavy boundary. (10 to 20 inches thick)
2C3--36 to 60 inches; light brownish gray (10YR 6/2) diatomaceous silt, white (10YR 8/1) dry; weak medium and thick platy structure; slightly hard, firm, nonsticky and nonplastic; slightly alkaline (pH 7.6).
TYPE LOCATION: Union County, Oregon; 40 feet east of the center of Godley Lane, SW corner of NW1/4 NW1/4 section 25, 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 14 to 20 inches. The solum is neutral to moderately alkaline. Redox features with chroma of 2 are within 10 to 20 inches of the surface. 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.
The A horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 1 or 2 dry and moist. It has a moist bulk density of 0.50 to 0.85 grams per cubic centimeter and 15-bar moisture of 15 to 25 percent based on an air-dried sample. It is estimated to have a phosphate retention of more than 25 percent, and acid oxalate extractable aluminum plus one-half iron of more than 0.4 percent.
The 2C horizon has value of 6 through 8 dry, 5 or 6 moist and chroma of 2 or 3 moist and 1 or 2 dry. It is silt loam or silt. It has a moist bulk density of 0.45 to 0.85 grams per cubic centimeter and 15-bar moisture of 5 to 10 percent based on an air-dried sample.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Hooly soils are on old lake basins and valley floors at an elevation of 2,600 to 2,800 feet. Slope is 0 to 2 percent. These soils formed in volcanic ash and loess over mixed volcanic ash and diatomaceous sediments. The climate is characterized by cool wet winters and hot dry summers. The mean annual temperature is 45 to 50 degrees F. The mean annual precipitation is 11 to 20 inches. The frost free period is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Catherine, Conley, Hoopal, Hot Lake and La Grande soils. Catherine and La Grande soils have a thick mollic epipedon. Conley soils have a mollic epipedon and a fine textured argillic horizon. Hoopal soils have a duripan. Hot Lake soils are more than 20 inches deep to diatomaceous sediments and have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderately slow permeability. A season high water table is at a depth of 18 to 30 inches from December through April.
USE AND VEGETATION: Hooly soils are now used primarily for small grains and alfalfa. The native vegetation consisted of sedges and rushes.
DISTRIBUTION AND EXTENT: Hooly soils are on small extent in the Grande Ronde Valley of Union County, Oregon; MLRA 9. The 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 Medial, mesic Aquic Vitrandepts based on the Andisol Order.
Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - from 0 to 17 inches
Andic properties - from 0 to 17 inches (Ap, A, and AC horizons)
Chroma of 2 - from 11 to 17 inches
The 15-bar moisture and 0.02 to 2.0 mm fraction is based on lab data from the associated Hot Lake series.
Particle-size control section - from 0 to 40 inches with 0 to 17 inches (Ap, A, and AC horizons) meeting the medial family criteria and 17 to 40 inches (2C1, 2C2, and 4 inches of 2C3 horizons) meeting the coarse-silty family criteria.