LOCATION TERLAN WAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Argiduridic Durixerolls
TYPICAL PEDON: Terlan gravelly loam - irrigated cropland (wheat), on a 1 percent slope at an elevation of 1,860 feet. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 7 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; moderate fine granular structure; slightly hard, very friable, nonsticky and slightly plastic; many very fine, fine roots; few very fine tubular pores; 15 percent pebbles; moderately acid (pH 6.0); abrupt wavy boundary. (5 to 10 inches thick)
Bt--7 to 15 inches; brown (10YR 5/3) gravelly clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine roots; common very fine tubular pores; few distinct clay films on faces of peds; 15 percent pebbles; neutral (pH 7.0); abrupt wavy boundary. (5 to 8 inches thick)
Bkq--15 to 18 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and slightly plastic; common very fine roots; violently effervescent, with disseminated lime, silica coatings on pebbles; 20 percent pebbles, 5 percent cobbles, 20 percent pebble-sized fragments of indurated duripan; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 4 inches thick)
2Bkqm--18 inches; indurated lime-silica gravelly duripan; violently effervescent.
TYPE LOCATION: Kittitas County, Washington; about 6 miles southeast of Kittitas in the Badger Pocket area; 2,200 feet east and 1,000 fee south of the northwest corner of sec. 8, T. 16 N., R. 20 E.; USGS East Kittitas topographic quadrangle; Lat. 46 degrees 53' 39" N. and Long. 120 degrees 21' 02" W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 54 degrees F. These soils are dry for one-half to three-fourths of the time in the moisture control section when the soil temperature is above 40 degrees F unless irrigated. Depth to the duripan is 10 to 20 inches. The mollic epipedon is 7 to 12 inches and may or many not include any or all of the Bt horizon. The particle-size control section contains 18 to 35 percent clay and 15 to 35 percent rock fragments. The rock fragments are mostly rounded basalt fragments.
The A horizon has value of 4 or 5 dry, and chroma of 2 or 3 dry and moist. It is moderately acid to slightly alkaline.
The Bt or Btk horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 dry. It is gravelly clay loam, gravelly silt loam or gravelly loam, with 15 to 20 percent gravel and 0 to 10 percent cobbles. It is slightly acid to moderately alkaline.
The Bkq or Bk horizons have value of 6 or 7 dry, chroma of 1 to 3 dry or moist. It is gravelly loam, gravely silt loam, very gravelly loam or gravelly clay loam. It averages 15 to 25 percent pebbles and 0 to 15 percent cobbles.
COMPETING SERIES: These are the Aned, Bluemass (T), Mudco, Oxendine and Roval soils. Aned soils have less than 15 percent coarse fragments in the argillic horizon and are noncalcareous. Mudco and Oxendine soils are noncalcareous in the lower part of the B horizon and in the duripan. Roval soils have an A horizon 1 to 3 inches thick. Bluemass soils have 10 to 18 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: Terlan soils are on dissected flat summit, fan terraces, and fan remnants which grade from mountain footslopes to basin drainageways and have slopes of 0 to 30 percent. They formed in alluvium mixed with loess over a gravelly duripan overlying the Ellensburg formation. Elevation is 1,600 to 2,600 feet. These soils are in a semiarid climate with warm, dry summers and cool, moist winters. The mean annual precipitation is 9 to 12 inches. The average January temperature is about 25 degrees F, the average July temperature is about 69 degrees F, and the mean annual temperature is about 48 degrees F. The frost-free season is 130 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Selah, Rollinger, and Wipple soils and the similar Gorskel soil. Selah soils on old alluvial fans are 20 to 40 inches to indurated duripan. Rollinger soils on north-facing toeslopes, hillslopes and piedmont slopes are fine loamy and are greater than 40 inches deep. Wipple soils on footslopes are clayey-skeletal and are deep.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability above the duripan, and very slow within the duripan.
USE AND VEGETATION: Irrigated cropland, rangeland, and wildlife habitat. Native vegetation is bluebunch wheatgrass, Sandberg bluegrass, and some big sagebrush.
DISTRIBUTION AND EXTENT: Central Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Kittitas County, Washington, Yakima Training Center, 1994.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 15 inches, an argillic horizon from 7 to 15 inches, a zone of lime and silica accumulation from 15 to 18 inches, and an indurated duripan cemented with lime and silica at 18 inches.