LOCATION RATLAKE WAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, calcareous, mesic, shallow Typic Petraquepts
TYPICAL PEDON: Ratlake silty clay loam - in a level closed depression under inland saltgrass, alkali bluegrass, and black greasewood, at an elevation of 1,300 feet.
Bgkzn1--0 to 2 inches; light gray (10YR 7/1) silty clay loam, gray (10YR 6/1) moist; massive; very hard, very firm, very sticky, very plastic; common very fine and fine roots; very strongly alkaline (pH 10.0) violently effervescent; clear wavy boundary.
Bgkzn2--2 to 18 inches; gray (10YR 6/1) silty clay loam, gray (10YR 5/1) moist; massive; very hard, very firm, very sticky, very plastic; few very fine and fine roots; very strongly alkaline (pH 10.0); violently effervescent; abrupt wavy boundary. (Combined thickness of the Bgkzn horizon is 10 to 20 inches)
Bkqm--18 to 22inches; light gray (10YR 7/1) lime-silica indurated duripan which crushes to loam, gray (10YR 6/1) dry; massive; extremely hard, extremely firm, slightly sticky and slightly plastic when crushed; very strongly alkaline (pH 9.6); violently effervescent.
TYPE LOCATION: Colville Indian Reservation; Okanogan County, Washington; about 16 miles west of the town of Nespelem; 850 feet south, 250 feet west of the northeast corner of sec. 5, T. 30 N., R. 28 E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at the contact with the duripan ranges from 50 to 52 degrees F. These soils are commonly saturated from the surface to the duripan from January until June. Depth to the duripan ranges from 10 to 20 inches. The particle-size control section is 22 to 35 percent clay.
The Bgkzn horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry, 4 through 6 moist. It is silt loam or silty clay loam and is 0 to 15 percent hard durinodes.
The Bkqm horizon has hue of 10YR or 2.5Y, value of 7 or 8 dry, 5 or 6 moist. This horizon is strongly cemented to indurated.
COMPETING SERIES: This is the Miskah series in another family. Miskah soils are frigid and more than 20 inches deep.
GEOGRAPHIC SETTING: Ratlake soils are in closed depressions and basins on valley flats. These soils formed in glaciolacustrine sediments with some additions of recent alluvium. Slopes are 0 to 2 percent. Elevations range from 1,100 to 1,350 feet. The climate is characterized by hot, dry summers and cool, moist winters. The average annual precipitation is 9 to 11 inches. The mean January temperature is about 25 degrees F, the mean July temperature is about 74 degrees F, and the mean annual air temperature is about 50 degrees F. The frost-free period is 140 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Couleedam, Gooseflats, Pogue, and Quincy soils. Couleedam soils are loamy-skeletal and shallow to a lithic contact. Gooseflats soils are deep and sandy. Pogue soils are deep, well drained, and coarse-loamy over sandy or sandy-skeletal. Quincy soils are deep, sandy, and excessively drained.
DRAINAGE AND PERMEABILITY: Poorly drained; moderately slow permeability above the duripan.
USE AND VEGETATION: Principal uses are wildlife habitat and limited livestock grazing. Native vegetation consists of a sparse cover of black greasewood, alkali bluegrass, inland saltgrass, mountain agoseris, and common yarrow.
DISTRIBUTION AND EXTENT: Northcentral Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Colville Indian Reservation; Okanogan County, Washington, 1987.
REMARKS: Diagnostic features recognized in this soil are an assumed sodium adsorption ratio of more than l3 in the layer from the surface to 18 inches, an aquic moisture regime, and a duripan at 18 inches.