LOCATION HAVILLAH WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy, glassy over isotic, frigid Humic Vitrixerands
TYPICAL PEDON: Havillah ashy silt loam, cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 12 inches; dark gray (10YR 4/1) ashy silt loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many roots, common fine pores; neutral (pH 6.8); abrupt smooth boundary. (8 to 12 inches thick)
A--12 to 19 inches; dark grayish brown (10YR 4/2) ashy silt loam, very dark brown (10YR 2/2) moist; weak medium prismatic structure; soft, very friable, slightly sticky and slightly plastic; common roots and pores; 10 percent gravel; neutral (pH 7.0); clear wavy boundary. (5 to 10 inches thick)
2Bw1--19 to 24 inches; grayish brown (10YR 5/2) gravelly silt loam, very dark grayish brown (10YR 3/2) moist; weak medium prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; many roots, common fine pores; 20 percent gravel; neutral (pH 7.0); clear wavy boundary. (5 to 10 inches thick)
2Bw2--24 to 27 inches; brown (10YR 5/3) gravelly silt loam, dark brown (10YR 3/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few roots and few fine and medium pores; 20 percent gravel; slightly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (2 to 8 inches thick)
2Cd--27 to 60 inches; pale olive (5Y 6/3) gravelly loam, olive (5Y 5/3) moist; massive; hard, firm, moderately sticky and moderately plastic; few roots; 30 percent gravel; strongly effervescent; strongly alkaline (pH 8.5).
TYPE LOCATION: Okanogan County, Washington; 660 feet west, 920 feet south of the NE corner sec. 15, T.39N., R.29E. (Latitude 48 degrees, 52 minutes, 59 seconds north., 119 degrees, 08 minutes, 44 seconds west.)
RANGE IN CHARACTERISTICS:
Soil moisture: usually moist but are dry for 60 to 75 consecutive days following summer solstice (xeric soil moisture regime).
Soil temperature: mean annual soil temperature is 45 to 47 degrees F.
Rock fragments: 0 to 20 percent in the upper part of the particle-size control section and 15 to 35 percent in the lower part.
Depth to densic contact: 20 to 40 inches
Andic soil properties: 14 to 20 inches thick having 30 to 40 percent glass, P retention of 25 to 50, ammonium oxalate aluminum plus one-half the iron of 0.4 to 1.0, 15-bar water of 5 to 12 percent on air-dried samples
Mollic epipedon: 14 to 27 inches thick.
A horizon
Value: 3 or 4, dry or moist
Chroma: 1 or 2 dry
Texture: ashy silt loam, stony phases are recognized
2Bw horizon
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4, dry and moist
Texture: silt loam, loam, or gravelly silt loam.
Clay content: 20 to 27 percent
Gravel content: 5 to 25 percent
2Cd horizon
Hue: 10YR, 2.5Y or 5Y
Value: 5 to 7 dry, 3 to 5 moist
Chroma: 2 or 3, dry or moist
Texture: gravelly loam, gravelly silt loam or gravelly clay loam
Clay content: 25 to 30 percent clay
Gravel content: 15 to 35 percent
Reaction: neutral to strongly alkaline
COMPETING SERIES: This is the Koepke series. Keopke soils are are 40 to 60 inches deep to a densic contact.
GEOGRAPHIC SETTING: Havillah soils are on till plains and mountains. Elevations range from 3,000 to 4,500 feet. Slope ranges from 0 to 45 percent. The soils formed in volcanic ash over calcareous glacial till. The mean annual temperature is 43 degrees F. The mean annual precipitation is 14 to 18 inches. The frost-free period is 95 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chesaw, Koepke, Hunters, Molson and Republic soils. Chesaw soils are coarse-textured. Hunters soils are nongravelly throughout. Koepke soils are moderately deep to a densic contact. Molson soils do not have a Cd horizon. Republic soils have sandy loam control sections.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Used for cropland and woodland. Alfalfa, grass hay, and small grains are common crops. The native vegetation is ponderosa pine and Douglas-fir with an understory of Idaho fescue, rough fescue, bluebunch wheatgrass, mallow ninebark, and common snowberry.
DISTRIBUTION AND EXTENT: North-central Washington; MLRA 43A. The soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Okanogan County, Washington, 1972.
REMARKS: Diagnostic horizons and feature recognized in this pedon are:
Mollic epipedon: from 0 to 27 inches (Ap, A and 2Bw horizons)
Densic contact: at 27 inches (2Cd)
Andic soil properties: from 0 to 19 inches (Ap and A horizons)
A prevoius draft reflected a change in classification from
Medial over loamy, mixed, frigid Mollic Vitrandepts to Ashy over loamy, glassy over mixed, superactive, frigid Humic Vitrixerands. This draft reflects a change in mineralogy from mixed to isotic.
Estimates of dry 15-bar water are based on samples from the Koepke and Molson series