LOCATION WEIRMAN WA+OREstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Torrifluventic Haploxerolls
TYPICAL PEDON: Weirman fine sandy loam, irrigated cropland. (Colors are for dry soil unless otherwise stated.)
Ap1--0 to 3 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many fine roots; neutral (pH 7.0); abrupt smooth boundary. (3 to 9 inches thick)
Ap2--3 to 9 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; many fine roots; common fine tubular pores; neutral (pH 7.0); abrupt smooth boundary. (0 to 9 inches thick)
AC--9 to 20 inches; brown (10YR 5/3) loamy fine sand, dark brown (10YR 3/3) moist; single grain; loose, nonsticky and nonplastic; many fine roots; neutral (pH 7.0); gradual wavy boundary. (6 to 20 inches thick)
2C1--20 to 43 inches; grayish brown (10YR 5/2) extremely gravelly loamy sand, dark grayish brown (10YR 4/2) moist; single grain; loose, nonsticky and nonplastic; few fine roots; 75 percent gravel; neutral (pH 6.8); gradual wavy boundary. (14 to 30 inches thick)
2C2--43 to 60 inches; grayish brown (10YR 5/2) extremely gravelly loamy sand; dark grayish brown (10YR 4/2) moist; single grain; loose; few fine roots; 75 percent gravel; common prominent redox concentrations, yellowish red (5YR 4/6) moist; neutral (pH 6.8).
TYPE LOCATION: Yakima County, Washington; 150 feet southeast of Brooks and Weirman Road intersection; northeast 1/4 northeast 1/4, section 30, T.11N., R.20E., WM.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 49 to 54 degrees F. These soils are usually dry although may be saturated with water at depths of 40 to 72 inches. When present, water tables are a combination of natural conditions and artificially induced high water due to irrigation. Depth to bedrock is greater than 60 inches. The particle-size control section averages 35 to 60 percent rock fragments. The mollic epipedon is 10 to 20 inches thick. The organic carbon is assumed to be less than 1 percent below the A horizon. Reaction is neutral or slightly alkaline.
The A or Ap horizon has value of 4 or 5 dry, 2 or 3 moist and chroma of 2 or 3 dry or moist. Texture is L, SIL, SL, FSL, GR-FSL, GR-S, GR-SIL, GRV-SL, CBV-SL, STV-L or STV-SL. It has 0 to 10 percent clay.
The AC, and C horizon when present, horizon has value of 4,5 or 6 dry, 3 or 4 moist and chroma of 2 or 3 dry or moist. Texture is S, LS, LFS, GR-LS, or GRV-LS. It has thin strata of fine sandy loam or sandy loam in some pedons. It has 2 to 5 percent clay.
The 2C horizon has value of 4 or 5 dry, 3 or 4 moist and chroma of 2 or 3 moist or dry. Texture is GRV-S, GRV-LS, GRX-S, or GRX-LS. It has 0 to 2 percent clay.
COMPETING SERIES: There are no competing series. The
Camas,
Hoypus,
Logy and
Yakima series are in similar families.
Camas soils are usually dry for 45 to 75 consecutive days following the summer solstice (xeric soil moisture regime)
Hoypus soils dry for 75 to 90 consecutive days following the summer solstice (xeric soil moisture regime); moderately acid or strongly acid soil reaction throughout solum; lack mollic epipedon
Logy soils loamy-skeletal
Yakima soils coarse-loamy over sandy or sandy-skeletal control section.
GEOGRAPHIC SETTING: These soils are on flood plains and low terraces at elevations of 250 to 2,600 feet. They formed in alluvium. Slopes are 0 to 5 percent. The climate is characterized by hot, dry summers and cool, moist winters. The mean annual precipitation is 6 to 14 inches. The mean January temperature is 29 degrees F. and the mean July temperature is 73 degrees F. The mean annual temperature is 48 to 53 degrees F. The frost-free season is 110 to 195 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashue and Naches soils and the similar Yakima soils. Ashue and Naches soils on terraces have an argillic horizon. Yakima soils are on bottomlands and are non-skeletal.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow and very slow runoff; rapid permeability. When present, these soils may have an irrigation induced water table with its uppermost limit occurring between 40 and 60 inches at some time between April and November. An apparent water table, when present, is at a depth of 40 to 72 inches some time between November and April. The Weirman soils may be subject to periods of frequent flooding for brief to long durations unless protected.
USE AND VEGETATION: These soils are used dominantly for irrigated cropland, hay and pasture. Native vegetation is bluebunch wheatgrass, basin wildrye, big bluegrass, big sagebrush, and scattered willow and black cottonwood along stream channels.
DISTRIBUTION AND EXTENT: South-central and southeastern Washington and east-central Oregon. MLRA 7, 8, 10. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Yakima County, Washington, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 20 inches and an assumed irregular decrease in organic carbon with depth
Particle-size control section - the zone from 10 to 40 inches
Soil moisture regime aridic bordering xeric