LOCATION HANNING WAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Pachic Argixerolls
TYPICAL PEDON: Hanning silt loam, cultivated. (Colors are for dry soil unless otherwise stated.)
Ap1--0 to 4 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; neutral (pH 7.0); abrupt smooth boundary. (3 to 12 inches thick)
Ap2--4 to 11 inches; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; many very fine interstitial pores; neutral (pH 7.0); clear smooth boundary. (0 to 9 inches thick)
A--11 to 21 inches; brown (10YR 4/3) silt loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; soft, friable, slightly sticky and slightly plastic; many very fine roots; many very fine interstitial pores; slightly alkaline (pH 7.6); clear smooth boundary. (8 to 12 inches thick)
Bt1--21 to 27 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak medium prismatic structure parting to weak medium subangular blocky; hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine interstitial pores; few faint clay films on faces of peds; slightly alkaline (pH 7.6); abrupt smooth boundary. (5 to 7 inches thick)
Bt2--27 to 38 inches; yellowish brown (10YR 5/4) silt loam, dark yellowish brown (10YR 4/4) moist; moderate medium prismatic structure; hard, friable, moderately sticky and moderately plastic; common very fine roots; few very fine pores; common faint clay films on faces of peds; slightly alkaline (pH 7.8); clear smooth boundary. (9 to 13 inches thick)
Bt3--38 to 49 inches; light yellowish brown (10YR 6/4) silt loam, dark yellowish brown (10YR 4/4) moist; moderate medium prismatic structure; hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine interstitial pores; very few faint clay films on faces of peds; slightly alkaline (pH 7.8); clear smooth boundary. (9 to 16 inches thick)
C--49 to 60 inches; pale brown (10YR 6/3) silt loam, dark yellowish brown (10YR 4/4) moist; massive; soft, friable, slightly sticky and plastic; common very fine roots; common very fine interstitial and tubular pores; slightly alkaline (pH 7.8).
TYPE LOCATION: Lincoln County, Washington; approximately 6 miles southeast of Davenport; 20 feet east, 80 feet north of SW corner sec. 4, T.24N., R.38E.
RANGE IN CHARACTERISTICS: The mollic epipedon is 20 to 33 inches thick. The mean annual soil temperature is 47 to 50 degrees F. These soils are usually moist, but are dry in all parts between depths of 4 and 12 inches for 70 to 80 consecutive days following the summer solstice. The particle-size control section contains 18 to 27 percent clay and less than 15 percent fine sand or coarser throughout. Depth to cemented pan is 40 to more than 60 inches. Some pedons have Bk horizons at depths greater than 44 inches.
The A horizon has value of 4 or 5 dry, 2 or 3 moist and chroma of 2 or 3 dry or moist. It has weak or moderate granular structure and has 11 to 18 percent clay. This horizon is moderately acid to slightly alkaline.
The Bt horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 dry or moist. It has weak to strong prismatic or blocky structure. Reaction is neutral to moderately alkaline.
The C horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 dry or moist. It is slightly alkaline to strongly alkaline.
COMPETING SERIES: These are the Hendricks, Mohler and Van Nostern (T) series. Hendricks soils have 27 to 35 percent clay throughout the particle-size control section. Moler soils are dry for 45 to 60 consecutive days. Van Nostern soils are 20 to 40 inches to bedrock.
GEOGRAPHIC SETTING: Hanning soils are on uplands with long, broad, nearly level to steep concave slopes. Slopes range from 0 to 25 percent. The soils formed in loess. Elevation ranges from 2,300 to 3,000 feet. These soils are in a Mediterranean climate with annual precipitation of 15 to 18 inches; mean January temperature of 25 degrees F., mean July temperature of 68 degrees F., and mean annual temperature of 48 degrees F. The frost-free season is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bagdad, Broadax, Cheney, Lance, Reardan and Tucannon soils. Bagdad soils have a mollic epipedon 14 to 18 inches thick and depth to secondary carbonates is 30 to 43 inches. Broadax soils have a mollic epipedon 10 to 20 inches thick and depth to secondary carbonates is 17 to 36 inches. Cheney soils are underlain by gravelly or cobbly sand at a depth of 20 to 40 inches. Lance soils lack a mollic epipedon. Reardan soils have more than 35 percent clay in the control section. Tucannon soils are underlain by basalt at a depth of 30 to 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff depending on slope; moderate permeability; slow permeability through the duripan, if present, at 40 or more inches depth.
USE AND VEGETATION: Used for the production of dryland small grain and grasses for hay and pasture. Native vegetation is mostly bluebunch wheatgrass, Sandberg bluegrass, Idaho fescue, prairie junegrass, lupine, rose and scattered Wyoming big sagebrush.
DISTRIBUTION AND EXTENT: Eastern Washington. Hanning series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lincoln County, Washington, 1978.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 21 inches, an argillic horizon from 21 to 49 inches. The particle-size control section is the zone from 21 to 41 inches (Bt1, Bt2 and part of Bt3 horizon).
ADDITIONAL DATA: NSSL characterization data pedon number 92P170.