LOCATION BALE CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Cumulic Ultic Haploxerolls
TYPICAL PEDON: Bale loam - cultivated. (Colors are for dry soil unless otherwise noted).
Ap--0 to 6 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak fine crumb structure; hard, very friable, slightly sticky, slightly plastic; common very fine roots; many very fine interstitial and tubular pores; slightly acid (pH 6.3); clear smooth boundary. (6 to 8 inches thick)
B21--6 to 17 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic; few coarse and common fine roots; common medium and fine tubular and interstitial pores; common thin clay films on peds; slightly acid (pH 6.3); clear smooth boundary. (6 to 12 inches thick)
B22--17 to 24 inches; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure very hard, friable, slightly sticky, slightly plastic; few very fine roots; common very fine tubular and interstitial pores; slightly acid (pH 6.3); gradual smooth boundary. (8 to 12 inches thick)
A11b--24 to 33 inches; gray (10YR 5/1) loam, black (10YR 2/1) moist; medium fine subangular blocky structure; extremely hard, friable, slightly sticky, slightly plastic; few fine and coarse roots; few fine and very fine tubular and interstitial pores; common thin clay films on peds and in pores; slightly acid (pH 6.3); gradual smooth boundary. (8 to 10 inches thick)
A12b--33 to 44 inches; gray (10YR 5/1) loam, very dark grayish brown (10YR 3/2) moist, weak fine subangular blocky structure; extremely hard, friable, slightly sticky, slightly plastic; few fine roots; common very fine tubular and interstitial pores; slightly acid (pH 6.3); gradual smooth boundary. (6 to 15 inches thick)
IIC1--44 to 50 inches; pale brown (10YR 6/3) gravelly sandy loam, dark brown (10YR 3/3) moist; moderate medium granular structure; hard, friable, nonsticky, nonplastic; many fine interstitial pores; about 20 percent fine gravel; slightly acid (pH 6.30; clear smooth boundary. (5 to 10 inches thick)
IIIC2--50 to 58 inches; pale brown 910YR6/3) sandy loam, dark brown (10YR 3/3) moist; moderate medium granular structure; hard, friable, nonsticky, nonplastic; many fine interstitial pores; slightly acid (pH 6.3).
TYPE LOCATION: Napa County, California; about 1 mile southeast of Calistoga; 950 feet, southwest from Silverado Trail Road on Pickett Road and 100 feet northwest along a lane between vineyards; NE 1/4 section 6 (projected), T. 8 N., R. 6 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is about 60 to 63 degrees F and the soil temperature usually is not below 47 degrees F at any time. The soil between depths of 5 to 25 inches is usually dry from June until November 15 and is moist in some or all parts the rest of the year.
Rock fragments make up about 10 to 25 percent of the 10 to 40 inch control section. The fragments consist of rounded pebbles ranging in diameter from 2 mm to 1 inch and very few up to 3 inches. Thin very gravelly horizons occur at depths of 26 to 40 inches. The 10 to 40 inch control section averages 18 to 28 percent clay. Some pedons have a few mottles below a depth of 2 feet. Reaction is slightly acid or medium acid with some pedons strongly acid.
The Ap horizon is dark gray to very dark grayish brown in 10YR or 7.5YR hue and has value of 3, 5 or 5 dry and 2 or 3 moist and chroma of 1 or 2 dry or moist. Texture is loam, or clay loam. Structure is weak or moderate crumb, subangular blocky or is massive. This horizon is slightly hard or hard but is not massive and hard when dry.
The B2 horizon is dark gray and dark grayish brown to brown in 10YR or 7.5YR hue with value of 3, 4 or 5 dry and chroma of 1, 2 or 3 dry or moist. It is loam, heavy loam, sandy clay loam or clay loam. There is a slight clay increase with some thin clay films but not enough to qualify for an argillic horizon. This horizon has weak or moderate subangular blocky structure.
The horizons below the B2 horizon are buried A horizons or highly stratified C horizons. They are light gray to dark grayish brown in 10YR hue with value of 4 to 7 and chroma of 1 to 3. Texture is sand, loamy sand, sandy loam, loam, sandy clay loam or clay loam. Rock fragments, as described above, make up less than 50 percent of the C horizon.
COMPETING SERIES: These are the Cole, Pacheco, Pajaro, and Soquel series. Cole soils have a fine particle-size class, an argillic horizon, and have more than 75 percent base saturation. Pacheco soils have a mollic epipedon less than 20 inches thick and have mottles with chroma of 2 or less within depth of 30 inches. Pajaro soils have an aquic moisture regime, have mesic temperature, and have a coarse-loamy control section. Soquel soils have a regular decrease in organic matter, more than 75 percent base saturation throughout and have mesic temperature.
GEOGRAPHIC SETTING: Bale soils are on nearly level to gently sloping alluvial fans and terraces at elevations of 100 to 300 feet. They formed in stratified, gravelly and sandy alluvium from mixed sources. The climate is subhumid mesothermal with hot dry summers and cool moist winters. Mean annual precipitation is 32 to 40 inches. Average January temperature is 46 degrees F; average July temperature is 70 degrees F; mean annual temperature is 59 to 60 degrees F. The frost-free season is 220 to 270 days.
GRAPHICALLY ASSOCIATED SOILS: These are the competing Cole soils and the Cortina and Yolo soils. Cortina soils have an ochric epipedon and a loamy-skeletal control section. Yolo soils have an ochric epipedon, lack stratification, and have a fine-silty control section.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderate permeability. Some areas have a water table within 4 feet of the surface, and are ponded for short periods in the winter. Most areas are artificially drained.
USE AND VEGETATION: Used mostly for wine grape production with small acreages of orchards and irrigated pasture. Native vegetation was oak-grass and willows, blackberry and poison oak.
DISTRIBUTION AND EXTENT: Napa County, California. The soils are moderately extensive. MLRA 14.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Napa Area, California, 1933.
REMARKS: Bale soils formerly were classified as Brunizems. The classification is changed from Typic Umbraqualfs to Cumulic Ultic Haploxerolls. No other soils are presently placed in the fine-loamy, mixed, thermic family.
ADDITIONAL DATA: NSSL pedon S72CA-055-007 (type location; not in Ultic subgroup) and pedon S91CA-055-001 (which would be a better type location)
Last revised by the state on 10/74.