The Bale series consists of somewhat poorly drained soils on alluvial fans, flood plains, and low terraces. Slope is 0 to 5 percent. Elevation is 100 to 300 feet. These soils formed in alluvium derived from rhyolite and basic igneous rock. The plant cover is oak, blackberry, annual grasses, poison-oak, and willows. Mean annual precipitation is 25 to 35 inches. Mean annual air temperature is 58° to 61° F. Summers are hot and dry, and winters are cool and moist. The frost-free season is 220 to 270 days.

In a representative profile the surface layer is dark gray, slightly acid loam 6 inches thick. The subsoil is 18 inches thick. The upper 11 inches is grayish brown, slightly acid loam, and the lower 7 inches is brown, slightly acid loam. Between depths of 24 and 60 inches or more are stratified layers of gray and pale brown slightly acid loam, gravelly sandy loam, and sandy loam.

Permeability is moderate. Temporary ponding is common during periods of high rainfall. The effective rooting depth is 60 inches or more. The available water capacity is 6 to 9 inches.

Bale soils are used mainly for vineyards, but some small areas are used for irrigated pasture and prune orchards.

Representative profile of Bale loam, 0 to 2 percent slopes, 950 feet south of Silverado Trail from Picket Road and 100 feet west along vineyard, NE¼NE¼ sec. 6, T. 8 N., R. 6 W.:

Ap-0 to 6 inches, dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak fine granular structure; hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular and interstitial pores; 10 percent gravel; slightly acid (pH 6.3) clear smooth boundary.

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 and slightly plastic; few coarse and common fine roots; common medium and fine tubular and interstitial pores; 10 percent gravel; slightly acid (pH 6.3); clear smooth boundary.

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 and slightly plastic; few very fine roots; common very fine and fine tubular and interstitial pores; 10 percent gravel; slightly acid (pH 6.3) gradual smooth boundary.

A11b-24 to 33 inches, gray (10YR 5/1) loam, black (10YR 2/1) moist; moderate fine subangular, blocky structure; extremely hard, friable, slightly sticky and 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.

A12b-33 to 44 inches, gray (10YR 5/11) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; extremely hard, friable, slightly sticky and slightly plastic; few fine roots; common very fine tubular and interstitial pores; slightly acid (pH 6.3); gradual smooth boundary.

IICI-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 and nonplastic; many fine interstitial pores; 20 percent gravel; slightly acid (pH 6.3); clear smooth boundary.

IIIC2-50 to 60 inches, pale brown (10YR 6/3) sandy loam, dark brown (10YR 3/3) moist; moderate medium granular structure; hard, friable, nonsticky and nonplastic; many fine interstitial pores; slightly acid (pH 6.3).

The Ap horizon is dark gray, very dark gray, grayish brown, or dark grayish brown (10YR 4/1, 3/1, 5/2, and 4/2) loam or clay loam. Structure is granular or subangular blocky. Reaction is mainly medium acid or slightly acid, but it is moderately alkaline in places.

The B2 horizon is dark grayish brown, grayish brown, dark brown, or brown (10YR 4/2, 5/2, 4/3, and 5/3) loam, gravelly heavy loam, clay loam, or gravelly clay loam. Gravel content is as much as 20 percent in some small areas. Structure is weak, fine or moderate, subangular blocky. Reaction is mainly medium acid, but it is moderately alkaline in places.

The B2 horizon is underlain by light gray to dark grayish brown (10YR 7/1, 7/3, 6/1, 6/2, 5/1, 5/2, 4/2, 6/3, and 5/3), stratified sandy loam, loam, or clay loam. Gravel content is 10 to 20 percent. Structure is granular or subangular blocky. Reaction is mainly medium acid or slightly acid, but it is moderately alkaline in places.

103-Bale loam, 0 to 2 percent slopes. This nearly level soil is on alluvial fans and flood plains. It has the profile described as representative for the series.

Included with this soil in mapping were small areas of Cole, Clear Lake, Cortina, and Yolo soils. Also included are areas of Bale soils near Calistoga that have a surface layer of gravelly loam.

Runoff is slow, and the hazard of erosion is slight. The water table is at a depth of more than 4 feet.

This soil is mainly used for vineyards. A few small areas that have not been drained are in pasture. Capability unit IIw-2 (14).

104-Bale clay loam, 0 to 2 percent slopes. This nearly level soil is on alluvial fans and flood plains. It has a profile similar to the one described as representative for the series, but the surface layer is clay loam.

Included with this soil in mapping were small areas of Clear Lake, Cole, and Yolo soils. Also included were areas of soils that have a hardpan at a depth of more than 40 inches.

Runoff is slow, and the hazard of erosion is slight. The water table is at a depth of more than 4 feet.

This soil is used mainly for vineyards. Capability unit IIw-2 (14).

105-Bale clay loam, 2 to 5 percent slopes. This gently sloping soil is on flood plains and low terraces. It has a profile similar to the one described as representative of the series, but the surface layer is clay loam.

Included with this soil in mapping were small areas of Cole, Cortina, and Yolo soils.

Runoff is slow, and the hazard of erosion is slight. The water table is at a depth of more than 4 feet.

Nearly all the acreage of this soil is used for vineyards. Capability unit IIw-2 (14).

106-Bale complex, 0 to 2 percent slopes, seeped. This complex consists of nearly level, stratified loam, clay loam, and gravelly loam.