LOCATION PINOLE CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, thermic Ultic Argixerolls
TYPICAL PEDON: Pinole gravelly loam; in an open field on an east-facing slope of 7 percent at 920 feet elevation. (Colors are for dry soil unless otherwise noted. When described July 13, 1983, the soil was moist below a depth of 15 inches).
Oi--0.5 inch to 0; roots and decomposed grass material.
A--0 to 10 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure breaking to moderate fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; common very fine, fine, medium and coarse tubular and interstitial pores; 15 percent 2 to 25mm pebbles; neutral (pH 6.8); clear wavy boundary. (10 to 16 inches thick)
Bt1--10 to 15 inches; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; many very fine and common fine, medium and coarse tubular and interstitial pores; few thin clay films on peds and in pores; 10 percent 2 to 25mm pebbles; neutral (pH 6.8); gradual wavy boundary. (9 to 14 inches thick)
Bt2--15 to 37 inches; variegated strong brown and yellow (7.5YR 5/6, 10YR 7/6) clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure parting to strong fine subangular blocky; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and common fine and medium interstitial and tubular pores; many moderately thick clay films on peds and in pores; 10 percent 2 to 25mm pebbles; slightly acid (pH 6.5); gradual wavy boundary. (10 to 14 inches thick)
Bt3--37 to 61 inches; variegated strong brown and brownish yellow (7.5YR 5/8, 10YR 6/6) sandy clay loam, variegated dark brown and brown (7.5YR 3/4, 7.5YR 4/4) moist; strong fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine roots; few fine tubular and interstitial pores; common moderately thick clay films on peds and in pores; 5 percent 2 to 25mm pebbles; few black (N 3/0) manganese stains; slightly acid (pH 6.2).
TYPE LOCATION: Mendocino County, California; 1 mile north on Tomki road from intersection with Eastside-Westside Road, Redwood Valley, California, 0.4 mile northwest on dirt farm road, 0.3 mile east on side road to vineyards, 150 feet east of road in open field; 1650 feet south and 750 feet east of the northeast corner of section 18, T.17 N., R.12 W., M.D.B.M., Redwood Valley Quadrangle.
RANGE IN CHARACTERISTICS: Depth of solum is greater than 60 inches. Where not irrigated, the soil between a depth of 8 to 23 inches is dry in all parts from June to October and is moist in all parts from November to May. The mean annual soil temperature varies from 59 to 62 degrees F. Mean January soil temperature is 46 degrees F and mean July temperature is 72 degrees F. Organic matter content to a depth of 10 inches is 1 to 5 percent. Coarse fragment content in the particle-size control section averages 10 to 35 percent.
The A horizon is 10YR 4/2, 4/3, 5/2, 5/3; 7.5YR 4/3, 5/2 or 5/3. Moist colors are 10YR 3/2, 3/3, 7.5YR 3/2 or 3/3. It is loam, gravelly loam or very gravelly loam with 15 to 27 percent clay, and 2 to 40 percent gravel. Base saturation is 50 to 75 percent. It is moderately acid through neutral.
The Bt horizon is 10YR 4/4, 5/4, 6/4, 6/6, 7/6; 7.5YR 4/4, 5/4, 4/6, 5/6 or 5/8. Moist colors are 10YR 3/4, 4/3, 4/4 5/6; 7.5YR 3/4, 4/3, 4/4 or 4/6. It is sandy clay loam or clay loam or gravelly or very gravelly sandy clay loam or clay loam. It has 20 to 35 percent clay and 2 to 50 percent gravel. Base saturation is 50 to 75 percent in the upper part and ranges to 90 percent in the lower part. Gravel often occurs in lenses 3 to 6 inches thick below 30 inches. It is strongly acid through neutral.
COMPETING SERIES: This is the Boontling (CA) series. The Boontling soils has low chroma mottles in the lower Bt horizon and are somewhat poorly drained.
GEOGRAPHIC SETTING: The Pinole soils are on terraces and have slopes of 0 to 30 percent. The formed in alluvium from sedimentary and other rock sources at elevations of 200 to 1500 feet. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation varies from 32 to 50 inches. Mean January temperature is about 46 degrees F; mean July temperature is about 72 degrees F; mean annual temperature varies from 56 degrees to 59 degrees F. Frost-free period is 175 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pinnobie, Redvine, and Yokayo soils. Redvine and Yokayo soils have ochric epipedons and are fine. Pinnobie soils do not have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used for vineyards, orchards and urban development. Vegetation was annual grasses, manzanita, liveoak, white oak, black oak, madrone, blue oak poison-oak, and ponderosa pine. Most areas of this soil are cleared and cultivated.
DISTRIBUTION AND EXTENT: Northern California in the Coast Range. The soils are not extensive. MLRA 14.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, California, 1914.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
Diagnostic features and horizons recognized in this pedon are:
Mollic epipedon -- the zone from 0 to 10 inches (A)
Argillic Horizon - the zone from 10 to 60 inches (Bt)