LOCATION HOTAW CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Ultic Haploxeralfs
TYPICAL PEDON: Hotaw coarse sandy loam-on a west facing slope of 25 percent under ponderosa pine, black oak, canyon live oak, brush and mountain misery. (Colors are for dry soil unless otherwise stated. When described, May 20, 1966, the soil was moist below 12 inches.)
Oi--1 inch to 0; litter and duff.
A--0 to 12 inches; grayish brown (10YR 5/2) coarse sandy loam, dark brown (10YR 3/3) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and medium roots; many very fine and fine tubular and interstitial pores; slightly acid (pH 6.1); clear wavy boundary. (6 to 12 inches thick)
BAt--12 to 22 inches; pale brown (10YR 6/3) coarse sandy loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, nonsticky and nonplastic; many very fine, fine and medium roots; many very fine and fine tubular and interstitial pores; few thin clay films line pores; moderately acid (pH 5.9); clear smooth boundary. (8 to 12 inches thick)
Bt--22 to 35 inches; light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 4/4) moist; moderate medium and coarse subangular blocky structure; very hard, firm, sticky and slightly plastic; many fine and medium roots; common very fine and fine tubular pores; many moderately thick clay films on ped faces, lining pores and as bridges; strongly acid (pH 5.5); clear wavy boundary. (8 to 16 inches thick)
Cr--35 to 45 inches; weathered granodiorite.
TYPE LOCATION: El Dorado County, California; 0.5 miles east of Aukum; 0.1 mile northeast of southwest corner of section 12, T. 8 N., R. 11 E. Aukum Quadrangle.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact is 20 to 40 inches. Mean annual soil temperature is 52 to 59 degrees F. The soil between depths of about 8 and 33 inches is dry in all parts for about 120 to 150 days from sometime in June or early July through October. It is moist in some or all parts the rest of the year. Some pedons have stones, cobbles, or gravel; however, they usually average less than 15 percent by volume. The particle-size control section averages 18 to 25 percent clay. Some pedons have a BC or BCt horizon above the paralithic contact.
The A horizon is 10YR 5/8, 5/6, 6/4, 5/4, 6/3, 5/3, 4/3, 5/2, 4/2, 3/4; 7.5YR 6/4, 5/4, 4/4, 5/2 or 4/2. Moist colors are 10YR 4/4, 4/3, 3/3, 3/2; 7.5YR 4/4, 3/4, 3/2. It is loam, sandy loam, or coarse sandy loam. It has 1 to 5 percent organic matter in the upper part. Organic matter is less than 1 percent within 7 inches or the color value is 6 or more dry or 4 or more moist. It is slightly acid or moderately acid. The lower boundary is gradual or there is a transitional horizon.
The Bt horizon is 10YR 6/4, 5/6, 5/4, 6/3, 5/3, 4/3; 7.5YR 6/8, 5/8, 5/6, 6/4, 5/4, 4/6, 4/4, 5/2 or 4/2. Moist soil colors are 10YR 4/3, 3/3; 7.5YR 5/8 4/4, 3/2. It is sandy clay loam or clay loam with 25 to 35 percent clay and 16 to 26 percent coarse and very coarse sand. It is slightly acid through strongly acid. Base saturation is 35 to 70 percent and increases with depth.
COMPETING SERIES: These are the Bigridge, Hospiter, Millerridge, Minniecreek, Sitton, Spekaer and Willakenzie soils. Bigridge is deep and has hue of 5YR. Hospiter soils are very deep and has hue of 5YR. Millercreek and Minnecreek have hue of 5YR. Sitton is very deep. Speaker has hue of 5YR and rock fragments throughout. Willakenzie has hue of 7.5YR and is pargravelly in the lower subsoil.
GEOGRAPHIC SETTING: Hotaw soils are on mountains at elevations of 2,000 to 5,000 feet. In some areas on north aspects the elevation is as low as 1,200 feet. Slope is 2 to 75 percent. Rock outcrops are common. The underlying rock is quartz diorite or granodiorite. The climate is subhumid with warm, dry summers and cool, moist winters. Mean annual precipitation is 30 to 80 inches some of which occurs as snow. Mean annual temperature is 50 to 59 degrees F, average January temperature is about 40 degrees F, average July temperature is about 72 degrees F. Frost-free season is 160 to 230 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chaix, Chawanakee, and the competing Holland and Musick soils. Chaix and Chawanakee soils lack an argillic horizon. Also, Chawanakee soils are less than 20 inches to bedrock. All are in similar landscape positions, often mapped in complex.
DRAINAGE AND PERMEABILITY: Well drained; low to very high runoff; moderately slow permeability.
USE AND VEGETATION: Largely used for timber production. Vegetation is ponderosa pine, sugar pine, Douglas-fir, incense-cedar, California black oak, and canyon live oak with an understory of shrubs, grasses, and forbs.
DISTRIBUTION AND EXTENT: Sierra Nevada and Cascade ranges of California. The soils are of moderate extent. MLRA is 22.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Nevada County Area, California, 1970.
REMARKS:
10/2006 changed runoff terminology- DWB. 5/25/2005 Changed CEC class to active from subactive based on lab data, landscape position and surrounding soils. Competing series were then updated. - SS
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this profile are:
Ochric epipedon - the zone from the soil surface to about 12 inches (A horizon).
Argillic horizon - the zone from about 12 to 35 inches (the BAt and Bt horizon).
Paralithic contact - the boundary at 35 inches.
Particle size control section - the zone from about 12 to 32 inches (the BAt and a portion of the Bt horizon).