LOCATION KYBURZ CA

Established Series
Rev. JWF/BES/DJE/ET
12/2022

KYBURZ SERIES

The Kyburz series consists of moderately deep, well drained soils formed in material weathered from basic volcanic rock. Kyburz soils occur on uplands and have slopes of 2 to 50 percent. The mean annual precipitation is about 25 inches and the mean annual temperature is about 45 degrees.

TAXONOMIC CLASS: Fine-loamy, mixed, active, frigid Ultic Haploxeralfs

TYPICAL PEDON: Kyburz gravelly sandy loam--on an east facing slope of 12 percent under mixed conifers at 6440 feet elevation. (Colors are for dry soil unless otherwise stated. When described on 7/17/79 the soil was dry throughout).

O1--2 to 0 inches; needles, twigs and duff.

A1--0 to 6 inches; brown (10YR 4/3) gravelly sandy loam, dark brown (7.5YR 3/2) moist; moderate very fine and fine granular structure, soft, very friable, nonsticky and slightly plastic; many very fine and few fine roots; many very fine interstitial pores; 10 percent pebbles and 5 percent cobbles; slightly acid (pH 6.5); clear wavy boundary. (4 to 9 inches thick)

Bt1--6 to 12 inches; reddish brown (5YR 4/4) gravelly loam, dark reddish brown (5YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine and few fine, medium and coarse roots; many very fine interstitial pores; few thin clay films as bridges between mineral grains; 10 percent pebbles and 5 percent cobbles; slightly acid (pH 6.5); clear wavy boundary. (4 to 8 inches thick)

Bt2--12 to 23 inches; reddish brown (5YR 5/4) gravelly clay loam, dark reddish brown (5YR 3/4) moist; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; many very fine interstitial pores and few very fine tubular pores; many thin clay films in pores and as bridges between mineral grains; 15 percent pebbles and 5 percent cobbles; very strongly acid (pH 5.0); gradual wavy boundary. (8 to 16 inches thick)

Bt3--23 to 34 inches; reddish brown (5YR 5/4) gravelly light clay loam, dark reddish brown (5YR 3/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; many very fine interstitial and few fine tubular pores; common thin clay films in pores and as bridges between mineral grains; 20 percent pebbles; very strongly acid (pH 5.0); abrupt wavy boundary. (O to 11 inches thick)

Cr--34 to 41 inches; weathered volcanic rock. Few roots in fractures 5 to 9 inches apart.

TYPE LOCATION: Nevada County, Tahoe National Forest, California; about 0.4 miles northwest of Woodchoppers Spring, in the SW1/4 of the SE1/4 of sec. 13, T.18N., R.16E., MDB&M.

RANGE IN CHARACTERISTICS: The thickness of the solum and depth to weathered bedrock is 20 to 40 inches. The soil between depths of about 10 to 20 inches is usually dry all of the time from July 15 until November 1 and is moist in some or all parts the rest of the year. Mean annual soil temperature is about 43 degrees to 47 degrees. Rock fragments make up 5 to 35 percent of the profile. Base saturation is 50 to 75 percent throughout the argillic.

The A horizon has dry color of 10YR 4/2, 4/3, 5/2, 5/3; 7.5YR 4/2, 5/2; 5YR 4/3, 4/4 and 5/3. Moist colors are 10YR 2/2, 3/2, 3/3, 3/4; 7.5YR 3/2; 5YR 3/2, 3/3, 3/4 with moist chromas of 3 or less above 7 inches. It is sandy loam or loam. It is slightly acid to medium acid.

The Bt horizon has dry color of 7.5YR 4/4, 5/4; 5YR 4/4 and 5/4, and has moist color of 7.5YR 3/4, 4/4; 5YR 3/3, 3/4, 4/3, 4/4. It is loam, clay loam or sandy clay loam and averages less than 35 percent clay. It is slightly to very strongly acid.

COMPETING SERIES: These are the Fugawee, Ketchly, Kruse, McEwen, Martis, Mimus, Tepping and Wintoner soils. Fugawee soils have base saturation of less than 50 in the argillic horizon. Ketchly, Kruse, McEwen, Martis, Mimus, Tepping and Wintoner soils lack paralithic contacts. Ketchly and Martis soils have umbric epipedons.

GEOGRAPHIC SETTING: Kyburz soils are on gently sloping plateaus and moderately steep to steep mountain side slopes at elevations of 5500 to 6400 feet. Slope ranges from 2 to 50 percent. These soils formed in residuum from basic volcanic flows, breccias and agglomerates. The mean annual precipitation is 18 to 35 inches and the mean annual temperature is 43 degrees to 47 degrees F., mean January temperature is about 27 degrees F. and mean July temperature is about 60 degrees F. The frost-free season is less than 30 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sattley, Sierraville and Trojan soils. All these soils lack a paralithic contact within 40 inches. Sattley soils have more than 35 percent rock fragments in the control section and have mollic epipedons. Sierraville soils are clayey in the texture control section. Trojan soils have mollic epipedons.

DRAINAGE AND PERMEABILITY: Well drained, slow to rapid runoff, moderate to moderately slow permeability.

USE AND VEGETATION: Used for commercial timber production, wildlife habitat, watershed and recreation. Principal species are Jeffrey pine and ponderosa pine.

DISTRIBUTION AND EXTENT: Northern part of Sierra Nevada Range of California. The soils are moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Nevada County (Tahoe National Forest Area), California, 1982.

REMARKS: Series was entered into Ames database 04/2000, format only was changed to current standards.

National Cooperative Soil Survey
U.S.A.