LOCATION CUMMISKEY CA

Established Series
Rev. RHB/RFH/DJE
12/2022

CUMMISKEY SERIES

The Cummiskey series consists of very deep, well drained soils formed in material weathered from metasedimentary rock. Cummiskey soils are on hills and mountains and have slopes of 30 to 75 percent. The mean annual precipitation is about 42 inches and the mean annual temperature is about 57 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, parasesquic, mesic Pachic Ultic Argixerolls

TYPICAL PEDON: Cummiskey gravelly loam - on a NW facing convex slopes of 55 percent under white oak, blue oak, madrone, and poison oak at 820 feet elevation. (Colors are for dry soil unless otherwise stated. When described July 26, 1977, the soil was dry.)

0--1 inch to 0; consists of leaf and twig litter in all stages of decomposition. (1/2 to 3 inches thick)

A1--0 to 4 inches; weak red (2.5YR 5/2) gravelly loam, dusky red (2.5YR 3/2) moist; weak medium subangular blocky structure parting to strong granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and common medium roots; common medium and many very fine and fine interstitial pores; 30 percent 2 to 50 mm pebbles; slightly acid (pH 6.4); abrupt smooth boundary. (3 to 6 inches thick)

A2--4 to 19 inches; weak red (2.5YR 5/2) gravelly loam, dusky red (10R 3/2) moist; weak medium subangular blocky structure parting to moderate granular; slightly hard, very friable, and slightly plastic; common very fine, fine, medium and coarse roots; common fine and medium tubular and many very fine interstitial and tubular pores; 30 percent 2 to 50 mm pebbles; moderately acid (pH 6.0); clear smooth boundary. (15 to 24 inches thick)

Bt1--19 to 25 inches; weak red (2.5YR 5/2) gravelly clay loam, dusky red (10R 3/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; common very fine and fine and few medium and coarse roots; common very fine interstitial and tubular and many fine and medium tubular pores; few thin clay films in pores; 30 percent 2 to 75 mm pebbles; moderately acid (pH 5.8); gradual wavy boundary. (4 to 6 inches thick)

Bt2--25 to 32 inches; weak red (2.5YR 5/2) very gravelly clay loam; weak red (2.5YR 4/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; few very fine and fine roots; common very fine and fine tubular pores; common thin clay films on peds and in pores; 45 percent 2 to 75 mm pebbles; moderately acid (pH 5.8); clear wavy boundary. (6 to 10 inches thick)

Bt3--32 to 48 inches; pale red (2.5YR 6/2) very gravelly clay loam; weak red (2.5YR 4/2) moist; weak medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine and fine roots; common very fine and fine tubular pores; common thin clay films on peds and in pores; 50 percent 2-75 mm pebbles; moderately acid (pH 5.8); clear irregular boundary. (15 to 17 inches thick)

Bt4--48 to 64 inches; weak red (2.5YR 5/2) gravelly clay; dusky red (10R 3/2) moist; weak medium subangular blocky structure; hard, firm, very sticky and very plastic; few very fine and fine roots; common very fine and fine tubular pores; many moderately thick clay films on peds; 20 percent 2 to 75 mm pebbles; moderately acid (pH 5.8).

TYPE LOCATION: Mendocino County, California, approximately 1.4 miles from Mountain House Road on the jeep trail that starts at the old Rodeo grounds. It is on the left side of the trail about 150 feet up slope, 1,250 feet south and 1,450 feet west of northeast corner of sec. 10, T. 12 N., R. 11 W., MDBM, Hopland Quadrangle.

RANGE IN CHARACTERISTICS: Thickness of the solum is more than 60 inches. The soil between a depth of 8 to 24 inches is dry in all parts, from June through October and is moist in all parts from December through May. The mean annual soil temperature is 54 to 59 degrees F. The mollic epipedon is more than 20 inches thick. The base saturation is 50 to 90 percent throughout the profile, and is less than 75 percent in some part of the top 30 inches. The particle-size control section has 28 to 50 percent rock fragments.

The A horizon is 5YR 4/2, 4/3, 5/2; 2.5YR 5/2 or 5/3. Moist colors are 5YR 3/2; 2.5YR 3/2; 10R 3/2 or 3/3. It is gravelly loam with 20 to 35 percent gravel. It is medium acid to neutral.

The Bt horizon is 5YR 4/3, 5/3; 2.5YR 5/2, 6/2; or 10R 5/2. Moist colors are 5YR 3/2, 3/3, 4/3; 2.5YR 4/2; 10R 3/2 or 3/3. It is gravelly clay loam, gravelly clay, very gravelly clay loam or very gravelly clay, with 25 to 50 percent gravel and 28 to 45 percent clay. It is medium acid or slightly acid.

COMPETING SERIES: There are no other series in this family. A competing series in another family is the Comptche series. Comptche soils have ustic moisture regimes, isomesic temperature regimes, fine particle-size control sections and are 40 to 80 inches deep.

GEOGRAPHIC SETTING: The Cummiskey soils are on hills and mountains and have slopes of 30 to 75 percent. They formed in material weathered from metasedimentary rock at elevations of 500 to 2,500 feet. The climate is subhumid with hot, dry summers and cool, moist winters. Mean annual precipitation is 35 to 50 inches. Mean January temperature is about 44 degrees F. Mean annual temperature is 54 to 59 degrees F. Frost-free season is 175 to 250 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hopland, Yorkville and Frogwoman soils. Hopland and Frogwoman soils are 20 to 40 inches deep. Yorkville soils are fine.

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

USE AND VEGETATION: This soil is used for wildlife habitat, watershed, recreation, firewood production and as a source of gravel for road construction. Natural vegetation is annual grasses, brush, Douglas-fir, madrone, and oaks.

DISTRIBUTION AND EXTENT: Northern coastal California. The soils are not extensive.

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

SERIES ESTABLISHED: Mendocino County, California 1985.

National Cooperative Soil Survey
U.S.A.