LOCATION HOGPEN CATentative Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Mollic Haploxeralfs
TYPICAL PEDON: Hogpen loam - on a northwest facing slope of 35 percent, under buckwheat, yucca, red brome and soft chess at an elevation of 1950 feet. (Colors are for dry soil unless otherwise stated. When described on June 6, 1984 the soil was slightly moist below 5 inches.)
A--0 to 5 inches; brown (7.5YR 5/4) loam, dark brown (7.5YR 3/2) moist; massive; hard, friable, nonsticky and nonplastic; few very fine roots; few very fine interstitial and common very fine tubular pores; 5 percent gravel; neutral; clear smooth boundary.
Bt1--5 to 11 inches; reddish brown (5YR 4/4) very gravelly clay loam, dark brown (7.5YR 3/4) moist; massive; hard, friable, slightly sticky and nonplastic; few very fine roots; few very fine interstitial and common very fine tubular pores; few thin clay films on ped faces and in pores; 25 percent gravel and 15 percent cobbles; neutral; gradual wavy boundary.
Bt2--11 to 23 inches; reddish brown (5YR 4/3) very gravelly clay loam, dark reddish brown (5YR 3/4) moist; massive; hard, friable, sticky and plastic; few very fine roots; few very fine interstitial and tubular pores; common thin clay films on ped faces and in pores; 40 percent gravel and 20 percent cobbles; neutral; gradual wavy boundary.
R--23 inches; hard sandstone.
TYPE LOCATION: San Luis Obispo County, California; approximately 1000 feet northwest of jeep trail (magnetic bearing 335 degrees), 350 feet east and 2000 feet north of the southwest corner of section 32 T.32S., R.19E., San Bernardino Base Meridian, USGS Taylor Canyon Quadrangle; lat. 35 degrees, 5 min. 38 sec. N, long. 119 degrees, 58 min. 3 sec. W. (Colors are for air dry soil unless otherwise noted)
RANGE IN CHARACTERISTICS: Depth to a lithic contact of sandstone ranges from 20 to 40 inches. The mean annual soil temperature ranges from 60 to 68 degrees F. The moisture control section is moist in all parts for 60 consecutive days between mid January and April. It is also moist in some part from December to May and is dry in all parts for about 180 days from June to December. Reaction is neutral to mildly alkaline and some pedons are calcareous throughout. The surface is covered with up to 15 percent gravel and cobbles.
The A horizon is 10YR 5/4; 7.5YR 4/4 or 5/4. Moist colors are 10YR 3/4; 7.5YR 3/2, 3/3 or 3/4. Textures are loam or sandy loam and gravel content is 0 to 10 percent.
The Bt horizon is 10YR 4/4; 7.5YR 4/4; 5YR 4/3, 4/4 or 5/4. Moist color is 10YR 3/4; 7.5YR 3/3 or 3/4. Textures are very gravelly clay loam, very cobbly clay loam, gravelly clay loam, gravelly sandy loam or gravelly sandy clay loam. Gravel content is 25 to 50 percent and cobble content is 10 to 20 percent.
COMPETING SERIES: These are the Agua Dulce, Akad, and Buttes series. Agua Dulce soils are slightly acid to medium acid over weakly consolidated conglomerate and do not have 5 YR hues. Akad soils are 10 to 17 inches to bedrock. Buttes soils do not have 5YR hues and have 19 to 22 inches precipitation.
GEOGRAPHIC SETTING: Hogpen soils are on hills and mountains and have slopes of 30 to 75 percent. They formed in material weathered from sandstone. Elevations are 1800 to 2900 feet. The climate is semiarid with hot dry summers and cool moist winters. Mean annual precipitation is 10 to 12 inches. Mean January temperature is 49 degrees F, the mean July temperature is 77 degrees F. The mean annual temperature is 58 degrees to 62 degrees F. Frost-free season ranges from 175 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gaviota, Hillbrick, Kilmer and Saucito soils. Gaviota, Hillbrick, and Saucito soils are shallow. Kilmer soils do not have an argillic horizon.
DRAINAGE AND PERMEABILITY: Somewhat excessively or well drained; high runoff; moderately slow to moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing. Vegetation is buckwheat, yucca, and red brome.
DISTRIBUTION AND EXTENT: Hills of the Caliente Range in the Carrizo Plain area of Central California, MLRA 15. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: San Luis Obispo County, California; Carrizo Plain Area, 1989.