LOCATION MCKEONHILLS CA
Established Series
Rev. JCR/AJP/JTW
12/2018
MCKEONHILLS SERIES
The Mckeonhills series consists of moderately deep, well drained soils that formed in colluvium and/or residuum derived from calcareous sandstone. Mckeonhills soils are on hills. Slopes are 5 to 15 percent. The mean annual precipitation is about 445 millimeters and the mean annual air temperature is about 17 degrees C.
TAXONOMIC CLASS: Fine, smectitic, thermic Aridic Haploxererts
TYPICAL PEDON: Mckeonhills clay on a southeast facing, 10 percent, linear slope under annual grasses and forbs at an elevation of 103 meters. (Colors are for dry soil unless otherwise stated).
A--0 to 10 cm; dark gray (5YR 4/1) clay, very dark gray (7.5YR 3/1) moist; moderate medium subangular blocky structure; rigid, firm, very sticky, very plastic; few fine and many very fine roots; few medium tubular pores; strongly effervescent with disseminated carbonates, by HCl; moderately alkaline, pH 8.0; clear wavy boundary. (5 to 75 cm thick).
Bk1--10 to 23 cm; dark gray (5YR 4/1) clay, dark brown (7.5YR 3/2) moist; moderate coarse angular blocky structure; rigid, firm, very sticky, very plastic; few fine and many very fine roots; few very fine dendritic tubular pores; strongly effervescent, carbonates disseminated and segregated as few nodules; moderately alkaline, pH 8.0; clear wavy boundary.
Bk2--23 to 48 cm; dark gray (5YR 4/1) clay, dark brown (7.5YR 3/2) moist; moderate coarse angular blocky structure; rigid, firm, very sticky, very plastic; few fine and many very fine roots; few very fine dendritic tubular pores; few pressure faces on all faces of peds; strongly effervescent, carbonates disseminated and segregated as few nodules; moderately alkaline, pH 8.2; clear wavy boundary. (combined thickness of Bk horizons is 25 to 95 cm)
Bkss1--48 to 70 cm; dark gray (5YR 4/1) clay, dark brown (7.5YR 3/2) moist; moderate coarse wedge structure; extremely hard, firm, very sticky, very plastic; common very fine roots; few very fine dendritic tubular pores; few slickensides; strongly effervescent, carbonates disseminated and segregated as few nodules and carbonate coats; moderately alkaline, pH 8.2; clear wavy boundary.
Bkss2--70 to 99 cm; dark gray (5YR 4/1) clay, dark brown (7.5YR 3/2) moist; strong very coarse wedge structure; very hard, firm, very sticky, very plastic; few very fine roots; many slickensides; violently effervescent, carbonates disseminated and segregated as few nodules and carbonate coats; moderately alkaline, pH 8.2; clear wavy boundary. (combined thickness of Bkss horizons is 25 to 80 cm)
Cr--99 to 119 cm; light gray (2.5Y 7/2) broken face; excavation difficulty with a spade is moderate when moist; violently effervescent; moderately alkaline, pH 8.3; abrupt irregular boundary.
TYPE LOCATION: Stanislaus County, California; 30 meters (100 feet) west and 340 meters (1,120 feet) south of the northeast corner of sec. 1, T. 1 N., R. 10 E., MDB&M; USGS topographic quadrangle: Bachelor Valley, California. WGS84 37.9708061 degrees latitude -120.8163910 degrees longitude. UTM Zone 10 691803 meters E 4204825 meters N NAD83.
RANGE IN CHARACTERISTICS:
Soil temperature: The mean annual soil temperature 50 cm below the soil surface is 14 to 17 degrees C. The difference between the mean summer and mean winter soil temperature is greater than 6 degrees C.
Soil moisture: The moisture control section is dry in all parts from about May to October. The soils have a xeric moisture regime.
Diagnostic features:
Mollic epipedon thickness: 50 to 100 cm
Depth to secondary carbonates: 5 to 75 cm
Depth to slickensides: 20 to 75 cm
Depth to paralithic contact: 50 to 100 cm
Vertic features: When dry, cracks 1 to 10 cm wide extend from the surface to a depth of 70 cm, or to the paralithic contact, whichever is shallower. Cracks close sometime in December through April for 120 to 150 consecutive days.
Reaction: neutral to moderately alkaline throughout
Calcium carbonate equivalent: 0 to 3 percent throughout
Particle size control section weighted average:
Clay content: 35 to 60 percent
Rock fragments: 0 to 3 percent
A horizon
Hue: 7.5YR, 5YR
Value: 4 dry; 3 or 4 moist
Chroma: 1 or 2
Texture: clay
Organic matter: 1 to 3 percent
B horizons (and C horizons if present)
Hue: 7.5YR, 5YR
Value: 4 dry; 3 moist
Chroma: 1 or 2
Texture: silty clay loam, clay loam, silty clay, or clay
COMPETING SERIES: There are the
Aido,
Alo,
Altamont,
Auld,
Bosanko,
Cibo,
Cropley,
Diablo,
Fiale,
Filiorum,
Myers,
Porterville,
Sehorn, and
Vaquero series. Aido soils (MLRA 15) do not have strongly expressed intersecting slickensides and have cracks that close for less than 120 consecutive days. Alo soils (MLRA 15, 20) are on mountains and are not calcareous in the upper 30 to 50 cm. Bosanko soils (MLRA 20) have a paralithic contact of weathered igneous rock and their subsurface horizons with slickensides lack carbonates. Altamont (MLRA 15, 20), Auld (MLRA 19, 20) and Diablo soils (MLRA 15, 20) have paralithic contact greater than 100 cm deep. The Cropley (MLRA 14, 19), Myers (MLRA 17) and Porterville soils (MLRA 17, 18, 20) formed in alluvium and lack a paralithic contact. Cibo (MLRA 15, 18, 20), Filiorum (MLRA 15), and Sehorn soils (MLRA 15) have a lithic contact. Fiale soils (MLRA 15) lack carbonates. Vaquero soils (MLRA 15) soils do not have carbonates in all subsoil horizons and have soil colors with exclusively 10YR hues.
GEOGRAPHIC SETTING: Mckeonhills soils are on low hills at elevations of 85 to 130 meters. Slope is 5 to 15 percent.The soils formed in colluvium and/or residuum derived from calcareous sandstone. The climate is Mediterranean with hot, dry summers and cool, moist winters. The mean annual precipitation is 430 to 460 millimeters. The mean annual air temperature is about 17 degrees C, the mean July temperature is about 26 degrees C, and the mean January temperature is about 8 degrees C. The frost-free season is 325 to 335 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Pentz,
Peters,
Amador and
Auburn soils. Pentz and Peters soils form on hills in basic tuff (andesitic), and have a paralithic contact at a depth between 25 to 50 cm. Amador soils form on hills in acidic tuff (rhyolitic), and have a paralithic contact at a depth between 25 to 50 cm. Auburn soils form on hills from metavolcanic rocks and have a lithic contact at a depth between 25 to 50 cm.
DRAINAGE AND PERMEABILITY: Well drained; Moderately low to moderately high saturated hydraulic conductivity throughout the soil. Saturated hydraulic conductivity of the soil bedrock is moderately low.
USE AND VEGETATION: Used primarily for rangeland; some areas are used for dry farming. Natural vegetation is annual grasses and forbs consisting mainly of bromes, wild oat, bedstraw, and vetch.
DISTRIBUTION AND EXTENT: Sierra Nevada Foothills of California; MLRA 18. The soils are not extensive.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Stanislaus County, California 2006. The soil was named after a local ranch.
REMARKS:
Diagnostic horizons and features recognized in the pedon are:
Ochric epipedon - the zone from the surface to a depth of 4 inches (A horizon)
Secondary carbonates the zone from 4 to 39 inches (Bk1, Bk2, Bkss1, and Bkss2 horizon)
Slickensides the zone from 22 to 39 inches (Bkss1 and Bkss2 horizon)
Paralithic contact - the boundary 39 inches (Cr horizon)
Particle size control section for this pedon: 25 to 99 cm
Edit note 12/2018 - MLRA assignment changed from 17 (Sacramento and San Joaquin Valleys) to 18 (Sierra Nevada Foothills) because this is a bedrock-controlled soil in a bedrock-dominated landscape, which conforms to the definition of MLRA 18.
ADDITIONAL DATA:
NASIS User Pedon ID: S2004CA099001
Pedon Purpose: laboratory sampling site
Lab Sample #: 05N0392
Lab Source ID: SSL
Soil classified using the 12th Edition of the Keys to Soil Taxonomy
National Cooperative Soil Survey
U.S.A.