LOCATION PANHILL CAEstablished Series
TAXONOMIC CLASS: fine-silty, mixed, superactive, thermic Typic Haplargids
TYPICAL PEDON: Panhill silty clay loam - cultivated (Colors for dry conditions unless otherwise noted)
Ap--0 to 8 inches; light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (10YR 4/2) moist; strong moderate to coarse angular blocky structure; hard to very hard, friable, slightly sticky and plastic; abundant fine and medium roots; pip common fine medium tubular pores; slightly alkaline (pH 7.8); gradual wavy boundary. (6 to 10 inches thick).
B2t--8 to 20 inches; brown (10YR 5/3) silty clay loam, dark grayish brown (10YR 4/2) moist; weak coarse angular blocky structure; hard to very hard, very firm, sticky and plastic; abundant fine and medium roots; common fine open tubular pores and common fine open interstitial pores; few thin darker clay films on ped faces and in pores; slightly alkaline (pH 7.8); gradual wavy boundary. (10 to 14 inches thick).
C1--20 to 32 inches; yellowish brown (10YR 5/4) with common medium distinct mottles of yellowish brown (10YR 5/6) silty clay loam, brown (10YR 4/3) with common medium faint mottles of dark yellowish brown when moist; weak coarse angular blocky structure; hard, firm, slightly sticky, plastic; plentiful very fine and fine roots; many very fine continuous open tubular pores; few thin clay films; moderately alkaline (pH 8.0), violently effervescent, segregated lime in filaments; diffuse wavy boundary, (10 to 15 inches thick).
2C2--32 to 56 inches; yellowish brown (10YR 5/4) sandy loam, dark yellowish brown (10YR 4/4) with many medium faint mottles of dark yellowish brown (10YR 3/4) moist, dark yellowish brown (10YR 4/4) rubbed; massive; slightly hard, friable, non-sticky, nonplastic; abundant very fine, fine and medium roots; many very fine and fine continuous open tubular pores; no clay films; moderately alkaline (pH 8.2), strongly effervescent, disseminated and large, generally rounded soft masses of lime; abrupt smooth boundary. (23 to 25 inches thick).
3C3--56 to 63 inches; light yellowish brown (2.5Y 6/4) silt loam, olive brown (2.5Y 4/4) moist; weak fine platy structure; hard, friable, nonsticky, nonplastic; abundant very fine, fine and medium roots; many very fine and fine continuous open tubular pores; moderately alkaline (pH 8.4), strongly effervescent with disseminated lime. Lime also occurs as large, irregular soft masses.
TYPE LOCATION: Merced County, California. About 7 miles southwest of Dos Palos, at a point 2,500 feet south of Bagle Field Road and 300 feet west of the east boundary of Sec. 15, SE4, NE4 Sec. 15, T.12S., R. llE.
RANGE IN CHARACTERISTICS: The soils have ochric epipedons argillic horizons, are dry for more than 60 consecutive days in all parts from 10 to 40 inches, have soil temperatures greater than 59 degrees F., and are of mixed mineralogy. The solum is 16 to 24 inches thick and depth to stratified layers is about 26 to 39 inches. There may be some gravels throughout the profile.
The A horizons have weak to strong structure and slightly hard to very hard consistencies. The A horizons range in color from light brownish gray, pale brown, brown to yellowish brown in 10YR and 2.5YR hues with values of 5 to 6 and chromas of 2 to 4; in texture from silty clay loam to fine sandy loam; in reaction from neutral to moderately alkaline.
The Bt horizon ranges in color from brown to yellowish brown in 10YR hue; in texture from loam to silty clay loam; reaction from mildly to moderately alkaline and they may or may not be calcareous. The B horizons have minimal development with slight increase in clay from A to B and few to common clay films on ped faces and in pores. Structure is weak blocky and consistence is slightly hard to very hard.
The upper C horizons are yellowish brown or light yellowish brown silty clay loams or loams which may be underlain by stratified sandy loam to silt loam, which may be gravelly to very gravelly.
COMPETING SERIES: There are no other series in the same family. In the same subgroup the McAllister and Teague series are in a fine loamy family. Similar soils in another order are the Mocho, Sorrento, Panoche, and Lost Hills soils which lack argillic horizons.
GEOGRAPHIC SETTING: The Panhill soils occur on level to gently sloping alluvial fans and terraces from sedimentary rock sources. They occur at elevations of 200 to 2000 feet, in a semiarid mesothermal climate with mean annual rainfall of 6 to 12 inches, with hot dry summers and cool moist winters. Mean annual temperature is about 63 degrees F., average January temperature about 46 degrees F., and average July temperature about 83 degrees F. Frost-free season averages about 256 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These include Panoche Lost Hills and Kettleman. Kettleman soils occupy the uplands underlain by sandstone bedrock.
DRAINAGE AND PERMEABILITY: Well drained; runoff is medium; permeability is moderate to moderately rapid.
USE AND VEGETATION: Cultivated for cotton, barley, sorghum alfalfa safflower, sugar beets, and other irrigated crops. Vegetation consists of annual grasses and herbs.
DISTRIBUTION AND EXTENT: West side of San Joaquin Valley south of Los Banos and in the arid valleys of the Coast Range, California. The soils are moderately extensive, comprising approximately 20,500 acres in San Benito, Merced, and Fresno Counties.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Los Banos Area, California, 1940.
REMARKS: The soils were formerly classified in the (minimal) Noncalcic Brown group. The series was added to the Ames database 04/2000. Classification and competing series were not done at that time.
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET