LOCATION HYTOP CAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Typic Palexeralfs
TYPICAL PEDON: Hytop sandy loam - on an east southeast facing slope of 34 percent under wild oats, purple needlegrass, tarweed and other grasses and forbs at an elevation of 2,240 feet. (Colors are for dry soil unless otherwise stated. When described June 9, l984, the soil was dry to 9 inches and slightly moist below.)
A1--0 to 5 inches; pale brown (10YR 6/3) sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine tubular pores; 19 percent clay content; 2.2 percent organic matter; neutral (pH 6.9); clear smooth boundary. (4 to 7 inches thick)
A2--5 to 10 inches; brown (10YR 5/3) sandy clay loam, brown (7.5YR 4/2) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; few very fine and fine roots; common very fine and few fine tubular pores; 22 percent clay content; neutral (pH 6.9); abrupt smooth boundary. (3 to 8 inches thick)
Bt1--10 to 17 inches; strong brown (7.5YR 4/6) clay, brown (7.5YR 4/4, 10YR 4/3) moist; strong medium prismatic structure; extremely hard, firm, sticky and very plastic; few very fine roots; few very fine tubular pores, many moderately thick clay films on peds; 44 percent clay content; neutral (pH 7.0); clear smooth boundary. (6 to 10 inches thick)
Bt2--17 to 22 inches; brown (7.5YR 5/4) clay, strong brown (7.5YR 5/6) and brown (10YR 4/3) moist; moderate medium prismatic structure; very hard, firm, sticky and very plastic; few very fine roots; few very fine tubular pores; common thin clay films on peds; 47 percent clay content; neutral (pH 7.0); clear wavy boundary. (4 to 7 inches thick)
C1--22 to 26 inches; brown (7.5YR 5/4) and strong brown (7.5YR 5/6) clay, strong brown (7.5YR 5/6) and reddish brown (5YR 4/4) moist; weak, medium subangular blocky structure; hard, friable, sticky and very plastic; no roots; common very fine interstitial and few very fine tubular pores; 42 percent clay content; neutral (pH 7.0); abrupt wavy boundary. (3 to 8 inches thick)
Cr--26 to 60 inches; brownish yellow (10YR 6/6), yellowish red (5YR 4/6), and white (N 8/0) strongly weathered basic volcanic rock; strongly effervescent with disseminated lime.
TYPE LOCATION: Merced County, California; about 20 miles west southwest of the city of Los Banos, 1,150 feet west and 900 feet north of the SE corner of Section 27, T. 11 S., R. 7 E., Mariposa Peak Quadrangle.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 59 degrees to 62 degrees F. The soil temperature is below 47 degrees F. from December 15 to March 1. The soil between 6 and 18 inches is moist throughout from November 15 to June 1 and dry throughout from July 1 to October 15 in most years. Depth to a paralithic contact ranges from 20 to 40 inches. Rock fragments are 0 to 10 percent gravel and cobbles, 2 to 15 cm in size, throughout. Reaction is neutral or slightly alkaline above the paralithic contact. Base saturation is over 75 percent.
The A horizon is 7.5YR 4/2, 4/3, 5/2, 5/4; 10YR 5/3, 5/4 or 6/3. Moist colors are 5YR 4/4, 4/2; 7.5YR 3/4, 4/2, 4/4; 10YR 4/2, 4/3, 4/4 or 5/4. Clay content is 15 to 25 percent and has less than 1.2 times clay increase within the horizon.
The Bt horizon is 2.5YR 5/4; 5YR 5/2, 5/4, 5/6; 7.5YR 4/4, 4/6, 5/4, 5/6; 10YR 5/4 or 5/6. Moist colors are 2.5YR 4/4; 5YR 4/2, 4/4; 7.5Y/YR 4/4, 4/6, 5/4, 5/6, 5/8; 10YR 4/3, 4/4 or 4/6. Clay content is 35 to 50 percent and is always 15 percent (absolute) more than the A horizon.
The C horizon is clay loam or clay with 35 to 45 percent clay content.
COMPETING SERIES: These are the Cometa (CA), Corning (CA), Millsap (CA), Orognen (CA) and Yokayo (CA) series. The Cometa, Corning, Millsap, Orognen and Yokayo soils do not have bedrock within 40 inches.
GEOGRAPHIC SETTING: Hytop soils are on hillslopes of mountains and have slopes of 30 to 75 percent. Elevations range from 1,000 to 3,300 feet. These soils formed in material weathered from basic volcanic rocks of the Quien Sabe formation. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation is 12 to 24 inches. Mean January temperature is about 44 degree F; mean July temperature is about 72 degrees F and the mean annual temperature is 59 to 62 degrees F. Frost-free season is 190 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Orognen, Honker and Gonzaga soils and the Laveaga soils. Laveaga soils have a mesic temperature regime and a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; high or very high runoff; very slow permeability.
USE AND VEGETATION: These soils are used as rangeland and upland wildlife habitat. The vegetation is wild oats, soft chess, purple needlegrass, foxtail fescue, tomcat clover, filaree, tarweed and other grasses and forbs.
DISTRIBUTION AND EXTENT: These soils are in the Coast Range of California. They are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced County, California 1984. Name is coined.
REMARKS: These soils were formerly mapped as Rough Stony Land in the Los Banos Area, Series 1939 report. They are being differentiated by being moderately deep, lacking stones and having a grass cover. pH determined by colormetic method using Hellige-Troug Triplex indicators. Base saturation determined by sum of the cations method using KC1-triethanolamine extract. Texture determined by modified boayucos hydrometer method. Organic matter determined by Walkley-black digestion method. Presence of lime determined by 10 percent HCl.
CEC/Clay ratio estimated from similar soils with laboratory data in the W. Stanislaus Soil Survey Area.
Rapid or very rapid runoff terminology adjusted 4/96 to very high new adjective criteria of the Soil Survey Manual, 10/93
Last review and transmission of file 5/98.