LOCATION MYFORD CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Palexeralfs
TYPICAL PEDON: Myford sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1 inch; pale brown (10YR 6/3) sandy loam, brown (10YR 4/3) when moist; weak, medium platy structure; slightly hard, friable, nonsticky and nonplastic; ;many very fine roots; many very fine tubular pores; medium acid (pH 6.0); abrupt smooth boundary (1 to 11 inches thick)
A2--1 to 4 inches; pinkish-gray (7.5YR 6/2) sandy loam, brown (7.5YR 4/2) when moist; weak, medium, platy structure; hard, friable, nonsticky and nonplastic; common very fine roots; many very fine tubular pores; medium acid (pH 6.0); clear, smooth boundary. (3 to 10 inches thick)
A3--4 to 12 inches; pinkish-gray (7.5YR 7/2) sandy, loam, brown (7.5YR 4/2) when moist; massive; hard; friable, nonsticky and nonplastic; common very fine roots; many very fine tubular pores; medium acid (pH 6.0); abrupt smooth boundary. (1 to 9 inches thick)
Bt1--12 to 18 inches; brown (7.5YR 4/2) sandy clay, dark brown (7.5YR 3/2) when moist; strong, very coarse, prismatic structure; extremely hard, very firm, very sticky and very plastic; few very fine roots; common very fine pores; common moderately thick clay films on peds and in pores; medium acid (pH 6.0); clear, smooth boundary. (5 to 9 inches thick)
Bt2--18 to 28 inches; brown (7.5YR 4/2) sandy clay loam, dark brown (7.5YR 3/2) when moist; moderate, coarse, prismatic parting to strong, coarse, angular blocky structure; extremely hare\d, very firm, very sticky and very plastic; few very fine roots; common very fine pores; few thin clay films line pores; neutral (pH 7.0); clear, smooth boundary. (7 to 10 inches thick)
Btk1--28 to 35 inches, brown (10YR 5/3) sandy clay loam, dark brown (10YR 4/3) when moist; weak, coarse, prismatic parting to moderate, coarse, angular blocky structure; very hard, firm, sticky and plastic; few very fine roots; common very fine pores; few thin clay films line pores; violently effervescent, lime occurs in small masses; moderately alkaline (ph 8.0); clear, smooth boundary. (5 to 10 inches thick)
Btk2--35 to 41 inches; light-brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 4/2) when moist; weak, coarse, prismatic parting to moderate, coarse, angular blocky structure; very hard, firm, slightly sticky and plastic; few very fine roots; common very fine pores; common moderately thick clay films on peds and lining pores; slightly effervescent, lime occurs in filaments; moderately alkaline (pH 8.0); diffuse, smooth boundary. (4 to 7 inches thick)
Bt1--41 to 49 inches; light-brown (7.5YR 6/4) light sandy clay loam, brown (7.5YR 4/2) when moist; weak, coarse, prismatic parting to moderate, coarse, angular blocky structure; very hard, firm, slightly sticky and plastic; few very fine roots; common moderately thick clay films on peds and lining pores; moderately alkaline (pH 8.0); diffuse, smooth boundary. (6 to 9 inches thick)
Bt2--49 to 61 inches; light-brown (7.5YR 6/4) light sandy loam, brown (7.5YR 4/2) when moist; weak, coarse, prismatic parting to moderate, coarse, angular blocky structure; very hard, firm, slightly sticky and plastic; few very fine roots; many very fine pores; common moderately thick clay films on peds and lining pores; slightly acid (pH 6.5); diffuse, smooth boundary. (7 to 12 inches thick)
Bt3--61 to 71 inches; light-brown (7.5YR 6/4) light sandy clay loam, brown (7.5YR 4/2) when moist; weak, coarse, prismatic parting to moderate, coarse, angular blocky structure; very hard, firm, slightly sticky and plastic; few very fine roots; many very fine pores; common moderately thick clay films on peds and lining pores; slightly acid (pH 6.5); clear, wavy boundary. (6 to 10 inches thick)
C--71 to 79 inches; very pale-brown (10YR 7/3) sandy loam, brown (10YR 5/3) when moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine pores; slightly acid (pH 6.5).
TYPE LOCATION: Orange County, California; about 1.2 miles east of the junction of San Diego and Santa Ana Freeways, Irvine Ranch; E1/4 E1/4 sec. 172 projected (section numbered from a private survey shown on U.S.G.S. El Toro Quadrangle, Topographic map), T.6S., R.8W., SBBM.
RANGE IN CHARACTERISTICS: The solum ranges from 45 to 75 inches thick. Mean annual soil temperature at a depth of 20 inches is 60 to 63 degrees F. The soil between depths of about 5 and 15 inches is usually moist in some part from about November 15 until late May, and is continuously dry the rest of the year.
The A horizon is pinkish gray or light brown, light brownish gray, pale brown, grayish brown or brown in 7.5YR or 10YR hue. It is sandy loam, or fine sandy loam. This horizon has weak structure or is massive and ranges from strongly acid to slightly acid. The A3 horizon is one unit higher in value than the A1 horizon.
The Bt horizon is brown, dark brown, or yellowish brown in 7.5YR or 10YR hue. It is sandy clay or heavy clay loam in the upper part and sandy clay loam or clay loam in the lower part and averages 28 to 30 percent clay in the entire horizon. The upper boundary of the Bt horizon is abrupt and the clay increase from the A horizon to the Bt horizon is 18 to 28 percent. This horizon has prismatic or angular blocky structure. It ranges from medium acid to moderately alkaline in the upper part and is moderately alkaline in the lower part. Exchangeable sodium is 15 to 35 percent below depth of one meter.
COMPETING SERIES: These are the Antioch, Bonsall, Las Flores, Milpitas, Placentia, San Miguel, Solano, Stockpen, Tierra, and Waukena series. Antioch, Placentia, San Miguel, Solano, Stockpen, Tierra, and Waukena series. Antioch, Placentia, San Miguel, and Stockpen soils have natric horizons and fine control sections. Bonsall and Las Flores soils have fine control sections and have more than 15 percent sodium in the lower part of the argillic horizon, but above depth of one meter. Milpitas and Tierra soils have argillic horizons with fine control sections. Solano and Waukena soils have natric horizons.
GEOGRAPHIC SETTING: Myford soils are nearly level to moderately steep and are on terraces at elevations of less than 1,500 feet. The climate is dry subhumid mesothermal with dry summers and cool moist winters. Mean annual precipitation is 12 to 20 inches. Mean annual temperature is about 62 degrees F.; average January temperature is about 53 degrees F.; average July temperature is about 70 degrees F. The frost-free season is 270 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Botella, Capistrano, Chesterton, Cieneba, Marina, San Andreas, and Yorba soils. Botella soils lack abrupt A-B horizon boundaries. Capistrano, Cieneba, Marina, and San Andreas soils lack argillic horizons. Chesterton soils have strongly cemented hardpans. Yorba soils have more than 35 percent coarse fragments in their control section.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium to rapid runoff; very slow permeability.
USE AND VEGETATION: Used for production of citrus, pasture, range, barley, and for urban development. Principal vegetation is annual grasses and forbs with some scattered low-growing brush.
DISTRIBUTION AND EXTENT: Southern California. The series is of moderate extent in MLRA 19.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Orange County (Orange and Western Part of Riverside Counties), California, 1974.
REMARKS: The Myford soils would have been classified as Noncalcic Brown soils.
ADDITIONAL DATA: NSSL pedon S71CA-059-010 (type location)
OSED scanned by SSQA. Last revised by state on 10/74.