LOCATION DEVRIES CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Typic Duraquolls
TYPICAL PEDON: Devries sandy loam - on a nearly level slope of less than 1 percent under annual grasses and forbs at an elevation of 8 feet. (Colors are for dry soil unless otherwise stated. When described on November 13, 1980, the soil was dry from 0 to 4 inches and moist below.)
A1--0 to 4 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium angular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine roots; few fine and common very fine interstitial pores; neutral (pH 7.0); gradual wavy boundary. (4 to 10 inches thick)
A2--4 to 13 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; few fine distinct light olive brown (2.5Y 5/4) mottles, olive brown (2.5Y 4/4) moist; moderate medium angular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; few fine and common very fine interstitial pores; slightly alkaline (pH 7.5); gradual smooth boundary. (6 to 9 inches thick)
Bt--13 to 28 inches; light gray (10YR 7/2) sandy loam, dark grayish brown (10YR 4/2) moist; few fine distinct light yellowish brown (2.5Y 6/4) mottles, olive brown (2.5Y 4/4) moist; moderate medium angular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; few fine and very fine interstitial pores; very few thin clay films bridging sand grains and lining pores; slightly effervescent with disseminated lime; moderately alkaline (pH 8.0) abrupt wavy boundary. (10 to 21 inches thick)
Bkqm--28 to 80 inches; light gray (10YR 7/2) duripan, dark grayish brown (2.5Y 4/2) moist; common fine faint light yellowish brown (2.5Y 6/4) mottles, olive brown (2.5Y 4/4) moist; massive; indurated continuous laminar capping 3 to 4 mm thick; strongly cemented in 75 percent of the matrix and weakly cemented in the remainder; strongly effervescent with disseminated lime and segregated soft masses of gypsum in remnant pores; primary cementing agent is silica; moderately alkaline (pH 8.0).
TYPE LOCATION: San Joaquin County, California; approximately 6 miles west of Lodi near Interstate 5, 2,110 feet south of Hwy. 12, 200 feet west of Thornton Road; 38 degrees 06' 38" north Lat., 121 degrees 23' 35" west Long. (in an unsectionized area) Terminous quadrangle.
RANGE IN CHARACTERISTICS: Depth to duripan is 20 to 40 inches. The mean annual soil temperature is 62 to 63 degrees F. The soil between the depth of 8 inches to the duripan is not dry at any time unless artificially drained. The texture control section from a depth of 10 inches to the duripan is 7 to 18 percent clay. Content of gravel is 0 to 5 percent.
The A horizon has dry color of 10YR 5/2, 5/1, 4/2, 4/1; 2.5Y 5/2, or 4/2 and moist color of 10YR 3/2, 3/1, or 2.5Y 3/2. Distinct or prominent mottles are present in lower A horizons. Organic matter ranges from 1 to 3 percent. It is neutral to moderately alkaline.
The Bt horizon has dry color of 10YR 5/2, 5/3, 6/3, 7/2, 4/2; 2.5Y 5/2 or 4/2 and moist color of 10YR 4/3, 4/2, 4/4, 5/2 or 2.5Y 4/2. Mottles are distinct or prominent. It is mildly or moderately alkaline and slightly or strongly effervescent. It is sandy loam or fine sandy loam.
The Bkqm horizon has a strongly cemented to indurated continuous laminar capping over weakly to strongly cemented material. The cementation typically decreases with depth. It has dry color of 10YR 7/2, 6/2, 6/3, 6/4, 5/4; 2.5Y 6/2, 6/4, 5/2; 5Y 6/2, 5/2, 5/3 or 5/4 and moist color of 10YR 5/2, 5/3, 4/2, 4/3; 2.5Y 5/2, 4/2; 5Y 4/2 or 4/3. Mottles are faint to prominent.
COMPETING SERIES: There are no other soils in this family. Rioblancho (T) and Guard (T) series are similar soils in other families. Rioblancho soils are fine-loamy and have calcic horizons. Guard soils are weakly cemented but lack a duripan.
GEOGRAPHIC SETTING: Devries soils are on basin rims of the San Joaquin Delta. Slopes are 0 to 2 percent. The soils formed in alluvium from mixed sources. Elevations are 5 below sea level to 35 feet. The climate is subhumid with hot dry summers and cool moist winters. Dense ground fog often occurs in the winter months. Mean annual precipitation is 14 to 16 inches. The mean January temperature is 45 degrees F; mean July temperature is 77 degrees F; mean annual temperature is 60 degrees F. Frost-free period is 260 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Egbert, Kingile and Ryde soils. Egbert, Kingile and Ryde soils do not have duripans.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderately rapid permeability. Depth to the apparent water table is presently greater than 5 feet, but the soil may be saturated above the hardpan for short periods after heavy rain in the winter months.
USE AND VEGETATION: Mostly irrigated field and row crops. Vegetation is soft chess, rye grass, salt grass, plantain and other annual grasses, forbs and scattered valley oaks.
DISTRIBUTION AND EXTENT: Devries soils occur on the eastern rim of the San Joaquin delta in Central California. The soils are not extensive in MLRA-17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Joaquin County, California 1990.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of 13 inches (A1,A2)
Cambic horizon - the zone from 13 to 28 inches (Bt)
Duripan - the zone from 28 to 80 inches (Bkqm)