LOCATION DIERSSEN CAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Haplic Durixerolls
TYPICAL PEDON: Dierssen sandy clay loam - used for irrigated pasture on a less than 1 percent south facing slope. Elevation is 6 feet. (Colors are for dry soil unless otherwise stated. When described December 13, 1976, the soil was moist below 14 inches.)
Ap--0 to 10 inches; dark grayish brown (10YR 4/2) sandy clay loam, very dark brown (10YR 2/2) moist; weak coarse subangular blocky structure; hard, friable, sticky and plastic; common very fine, fine, medium and coarse roots; common very fine and fine interstitial and tubular pores; slightly alkaline (pH 7.4 CR); clear wavy boundary. (10 to 15 inches thick)
AB--10 to 14 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 4/3) moist; common medium distinct strong brown (7.5YR 5/6) mottles, dark brown (7.5YR 4/4) moist; weak coarse subangular blocky structure; hard, firm, sticky and plastic; few coarse, common fine and medium roots; few very fine and fine tubular and few very fine interstitial pores; common fine distinct black (N2/0) manganese stains and concretions 2 to 10 mm in diameter; slightly alkaline (pH 7.8 CR); abrupt wavy boundary. (3 to 7 inches thick)
Btk--14 to 31 inches; yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 4/4) moist; strong very coarse prismatic structure; very hard, very firm, very sticky and very plastic; common fine roots; common very fine and fine tubular pores; many moderately thick clay films bridging mineral grains and lining pores; many black (N 2/0) manganese stains and concretions 2 to 10 mm in diameter,vertical cracks contain surface soil; violently effervescent, lime segregated in common fine and medium irregularly shaped soft masses (7 percent calcium carbonate);moderately alkaline (pH 8.0 CR); clear smooth boundary. (15 to 20 inches thick)
Bkq--31 to 36 inches; light yellowish brown (10YR 6/4) weakly cemented silica duripan, yellowish brown (10YR 5/4) moist; massive; brittle common very fine and fine tubular pores; many discontinuous strongly silica cemented laminar bands; violently effervescent, lime segregated in few fine irregularly shaped soft masses (8 percent calcium carbonate); moderately alkaline (pH 8.0 CR); clear smooth boundary. (3 to 7 inches thick)
Bq--36 to 60 inches; very pale brown (10YR 7/4) weakly cemented silica duripan, dark brown (10YR 4/3) moist; massive; brittle; few very fine tubular pores; black (N 2/0) manganese stains and opal coatings along fractures; slightly alkaline (pH 7.8 CR).
TYPE LOCATION: Sacramento County, California; about 2.4 miles southwest of Pt. Pleasant, 2.2 miles west from the intersection of Dierssen Road and Franklin Blvd. and 30 feet due north from Dierssen Road in an unsectionized area of T.5 N., R.5 E., 38 degrees 17' 48" N. Lat., 121 degrees 28' 06" W. Long.
RANGE IN CHARACTERISTICS: The soil between the depths of 6 and 20 inches is usually dry in all parts from mid-June through October and is usually moist in all parts from December to late April. The mean annual soil temperature is about 62 to 65 degrees F and remains above 47 degrees F throughout the year. Depth to the duripan is 20 to 40 inches. The argillic horizon averages 35 to 50 percent clay.
The Ap horizon is 10YR 4/2, 4/3, 5/3, 5/2. Moist color is 10YR, 2/2, 3/2. Texture is sandy loam, sandy clay loam or clay loam. Most pedons have mottles with chroma greater than 3 in the lower part. Reaction ranges from slightly acid to mildly alkaline. Organic matter content is 1 to 3 percent.
The Btk horizon is 10YR 5/2, 5/4, 6/3, 6/4; 7.5YR 5/4. Moist color is 10YR 4/2, 4/3, 4/4, 5/4; 7.5YR 4/4. It is clay loam or clay with 35 to 50 percent clay. Some pedons have mottles with chroma greater than 3 in the upper part. Reaction ranges from mildly alkaline to moderately alkaline. Calcium carbonate equivalent is 5 to 10 percent.
Bkq and Bq horizons are 10YR 6/2, 6/3, 6/4, 7/3, 7/4. Moist color is 10YR 4/2, 4/3, 5/3, 5/4; 7.5YR 4/4. Less than half of the upper boundary is coated with opal or opal and sesquioxides, or durinodes are present. Silica cementation of the matrix is weak to strong. Lime is always present in the upper part of the duripan and is sometimes present in the lower part.
COMPETING SERIES: These are the Alamo, Madera and San Joaquin soils in other families. Alamo soils do not have an argillic horizon. Madera and San Joaquin soils have ochric epipedons.
GEOGRAPHIC SETTING: Dierssen soils are on basin rims. Elevations range from 0 to 25 feet. Slope is 0 to 2 percent. The soils formed in mixed alluvium derived dominantly from granitic rocks. The climate is characterized by hot dry summers and cool moist winters. Mean annual precipitation is 15-18 inches. Average January temperature is about 45 degrees F; average July temperature is about 75 degrees F; the average annual temperature is about 60 degrees F. Frost-free season is about 250 to 275 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing San Joaquin soils and the Egbert, Galt and Tinnin soils. Egbert soils lack a duripan and are on the high floodplain. Galt soils have intersecting slickensides and cracks that open to the surface and are on low terraces. Tinnin soils are sandy, lack a duripan and are on mounds and ridges on the basin rim.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; very slow runoff; slow permeability. A perched watertable occurs above the subsoil during the winter and early spring months at a depth of 0.5 to 2 feet. The hazard of flooding is rare if protected by levees, or occasional. Periods of flooding are brief to long and occur in the months of December through April.
USE AND VEGETATION: The soils are used for irrigated pasture and irrigated cropland. The principle crops are corn, wheat, safflower and rice. Native vegetation is mainly water tolerant grasses and sedges.
DISTRIBUTION AND EXTENT: Lower Sacramento Valley. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Sacramento County 1987.
REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as fine, mixed, thermic Haplic Durixerolls. Although the upper profile is saturated with water during the winter months, there is no provision for an Oxyaquic subgroup. Competing series were not checked at that time.