LOCATION PIPER CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, active, calcareous, thermic Mollic Endoaquepts
TYPICAL PEDON: Piper fine sandy loam - annual grass (Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; very dark gray (10YR 3/1) fine sandy loam, black (10YR 2/1) moist; weak crumb structure; loose, nonsticky and nonplastic; many very fine roots; strongly effervescent with disseminated lime and few fine concretions; moderately alkaline (pH 8.0); clear wavy boundary. (0 to 8 inches thick)
Bkg--4 to 10 inches; light gray (10YR 7/1) fine sandy loam, grayish brown (10YR 5/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine roots; pores have rust colored coatings; common krotovinas; violently effervescent with disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (5 to 7 inches thick)
Bkg1--10 to 24 inches; light gray (10YR 7/1) fine sandy loam, grayish brown (10YR 5/2) moist; common medium prominent reddish yellow (7.5YR 6/6) and yellowish brown (10YR 5/6) mottles; massive; hard, slightly brittle, weakly cemented in part of horizon, friable, nonsticky and nonplastic; few fine, medium and coarse roots; few fine and medium tubular pores; violently effervescent with lime disseminated and in soft bodies; moderately alkaline (pH 8.2); diffuse smooth boundary. (12 to 16 inches)
Bkg2--24 to 38 inches; light gray (10YR 7/2) fine sandy loam, light brownish gray (10YR 6/2) moist; many prominent reddish yellow (7.5YR 6/6) and yellowish brown (10YR 5/6) mottles; massive; hard, slightly brittle, weakly cemented in part of horizon, friable, nonsticky and nonplastic; few coarse roots; few medium pores; violently effervescent with lime disseminated and in soft bodies; moderately alkaline (pH 8.2).; clear smooth boundary. (12 to 18 inches thick)
2C--38 to 60 inches; pale brown (10YR 6/3) fine sand, yellowish brown (10YR 5/4) moist; many coarse distinct mottles (7.5YR 5/6); massive; slightly hard, friable, nonsticky and nonplastic; violently effervescent; moderately alkaline (pH 8.2). (10 to 30 inches thick)
TYPE LOCATION: Contra Costa County, California; Bethel Island in the SEl/4 SW1/4 SW1/4 section 23, T.2 N., R.3 E., projected.
RANGE IN CHARACTERISTICS: Without altered drainage these soils are saturated in some part between the surface and a depth of 20 inches for 4 to 12 months each year. The mean annual soil temperature is 61 degrees to 66 degrees F. Faint to prominent mottles are present in all but the uppermost 5 to 15 inches of the profile. From a depth of 10 to 30 inches or more the dominant matrix moist chroma is 2 and the dominant moist value is 5. Hue is 10YR, 5Y or 2.5Y. Moist mottles have a chroma of 4, 6 or 8 and a hue of 10YR or 7.5YR. Sodium saturation is less than 15 percent in all parts or is less than 15 percent to a depth of 30 inches or more. The profile is calcareous throughout. The average texture of the control section is sandy loam or fine sandy loam. Strata of minor thickness of loamy sand or sand occur below the control section. Average clay content is about 9 to 14 percent. Natural drainage prior to reclamation and regional subsidence in the Sacramento - San Joaquin Delta may have been better than poorly drained.
Some pedons have a dark gray to very dark gray upper A horizon as much as 8 inches thick that has about 2 to 50 percent organic matter. (This horizon is too thin to qualify as a histic or mollic epipedon. Where formerly present, histic or mollic epipedons have been destroyed or removed by subsidence, plowing or land leveling).
The upper part of the A may be 10YR 4/1, 4/2, 3/1, 5/3 or 4/3. Moist colors are 10YR 4/1, 3/4, 3/1, 4/3 or 3/3. Textures range from sandy loam to fine sandy loam. Reaction is mildly or moderately alkaline. The lower part or all of the A horizon is 10YR 5/2, 6/2, 7/2, 7/1; 2.5Y 5/2, 6/2 or 7/2 dry. Moist colors are 10YR 3/2, 4/2, 5/2; 2.5Y 3/2, 4/2 or 5/2. Texture ranges from fine sandy loam, sandy loam, sand, or loamy sand.
The Bkq is 10YR 7/1, 7/2; 2.5Y 7/2. Moist colors are 10YR 6/2, 5/2; 2.5Y 5/2; 5Y 5/2, 5/3. Textures range from fine sandy loam to sandy loam. Lime is segregated in the form of few to many seams or soft rounded bodies. Small to a large portion of this horizon has weak cementation, mostly by calcium carbonate but cementation by silica also seems to be present.
The 2C horizon or the soil below the depth of about 40 inches has 10YR 6/2, 6/3, 6/4; 2.5Y 6/2 or 6/4. Moist colors are 10YR 5/4, 5/3, 5/2; 2.5Y 5/2, 4/2 or 4/4. It is sand, loamy sand or fine sand, and in most pedons is somewhat stratified and is more sandy than the Bkg horizon.
COMPETING SERIES: This is the Lemoore series. Lemoore soils have a sodium adsorption ratio greater than 15 percent below a depth of 30 inches.
GEOGRAPHIC SETTING: Piper soils are on nearly level flood plains or are on sloping natural levees 15 feet below to 5 feet above sea level or at elevation of 300 feet. They formed in sandy or coarse-loamy alluvium mostly from granitic sources along streams in low basins and in the Sacramento-San Joaquin Delta. The climate is dry subhumid with hot dry summers and cool moist winters. Mean annual precipitation is 9 to 16 inches. Average July temperature is 74 degrees to 82 degrees F., average January temperature is about 49 degrees F., and mean annual temperature is 60 to 64 degrees F. The frost-free period is 225 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kingile, Shima and Sacramento soils. Kingile and Shima soils are organic soils. Sacramento soils are fine textured and have mollic epipedons.
DRAINAGE AND PERMEABILITY: Poorly drained. The water table is now controlled by levees, drainage ditches and pumping. In the San Joaquin Valley, water tables have been lowered by pumping for irrigation and stream diversion. Slow to medium runoff. Moderate slow permeability. Permeability somewhat variable due to varied amount of cementation and pore filling by calcium carbonate. Saline phases are dependent upon local water management.
USE AND VEGETATION: Used for growing irrigated field crops including cotton and small grains and for pasture. Vegetation of uncultivated areas is annual grasses, saltgrass and salt tolerant shrubs.
DISTRIBUTION AND EXTENT: Sacramento-San Joaquin Delta and trough of San Joaquin Valley. The soils are of small extent in MLRA-17,16.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Contra Costa County, California, 1933
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to a depth of 10 inches (A1, A2).
Series reclassified 7/98. Competing series not updated at that time.
ADDITIONAL DATA: NSSL pedon S57CA-013-003 and S57CA-013-004.