LOCATION EDMINSTER CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Glossic Natraqualfs
TYPICAL PEDON: Edminster loam - on a slope of 2 percent under saltgrass, alkali sacaton, lippia, and other annual grasses and salt tolerant herbs at 75 feet elevation. (Colors are for dry soil unless otherwise stated. When described on November 10, 1977, the soil was moist below 11 inches.)
A--0 to 1 inch; gray (N 5/0) loam, dark gray (N 4/0) moist; moderate fine granular structure; soft, friable, very sticky and plastic; common very fine roots; few very fine tubular pores; slightly acid (pH 6.5); abrupt smooth boundary. (1/2 to 3 inches thick)
E--1 to 4 inches; gray (10YR 6/1, N 5/0) loam, gray and dark gray (10YR 5/1, N 4/0) moist; strong medium prismatic structure; slightly hard, firm, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; common thin clay films on peds and line pores; neutral reaction (pH 7.0); abrupt irregular boundary. (1 to 3 inches thick)
Btk1--4 to 9 inches; gray and olive (5Y 5/1, 5/3) clay loam, dark gray and olive gray (5Y 4/1, 5/2) moist; strong medium prismatic structure; very hard, firm, sticky and very plastic; few very fine roots; common very fine tubular pores; clean sand grains coat columns; many moderately thick clay films on peds and many thick clay films line pores; slightly effervescent with disseminated lime, strongly effervescent, lime segregated in few fine soft masses; ESP is 20; strongly alkaline (pH 9.0); clear wavy boundary. (3 to 6 inches thick)
Btk2--9 to 18 inches; olive gray (5Y 4/2) clay loam, very dark gray (5Y 3/1) moist; common medium distinct dark gray (N 4/0) mottles; common medium distinct very dark brown (2.5Y 2/2) mottles moist; moderate medium prismatic structure; very hard, very firm, sticky and very plastic; few fine and medium roots; few very fine tubular pores; clean sand grains coat prisms; many thick clay films on peds and line pores; strongly effervescent with disseminated lime; ESP is 16; strongly alkaline (pH 9.0); clear wavy boundary. (7 to 12 inches thick)
BC--18 to 26 inches; grayish brown (2.5Y 5/2) clay loam, gray (5Y 5/1) moist; many medium prominent light gray (2.5Y 7/2, 5Y 7/2) mottles, common fine distinct dark gray and light brownish gray (5Y 4/1, 2.5Y 6/2) mottles moist; weak fine prismatic structure; very hard, very firm, sticky and plastic; no roots; common very fine tubular pores; many thick clay films on peds and line pores; slightly effervescent with disseminated lime, strongly effervescent, lime segregated in common fine concretions; ESP is 15; moderately alkaline (pH 8.2); clear wavy boundary. (4 to 11 inches thick)
C--26 to 39 inches; grayish brown and light brownish gray (2.5Y 5/2, 6/2) clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium angular blocky structure; hard, very firm, sticky and very plastic; common very fine tubular pores; many moderately thick films on peds and staining mineral grains; strongly effervescent with disseminated lime, strongly effervescent, lime segregated in common medium concretions; ESP is 10; strongly alkaline (pH 8.7); clear wavy boundary. (5 to 16 inches thick)
2Ck--39 to 50 inches; pale yellow and light olive gray (5Y 7/3, 6/2) clay loam, greenish gray and olive (5GY 5/1, 5Y 5/3) moist; few fine prominent olive yellow (2.5Y 6/6) mottles, common fine prominent yellowish brown and light gray (10YR 5/8, 7/2) and few fine prominent brownish yellow (10YR 6/6) mottles moist; moderate medium angular blocky structure; hard, firm, sticky and plastic; common very fine tubular pores; many moderately thick clay and silt films on peds and staining mineral grains; strongly effervescent with disseminated lime and segregated as common fine and medium concretions; ESP is 7; strongly alkaline (pH 8.5); clear wavy boundary. (8 to 14 inches thick)
3C--50 to 60 inches; pale yellow (5Y 8/3) loam, olive (5Y 5/3) moist; many fine prominent brownish yellow (10YR 6/6) mottles, many fine prominent yellowish brown (10YR 5/8) mottles moist; massive; slightly hard, firm, sticky and plastic; common very fine tubular pores; many moderately thick clay films line pores; slightly effervescent with disseminted lime, strongly effervescent, lime segregated in few fine soft masses; moderately alkaline (pH 8.0).
TYPE LOCATION: Merced County, California; 3.5 miles south of the city of Stevinson. 2,600 feet west of N. Mercy Springs Road (J-14), 800 feet west of the San Joaquin River, 4,400 feet east and 800 feet north of the SW corner of section 35, T.7 S., R.10 E. 37 degrees North latitude, 16 minutes, 40 seconds; 120 degrees West longitude, 50 minutes, 10 seconds
RANGE IN CHARACTERISTICS: These soils are saturated with stagnant water for at least a few days. The depth from the surface to the natric horizon (Btk1, Btk2, BC) ranges from 2 to 6 inches. Organic matter is less than 1 percent throughout.
The A horizon is 10YR 4/1, 4/2, 5/1, 5/2; N 4/0 or N 5/0. Moist colors are 10YR 3/1, 3/2, 4/1, 4/2; N 3/0 or N 4/0. It is sandy loam, fine sandy loam or loam with 10 to 20 percent clay content. It is slightly acid or neutral. Some pedons do not have an A horizon.
The E horizon is 10YR 5/1, 6/1, 7/1 or N 5/0. Moist colors are 10YR 3/1, 3/2, 4/1, 4/2, 5/1 or N 4/0. It is sandy loam or loam and is neutral or mildly alkaline.
The Btk horizon is 10YR 3/2; 2.5Y 5/2, 6/2, 6/4; 5Y 4/2, 5/1, 5/2, 5/3, 6/2, or 6/3. Moist colors are 2.5Y 3/2; 5Y 3/1, 4/1, 5/2; 10YR 3/1, 3/2 or 4/2. It is loam or clay loam with 25 to 35 percent clay content. Electric conductivity ranges from 2 to 8 mmhos/cm. Exchangeable sodium percentages range from 15 to 35. Calcium carbonate equivalent varies from 2 to 12 percent. It is moderately alkaline or strongly alkaline.
The C horizons are 2.5Y 5/2, 6/2, 6/4, 7/4; 5Y 5/3, 6/2, 7/3 or 8/3. Moist colors are 2.5Y 3/2, 4/2; 5Y 4/3, 5/3; 10YR 4/3, 5/4 or 5GY 5/1. It is sandy loam, loam, sandy clay loam or clay loam, and may be stratified. Clay content ranges from 10 to 30 percent. The exchangeable sodium percentage ranges from 5 to 25. It is moderately alkaline or strongly alkaline and has calcium carbonate of 2 to 12 percent throughout the horizon.
COMPETING SERIES: These are the Kesterson series in the same family and the Rossi series in another family. Kesterson soils have a calcic horizon. Rossi soils are fine and have a 1xeric moisture regime.
GEOGRAPHIC SETTING: Edminster soils are in valley basins. Slopes are 0 to 2 percent. The soils formed in alluvium from mixed but dominantly granitic rocks. Most of these soils have a hummocky or channeled landscape. Elevations are 70 to 110 feet. The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is about 11 inches. The mean annual temperature is about 62 degrees F. The frost-free season is 210 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Kesterson soils and the Bolfar, Bisgani, and Dospalos soils. Bolfar soils have a thick mollic epipedon and do not have a natric horizon. Bisgani soils have a sandy control section and do not have a natric horizon. Dospalos soils have a thick mollic epipedon, are fine, and do not have a natric horizon.
DRAINAGE AND PERMEABILITY: Poorly drained; very slow runoff; very slow permeability. These soils were ponded and formed under very poor drainage with stagnant water but have had their source of water intercepted by flood protection levees and reservoirs. They are now ponded for periods of 7 to 21 days December through February. The water table is now 1 to 3 feet December through April.
USE AND VEGETATION: These soils are used for annual grass range and irrigated pasture.
DISTRIBUTION AND EXTENT: These soils occur near the San Joaquin River in the central part of the San Joaquin Valley of California. They are not extensive in MLRA 17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced County 1984.
REMARKS: These soils were formerly included with and surveyed as the Waukena series in the Los Banos Area, series 1939 report. These soils are being differentiated by characteristics that show a reducing environment (Aquic moisture regime) that is not characteristic of the Waukena series. pH determined by colorimetric method using Thymol-Blue indicator. Texture determined by modified Bouyoucos method. ESP determined by versenate method.
ADDITIONAL DATA: NSSL pedon S79CA-047-003 (type location)