LOCATION TURMOUND CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Glossic Natraqualfs
TYPICAL PEDON: Turmound sandy loam - on a nearly level mound of 2 percent under saltgrass and other grasses and forbs. The elevation is 80 feet. (Colors are for dry soil unless otherwise stated. When described June 24, 1977, the soil was moist throughout.)
A--0 to 3 inches; dark gray (10YR 4/1) sandy loam, very dark brown (10YR 2/2) moist; moderate coarse platy structure; loose, nonsticky and nonplastic; few fine and common medium roots; many very fine interstitial pores; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 6 inches thick)
An1--3 to 11 inches; gray (10YR 5/1) sandy loam, very dark grayish brown (10YR 3/2) moist; massive, parting to weak medium and coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and common fine roots; few very fine tubular and interstitial pores; 7 percent clay content; exchangeable sodium percent is 42; strongly alkaline (pH 8.5); clear wavy boundary. (4 to 14 inches thick)
An2--11 to 13 inches; gray (10YR 5/1) sandy loam, very dark gray (10YR 3/2) moist; massive; very hard, very firm, nonsticky and nonplastic; few very fine and fine roots; few very fine tubular and common very fine interstitial pores; strongly alkaline (pH 8.5); abrupt wavy boundary. (1 to 4 inches thick)
2Btn1--13 to 15 inches; grayish brown (10YR 5/2) sandy clay loam, dark grayish brown (2.5Y 4/2) and very dark grayish brown (10YR 3/2) moist; weak medium and coarse prismatic structure; very hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; few very fine and fine tubular pores; common thin clay films on peds and in pores; strongly alkaline (pH 8.5); clear wavy boundary. (2 to 6 inches thick)
2Btn2--15 to 20 inches; grayish brown (10YR 5/2) and dark grayish brown (10YR 4/2) sandy clay loam, dark grayish brown (2.5Y 4/2) moist; few fine distinct black (N 2/0) manganese stains; weak medium an coarse prismatic structure; very hard, firm, slightly sticky and plastic; few very fine roots; few very fine tubular pores; 20 percent clay content; common thin clay films on peds and in pores; exchangeable sodium percent is 43; strongly alkaline (pH 8.5); clear irregular boundary. (3 to 8 inches thick)
2BC--20 to 30 inches; brown (10YR 5/3) and pale brown (10YR 6/3) sandy clay loam, olive brown (2.5Y 4/4) moist; few medium faint light olive brown (2.5Y 5/4) mottles moist; few fine white (10YR 8/2) lime masses; massive, parting to weak medium and coarse angular blocky structure; hard, firm, slightly sticky and lightly plastic; few very fine roots; few very fine and fine tubular pores; common thin clay films bridging sand grains; slightly effervescent with disseminated lime and segregated as few fine irregular soft masses; strongly alkaline (pH 8.5); clear wavy boundary. (8 to 14 inches thick)
2Cn--30 to 38 inches; grayish brown (10YR 5/2) sandy clay loam, olive brown (2.5Y 4/4) moist; common fine brownish yellow (10YR 6/6) mottles, few fine faint light olive brown (2.5Y 5/4) mottles moist; slightly sticky and plastic; common very fine and fine roots; common very fine and few fine tubular pores; 31 percent clay content; common thin clay films bridging sand grains; slightly effervescent with disseminated lime and segregated as few fine irregular soft masses; exchangeable sodium percentage is 41; strongly alkaline (pH 8.5); clear irregular boundary. (6 to 10 inches thick)
3Ckn--38 to 60 inches; light brownish gray (2.5Y 6/2) clay, olive brown (2.5Y 4/4) moist; few fine distinct olive yellow and white (2.5Y 6/6, 8/2) mottles, many fine to large prominent dark greenish gray (5G 4/1) mottles moist; massive; hard, friable, slightly sticky and plastic; few very fine and fine roots; few very fine tubular pores; 31 percent clay content; common thin clay films bridging sand grains; slightly effervescent with disseminated lime and segregated as many fine irregular soft masses; exchangeable sodium percent is 37; strongly alkaline (pH 8.5).
TYPE LOCATION: Merced County, California; about 8 miles north northwest of the city of Los Banos, 400 feet east and 400 feet north ofthe SW corner of Section 4, T. 9 S., R. 10 E., Ingomar Quadrangle.
RANGE IN CHARACTERISTICS: These soils are saturated with stagnant water for at least a few days in most years. Uncoated sand grains (Tonguing of albic materials) are down into the part of 2Btn1. The 2Btn1 has more than 1.2 times clay content of An2 horizon.
The A horizon is 10YR 3/2, 3/3, 4/1, 5/1 or 5/2. Moist colors are 10YR 2/2, 3/1, 3/2 or 4/2. Thickness ranges from 7 to 24 inches depending on topography. Reaction is strongly alkaline except the top 3 inches of which ranges from moderately alkaline to strongly alkaline. Typically there is more than 15 percent exchangeable sodium between 3 to 13 inches, ranging from 15 to 43 percent. EC is 8 to 16 mmhos/cm.
The B horizon is 10YR 3/2, 4/2, 4/3, 4/4, 5/1, 5/2, 5/3, 6/3, 6/6; 2.5Y 4/4; 5Y 4/3 or 5/3. Moist colors are 10YR 3/2, 3/3, 4/2, 4/3, 5/3; 2.5Y 4/2, 4/4; or 5Y 5/3. Texture is sandy clay loam or rarely clay loam. Exchangeable sodium ranges from 15 to 45 percent. It has 20 to 35 percent clay content. EC is 8 to 16 mmhos/cm.
The C horizon is 10YR 5/1, 5/2, 6/1, 6/2, 6/3, 7/2; or 2.5Y 6/2. Moist colors are 10YR 3/2, 3/3, 4/2, 4/3, 5/3, 6/2; 2.5Y 4/4; 5Y 4/3, 5/2 or 5/3. Textures are sandy clay loam, clay loam, clay, silty clay loam or loam and clay content ranges from 25 to 45 percent. Exchangeable sodium ranges from 15 to 45 percent. EC is 8 to 16 mmhos/cm.
COMPETING SERIES: These are the Edminster and Kesterson series in the same family and the Britto, Santanela and Turlock series in other families. Edminster soils have a thin ochric epipedon with an EC of less than 2 mmhos/cm. Kesterson soils have a calcic horizon. Britto, Santanela and Turlock soils do not have tonguing of albic material into the upper Bt horizon in addition Britto is fine.
GEOGRAPHIC SETTING: Turmound soils are mounds in ponded areas that are in the valley basin and basin rim and have slopes of 0 to 2 percent. Elevations range from 70 to 80 feet. These soils are formed in mixed alluvium dominantly from granitic rock. The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is 9 to 12 inches. The mean January temperature is 46 degrees F; mean July temperature is 79 degrees F and the mean annual temperature is 62 degrees F. The frost-free season is 210 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Turlock soils and the Pedcat and Triangle soils. Pedcat soils have aquic intergrade moisture regimes and do not have tonguing of albic material into the upper Bt horizon. Triangle soils develop wide cracks upon drying, have intersecting slickensides and are fine.
DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff; slow permeability. Water table is 18 to 30 inches September to March.
USE AND VEGETATION: These soils being on large long mounds are used as waterfowl hunting habitat, hunting access ways and as rangeland. The areas adjacent are ponded from September to March. The range vegetation includes saltgrass, rabbitfoot grass, Baltic rush, annual barley, alkali sacaton, iodine bush, fat-hen and other grasses and forbs.
DISTRIBUTION AND EXTENT: These soils occur as mounds in the valley basin and basin rim of the Central San Joaqauin Valley. They are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced County, California 1984. Name is coined.
REMARKS: These soils were mapped as Waukena in the Los Banos Area, Series 1939 report. They are being differentiated by having an aquic moisture regime and tonguing of albic material in the upper Bt horizon. pH determined by colormetric method using Thymol Blue and Hellige-Troug Triplex indicators. Texture determined by hydrometer method. Soluble salts and exchangeable sodium determined by saturation extract. Organic matter estimated by comparing with adjacent soils determined by Walkley-Black digestion method. Presence of lime determined with 10 percent HC1.
The activity class was added to the classification in March of 2003. Competing series were not checked at that time. - ET