LOCATION ELNIDO CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Typic Endoaquolls
TYPICAL PEDON: Elnido sandy loam - on a slope of 1 percent in a cultivated cotton field at 95 feet elevation. (Coloris for dry soil unless otherwise stated. When described on November 29, 1976, the soil was moist throughout).
Ap--0 to 10 inches; dark grayish brown (10YR 4/2) sandy loam, very dark gray (10YR 3/1) moist; weak medium and coarse subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; common very fine and fine roots; many very fine interstitial and few fine tubular pores; moderately alkaline (pH 8.0); gradual smooth boundary. (5 to 12 inches thick)
A--10 to 18 inches; dark grayish brown (10YR 4/2) sandy loam, very dark brown (10YR 2/2) moist; few medium distinct dark yellowish brown (10YR 3/4) moist redox concentrations ; weak medium and coarse subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; few very fine roots; many very fine interstitial pores; moderately alkaline (pH 8.3); abrupt smooth boundary. (5 to 10 inches thick)
Bwg--18 to 27 inches; grayish brown (2.5Y 5/2) sandy loam, dark grayish brown (2.5Y 4/2) moist; common medium prominent brown (7.5YR 4/4) moist redox concentrations ; weak medium and coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; moderately alkaline (pH 8.3); gradual smooth boundary. (8 to 18 inches thick)
Cg--27 to 60 inches; grayish brown (2.5Y 5/2) sandy loam, dark olive gray (5Y 3/2) moist; few fine prominent brown (7.5YR 4/4) moist redox concentrations; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; moderately alkaline (pH 8.3).
TYPE LOCATION: Merced County, California; about 5 miles northeast of the city of Los Banos, 0.8 mile northwest of the intersection of Henry Miller Avenue and Delta Road; 100 feet east of Devon drain; 2,200 feet north and 800 feet east of the southwest corner of section 33, T.9 S., R.11 E., MDB&M; Latitude 37 degrees, 06 minutes, 18 seconds north, Longitude 120 degrees, 46 minutes, 33 seconds west; USGS Los Banos Topographic Quadrangle, NAD 27.
RANGE IN CHARACTERISTICS: These soils are saturated with stagnant water for at least a few days. The thickness of the mollic epipedon is 10 to 22 inches. The clay content of the 10- to 40-inch particle-size control section is 5 to 18 percent but averages 8 to 16 percent. Organic matter is 1 to 3 percent in the upper 10 to 22 inches and decreases regularly to less than 1 percent at 22 inches.
The A horizon has color of 10YR 4/1, 4/2, 4/3, 5/1, 5/2, 5/3 or 2.5Y 4/2. Moist coloris 10YR 2/2, 3/1, 3/2 or 2.5Y 3/2. Texture is sandy loam, loam, silt loam or clay loam. Redoximorphic masses of recent iron accumulations occur in the lower part in some pedons. Reaction is slightly acid to moderately alkaline.
The Bwg horizon has color of 10YR 4/3, 5/2, 5/3, 6/2; 2.5Y 5/2 or 6/2. Moist coloris 10YR 4/2, 4/4, 5/4; 2.5Y 4/2 or 5Y 4/1. Texture is sandy loam, fine sandy loam, loam or silt loam. Reaction is neutral to moderately alkaline. Some pedons have segregated and/or disseminated carbonates. In some pedons there are horizons that have segregated carbonates that are designated Bkg horizons.
The Cg horizon has color of 10YR 5/3, 6/3, 7/2: 2.5Y 5/2, 6/2; 5Y 6/2 or 6/3. Moist coloris 10YR 4/3, 5/3, 5/4; 2.5Y 4/2 4/4, 5/2; 5Y 3/2, 4/1, 4/2, 5/2 or 5/3. Some pedons do not have redoximorphic features. Texture is sandy loam, loam, silt loam, loamy sand or sand. Reaction is neutral to strongly alkaline. In some pedons there are horizons that have segregated carbonates that are designated Ckg horizons.
COMPETING SERIES: There are no other soil series in this family.
GEOGRAPHIC SETTING: Elnido soils are on channels, flood plains, basin floors and valley basins. Slopeis 0 to 2 percent. The soils formed in alluvium derived dominantly from granitic rocks. Most of this soil has been land leveled, but the natural landscape had bar and channel topography. Elevationis 75 to 170 feet. Climate is semiarid with hot dry summers and cool moist winters. Mean annual precipitation is 8 to 12 inches. Themean annual temperature is 62 to 64 degrees F. The frost-free season is 210 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alros, Bisgani, Dospalos, Escano, Kesterson and Palazzo soils. Alros, Escano and Kesterson soils have a fine-loamy particle-size control section, have a calcic horizon and are on valley basins. Bisgani soils have a sandy particle-size control section. Dospalos soils have a fine particle-size control section. Palazzo soils have a fine-loamy particle-size control section. Bisgani, Dospalos and Palazzo soils are on flood plains.
DRAINAGE AND PERMEABILITY: Poorly drained; negligible or very low runoff; moderately rapid permeability. Some pedons have very rapid permeability in the lower part of the profile. In clay loam phases permeability is moderately slow in the surface and moderately rapid below. In most areas of Elnido soils the natural hydrology has been altered so that the soils are now considered to be drained. The presence of dams and reservoirs in the Sierra Nevada, pumping from the water table, use of tile and interceptor drains, filling of local sloughs and leveling of bar and channel topography help explain the altered hydrology. Prior to the altered hydrology Elnido soils were subject to occasional flooding with long duration from January through March, consequently, the native soils were very poorly drained having ponded channels with stagnant water for extended periods during the winter and spring months. Currently, depth to the water table is generally greater than 3.5 feet. Most areas are protected from major flooding by levees and reservoirs. Some areas are subject to rare, brief periods of flooding from December through June in years of abnormally high precipitation. In areas unprotected by levees, flooding is occasional or frequent.
USE AND VEGETATION: Most of these soils are cultivated and irrigated. They are principally used for field crops and vegetable production with small acreages of orchards and pastures. In some areas these soils are used for waterfowl hunting and as rangeland for limited grazing during the spring and summer months between hunting season.
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. MLRA 17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced County, California, 1984.
REMARKS: These soils were formerly included with and surveyed as Grangeville series in the Los Banos Area, series 1939 report. They are being differentiated by characteristics that show a reducing environment (Aquic moisture regime) which is not characteristic of the Grangeville series. The pH was determined by colorimetric method using Thymol Blue and Hellige-Truog Triplex indicators. Texture was determined by modified Bouyoucos method.
Series reclassified 5/95.
Very slow runoff terminology adjusted 12/96 to negligible or very low, to comply with adjective criteria of the Soil Survey Manual dated 10/93.
Major Diagnostic Horizons and Features:
1. Mollic Epipedon --The zone from 0 to 18 inches (Ap,A) - Organic matter is assumed to be 1 to 3 percent and decreases regularly to less than 1 percent below 10 inches. The thickness is 10 to 22 inches.
2. Aquic moisture regime - Formed under aquic conditions with most areas now drained and protected. Still, many areas will have the entire profile saturated for a short period of time by the water table and stagnant surface water.
3. Coarse-loamy family - Clay content of the particle-size control section (10 to 40 inches) is 5 to 18 percent but averages 8 to 16 percent(Hydrometer method).