LOCATION EDNA TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Aquertic Chromic Hapludalfs
TYPICAL PEDON: Edna loam--pasture. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; dark gray (10YR 4/1) loam, light gray (10YR 6/1) dry;; massive; extremely hard, friable; many fine roots; few fine distinct brownish yellow (10YR 6/6) masses of iron accumulation; moderately acid; abrupt wavy boundary. (4 to 20 inches thick)
Bt1--9 to 19 inches; gray (10YR 5/1) clay, light gray (10YR 6/1) dry; moderate medium and coarse blocky structure; extremely hard, very firm, very sticky; common fine roots; few small slickensides and pressure faces; vertical cracks 0.4 inch wide and 18 to 24 inches apart; few thin clay films on surfaces of peds; many fine, faint dark gray (10YR 4/1) and grayish brown (2.5Y 5/2) iron depletions, and many distinct yellowish brown (10YR 5/6) masses of iron accumulation; few fine dark brown and black iron-manganese concretions; slightly acid; gradual wavy boundary. (5 to 15 inches thick)
Bt2--19 to 38 inches; light gray (5Y 6/1) clay; moderate medium and coarse blocky structure; extremely hard, very firm, very sticky; common fine roots along surfaces of peds; few thin clay films on surfaces of peds; vertical cracks from horizon above extend through horizon; few pressure faces; common medium light olive gray (5Y 6/2) iron depletions; common fine faint olive (5Y 4/4) masses of iron accumulation; few fine dark brown and black iron-manganese concretions; slightly acid; gradual wavy boundary. (10 to 30 inches thick)
Bt3--38 to 50 inches; medium and coarsely mottled light brownish gray (2.5Y 6/2) and light yellowish brown (2.5Y 6/4) clay loam; weak medium and coarse blocky structure; extremely hard, firm, sticky; few fine roots along surfaces of peds; few thin clay films on surfaces of peds; few fine dark brown and black iron-manganese concretions; slightly alkaline; gradual wavy boundary. (0 to 20 inches thick)
BCt--50 to 65 inches; light olive gray (5Y 6/2) sandy clay loamweak medium and coarse blocky structure; very hard, firm, sticky; few roots; few thin clay films on surfaces peds; , few fine faint olive (5Y 4/4) masses of iron accumulation; few fine iron-manganese concretions; few fine pitted concretions of calcium carbonate; moderately alkaline.
TYPE LOCATION: Wharton County, Texas; 2.1 miles northeast of the intersection of U. S. Highway 59 and State Highway 60 in Hungerford; 0.9 mile east on paved county road; 0.6 mile south on shell road; 0.3 mile southwest on private road and 120 feet north of gate.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. The soil cracks when dry but cracks rarely extend upward through the A horizon.
The A horizon is less than 10 inches thick in more than 50 percent of any pedon, but ranges up to 20 inches thick. This horizon has hue of 10YR, value of 3 to 7, and chroma of 1 or 2. Texture is fine sandy loam or loam. When dry, this horizon is massive and very hard or extremely hard. Some pedons have an E horizon of higher value than the Ap or A horizon. Reaction ranges from strongly acid to neutral. Some pedons have an overwash of calcareous clay or silty clay 8 to 20 inches thick.
The Bt horizon has hue of 10YR to 5Y, values of 4 to 7, and chroma of 1 or 2. Texture is clay loam or clay. Clay content of the upper Bt horizon ranges from 35 to 55 percent clay and silt content from 32 to 40 percent. Few to common, fine or medium, yellow, brown, red, and olive masses of iron accumulation are throughout the horizon. Coatings of darker colors are on surfaces of peds in some pedons. Reaction is moderately acid to neutral in the upper part and ranges to moderately alkaline in the lower part. COLE ranges from 0.09 to 0.11.
The BCt horizon is mottled or has a mixed grayish matrix with few to common redoximorphic features in shades of olive, brown, yellow, or red. Dominant colors are in hue of 10YR to 5Y, value of 4 to 7, and chroma of 1 to 4. Texture is commonly sandy clay loam or clay loam and less commonly clay or sandy clay. Concretions, masses, films and threads of calcium carbonate range from none to common. Reaction ranges from slightly acid to moderately alkaline. Some pedons are calcareous. Some pedons have 2C horizons of sandy or loamy materials below 60 inches.
COMPETING SERIES: These are the Telferner and Inez series. Similar soils are the Edco, Katy, Mentz, Telf, Texana, and Yeaton series. Telferner and Inez soils have an ochric epipedon from 10 to 20 inches thick. Texana soils have a mollic epipedon. Katy and Yeaton soils have chroma of 4 or more in the argillic horizon. In addition, Katy soils are in the fine-loamy family, and Yeaton soils are in the thermic temperature regime. Mentz soils are in the thermic temperature regime and developed in materials weathered from the Goliad Formation. Edco and Telf soils have mixed mineralogy, and are derived from sediments of the Lissie Formation.
GEOGRAPHIC SETTING: Edna soils are on broad, nearly level coastal prairies. Slopes are mainly less than 1 percent, but some along narrow drainageways are as much as 5 percent. The soil formed in clayey sediments of the Pleistocene age Beaumont Formation. Mean annual temperatures ranges from 68 to 70 degrees F., and mean annual precipitation ranges from 35 to 55 inches. Frost free days range from 250 to 280 days, and elevation ranges from 10 to 150 feet. Thornthwaite annual P-E indices range from 44 to 66.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aris, Bernard, Clodiine, Gessner, Inez, Katy, Laewest, and Lake Charles series. Aris and Inez soils have more than 10 inches of A horizon and Aris soils have tongues of albic material in the Bt. Bernard soils have A and upper Bt horizons having moist color values darker than 3.5. Katy soils have chroma of more than 2 and do not have vertic properties. Lake Charles and Laewest soils are Vertisols.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Permeability is very slow. Runoff is low on 0 to 1 percent slopes, medium on 1 to 3 percent slopes, and high on 3 to 5 percent slopes. Water perches on top of the argillic horizon for periods of 2 to 4 weeks following extended heavy rain.
USE AND VEGETATION: Mainly used for growing rice and for native range for beef cattle. Some is used for growing cotton and grain sorghum. Native grasses are mainly prairie grasses of species of Andropogon, Paspalum, Panicum, and Sporobolus. Oak, elm, and Hackberry trees have encroached in some areas.
DISTRIBUTION AND EXTENT: Coastal Prairie of Texas. The series is of large extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Victoria County, Texas; 1910.
REMARKS: The classification was changed from Vertic Albaqualfs to Vertic Hapludalfs based on the soil moisture study "ISCOM VIII, Classification and Management of Wet Soils, 1990." This soil does not have an aquic moisture regime. Classification change from Vertic Hapludalfs to Aquertic Chromic Hapludalfs based on a study of associated soils where significant iron reduction and depletion has been measured in the A and, to a lesser extent, the upper part of the Bt horizon. Aquic conditions occur for periods long enough in most years to cause iron reduction and mobility, as well as iron oxidation. In addition, the majority of pedons have value moist of 4 or more and value dry of 6 or more, supporting the Chromic subgroup.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 9 inches. (Ap horizon)
Argillic horizon - 9 to 65 inches. (Bt and BCt horizons)
Aquertic feature - Cracks and/or wedge-shaped aggregates within the upper part of the argillic horizon. Intermittent aquic conditions are expressed by value of 5 and chroma of 1 or 2 in the matrix of the upper part of the argillic horizon, in association with masses of iron accumulation in this zone.
ADDITIONAL DATA: S55TX-79-92, published in SSIR-30.