LOCATION SEAGOVILLE TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Entic Udic Haplusterts
TYPICAL PEDON: Seagoville loam--cultivated. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; moderate medium and fine blocky structure; very hard, very firm, very sticky and plastic; few fine roots; common fine pores; common wormcasts; strong effervescence; moderately alkaline; abrupt smooth boundary. (4 to 8 inches thick)
A--6 to 14 inches; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; moderate fine blocky structure; extremely hard, very firm, very sticky and plastic; few fine roots; many shiny pressure faces; strong effervescence; moderately alkaline; gradual wavy boundary. (6 to 17 inches)
Bss1--14 to 30 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; moderate medium and coarse blocky grooved natural fragments; extremely hard, very firm, very sticky and plastic; few fine roots; common coarse slickensides; strong effervescence; moderately alkaline; gradual wavy boundary. (6 to 30 inches thick)
2Ab--30 to 38 inches; dark grayish brown (10YR 4/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, friable; moderately alkaline; gradual wavy boundary. (6 to 20 inches thick)
2Btb--38 to 75 inches; brownish yellow (10YR 6/6) sandy clay loam, yellowish brown (10YR 5/6) moist; common medium prominent red (2.5YR 4/6) mottles; moderate coarse subangular blocky structure; hard, friable; few clay films; few fine black concretions; moderately alkaline.
TYPE LOCATION: Dallas County, Texas; 8.5 miles south of Seagoville, Texas, on Malloy Bridge Road to Blindsey Road; then 5.0 miles southeast on Blindsey Road and 600 feet south into cultivated field.
RANGE IN CHARACTERISTICS: Depth to horizons having less than 35 percent clay ranges from 25 to 39 inches. The upper clayey solum has a weighted average clay content of 40 to 60 percent. The loamy lower part has clay content of 15 to 35 percent. When dry, cracks 1/2 to more than 3 inches wide extend from the surface to a depth of more than 12 inches. Cracks remain open 90 to 150 cumulative days in most years.
The horizon has hue of 10YR or 2.5Y, value 4 or 5 and chroma 2. These horizons are clay or silty clay. Reaction ranges from slightly alkaline to moderately alkaline and they are calcareous.
The 2Ab horizon is dark brown (10YR 3/3, 4/3), dark grayish brown (10YR 4/2; 2.5Y 4/2), or grayish brown (10YR 5/2, 4/2). Mottles of yellowish brown, brown, strong brown, or reddish brown range from none to common. It is fine sandy loam, loam, or sandy clay loam. Reaction ranges from slightly alkaline to moderately alkaline and they are calcareous. A yellowish brown, brown, or strong brown B2 horizon is present in some pedons.
The 2Btb horizon is brownish yellow, yellowish brown, brown, pale brown, light yellowish brown, or strong brown. Texture is extremely variable and ranges from sandy clay loam to sandy loam. Some pedons have 2C horizons within 40 inches of the surface that are loamy fine sand or fine sand. Reaction ranges from neutral to moderately alkaline.
COMPETING SERIES: These include the Navaca in the same family and the similar Belk, Frio, Kufman, Ovan, Tinn and Trinity seies. Belk soils have colors in hue of 7.5YR and redder. Navaca, Kaufman, Tinn and Trinity soils have chroma of 1 in the upper 24 inches of the soil and Frio, Kaufman, Ovan, Tinn and Trinity soils do not have contrasting textures within 40 inches of the soil surface.
GEOGRAPHIC SETTING: Seagoville soils are on nearly level to gently sloping flood plains. Slopes are dominantly less than 1 percent but range from 0 to 2 percent. The soil formed in clayey alluvium deposited over low lying loamy terrace sediments. The mean annual precipitation ranges from 30 to 40 inches. Mean annual temperature ranges from 64 to 65 degrees F. The Thornthwaite P-E index is 44 to 64. Frost free days range from 200 to 240. The elevation ranges from 450 to 650.
Geographically Associated Soils; These are the competing Kaufman, Ovan, and Trinity series as well as the Aquilla, Bastrop, and Silstid series. Aquilla, Bastrop, and Silstid soils lack intersecting slickensides and have less than 35 percent clay in the control section. Kaufman, Ovan, Tinn and Trinity are in similar positions to Seagoville. Aquilla, Bastrop and Silstid are on slightly higher positions.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; very slow permeability in the upper 23 to 35 inches, moderately permeable below. Flooding occurs from once each year to once each 2 to 5 years for less than 2 days duration unless protected.
USE AND VEGETATION: Mainly pastureland of improved bermudagrass. Some areas are planted to crops of grain sorghum and small grain. Accessible areas are being strip mined for sandy resource materials.
DISTRIBUTION AND EXTENT: North Central Texas mostly along the Trinity River and its major tributaries. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Dallas County, Texas; 1975.
REMARKS: These soils would have been formerly included in the Trinity or Ovan series.
Diagnostic horizons and features in this pedon:
Mollic epipedon - 0 to 14 inches.
cambic horizon - 14 to 30 inches.
Buried soil (Alfisol) below 30 inches.
Vertisol features - Slickensides at a depth of 14 to 30 inches. High shrink-swell potential and cracks that are 1/2 to 3 inches wide at a depth of 12 inches or more during dry periods.
SIR Number. TX0532