LOCATION ENGLE TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Calciustolls
TYPICAL PEDON: Engle clay loam - cropland. (Colors are for dry soil unless otherwise stated.)
A--0 to 12 inches; very dark grayish brown (10YR 3/2) clay loam, very dark brown (10YR 2/2) moist; moderate medium granular structure; very hard, firm; few fine roots; many worm casts; strongly effervescent; moderately alkaline; gradual smooth boundary. (5 to 13 inches thick)
Bw--12 to 22 inches; grayish brown (10YR 4/2) clay loam, dark grayish brown (10YR 4/2) moist; moderate medium and coarse granular structure; hard, friable; few fine roots; many worm casts of darker material from above and of more yellow soils from below; few weakly cemented pale-olive (5Y 6/3) sandstone pebbles; violently effervescent; moderately alkaline; gradual wavy boundary. (6 to 24 inches thick.)
Bk--22 to 28 inches; pale yellow (2.5Y 7/4) clay loam, light yellowish brown (2.5Y 64/) moist; weak fine subangular blocky structure; hard, friable; 1/2 to 2 percent by volume masses and 5 percent weakly cemented calcium carbonate concretions; violently effervescent; moderately alkaline; clear wavy boundary. (6 to 10 inches thick.)
Cr--28 to 32 inches, pale yellow (2.5Y 8/4) weakly cemented calcareous sandstone; moderately alkaline.
TYPE LOCATION: Navarro County, Texas; in Richland at the intersection of Farm Road 1394 and State Highway 14, 4.95 miles northeast on Farm Road 1394, 350 feet northeast of fence in pasture. (Latitude: 31 degrees, 52 minutes, 54 seconds North; Longitude: 96 degrees, 30 minutes, 50 seconds West.)
RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 40 inches which corresponds to a paralithic contact consisting of weakly or strongly cemented calcareous sandstone layers that are interbedded with loamy material. The average clay content of the control section ranges from 18 to 35 percent. Fragments of weakly cemented sandstone ranges from 0 to 15 percent by volume throughout the solum.
The A horizon has hue of 10YR or 7.5YR, value of 3 to 5, and chroma of 1 to 3. Texture is loam, clay loam or sandy clay loam.
The Bw and Bk horizons have hue of 7.5YR to 2.5Y, value of 5 to 8, and chroma of 2 to 4. Texture is loam, clay loam or sandy clay loam. Clay content ranges from 18 to 35 percent. Calcium carbonate equivalent in the Bk ranges from 15 to 40 percent.
The Cr horizon ranges from weakly cemented to strongly cemented sandstone that is interbedded with loamy materials. It can be cut with spade or auger. Roots penetrate only in occasional fractures or in loamy interbedded material.
COMPETING SERIES: These are the Clark series and the similar Brenham, Carbengle, Lewisville, Sunev, Velow and Venus series. Clark and Venus soils lack Cr horizons of weakly consolidated sandstone within 40 inches. Brenham and Lewisville soils are fine-silty. Carbengle and Sunev soils have carbonatic mineralogy. Velow soils are noncalcareous in the upper part of the solum.
GEOGRAPHIC SETTING: Engle soils are on gently sloping to rolling uplands. Slopes range from 1 to 10 percent, but are mostly 1 to 5 percent. These soils formed in calcareous loamy material containing thin strata of calcareous sandstone. Mean annual temperature ranges from 63 to 70 degrees F. and mean annual precipitation ranges from 30 to 40 inches; Frost free days range from 220to 260 days and elevation ranges from 400 to 750 feet. Thornthwaite annual P-E indices ranges from 44 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Altoga, Heiden, Lamar, and Wilson series. Altoga and Lamar soils lack a mollic epipedon. Heiden soils are clayey and have intersecting slickensides. Wilson soils have an argillic horizon with more than 35 percent clay.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is negligible to medium. Permeability is moderate.
USE AND VEGETATION: Mainly cultivated, with cotton, corn, grain sorghum and small grain being the principal crops. Native vegetation includes little bluestem, indiangrass, sideoats grama and big bluestem.
DISTRIBUTION AND EXTENT: Mainly in the Blackland Prairies of north central Texas. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Collin County, Texas; 1975.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 12 inches. (A horizon)
Cambic horizon - 12 to 22 inches. (Bw horizon)
Calcic horizon - 22 to 28 inches. (Bk horizon).