Established Series


The Bunyan series consists of very deep, well drained, moderately permeable soils that formed in stratified loamy alluvium. These soils are on nearly level bottomlands. Slopes range from 0 to 1 percent.

TAXONOMIC CLASS: Fine-loamy, mixed, active, nonacid, thermic Typic Ustifluvents

TYPICAL PEDON: Bunyan fine sandy loam--cultivated field. (Colors are for dry soil unless otherwise stated.)

Ap--0 to 10 inches; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; hard, friable; few fine roots; neutral; abrupt smooth boundary. (6 to 10 inches thick)

A1--10 to 16 inches; very dark grayish brown (10YR 3/2) clay loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; hard, firm; few fine roots; slightly acid; abrupt smooth boundary. (0 to 8 inches thick)

C1--16 to 22 inches; grayish brown (10YR 5/2) sandy clay loam, dark grayish brown (10YR 4/2) moist; massive, breaks to fragments; thin strata of fine sandy loam and clay loam with evident bedding planes; hard, firm; few fine roots; slightly alkaline; abrupt smooth boundary. (5 to 18 inches thick)

C2--22 to 46 inches; pale brown (10YR 6/3) sandy clay loam, brown (10YR 4/3) moist; with a few fine yellowish brown (10YR 5/6) redoximorphic concentrations; massive, breaks to fragments; stratification and bedding planes as in layer above; hard, firm; few fine roots; moderately alkaline; abrupt smooth boundary. (8 to 12 inches thick)

C3--46 to 54 inches; gray (10YR 6/1) clay loam, dark gray (10YR 4/1) moist; contains a few fine yellowish brown (10YR 5/6) redoximorphic concentrations; massive; hard, firm; few ferromanganese concretions; moderately alkaline; clear smooth boundary. (6 to 12 inches thick)

C4--54 to 62 inches; gray (10YR 6/1) clay loam, gray (10YR 5/1) moist; massive; hard, firm; few concretions and masses of calcium carbonate; moderately alkaline and calcareous.

TYPE LOCATION: Erath County, Texas; from the County Courthouse in Stephenville, Texas; 9.5 miles southwest on U. S. Highway 67; north on county road 0.4 mile and 150 yards east of county road in a cultivated field.

RANGE IN CHARACTERISTICS: The 10 to 40 inch control section is fine sandy loam, loam, sandy clay loam, or clay loam with 18 to 35 percent clay and more than 15 percent coarser than very fine sand. Stratification varies from scarcely evident to pronounced.

The A horizon has hue of 7.5YR or 10YR, value of 4 through 6, and chroma of 2 through 4. When moist, value is 3 and chroma is 2 or 3, the A horizon is less than 10 inches thick. Thin layers may occur below a depth of 10 inches with a color darker than the allowable range of the surface layer. The A horizon is usually fine sandy loam or loam, but is sandy clay loam or clay loam in a few pedons. It is slightly acid or neutral.

The C horizons have a hue of 7.5YR through 2.5Y, value of 4 through 6, and chroma of 2 through 4. Thin strata of very dark grayish brown, dark grayish brown, or dark brown also occur in the control section. The C3 and C4 horizons also include gray (10YR 5/1, 6/1), and light gray (10YR 7/1). The C horizons range from moderately acid in the upper part through moderately alkaline and calcareous in the lower part. Interbedded strata of noncalcareous and calcareous materials are common.

COMPETING SERIES: These include the Bosque, Clairemont, Colorado, Congaree, Gowen, Loire, Pulaski, Spur, Uhland, and Yahola series. Bosque, Gowen, and Spur soils have mollic epipedons. Clairemont, Colorado, and Yahola soils are calcareous. In addition, Clairemont soils have fine-silty control sections and Yahola soils have coarse-loamy control sections. Congaree soils occur in a more moist climate and are strongly acid in some part of the 10 to 40 inch conrol section. Loire soils are calcareous and have mean annual soil temperatures of more than 72 degrees F. Pulaski and Uhland soils have less than 18 percent clay in the 10 to 40 inch control section.

GEOGRAPHIC SETTING: Bunyan soils are on nearly level flood plains of small streams. The soil floods rarely to commonly for brief periods during the spring and fall months. The soil formed in loamy stratified alluvium of mixed origin. The location of probable occurrence has a range of mean annual temperature of 64 degrees to 70 degrees F., average annual precipitation of 28 to 40 inches and Thornthwaite annual P-E indices of 40 to 64. Frost free days range from 200 to 230. Elevation ranges from 700 to 1300 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Bosque and Gowen series and the Duffau, May, and Windthorst series. Duffau, May, and Windthorst soils have argillic horizons and are soils of the uplands.

DRAINAGE AND PERMEABILITY: Well drained; moderately permeability. Surface runoff is negligible. These soils are rarely to frequently flooded for periods of short duration.

USE AND VEGETATION: Most areas are being farmed in peanuts, sorghums, and pecan orchards. Areas that flood frequently are used mainly for bermuda pastures and pecan orchards.

DISTRIBUTION AND EXTENT: This soil occurs mainly in the Cross Timbers Major Land Recource Area of north-central Texas and possibly southern Oklahoma. It is moderate to large extent.


SERIES ESTABLISHED: Erath County, Texas; 1970.

REMARKS: These soils were formerly classified in the Alluvial great soil group.

National Cooperative Soil Survey