LOCATION MAY TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, active, thermic Udic Haplustalfs
TYPICAL PEDON: May fine sandy loam--cultivated.
(Colors are for dry soil unless otherwise stated.)
Ap--0 to 5 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; massive; slightly hard, friable; neutral; abrupt smooth boundary. (3 to 8 inches thick)
A--5 to 16 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak very fine subangular blocky and granular structure; slightly hard, friable; few fine siliceous pebbles; neutral; clear smooth boundary. (5 to 12 inches thick)
Bt1--16 to 30 inches; brown (10YR 4/3) sandy clay loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; hard, firm; thin discontinuous clay films on faces of peds; mildly alkaline; gradual smooth boundary. (8 to 20 inches thick)
Bt2--30 to 42 inches; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; hard, firm; thin discontinuous clay films on faces of peds; mildly alkaline; clear wavy boundary. (7 to 20 inches thick)
BC--42 to 50 inches; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 4/4) moist; weak very fine subangular blocky structure; hard, friable; moderately alkaline; calcareous; gradual smooth boundary. (0 to 12 inches thick)
Ck--50 to 60 inches; light yellowish brown (10YR 6/4) sandy clay loam, yellowish brown (10YR 5/4) moist; massive; hard, friable; common films and threads and a few soft masses of calcium carbonate; moderately alkaline; calcareous.
TYPE LOCATION: Erath County, Texas; from the county courthouse in Stephenville, Texas, about 14 miles north on Texas Highway 108 to the Hannibal store, then north on Highway 108, 0.9 mile, then west by northwest 2.9 miles on a county road to its intersection with a north-south county road, then 5.8 miles west on a county road and 0.4 mile south of road in a cultivated field.
RANGE IN CHARACTERISTICS: The solum is 40 to 70 inches thick. Depth to secondary carbonates ranges from 36 to 62 inches. The clay content of the control section ranges from 18 to 30 percent.
The A horizon has hue of 10YR, value of 4 through 6, and chroma of 2 through 4. Texture is fine sandy loam or very fine sandy loam. Reaction ranges from slightly acid through mildly alkaline with less than 1 percent organic matter.
The Bt horizon has hue of 7.5YR and 10YR, value of 4 through 6, and chroma of 2 through 6. Colors are brown, dark grayish brown, or yellowish brown. Some pedons have few to common reddish or yellowish mottles in the lower part. Texture is sandy clay loam, clay loam, or fine sandy loam. Reaction is neutral or mildly alkaline.
The BC or BCk horizon is in shades of brown. Some pedons contain mottles in shades of yellow or brown. Texture is sandy clay loam, loam, or fine sandy loam. Reaction is mildly alkaline or moderately alkaline and calcareous. Soft masses, threads or films of calcium carbonate ranges from none to common.
The Ck horizon is in shades of brown, gray, or white with or without mottles or streaks or these colors. It is sandy clay loam, loam, or fine sandy loam. Concretions, soft masses, threads, and films of calcium carbonate range from few to many.
COMPETING SERIES: These include the Cisco series in the same family and Altus, Cobb, Devol, Duffau, Grandfield, and Konawa series in similar families. Altus soils have mollic epipedons thicker than 20 inches and occur in a drier climate. Cisco, Cobb, Devol, Grandfield, and Konawa soils have hue redder than 7.5YR. In addition, Cobb, Grandfield, and Konawa soils have mixed mineralogy. Devol soils have coarse-loamy control sections. Duffau soils lack carbonates and have an argillic horizon with hue redder than 10YR.
GEOGRAPHIC SETTING: May soils are on nearly level stream terraces or shallow upland valleys with plane or concave surfaces. Slope gradients are 0 to 3 percent. The soils formed in local, loamy alluvium. Mean annual temperature is 64 to 67 degrees F., average annual precipitation is 26 to 40 inches, and Thornthwaite P-E indices are 40 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Cisco and
Duffau, and the
Bosque,
Nimrod,
Pedernales, and
Windthorst series. Cisco and Duffau soils are higher in the landscape on stream divides and along upland drainageways. Bosque soils have mollic epipedons and are lower in the landscape on flood plains. Nimrod soils have sandy epipedons 20 to 40 inches thick and are higher in the landscape on stream divides and low ridges. Pedernales and Windthorst soils have reddish clayey argillic horizons and are higher in the landscape on hillsides and stream divides.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability. Most of May soils are in positions that receive extra water from adjacent higher areas.
USE AND VEGETATION: Mainly cultivated; grain sorghum, peanuts, and truck crops are the principal crops. Native vegetation is mid and tall grasses and post oak, live oak, and mesquite trees.
DISTRIBUTION AND EXTENT: In the Cross Timbers, Central Rolling Red Prairies and fringe areas of the Grand Prairie in central Texas.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Brown County, Texas; 1939.