LOCATION DESAN TXEstablished Series
TAXONOMIC CLASS: Loamy, siliceous, active, thermic Grossarenic Paleustalfs
TYPICAL PEDON: Desan loamy fine sand--orchard. (Colors are for dry soil unless otherwise stated).
Ap--0 to 8 inches; brown (10YR 5/3) loamy fine sand, brown (10YR 4/3) moist; single grained; loose, very friable; common fine and medium roots; slightly acid; abrupt smooth boundary. (5 to 20 inches thick)
E--8 to 54 inches; reddish yellow (7.5YR 6/6) loamy fine sand, strong brown (7.5YR 5/6) moist; single grained; loose, very friable; few fine and medium roots; moderately acid; clear wavy boundary. (34 to 60 inches thick)
Bt1--54 to 75 inches; yellowish red (5YR 5/6) sandy clay loam, yellowish red (5YR 4/6) moist; moderate coarse prismatic structure parting to moderate coarse subangular blocky; very hard, firm; few fine roots; common fine and medium pores; thin patchy clay films on surfaces of peds; slightly acid; clear wavy boundary. (10 to 38 inches thick)
Bt2--75 to 93 inches; yellowish red (5YR 5/6) sandy clay loam, yellowish red (5YR 4/6) moist; moderate coarse prismatic parting to weak coarse subangular blocky structure; very hard, firm; few fine roots; many fine and medium pores; thin patchy clay films on surfaces of peds; moderately acid; gradual wavy boundary. (10 to 62 inches thick)
BC--93 to 114 inches; yellowish red (5YR 5/6) sandy loam, yellowish red (5YR 4/6) moist; moderate coarse prismatic structure; slightly hard, friable; few fine roots; many fine and medium pores; moderately acid; gradual wavy boundary. (0 to 32 inches thick)
2C--114 to 136 inches; yellowish red (5YR 5/6) loamy fine sand, yellowish red (5YR 5/6) moist; massive; soft, very friable; moderately acid.
TYPE LOCATION: Mills County, Texas; from the Mills County Courthouse in Goldthwaite, 10 miles southwest on Texas Highway 16; then 1.3 miles west on a gravel road to the Lower Big Valley Cemetery; 0.5 mile north and 0.5 mile east to a field corner, and 80 yards southeast into a pecan orchard.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 65 to more than 120 inches. The combined thickness of the A and E horizons is 40 to 80 inches.
The A horizon has hue of 5YR to 10YR, value of 5 to 7, and chroma of 3 to 6. The E horizon has hue of 5YR to 10YR, value of 6 to 8, and chroma of 3 to 6. Texture is fine sand or loamy fine sand. Reaction ranges from strongly acid to neutral.
The Bt horizon has hue of 2.5YR to 7.5YR, value of 4 to 6, and chroma of 6 to 8. Texture is fine sandy loam, or sandy clay loam. Redoximorphic features in shades of red, yellow, brown and gray are none to common. Clay content ranges from 18 to 35 percent. Reaction ranges from strongly acid to slightly acid.
The BC horizon has hue of 2.5YR to 7.5YR, value of 5 or 6, and chroma of 6 to 8. Texture is sandy loam to sandy clay loam. Reaction ranges from strongly acid to slightly acid.
The 2C horizon has hue of 2.5YR to 10YR, value of 5 to 7, and chroma of 4 to 8. Texture is loamy sand, loamy fine sand, sandy loam, or sandy clay loam.
COMPETING SERIES: These are Catilla, Matilo, Navasan, Padina, and Patilo series. Similar soils include the Eufaula, Heaton, Nimrod, Sarita, and Silvern series. Catilla, Navasan, Padina, and Patilo soils have mottled Bt horizons. Matilo soils have a paralithic contact between 60 and 80 inches. Eufaula soils have sandy control sections and Bt horizons that consists of lamellae. Heaton and Nimrod soils are in arenic subgroups. In addition, Nimrod soils have mottles associated with wetness. Sarita soils are in the hyperthermic family. Silvern soils are in the loamy-skeletal family.
GEOGRAPHIC SETTING: Desan soils occupy nearly level to moderately sloping uplands and ancient stream terraces. Surfaces are complex and slope gradients are 0 to 8 percent. The soil formed in sandy and loamy alluvium. The surface may have been reworked by wind. Mean annual precipitation ranges from 27 to 40 inches, and mean annual temperature ranges from 64 to 68 inches. Frost free days range from 230 to 275 days, and elevation ranges from 300 to 1,500 feet. Thornthwaite P-E index ranges from 40 to 58.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Aquilla, Bastrop, Clairemont, Heaton, miles, and Winters series. Bastrop, Miles, and Winters soils are at slightly higher positions in the landscape, and have A horizons less than 20 inches thick. Aquilla soils or on about the same positions and have lamella of fine sandy loam within 40 miles of the surface. Clairemont soils have loamy A horizons, do not have argillic horizons, and have irregular decrease in organic matter with depth. Heaton soils have sandy A horizons 20 to 40 inches thick.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained. Permeability is moderate. Runoff is negligible on 1 to 3 percent slopes, very low on 3 to 5 percent slopes, and low on 5 to 8 percent slopes.
USE AND VEGETATION: Mostly cultivated to peanuts and in pecan orchards. Some acreage is cultivated to melons and fruits. A few areas remain in native post oak and blackjack oak timber.
DISTRIBUTION AND EXTENT: Central Texas. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Falls County, Texas; 1975.
REMARKS: Active cation exchange activity class. Diagnostic horizons and features recognized in this pedon:
Ochric epipedon (grossarenic) - 0 to 54 inches. (A and E horizons.
Argillic horizon - 54 to 93 inches. (Bt horizons)
Pale feature - No clay decrease with increasing depth by as much as 20 percent (absolute) from the maximum within 60 inches of the surface. In addition, chroma of more than 5 within the Bt1 horizon.
ADDITIONAL DATA: Falls County, Texas: NSSL - S74TX-145-(1-2), 74L343-344.
Soil Interpretation Record: TX0284