LOCATION REAGAN TX+NMEstablished Series
The Reagan series consists of very deep, well drained, moderately permeable calcareous soils that formed in calcareous loamy materials. These nearly level to gently sloping upland soils are on broad flats, filled valleys and fans. Slopes range from 0 to 3 percent.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Ustic Haplocalcids
TYPICAL PEDON: Reagan loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 3 inches; brown (10YR 5/3) loam, brown (10YR 4/3) moist; weak fine and medium granular structure; slightly hard, friable; common fine roots; surface crust about 3 mm thick, slightly effervescent; moderately alkaline; clear smooth boundary. (0 to 4 inches thick)
A2--3 to 8 inches; brown (7.5YR 5/4) loam, brown (7.5YR 4/4) moist; moderate fine and very fine subangular blocky structure; slightly hard, friable; few fine roots; common fine wormcasts, insect cavities and old root channels; slightly effervescent; moderately alkaline; diffuse smooth boundary. (4 to 8 inches thick)
Bw--8 to 17 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; weak coarse prismatic structure parting to moderate fine and medium subangular blocky; hard, friable; few fine roots; common fine wormcasts and insect cavities partially filled with material of same color as A2 horizon; few fine threads and films of calcium carbonate; strongly effervescent; moderately alkaline; diffuse smooth boundary. (6 to 28 inches thick)
Bk1--17 to 30 inches; light brown (7.5YR 6/4) clay loam; brown (7.5YR 5/4) moist; weak coarse prismatic structure parting to moderate fine and medium subangular blocky; hard, friable; few fine roots; common fine wormcasts and partially filled insect cavities; common fine masses of calcium carbonate in lower part; violently effervescent; moderately alkaline; clear wavy boundary. (0 to 16 inches thick)
Bk2--30 to 50 inches; reddish yellow (7.5YR 7/6) clay loam; strong brown (7.5YR 5/6) moist; weak coarse prismatic structure parting to weak medium subangular blocky; slightly hard, friable; 35 percent pinkish white (7.5YR 8/2) fine soft concretions and masses of segregated calcium carbonate; violently effervescent; moderately alkaline; diffuse wavy boundary. (10 to 30 inches thick)
Bk3--50 to 80 inches; reddish yellow (7.5YR 6/6) clay loam; strong brown (7.5YR 5/6) moist; weak coarse prismatic structure parting to weak medium subangular blocky; hard, friable; 5 percent fine masses of calcium carbonate; strongly effervescent; moderately alkaline.
TYPE LOCATION: Upton County, Texas; approximately 22 miles north 10 degrees east of Rankin; 9.0 miles south and west of Midkiff along Farm Road 2401, then 500 feet southeast of road and 150 feet east of fence in rangeland.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 80 inches. Depth to part of the Bk horizon that meets the requirement of a calcic horizon is 15 to 40 inches. The 10- to 40- inch control section has a silicate clay content that ranges from 18 to 35 percent, with less than 15 percent coarser than very fine sand. Calcium carbonate equivalent ranges from 15 to 40 percent.
The A horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 2 to 4. When moist, value and chroma are less than 3.5. Texture is loam, clay loam, silt loam, or silty clay loam.
The Bw horizon has hue of 7.5YR or 10YR, value of 5 to 7, and chroma of 2 to 4. Visible calcium carbonate in the Bw horizon ranges from few films and threads to about 5 percent by volume fine masses or weakly to strongly cemented concretions. Texture is silt loam, silty clay loam, or silty clay.
The Bk horizon has hue of 5YR to 10YR, value of 6 to 8, and chroma of 2 to 6. Texture is silt loam, silt clay loam, or silty clay. Visible secondary calcium carbonate in the Bk2 horizon ranges from about 15 to 50 percent. Where this horizon is at or near the minimum depth of 20 inches, the upper part is intermittently, weakly to strongly cemented.
COMPETING SERIES: These are Conchas (NM), Hoban (TX), Pandale (TX), Poquita (NM) and Stovall (TX) series in the same family. Similar series are the Angelo, Hodgins, McAllen, Midessa, Ratliff, Reakor and Seferino series. Conchas soils have a lithic contact between 20 and 40 inches. Hoban soils have accumulations of gypsum in the lower part of the calcic horizon. Poquita soils have hue of 2.5YR or 5YR in the particle size control section and solum thickness less than 60 inches. Pandale soils have a fine-loamy particle size class. Stovall soils have calcic horizons within 6 to 15 inches of the surface. Angelo soils have an ustic soil moisture regime and have a mollic epipedon. Hodgins soils do not have a calcic horizon within 40 inches of the surface. Midessa and Ratliff soils are in the fine-loamy family. Reakor soils are dry in the soil moisture control section for longer periods. Seferino soils have carbonatic mineralogy.
GEOGRAPHIC SETTING: Reagan soils are on broad, nearly level to gently sloping limestone plateaus, in filled valleys, and on alluvial fans. Slopes are plane and mostly of less than 1 percent gradient, but some are as much as 3 percent. The regolith in most places appears to be an eolian mantle, but in some places, mostly on alluvial fans, it is apparently alluvium. The regolith on the limestone plateaus is mostly 4 to 12 feet in thickness. Mean annual precipitation ranges from 10 to 17 inches, and mean annual temperature ranges from 60 to 70 degrees F. Frost-free period ranges from 210 to 240 and elevation ranges from 1,500 to 4,000 feet. Thornthwaite P-E indices range from about 14 to 26.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hodgins, Conger, Sanderson, and Upton series. Conger and Upton soils have petrocalcic horizons within 20 inches of the surface and are on fans and footslopes in higher positions. Sanderson soils have loam- skeletal control sections and are on fans and footslopes in higher positions.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is negligible on slopes less than 1 percent, and very low on 1 to 3 percent slopes.
USE AND VEGETATION: Mainly used for rangeland. Some areas are irrigated and used for growing cotton and sorghum. Native vegetation was short and midgrasses. Range now consists dominantly of burrograss and an overstory of tarbush and scrub mesquite trees.
DISTRIBUTION AND EXTENT: Western and southwestern Texas (MLRA 81A, 81D) and southeastern New Mexico. The series is of large extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Reagan County, Texas (Reconnaissance Soil Survey of West Central Texas); 1922.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 8 inches. (A1 and A2 horizons)
Cambic horizon - 8 to 17 inches. (Bw and Bk1 horizons)
Calcic horizon - 17 to 80 inches. (Bk2 and Bk3 horizons)
Ustic feature -The soil has an aridic moisture regime that borders on the ustic regime.
ADDITIONAL DATA: Beltsville Laboratory Data available for 3 pedons; samples No. 16492-16500.
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006