LOCATION TONIO TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, hyperthermic Ustic Calciargids
TYPICAL PEDON: Tonio fine sandy loam, on a east facing, convex 2.0 percent in rangeland; elevation is 128 m (420 ft). (Colors are for dry soil unless otherwise stated.)
A--0 to 25 cm (0 to 10 in); brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, very friable; few fine roots; many fine pores; 2 percent threads and films of calcium carbonate; slight effervescence; moderately alkaline; gradual smooth boundary. (18 to 46 cm [7 to 18 in] thick)
Bt1--25 to 76 cm (10 to 30 in); brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, very friable; few patchy clay films on faces of peds; few fine roots; many fine pores; 2 percent threads and films of calcium carbonate strong effervescence; moderately alkaline; gradual smooth boundary. (15 to 61 cm [6 to 24 in] thick)
Bt2--76 to 102 cm (30 to 40 in); light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 5/4) moist; moderate fine and medium subangular blocky structure; hard, friable, few patchy clay films on faces of peds; few fine roots; many fine pores; 7 percent threads and films of calcium carbonate; strong effervescence; moderately alkaline; gradual wavy boundary. (15 to 41 cm [6 to 16 in] thick)
Btk--102 to 137 cm (40 to 54 in); very pale brown (10YR 7/4) sandy clay loam, light yellowish brown (10YR 6/4) moist; weak fine and medium subangular blocky structure; hard, friable; few fine pores; 10 percent soft masses of calcium carbonate up to 12mm (1/2 in) diameter; strong effervescence; moderately alkaline; abrupt wavy boundary. (25 to 61 cm [10 to 24 in] thick)
Cr--137 to 203 cm (54 to 80 in); pink (7.5YR 7/4) sandstone, reddish yellow (7.5YR 6/6) moist; few yellowish red (5YR 5/6) streaks; weakly cemented; brittle; strong effervescence; moderately alkaline.
TYPE LOCATION: Dimmit County, Texas; 15.1 miles southwest of Carrizo Spring on Farm Road 186, then 2.7 miles west on private road to Hamilton Ranch Headquarters, then 3.4 miles north to corrals, continue 0.8 mile north to pipeline, then northwest 1.1 miles across pond dam to metal gate, then 0.7 mile northwest across pond dam, then 50 feet east in rangeland. Palo Blanco Tank, Texas USGS topographic quadrangle. Latitude: 28 degrees, 26 minutes, 12.636 seconds, N; Longitude: 100 degrees, 3 minutes, 51.104 seconds, W; NAD 83.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 102 to 152 cm (40 to 60 in) over weakly to strongly cemented sandstone. Conductivity of the saturation extract is about 1 to 4 mmhos/cm.
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 2 to 4
Texture: fine sandy loam, loam, or sandy clay loam
Clay content: 15 to 22 percent
Calcium carbonate equivalent: 1 to 10 percent.
Mollic colors are less than 15 cm (6 in) thick in the A horizon.
Hue: 10YR, 7.5YR or 2.5Y
Value: 4 to 8
Chroma: 3 to 6
Texture: fine sandy loam, loam, sandy clay loam, or clay loam
Clay content: 19 to 24 percent
Calcium carbonate equivalent: 10 to 30 percent
Identifiable secondary carbonates: 1 to 25 percent calcium carbonate threads, films, masses, or concretions in some part of the B horizon. The lower part of the B horizon is usually of lighter color than the upper part.
The Cr horizon is weakly to strongly cemented calcareous sandstone. The sandstone is interbedded with shale, calcium carbonate, or gypsum layers in some pedons.
COMPETING SERIES: There are no series in the same family. Similar soils include
Mavco (TX), and
Verick (TX) series.
Cabreros soils: have a mesic soil temperature regime.
Copita soils: are moderately deep to sandstone and do not have argillic horizons.
Dilley and Verick soils: are shallow to sandstone.
Faskin and Grizzle soils: have a thermic soil temperature regime.
Mavco soils: have fine-silty control sections with carbonatic mineralogy.
Parent material: calcareous loamy residuum weathered from sandstone.
Landform: ridges on interfluves.
Slope: 0 to 5 percent.
Mean annual air temperature: 21 to 23 degrees C (70 to 74 degrees F).
Mean annual precipitation: 432 to 660 mm (17 to 26 in).
Frost-free period: 265 to 340 days.
Elevation: 98 to 198 m (320 to 650 ft).
Thornthwaite P-E index: 20 to 31.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the
Brystal and Zavco soils: are noncalcareous in the upper sola and have redder hues throughout and are on similar to slightly lower positions.
Caid and Uvalde soils: have mollic epipedons and are in lower positions
Copita soils: are moderately deep and are on similar positions
Mavco and Pryor soils: are on broad outwash plains at slightly lower positions. In addition, Mavco soils are fine-silty and Pryor soils are fine.
Verick soils: are shallow and are more sloping areas at higher positions
Zavco soils: are very deep over sandstone and shale and are in lower positions
DRAINAGE AND PERMEABILITY: Well drained. Moderate permeability. Runoff is negligible on on slopes less than 1 percent and low on 1 to 5 percent slopes.
USE AND VEGETATION: Primarily rangeland and wildlife habitat. Small areas are culitivated to such crops as small grain, grain sorghum, introduced grasses and a few vegetables. Native grasses presently consist of red grama, threeawn, bristlegrass, Hall's panicum, hooded windmillgrass, pink pappusgrass, cottontop, and fall witchgrass. Woody plants include mesquite, black brush, white brush, guayacan, twisted acacia, lotebush, allthorn, goatbush, Texas persimmon, wolfberry, guajillo, leatherstem, and pricklypear. Forbes, such as rat ear and Russian thistle are common. The ecological site is Gray Sandy Loam 18-25 PZ (R083BY421TX).
DISTRIBUTION AND EXTENT: Western Rio Grande Plain, Texas; LRR I; MLRA 83B; the series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas.
SERIES ESTABLISHED: Dimmit County, Texas; 1982.
REMARKS: These soils were formerly classified in the Calcisol great soil group. These soils have been included with Copita soils in past surveys.
Diagnostic horizons and features:
Ochric epipedon: 0 to 25 cm (0 to 10 in) (A horizon)
Argillic horizon: 25 to 137 cm (10 to 54 in) (Bt and Btk horizons)
Paralithic contact: 137 to 203 cm (54 to 80 in) (Cr horizon)
ADDITIONAL DATA: NSSL data from Zapata County location S02TX-505-002.
Taxonomic version: Keys to Soil Taxonomy, Tenth Edition, 2006.