LOCATION NIDO TXEstablished Series
TAXONOMIC CLASS: Loamy, mixed, active, calcareous, hyperthermic, shallow Aridic Ustorthents
TYPICAL PEDON: Nido fine sandy loam in rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 18 cm (0 to 7 in); yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine roots; 10 percent rounded siliceous pebbles; 5 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline; abrupt wavy boundary. (8 to 31 cm [3 to 12 in] thick)
Crk--18 to 203 cm (7 to 80 in); brownish yellow (10YR 6/6) weakly cemented calcareous sandstone with thin coatings of calcium carbonate along cracks and fissures in upper part; few roots in upper part; fine sandy loam in cracks in upper part; strongly effervescent; moderately alkaline.
TYPE LOCATION: Webb County, Texas; from the intersection of Interstate Highway 35 and FM 1472 in Laredo; 8.0 miles northwest on Farm Road 1472 and 100 feet south into rangeland. Cuervo Creek, TX USGS topographic quadrangle. Latitude: 27 degrees, 39 minutes, 22.826 seconds N.; Longitude: 99 degrees, 34 minutes, 11.66 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Soil Moisture: An ustic soil moisture regime bordering on aridic. The soil moisture control section remains moist in some or all parts for less than 90 consecutive days in normal years. The soil is driest during the months of June through August and December through February. These soils are intermittently moist in September through November and March through May.
Mean annual soil temperature: 22 to 24 degrees C (72 to 76 degrees F).
Depth to paralithic contact: 8 to 31 cm (3 to 12 in).
Particle-size control section (weighted average)
Clay content: 11 to 25 percent
Coarse Fragments: 0 to 15 percent, increasing with depth
CEC/clay ratio: 0.40 to 0.60
A horizon
Hue: 7.5YR, 10YR, or 2.5Y
Value: 5 or 6
Chroma: 2 to 6
Texture: fine sandy loam or sandy clay loam
Clay content: 11 to 25 percent
Coarse fragments: 0 to 15 percent
Base saturation: 85 to 100 percent
Calcium carbonate equivalent: 1 to 10 percent
Identifiable secondary carbonate: 0 to 2 percent very fine and fine films and masses
EC (dS/m): 0 to 2
Gypsum: 0 to 2 percent
SAR: 0 to 1
Effervescence: strongly or violently effervescent
Reaction: moderately alkaline
The Cr horizon is weakly to strongly cemented alkaline sandstone that is interbedded with fine sandy loam and sandy clay loam. Cracks in the upper part have coatings of calcium carbonate.
COMPETING SERIES: There are no competing series in the same family. Similar soils are the
Dilley (TX),
Verick (TX), and
Zapata (TX) series.
Dilley and Verick soils: have an argillic horizon
Zapata soils: have a petrocalcic horizon
GEOGRAPHIC SETTING:
Parent material: calcareous loamy colluvium and residuum weathered from calcareous sandstone.
Landform: ridges
Slope: 1 to 20 percent.
Mean annual air temperature: 21 to 23 degrees C (70 to 74 degrees F).
Mean annual precipitation: 483 to 610 cm (19 to 24 in).
Precipitation pattern: moist spring and fall months and dry summer and winter months.
Frost-free period: 300 to 360 days.
Elevation: 91 to 213 m (300 to 700 ft).
Thornthwaite annual P-E indices: 20 to 26.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Copita,
Maverick,
Verick, and
Zapata series.
Copita soils: are moderately deep to sandstone, have a calcic horizon, and are on lower positions.
Maverick soils: are moderately deep to mudstone, are clayey, and are on similar to slightly lower positions.
Verick and Zapata soils: occur on similar positions.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate above a slowly permeable weathered bedrock material. Runoff is low on slopes of 1 to 5 percent and medium on 5 to 20 percent slopes.
USE AND VEGETATION: Used as native rangeland and wildlife habitat. These soils support a sparse cover of grasses and shrubs, such as Arizona cottontop, hooded windmillgrass, mesquite, spiny hackberry, guayacan, blackbrush, cenizo, guajillo, and ebony. The ecological site is Shallow Ridge 18-22 PZ (R083BY575TX).
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: Webb County, Texas, 1982. This series was proposed in Webb County, Texas, 1970.
REMARKS: Classification change from Ustic Torriorthents to Aridic Ustorthents based on geographic distribution of the series, rainfall patterns, and vegetative production and composition. The soil has an ustic soil moisture regime that borders an aridic moisture regime.
Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 0 to 18 cm (0 to 7 in) (A horizon)
Ochric epipedon: 0 to 18 cm (0 to 7 in). (A horizon)
Paralithic contact: The contact with sandstone at 18 cm (7 in) (Crk horizon)
ADDITIONAL DATA: The assignment of the cation-exchange activity class is inferred from lab data from surrounding counties in the region.
Taxonomic version: Keys to Soil Taxonomy, Tenth Edition, 2006.