LOCATION LOPENO TXEstablished Series
TAXONOMIC CLASS: Mixed, hyperthermic Oxyaquic Ustipsamments
TYPICAL PEDON: Lopeno fine sand--on a southeast facing, 2 percent slope in an area of Potrero-Lopeno-Noria complex, 0 to 5 percent slopes, in rangeland at an elevation of 3.4 meters (11 ft). (Colors are for moist soil unless otherwise stated)
A--0 to 13 cm (0 to 5 in); brown (10YR 5/3), fine sand, pale brown (10YR 6/3) dry; single grain; loose, loose; 7 percent fine and medium roots; 2 percent fine distinct brownish yellow (10YR 6/6) masses of oxidized iron; slightly acid; clear smooth boundary. (Thickness of the A horizon is 10 to 51 cm [4 to 20 in])
C1--13 to 48 cm (5 to 19 in); pale brown (10YR 6/3) fine sand, very pale brown (10YR 7/3) dry; single grain; loose, loose; many fine and medium roots; common fine pores; 3 percent fine distinct brownish yellow (10YR 6/6) masses of oxidized iron; faint thin bedding planes; slightly acid; gradual smooth boundary.
C2--48 to 104 cm (19 to 41 in); pale brown (10YR 6/3) fine sand; 3 percent clay; loose, loose; common fine and medium roots; common fine pores; 7 percent fine distinct yellowish brown (10YR 5/6) masses of oxidized iron; 4 percent medium distinct brownish yellow (10YR 6/8) masses of oxidized iron; faint thin bedding planes; moderately alkaline; clear smooth boundary. (Combined thickness of the C horizons is 38 to 89 cm [15 to 35 in])
Cg1--104 to 137 cm (41 to 54 in); light brownish gray (10YR 6/2) fine sand; single grain; loose, loose; common fine roots; common fine pores; 5 percent fine distinct brownish yellow (10YR 6/6) masses of oxidized iron; 2 percent medium distinct brownish yellow (10YR 6/6) masses of oxidized iron; faint thin bedding planes; slightly alkaline; gradual smooth boundary.
Cg2--137 to 165 cm (54 to 65 in); light brownish gray (2.5Y 6/2) fine sand; single grain; loose, loose; common fine roots; common fine pores; 2 percent fine distinct brownish yellow (10YR 6/6) masses of oxidized iron; faint thin bedding planes; slightly alkaline; abrupt smooth boundary. (Combined thickness of the Cg horizons is 38 to 76 cm [15 to 30 in])
Agb--165 to 175 cm (65 to 69 in); grayish brown (2.5Y 5/2) fine sand; single grain; loose, loose; common fine roots; common fine pores; 25 percent medium distinct dark grayish brown (10YR 4/2) masses of oxidized iron; 5 percent fine distinct light olive brown (2.5Y 5/4) masses of oxidized iron; 3 percent fine and medium distinct dark greenish gray (10Y 4/1) masses of oxidized iron; slightly alkaline; clear smooth boundary. (Thickness of the Agb horizon is 10 to 33 cm [4 to 13 in])
Bgb1--175 to 188 cm (69 to 74 in); grayish brown (2.5Y 5/2) loamy fine sand; weak fine and medium subangular blocky structure; slightly hard, friable; common fine roots; common fine pores; 25 percent medium and coarse distinct light brownish gray (2.5Y 6/2) masses of oxidized iron; 7 percent fine and medium distinct light yellowish brown (2.5Y 6/4) masses of oxidized iron; 5 percent fine and medium distinct dark greenish gray (10Y 3/1) masses of oxidized iron; 3 percent fine and medium prominent olive brown (2.5Y 4/4) masses of oxidized iron; neutral; clear smooth boundary. (Combined thickness of the Bgb horizons is 13 to 33 cm [5 to 13 in])
Bgb2--188 to 203 cm (74 to 80 in); light olive gray (5Y 6/2) fine sand; weak fine and medium subangular blocky structure; slightly hard, very friable; common fine roots; common fine pores; 7 percent fine and medium faint light yellowish brown (2.5Y 6/3) masses of oxidized iron; 7 percent fine and medium distinct light yellowish brown (2.5Y 6/4) masses of oxidized iron; 5 percent medium distinct greenish gray (10GY 5/1) masses of oxidized iron; 3 percent fine and medium distinct grayish green (5G 5/2) masses of oxidized iron; slightly alkaline.
TYPE LOCATION: Kenedy County, Texas; from the intersection of U.S. Highway 77 and La Parra Avenue in Sarita; 4.8 miles south on U.S. Highway 77; 19.6 miles east on ranch road; 1.25 miles south on ranch road; 3,200 feet south in rangeland. Yarborough Pass, Texas USGS topographic quadrangle; Latitude: 27 degrees, 10 minutes, 23.40 seconds N.; Longitude: 97 degrees, 29 minutes, 45.30 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Soil Moisture: An ustic moisture regime. The Soil Moisture Control Section is dry in some or all parts for more than 90, but less than 150 cumulative days in normal years. The SMCS is also either moist in some or all parts for 180 cumulative days or more, or moist for 90 or more consecutive days in normal years. A water table occurs in most pedons at a depth of 91 to 152 cm (36 to 60 in) for at least two months in most years. November through April are the driest months, with a second dry period in July. September is the wettest month.
Mean annual soil temperature: 23 to 24 degrees C (74 to 76 degrees F)
Depth to masses of iron accumulations: 0 to 51 cm (0 to 20 in)
Depth to iron depletions or depleted matrix: 107 to 191 cm (42 to 75 in)
Depth to endosaturation: 91 to 152 cm (36 to 60 in) for at least two months in most years
Depth to lithologic discontinuity: 86 to 137 cm (34 to 54 in)
A horizon
Hue: 10YR
Value: 4 to 6
Chroma: 2 to 4
Texture: fine sand
Redox concentrations: amount-0 to 3 percent, size-fine, contrast-distinct, boundary-clear or sharp, location-lining pores.
EC (dS/m): 0 to 2
SAR: 0 to 5
Reaction: moderately acid to neutral
C horizon
Hue: 10YR or 2.5Y
Value: 5 to 7
Chroma: 2 or 3
Texture: fine sand
Redox concentrations: amount-4 to 12 percent, size-fine or medium, contrast-faint or distinct, boundary-clear or sharp, location-lining pores.
EC (dS/m): 0 to 2
SAR: 0 to 4
Reaction: slightly acid to slightly alkaline
Ab or Agb horizon
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 1 or 3
Texture: fine sand, loamy fine sand, or fine sandy loam
Redox concentrations: amount-0 to 25 percent, size-fine to coarse, contrast-faint or distinct, boundary-diffuse to sharp, location-lining pores.
Redox depletions: amount-0 to 7 percent, size-fine or medium, contrast-faint or distinct, boundary-diffuse or clear, location-in the matrix.
EC (dS/m): 0 to 2
SAR: 0 to 4
Reaction: slightly acid to moderately alkaline
Bgb horizon
Hue: 10YR, 2.5Y or 5Y
Value: 4 to 6
Chroma: 1 or 2
Texture: loamy fine sand, fine sandy loam or sandy clay loam
Redox concentrations: amount-10 to 25 percent, size-fine to coarse, contrast-faint to prominent, boundary-diffuse to sharp, location-lining pores.
Redox depletions: amount-2 to 20 percent, size-fine to coarse, contrast-faint or distinct, boundary-diffuse or clear, location-in the matrix.
EC (dS/m): 0 to 2
SAR: 0 to 4
Reaction: slightly acid to slightly alkaline
COMPETING SERIES: There are no competing series in the same family. Similar soils include the
Arenisco (TX),
Atiras (TX),
Falfurrias (TX),
Medanito (TX), and
Potrero (TX).
Arenisco, Atiras, Medanito, and Falfurrias: do not have a water table within 102 cm (40 in) of the soil surface.
Potrero soils: have aquic conditions for sometime in normal years and a seasonal water table within 51 cm (20 in).
GEOGRAPHIC SETTING:
Parent material: Eolian sands of Holocene age overlying loamy eolian deposits of Quaternary age.
Landform: low dunes on deflation flats associated with an active or recently active dune complex.
Slope: 1 to 5 percent
Mean annual air temperature range: 22 to 23 C (72 to 74 degrees F)
Mean annual precipitation range: 635 to 711 mm (25 to 28 in)
Precipitation Pattern: November through April are the driest months, with a second dry period in July. September is the wettest month.
Frost-free period: 310 to 350 days
Elevation: 2 to 9 meters (5 to 30 ft)
Thornthwaite P-E Index: 31 to 36
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Arenisco,
Noria,
Potrero,
Saucel, and
Topo series.
Arenisco soils: have a water table between 102 to 203 cm (40 and 80 in) and are on lag dune ridges bordering the active or recently active dune complex.
Noria soils: have an SAR of 13 or more within 102 cm (40 in) of the surface and are on in blowout and dune slack areas.
Potrero soils: have aquic conditions and a buried soil between 51 to 102 cm (20 and 40 in) and are on interdunal flats.
Saucel and Topo soils: have a salic horizon and are on blowouts and troughs between dunes.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is rapid. Runoff is negligible. A seasonal water table is at depths of 91 to 152 cm (36 to 60 in) in most years. The soil is saturated below 152 cm (60 in).
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Native vegetation is dominantly seacoast bluestem. Other vegetation consists of gulfdune paspalum, balsamscale, gulf muhly and partridge pea. The ecological site is Low Coastal Sand, PE 31-44 (150BY650TX).
DISTRIBUTION AND EXTENT: Gulf Coast Saline Prairies (MLRA 150B in LRR T) of the coast areas of southern Texas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Kenedy County, Texas, 2007. The name is from a hill on a ranch in Kenedy County.
REMARKS: The series was formerly included in the Galveston series. The series was separated based on the presence of a buried soil.
Diagnostic horizons and features recognized in this pedon are:
Ochric Epipedon: 0 to 13 cm (0 to 5 in). (A horizon)
Redox Accumulations: 0 to 203 cm (0 to 80 in). (A, C1, C2, Cg1, Cg2, Abg, Bgb1, Bgb2 horizons)
Redox depletions or depleted matrix: 147 to 203 cm (58 to 80 in). (Agb, Bgb1 and Bgb2 horizons)
Endosaturation: The zone of saturation at 91 to 152 cm (36 to 60 in) for at least two months in most years. (Cg1, Cg2, Abg, Bgb1, Bgb2 horizons)
ADDITIONAL DATA: TAMU data from type location in Kenedy County, TX (S88TX-261-003).
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006