LOCATION LATTAS TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Typic Haplusterts
TYPICAL PEDON: Lattas clay--cropland, microlow.
(Colors are for dry soil unless otherwise stated.)
Ap--0 to 5 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; weak fine subangular blocky structure parting to weak fine granular; very hard, firm, sticky, plastic; few fine roots; few fine tubular pores; few very fine calcium carbonate concretions; few fine shell fragments; few clean sand grains; strongly effevescent; moderately alkaline; clear smooth boundary. (4 to 10 inches thick)
Bw--5 to 21 inches; very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; weak fine angular blocky structure; very hard, very firm, very sticky, very plastic; few fine roots; few fine tubular pores; common shiny pressure faces on peds; few vertical streaks of very dark gray (10YR 3/1); few very fine calcium carbonate concretions; strongly effervescent; moderately alkaline; gradual wavy boundary. (0 to 22 inches thick)
Bss--21 to 29 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; few vertical streaks of gray (10YR 5/1); weak fine and medium angular blocky structure; extremely hard, very firm, very sticky, very plastic; few fine roots; few fine tubular pores; many shiny pressure faces on peds; common prominent slickensides; few vertical streaks of black (10YR 2/1); few fine shell fragments; few discontinuous sand lenses; few fine calcium carbonate concretions; strongly effervescent; moderately alkaline; gradual wavy boundary. (0 to 24 inches thick)
Bkss1--29 to 37 inches; dark gray (10YR 4/1) clay; very dark gray (10YR 3/1 moist; moderate fine and medium angular blocky structure; extremely hard, very firm, very sticky, very plastic; few fine roots; few fine tubular pores; common prominent slickensides; common distinct calcium carbonate coats on peds; few masses of calcium carbonate; few vertical streaks of black (10YR 2/1); few fine shell fragments; few fine discontinuous sand lenses on vertical surfaces of peds; strongly effervescent; moderately alkaline; gradual wavy boundary.
Bkss2--37 to 53 inches; gray (10YR 5/1) clay, dark gray (10YR 4/1) moist; moderate fine and medium angular blocky structure; extremely hard, very firm, very sticky, very plastic; few fine roots; few fine tubular fine pores; common prominent slickensides; few vertical streaks very dark gray (10YR 3/1); few fine discontinuous sand lenses on vertical surfaces of peds; few fine and medium masses and concretions of calcium carbonate; strongly effervescent; moderately alkaline; gradual wavy boundary. (combined thickness of the Bkss horizons is 12 to 45 inches thick)
Bky1--53 to 70 inches; very pale brown (10YR 7/4) clay, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; extremely hard, very firm, sticky, plastic; few fine roots; few fine tubular pores; common fine and medium distinct brown (7.5YR 4/4) iron accumulations; few vertical streaks of dark gray (10YR 4/1); few fine discontinuous sand lenses on vertical surfaces of peds; few fine masses of calcium carbonate; common gypsum crystals; strongly effervescent; moderately alkaline; gradual smooth boundary.
Bky2--70 to 80 inches; very pale brown (10YR 8/4) clay; very pale brown (10YR7/4) moist; weak fine subangular blocky structure; extremely hard, very firm, sticky, plastic; few fine roots; common fine and medium distinct brown (7.5YR 4/4) iron accumulations; few fine masses of calcium carbonate; common gypsum crystals; strongly effervescent; moderately alkaline. (combined thickness of the Bky horizons is 20 to 40 inches).
TYPE LOCATION: Jim Wells County, Texas; 3.4 miles south on U. S. Highway 281 from its intersection with State Highway 359 in Alice; 5.6 miles east on Farm Road 1930 to curve; 0.25 mile east on caliche field road; 40 feet south in cropland. (Latitude 27N, 41, 48; Longitude 97W, 59, 00)
RANGE IN CHARACTERISTICS: The range in characteristics includes 50 percent or more of the pedon. Solum thickness is more than 80 inches. Amplitude of waviness and thickness of the mollic epipedon ranges from 14 to 40 inches. In over half the pedon, the dominant chroma is less than 1.5 to depths of 40 inches or more. Weighted average clay content of the particle-size control section ranges from 40 to 55 percent. Slickensides and wedge-shaped peds begin at a depth ranging from 5 to 24 inches. Undisturbed areas have gilgai mirorelief with microknolls 2 to 8 inches higher than microlows. Distance from the center of the microknoll to the center of the microlow ranges from 12 to 24 feet. When dry, these soils have cracks from 0.3 to 2.5 inches wide that extend from the surface, or from the base of the Ap horizon, into the Bky horizon. Electrical conductivity (EC) of the saturation extract above a depth of 40 inches ranges from 0.5 to 4 dS/m and ranges from 4 to 8 dS/m to 80 inches. Sodium adsorption ratio (SAR) ranges from 1 to 6 in the upper 20 inches, 5 to 15 from 20 to 40 inches, and 10 to 20 at 40 to 80 inches. Calcium carbonate concretions and masses range from few to common and gypsum crystal range from few to common in the Bky horizon. Reaction is moderately alkaline throughout the pedon.
The Ap or A horizon has hue of 10YR, value 3 or 4, and chroma 1. Texture of the Ap horizon is sandy clay loam, clay loam, or clay.
The Bw horizon has hue of 10YR, value 3 or 4, and chroma 1. Texture is clay loam, silty clay, or clay.
The Bss and Bssk horizon has hue of 10YR, value of 4 to 6 and chroma 1 or 2.
The Bky horizon has hue of 7.5YR or 10YR, value 6 to 8, and chroma 1 to 4. Iron accumulations are in shades of brown.
COMPETING SERIES: These are the Buchel, Danjer, Monteola, and Rosenbrock series in the same family. Similar soils include Benito, Lomalta, Mercedes, Montell, Tiocano, and Victoria series. Buchel soils do not have accumulations of gypsum in the lower part of the solum. and are on floodplains. Danjer soils have dominant chroma of more than 1.5 in the 10- to 40- inch control section. Monteola soils have less than 14 inches of amplitude in the boundary between the A and B horizons and are formed from clay and shale of the Oakville Formation. Rosenbrock soils are deep to siltstone. Benito and Lomalta soils have more than 60 percent clay in the particle-size control section. In addition, Lomalta soils, as well as Mercedes and Montell soils, have an ochric epipedon. Tiocano and Victoria soils are moist in the moisture control section for longer periods.
GEOGRAPHIC SETTING: Lattas soils occupy nearly level to gently sloping Gulf Coast Prairies of southern Texas. Slope range from 0 to 3 percent but are dominantly less than 1 percent. The soil formed in calcareous, clayey sediments of the Pliestocene age Beaumont Formation. Mean annual temperature ranges from 70 to 75 degrees F. Mean annual precipitation ranges from 23 to 30 inches. Frost free days range from 280 to 300 and elevation ranges from 100 to 225 feet. Thornthwaite P-E index ranges from 28 to 34.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clareville, Edroy, Orelia, Papalote, Pernitas, and Pharr series. These associated soils have Bt horizons and are not Vertisols. Edroy soils are in depressions. Pernitas and Pharr soils are at slightly higher elevations and have steeper slope gradients. Clareville, Orelia, and Papalote soils are slightly higher in the landsape in areas grading onto the Goliad Formation.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very slow. Runoff is low on 0 to 1 percent slopes and medium on 1 to 3 percent slopes.
USE AND VEGETATION: Used mainly for cropland. Crops are grain sorghum and cotton, with some corn grown. A few gently sloping areas are in improved pastures of coastal bermudagrass. Some areas are used for rangeland. Principal native grasses are little bluestem, four-flower trichloris, vine-mesquite, plains bristlegrass, and Arizona cottontop. Woody invaders are mainly mesquite, huisache, spiny hackberry, and whitebrush
DISTRIBUTION AND EXTENT: Coastal Prairies of southern Texas (MLRA 150A). The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jim Wells County, Texas; 1976.
REMARKS: These soils were formerly included with the Victoria and Raymondville series.
Diganostic horizons and features recognized in this pedon are:
Mollic epipedon--0 to 37 inches. (Ap, Bw, Bss horizon).
Cambic horizon--37 to 53 inches. (Bkss horizon).
Vertisol feature-- Slickensides, high shrink-swell potential, and cracks in all years.
Calcic horizon--53 to 80 inches. (Bky1 and Bky2 horizons).
ADDITIONAL DATA: NSSL data from type location in Jim Wells County, TX (S84TX-249-001) and NSSL data from Live Oak County, TX (S91TX-297-010).