LOCATION PREMONT TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, hyperthermic Typic Haplustalfs
TYPICAL PEDON: Premont fine sandy loam--on northeast facing, convex, 1 percent slope in cropland at an elevation of 84 meters (275 feet). (Colors are for dry soil unless otherwise noted.)
Ap--0 to 21 cm (0 to 8 in); brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; weak fine granular structure; hard, friable; few very fine and few medium roots; few fine and medium tubular pores; noneffervescent; slightly acid, pH 6.3; abrupt wavy boundary. (thickness of the A horizon is 15 to 46 cm [6 to 18 in])
Bt1--21 to 40 cm (8 to 16 in); brown (7.5YR 4/3) sandy clay loam, dark brown (7.5YR 3/3) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; hard, firm; common fine and few medium roots; common fine and few medium tubular pores; 30 percent distinct brown clay films on faces of peds; noneffervescent; neutral, pH 6.8; clear smooth boundary. (combined thickness of the Bt horizons is 64 to 145 cm [25 to 57 in])
Bt2--40 to 56 cm (16 to 22 in); brown (7.5YR 4/3) sandy clay loam, dark brown (7.5YR 3/3) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; hard, firm; few very fine and fine roots; few fine and medium tubular pores; 30 percent distinct brown clay films on faces of peds; noneffervescent; neutral, pH 7.4; abrupt wavy boundary.
Bt3--56 to 86 cm (22 to 34 inches); brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/4), moist; strong coarse prismatic structure; very hard, very firm; common fine roots and few medium roots; few fine and few medium tubular pores; 30 percent distinct clay films on faces of peds; noneffervescent; moderately alkaline, pH 7.9; clear wavy boundary.
Btk--86 to 95 cm (34 to 37 inches); strong brown (7.5YR 5/6) sandy clay loam, strong brown (7.5YR 4/6), moist; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, very firm; few very fine pores; few fine tubular pores; 20 percent distinct brown clay films on faces of peds; 2 percent fine prominent threads of extremely weakly cemented white (7.5YR 8/1) calcium carbonate masses with sharp boundaries in matrix and 1 percent fine prominent spherical extremely weakly cemented white (7.5YR 8/1) calcium carbonate masses with sharp boundaries in matrix; strongly effervescent; strongly alkaline, pH 8.3; abrupt wavy boundary. (thickness of the Btk horizon is 7 to 20 cm [3 to 6 in])
2Btk1--95 to 124 cm (37 to 49 in); strong brown (7.5YR 5/6) sandy clay loam, strong brown (7.5YR 4/6) moist; moderate medium subangular blocky structure; very hard, very firm; few fine roots; few fine and medium tubular pores; 5 percent faint pale brown clay films on surfaces along pores; 1 percent fine black (7.5YR 2.5/1) iron-manganese nodules; 14 percent fine prominent irregular extremely weakly cemented white (7.5YR 8/1) calcium carbonate masses with sharp boundaries in matrix and 20 percent medium prominent spherical moderately cemented white (7.5YR 8/1) calcium carbonate nodules with sharp boundaries between peds; violently effervescent; strongly alkaline, pH 8.7; clear wavy boundary. (combined thickness of the 2Btk horizon is 84 to 109 cm [33 to 43 in])
2Btk2--124 to 153 cm (49 to 60 in); reddish yellow (7.5YR 7/6) sandy clay loam, reddish yellow (7.5YR 6/6) moist; weak medium subangular blocky structure; hard, firm; few very fine and fine tubular pores; 3 percent faint light yellowish brown clay films on surfaces along pores; 5 percent very dark grayish brown (10YR 3/2) insect casts between peds; 35 percent coarse prominent irregular extremely weakly cemented white (7.5YR 8/1) calcium carbonate nodules with sharp boundaries throughout and 10 percent medium prominent irregular non-cemented white (7.5YR 8/1) calcium carbonate masses with sharp boundaries between peds; violently effervescent; strongly alkaline, pH 8.7; gradual smooth boundary.
2Bk--153 to 203 cm (60 to 80 in); reddish yellow (7.5YR 8/6) sandy clay loam, reddish yellow (7.5YR 6/6) moist; weak medium subangular blocky structure; hard, firm; few fine tubular pores; 5 percent finely disseminated weakly cemented white (7.5YR 8/1) calcium carbonate masses with diffuse boundaries throughout and 30 percent medium prominent spherical non-cemented white (7.5YR 8/1) calcium carbonate masses with sharp boundaries between peds; violently effervescent; strongly alkaline, pH 8.7
TYPE LOCATION: Duval County, Texas; from the intersection of Texas Highway 44 and FM 359 in San Diego; 1.15 south on FM 359 to FM 1329; 14.1 miles south on FM 1329 to ranch road; 1.57 miles west on ranch road; 200 feet south in cropland. San Jose, TX USGS topographic quadrangle; Latitude, 27 degrees, 32 minutes, 39.5 seconds N; Longitude, 98 degrees, 17 minutes, 33.8 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 180 cumulative days in normal years. June through August and December through February are the driest months. These soils are intermittently moist in September through November and March through May.
Mean annual soil temperature: 22.2 to 23.4 degrees C (72 to 74 degrees F).
Depth to secondary calcium carbonates: 74 to 152 cm (29 to 60 in).
Particle-size control section (weighted average): Clay content: 17 to 32 percent.
Some pedons have mollic colors but do not have enough organic carbon to meet the requirements for a mollic epipedon.
A horizon
Hue: 10YR
Value: 4 or 5
Chroma: 2 or 3
Texture: loamy fine sand or fine sandy loam
Clay content: 7 to 16 percent
EC: 0 to 2
SAR: 0 to 6
Effervescence: none
Reaction: strongly acid to neutral
Bt horizon
Hue: 7.5YR or 10YR
Value: 3 to 6
Chroma: 2 to 4
Texture: fine sandy loam or sandy clay loam
Clay content: 17 to 32 percent
Clay films: amount-10 to 30 percent, location-along faces of peds, contrast-faint to distinct
EC: 0 to 2
SAR: 0 to 6
Effervescence: noneffervescent to slight
Reaction: slightly acid to moderately alkaline
Btk horizon
Hue: 7.5YR or 10YR
Value: 3 to 6
Chroma: 3 to 6
Texture: sandy clay loam
Clay content: 20 to 32 percent
Clay films: amount-10 to 25 percent, location-along faces of peds, contrast-faint to distinct
EC: 0 to 2
SAR: 0 to 6
Effervescence: slight to strong
Reaction: neutral to strongly alkaline
2Btk horizon
Hue: 7.5YR or 10YR
Value: 4 to 7
Chroma: 3 to 6
Texture: sandy clay loam
Clay content: 20 to 26 percent
Clay films: amount-3 to 10 percent, location-on surfaces along pores, contrast-faint
Identifiable secondary carbonates: 5 to 45 percent threads, masses, and nodules, fine to coarse, infused in matrix and in matrix along faces of peds
EC: 0 to 2
SAR: 0 to 4
Effervescence: slight to violent
Reaction: slightly alkaline to strongly alkaline
2Bk horizon
Hue: 7.5YR or 10YR
Value: 4 to 8
Chroma: 3 to 6
Texture: sandy clay loam
Clay content: 20 to 26 percent
Identifiable secondary carbonates: 5 to 45 percent threads, masses, and nodules, fine to coarse, infused in matrix and in matrix along faces of peds
EC: 0 to 2
SAR: 0 to 4
Effervescence: slight to violent
Reaction: slightly alkaline to strongly alkaline
COMPETING SERIES: This is the tentative Raisin (TX) series. Similar soils include the Cobb (TX), Brennan (TX), Delfina (TX), Duval (TX), and Hebbronville (TX) Honeycreek (TX), and Menard (TX) series.
Raisin and
Delfina soils: have redox features in the argillic horizon.
Cobb,
Honeycreek, and
Menard soils: have a thermic temperature regime.
Brennan soils: have an aridic moisture regime.
Duval soils: have siliceous mineralogy.
Hebbronville soils: have a coarse-loamy particle-size control section and an aridic moisture regime.
GEOGRAPHIC SETTING:
Parent Material: loamy sediments over calcareous loamy alluvium of Quaternary age
Landform: crests on paleoterrace
Slope: 0 to 3 percent
Mean annual temperature: 22.2 to 23.4 degrees C (72 to 74 degrees F)
Mean annual precipitation: 610 to 762 mm (24 to 30 in)
Precipitation pattern: April through June and September and October are the wettest months. November through March are the driest months.
Frost-free period: 270 to 320 days
Elevation: 6.1 to 91 meters (20 to 300 feet)
Thornthwaite annual P-E indices: 28 to 36
GEOGRAPHICALLY ASSOCIATED SOILS: These include the
Clareville,
Colmena,
Czar,
Delfina, and
Gertrudis soils.
Clareville soils: are on concave stream terraces and have more than 35 percent clay in their particle-size control sections.
Colmena soils: are on planar to slightly convex shoulder positions and have a mollic epipedon.
Czar soils: are on concave steam terraces and have a mollic epipedon thicker than 50 cm (20 in).
Delfina soils: are on convex paleoterraces and have masses of oxidized iron in the control section.
Gertrudis soils: are on convex terrace remnants and are calcareous throughout.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is low.
USE AND VEGETATION: The major uses are crop production, livestock grazing, and wildlife habitat. Grasses present include false rhodesgrass, Kleberg bluestem, plains bristlegrass, shortspike windmillgrass, and guineagrass. Woody vegetation consists of mesquite, catclaw, elbowbush, limepricklyash, pricklypear, granjeno, and tasajillo. Crops grown include grain sorghum, watermelons and cotton. Sandy Loam (R083AY407TX).
DISTRIBUTION AND EXTENT: Northern Rio Grande Plain (MLRA 83A in LRR I) of southern Texas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Kleberg County, Texas; 2007.
REMARKS: The Premont soils were formerly included in the Delfina series. Future study is needed to verify the calcic horizon of these soils. The calcium carbonate masses appear to be degrading petrocalcic fragments and are being removed from the soil matrix. This is characterized by the sharp boundaries of the soft material surrounding, in some cases, nodules that vary in size. These are mostly in the lower materials below the lithologic discontinuity.
Diagnostic features and horizons recognized in this pedon are:
Particle-size control section: 21 to 71 cm (8 to 28 in). (Bt horizons)
Ochric epipedon: 0 to 21 cm (0 to 8 in).
Argillic horizon: 21 to 153 cm (8 to 60 in). (Bt and 2Btk horizons)
Calcic horizon: 95 to 203 cm (37 to 80 in). (2Btk horizons)
Lithologic discontinuity: 95 to 203 cm (37 to 80 in.) (2Btk horizons) Data shows the lithologic discontinuity is weakly expressed. Very fine to fine sand ration shows a significant decrease at 95 cm. The presence of coarse, spherical, moderately cemented, nodules indicate a deposition of alluvium with a different lithology than the recent alluvium in the upper part of the solum.
ADDITIONAL DATA: TAMU data from Duval County, Texas (S06TX-131-001)
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006.