LOCATION LAEWEST TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Typic Hapluderts
TYPICAL PEDON: Laewest clay--rangeland. (Colors are for moist soil unless otherwise stated.)
A1--0 to 10 inches; black (10YR 2/1) clay, very dark gray (10YR 3/1) dry; moderate fine subangular blocky structure; very hard, firm; common very fine and few fine and medium roots; common fine and few medium pores; neutral; clear wavy boundary.
A2--10 to 18 inches; black (10YR 2/1) clay, very dark gray (10YR 3/1) dry; moderate fine and medium angular blocky structure; very hard, firm; common very fine and few fine and medium roots; common fine and few medium pores; common pressure faces; few dark gray worm casts; neutral; gradual wavy boundary. (combined thickness of the A horizons is 12 to 24 inches)
Bss1--18 to 29 inches; black (10YR 2/1) clay, very dark gray (10YR 3/1) dry; moderate medium and coarse angular blocky structure; very hard, firm; few very fine, fine and medium roots; common fine and medium pores; many pressure faces and common prominent slickensides; few dark gray worm casts; neutral; gradual wavy boundary.
Bss2--29 to 37 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; moderate medium and coarse angular blocky structure; very hard, very firm; few very fine and fine roots; few fine and medium pores; many pressure faces and common prominent slickensides; few fine iron-manganese concretions; few gray worm casts; slightly alkaline; clear wavy boundary. (combined thickness of the Bss horizons is 10 to 45 inches)
Bkss1--37 to 46 inches; dark gray (10YR 4/1) clay, gray (10YR 5/1) dry; moderate coarse angular blocky structure parting to moderate fine and medium angular blocky; very hard, very firm; few very fine and fine roots; few fine and medium pores; many pressure faces and prominent slickensides; few fine iron-manganese concretions; about 3 percent concretions of calcium carbonate mainly less than 1/4 inch in diameter; few gray worm casts; slightly effervescent; moderately alkaline.
Bkss2--46 to 54 inches; gray (10YR 5/1) clay, light gray (10YR 6/1) dry; moderate coarse angular blocky structure parting to weak fine and medium angular blocky; very hard, very firm; few fine roots; few fine and medium pores; common medium faint grayish brown (10YR 5/2) redox depletions; common pressure faces and prominent slickensides; few fine iron-manganese concretions; about 2 percent concretions of calcium carbonate 1/8 to 1/4 inch in diameter; few dark gray worm casts; slightly effervescent; moderately alkaline. (combined thickness of the Bkss horizons is 10 to 24 inches)
BCkss--54 to 80 inches; light gray (10YR 7/2) clay, white (10YR 8/2) dry; weak medium and coarse angular blocky structure; very hard, very firm; few fine roots; few fine pores; common fine and medium distinct yellow (10YR 7/6) redox concentrations; common pressure faces and prominent slickensides; few fine iron-manganese concretions; about 2 percent concretions of calcium carbonate 1/8 to 1/4 inches in diameter; few dark gray worm casts; slightly effervescent; moderately alkaline.
TYPE LOCATION: Jackson County, Texas; From the intersection of Farm Road 234 and Farm Road 616 in Vanderbilt, 1.1 miles southwest on Farm Road 616, 0.2 of a mile south on paved private road, 200 feet west of road in rangeland in a micro-depression. (Longitude: 97W, 37, 59; Latitude: 28N, 48, 44)
RANGE IN CHARACTERISTICS: The solum thickness is 60 to more than 80 inches. The control section has 45 to 60 percent clay and more than 28 percent silt. Iron-manganese concretions, mainly less than 1/4 inch in diameter, range from none to few throughout, but commonly are in the lower part. This is a cyclic soil and undisturbed areas have gilgai microrelief with microknolls 6 to about 12 inches higher than microdepressions. Distance from the center of the microknoll to the center of the microdepression ranges from about 4 to 16 feet. The microknoll makes up about 20 percent, the intermediate, or area between the knoll and depression about 50 percent, and the microdepression about 30 percent. The amplitude of waviness between mollic colored materials in the upper part of the solum and the higher value colors in the lower part ranges from about 12 to 60 inches. The chimneys of high value materials on microknolls make up 2 to 5 percent of the surface area. They are mainly 2 to 8 feet long and 1/2 to 2 feet wide. When dry, the soil has cracks 1/2 to 2 inches wide at the surface and commonly 1/2 inch wide cracks extend to a depth of 4 feet during the summer. The cracks remain open for less than 90 cumulative days in most years. Slickensides begin at a depth of 12 to 24 inches and extend throughout the solum. The angle of the slickensides ranges from about 10 to 65 degrees from horizontal and tend to be more vertical in microknolls than in microdepressions. Some pedons have an overwash of calcareous clay or silty clay 8 to 20 inches thick.
The A horizon has hue of 10YR, 2.5Y or 5Y, value of 2 or 3, and chroma of 1 or less. Redox concentrations in shades of yellow or brown range from none to common and, where present, typically make up less than 5 percent. Texture is mainly clay but silty clay is allowed for moderately alkaline overwash phases. Reaction ranges from slightly acid to slightly alkaline.
The Bss horizon has hue of 10YR, 2.5Y or 5Y, value of 2 or 3, and chroma of 1 or less. Redox concentrations in shades of yellow or brown range from none to common. Hard pitted concretions of calcium carbonate range from none to few. Reaction ranges from slightly acid to slightly alkaline.
The Bkss horizon has hue of 10YR, 2.5Y, or 5Y, value of 4 to 6, and chroma of 1 or 2. Redox concentrations in shades of yellow or brown, or redox depletions in shade of gray range from few to common in some part. Spots of very dark gray or black soil materials from horizons above range from none to few. Concretions, threads, and masses of calcium carbonate range from 2 to 10 percent. Matrix effervescence ranges from very slight to strong.
The BCkss horizon, or 2BC horizon where present, have hue of 10YR, 2.5Y, or 5Y, value of 4 to 7, and chroma of 2 to 6. Redox concentrations in shades of yellow or brown, or redox depletions in shades of gray range from few to many. Concretions, threads, and masses of calcium carbonate range from 2 to 10 percent. Matrix effervescence ranges from very slight to strong.
A 2C horizon is present in some pedons. It has colors in shades of red, brown, or gray. The texture ranges from loam to clay. Effervescence ranges from very slight to violent.
COMPETING SERIES: These are the Francitas (TX), Ganado (TX), and Lake Charles (TX) series. Similar soils are the Bacliff, Pledger, and Victoria series. Francitas soils are saline. Ganado soils have mollic colors to a depth greater than 40 inches throughout the pedon. Lake Charles soils have less amplitude of waviness, and are moist in the moisture control section for slightly longer periods. Bacliff soils have colors with value greater than 3 throughout. Pledger soils have a very-fine particle-size control section. Victoria soils are typically calcareous and have cracks that remain open more than 90 days in most years.
GEOGRAPHIC SETTING: Laewest soils are on broad, nearly level areas or narrow moderately sloping areas along side slopes of drainageways. Slopes are plane and gradients are dominantly less than 1 percent but range to 8 percent on side slopes. They formed in clayey flood basin deposits on alluvial plains or deltas of the Beaumont Formation of Pleistocene Age. Mean annual precipitation ranges from 36 to 44 inches. The mean annual temperature ranges from 70 to 72 degrees F. Frost free days range from 280 to 300, and the elevation ranges from 10 to 100 feet above sea level. Thornthwaite annual P-E indices range from 46 to 60.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Bacliff and Francitas series and the Dacosta, Edna, and Faddin soils. Bacliff and Francitas soils are on lower slightly wetter positions. Dacosta soils are on slightly lower or similar positions. Edna and Faddin soils are on similar positions. Dacosta, Edna, and Faddin soils have loamy surface layers and argillic horizons.
DRAINAGE AND PERMEABILITY: Laewest soils are moderately well drained. The permeability is very slow. Water enters the soil rapidly when it is dry and cracked, but very slowly when the soil is wet and the cracks are sealed. Runoff is low on 0 to 1 percent slopes, medium on 1 to 3 percent slopes, high on 3 to 5 percent slopes and very high on 5 to 8 percent slopes.
USE AND VEGETATION: The soil is used mainly for rangeland and cropland. The most common crops grown are grain sorghum, corn, rice, and cotton. Turf grasses are also grown. Climax rangeland vegetation consists mainly of little bluestem, indiangrass, eastern gamagrass, switchgrass, big bluestem, and paspalums. Trees include liveoak, elm, hackberry, huisache, and mesquite along fence rows, drainageways and in scattered motts.
DISTRIBUTION AND EXTENT: The Gulf Coast Prairies (MLRA 150A) of Texas west of the Colorado River to about the central part of Refugio County. The series is extensive with about 370,000 acres.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jackson County, Texas; 1991.
REMARKS: These soils were previously included with the Lake Charles series. The name Laewest is coined.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 37 inches. (A1, A2, Bss1, Bss2 and horizons)
Cambic horizon: 18 to 80 inches. (Bss1, Bss2, Bkss1, Bkss2, and BCkss horizons)
Vertisol feature: deep wide cracks that open and close one or more times a year and remain open for less than 90 cumulative days in most years.
ADDITIONAL DATA: TAMU data S82TX-481-002, S82TX-481-001. NSSL data S89TX469-008,009,010,011,012,013,014 (Texas Vertisol Study)
Soil Interpretation Record Number: TX1216.