LOCATION COST TXTentative Series
TAXONOMIC CLASS: Clayey over sandy or sandy-skeletal, smectitic, hyperthermic Typic Natraqualfs
TYPICAL PEDON: Cost loamy fine sand -- rangeland. (Colors are for dry soil unless otherwise stated).
A--O to 3 inches; white (10YR 8/2) loamy fine sand, light gray (10YR 7/2) moist; weak fine subangular blocky structure; hard, very friable; many very fine and fine roots; many fine pores; few salt crystals on surface; slightly saline; moderately alkaline; abrupt smooth boundary. (2 to 7 inches thick)
Btnzg1--3 to 9 inches; gray (10YR 5/1) clay loam, dark gray 10YR 4/1) moist; moderate coarse columnar structure parting to moderate medium and coarse angular blocky; very hard, firm; many very fine and fine roots; common fine and medium pores; few patchy clay films on vertical surfaces of columns; few very dark gray (10YR 3/1) organic coatings on surfaces of peds; common fine and medium distinct black (10YR 2/1) and common fine distinct very dark grayish brown (10YR 3/2) iron-manganese masses in ped interiors; strongly saline; strongly alkaline; clear smooth boundary. (3 to 8 inches thick)
Btnzg2--9 to 17 inches; light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) moist; weak coarse columnar structure parting to weak coarse angular blocky; hard, friable; many fine roots; common fine and medium pores; few patchy clay films on vertical surfaces of peds; common fine distinct dark yellowish brown (10YR 4/4) iron accumulations in ped interiors; strongly saline; strongly alkaline; clear smooth boundary. (4 to 28 inches thick)
Btnzg3--17 to 30 inches; light brownish gray (2.5Y 6/2) clay, grayish brown (2.5Y 5/2) moist; weak coarse angular blocky structure; hard, friable; common fine and medium pores; patchy clay films on vertical surfaces of peds; few fine iron-manganese concretions; common fine and medium
distinct brown (10YR 4/3) iron accumulations in ped interiors; few fine distinct gray (10YR 5/1) iron depletions in ped interiors; strongly saline; strongly alkaline; clear smooth boundary. (8 to 24 inches thick)
2Bnzg1--30 to 48 inches; light gray (10YR 7/2) fine sand, light brownish gray (10YR 6/2) moist; weak medium subangular blocky structure; hard, very friable; common fine and medium pores; common coarse distinct brown (10YR 4/3) iron accumulations on surfaces of peds; strongly saline; very strongly alkaline; abrupt smooth boundary. (6 to 18 inches thick)
2Bnzg2--48 to 60 inches; light brownish gray (10YR 6/2) loam, grayish brown (10YR 5/2) moist; weak medium subangular blocky structure; hard, friable; common very fine and fine pores; common coarse and few fine brown (10YR 4/3) iron-manganese accumulations on surfaces of peds and in pore linings along root channels; common fine and medium distinct yellowish brown (10YR 5/6) iron accumulations and black (10YR 2/1) manganese accumulations in ped interiors; common fine black (10YR 2/1) iron-manganese concretions between peds; strongly saline; strongly alkaline; abrupt wavy boundary. (0 to 20 inches thick)
3BCnzg--60 to 80 inches; greenish gray (5GY 6/1) fine sand, greenish gray (5GY 5/1) moist; single grain to very weak fine and medium granular and subangular blocky structure; slightly hard, very friable; common fine distinct grayish green (5G 4/2) iron depletions along surfaces of peds; few fine calcium carbonate concretions; strongly saline; strongly alkaline.
TYPE LOCATION: Gonzales County, Texas; from the intersection of U.S. Highway 87 and Farm Road 1116 about 4 miles southeast of Smiley; 6.6 miles north on Farm Road 1116; 0.2 miles west; 1000 feet north in rangeland. (Latitude: 29N, 19, 09; Longitude: 97W, 32, 38).
RANGE IN CHARACTERISTIC: Solum thickness ranges from 60 to 80 inches. Electrical conductivity ranges from 12 to 35 dS/m throughout the pedon. Exchangeable sodium percentage is more than 75 throughout the control section. Sodium Absorption Ratio is more than 100 throughout the pedon.
Strongly contrasting particle size classes occur within the control section of these soils. Weighted average clay content of the upper part of the particle size control section ranges from 35 to 50 percent. Weighted average clay content of the lower part ranges from 5 to 25 percent. Reaction ranges from moderately alkaline to very strongly alkaline. The soil has aquic conditions in most years within 20 inches of the soil surface.
The A horizon has hue of 10YR, value of 4 to 8, and chroma of 1 to 4. Clay content ranges from 4 to 15 percent. Texture is loamy fine sand or fine sandy loam. Iron and manganese accumulations range from none to few in shades of brown, red or yellow and iron depletions in shades of gray.
The Btnzg horizon has hue of 10YR or 2.5Y, value of 3 to 7, and chroma of 2 or less. Texture is clay loam or clay with clay content ranging from 35 to 45 percent. Iron accumulations in shades of brown, red, or yellow range from none to common. Iron depletions range from none to few and are in shades of gray. Iron-manganese in the form of stains and concretions range from none to common. Calcium carbonate concretions range from none to few. The horizon contains a few silica concretions.
The 2Bnzg horizon has hue of 10YR or 2.5Y, value of 5 to 7, and chroma of 2 or less. Texture ranges from fine sand in the upper part to loam in thick, stratified layers. Iron and manganese masses and accumulations in shades of brown, black, or yellow range from few to common. Few iron depletions are in shades of gray. Iron-manganese and silica concretions range from few to none.
The 3BCnzg horizon has hue of 5B, 5GY, 10YR, 2.5Y, or is neutral. This horizon has value of 5 to 7, and chroma of 2 or less. Texture is loamy sand, loamy fine sand, or fine sandy loam with thin lenses of clayey materials. Iron masses and accumulations in shades of brown or yellow and depletions in shades of gray range from few to common. Clayey seams or pockets range from none to common. Iron manganese and silica concretions range from none to common.
COMPETING SERIES: There are no competing series. Similar soils are the Brundage, Casa Grande, Crot, Dietrich, Gothard, Imogene, Orelia, Palobio, and Willamar series. Brundage and Casa Grande soils are dry in the moisture control section for longer periods. Crot and Gothard soils are in the thermic family. Dietrich and Willamar soils have clay content of more than 20 percent throughout the subsoil. Imogene soils have darker surfaces and less saturation with sodium in the upper 40 inches. Orelia soils have Bt horizons that have less than 15 percent saturation with sodium. Palobio soils have sola 60 to more than 80 inches and have less sodium saturation.
GEOGRAPHIC SETTING: Cost soils are on nearly level to very gently sloping low stream terraces. Slopes are dominantly plain or slightly concave and are mostly less than 1 percent but range to 2 percent. The soils formed in saline, stratified sandy and loamy sediments presumed to be alluvium of Pleistocene age. Mean annual precipitation ranges from 28 to 36 inches, and mean annual temperature ranges from 70 to 74 degrees F. Frost free days ranges from 260 to 300 and elevation ranges from 200 to 500 feet. Thornthwaite P-E indices range from 44 to 48.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Degola, Imogene and Meguin soils. Degola and Meguin soils have a mollic epipedon and are on similar landscape positions. Imogene soils have lower salinity levels and on slightly higher landscape positions.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Permeability is very slow. Runoff is negligible on slopes less than 1 percent, and very low on slopes of 1 to 2 percent. Flooding by stream overflow for brief duration may occur at intervals of 1 or more times a year.
USE AND VEGETATION: Most areas are used as rangeland. Native vegetation is salt flat grass, gulf cordgrass, salt lavender and alkali sacaton. Woody invaders are mesquite, bushy sea-oxeye, and cactus.
DISTRIBUTION AND EXTENT: In the Northern Rio Grande Plain of Texas (83A). The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES PROPOSED: Gonzales County, Texas, 1995. The name is derived from a small town in Gonzales County.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 3 inches (A horizon)
Natric Horizon - 3 to 30 inches (Btnzg horizons)
Redoximorphic features - From 3 to 80 inches
Aquic feature - Aquic conditions within 20 inches of the soil surface (reduced matrix {10YR 5/1 and 2.5Y 6/2, 7/2} from 9 to 80 inches, saturation, and reduction in most years; and redox concentrations within peds.
ADDITIONAL DATA: Particle size family and textures within horizons based on NSSL data (S93TX-177-005) using the following formula: Clay % = 2.5(% water retained at 1500 kPa tension - % organic carbon).
Soil Interpretation Record: TX1288