LOCATION ALTITA TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Vertic Argigypsids
TYPICAL PEDON: Altita sandy clay loam--rangeland. (Colors are for dry soils unless otherwise stated.)
A--0 to 18 inches; grayish brown (10YR 5/2) sandy clay loam, dark grayish brown (10YR 4/2) moist; moderate fine and medium subangular blocky structure; very hard, firm, sticky and plastic; few very fine and fine roots; few fine tubular pores; 7 percent calcium carbonate equivalent; electrical conductivity is 0.6 dS/m; strongly effervescent; moderately alkaline; gradual smooth boundary. (10 to 22 inches thick)
Btk--18 to 28 inches; light brownish gray (10YR 6/2) clay loam, grayish brown (10YR 5/2) moist; moderate fine and medium angular blocky structure; very hard, firm, sticky and plastic; few very fine roots: few fine tubular pores; common faint clay films on surfaces of peds; few fine irregular threads of calcium carbonate; 9 percent calcium carbonate equivalent; electrical conductivity is 1.3 dS/m; violently effervescent; moderately alkaline; gradual wavy boundary. (8 to 14 inches thick)
Btyz--28 to 38 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; weak fine and medium subangular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots; few faint clay films on surfaces of peds; common fine and medium irregular masses and crystals of gypsum and other salts; about 7 percent calcium carbonate equivalent; electrical conductivity is 4.0 dS/m; violently effervescent; moderately alkaline; gradual wavy boundary. (8 to 14 inches thick)
Byz1--38 to 50 inches; very pale brown (10YR 7/3) clay loam, pale brown (10YR 6/3) moist; few fine distinct grayish brown vertical streaks in upper part; weak fine and medium subangular blocky structure; hard, firm, sticky and plastic; 20 percent white (5Y 8/2) soft shale fragments that slake in water; few fine and medium rounded yellow (10YR 7/6) weakly cemented nodules; 30 percent fine to coarse irregular masses and crystals of gypsum and other salts; 5 percent calcium carbonate equivalent; electrical conductivity is 6.8 dS/m; strongly effervescent; moderately alkaline; gradual wavy boundary. (0 to 20 inches thick)
Byz2-- 50 to 64 inches; very pale brown (10YR 8/4) clay loam, light yellowish brown (10YR 6/4) moist; weak fine and medium subangular blocky structure; hard, firm, sticky and plastic; 20 percent white (5Y 8/2) soft shale fragments that slake in water; few fine and medium rounded yellow (10YR 7/6) weakly cemented nodules; 30 percent fine to coarse irregular masses and clusters of crystals of gypsum and other salts; 3 percent calcium carbonate equivalent; electrical conductivity is 8.3 dS/m; slightly effervescent; moderately alkaline.
TYPE LOCATION: La Salle County, Texas; from Cotulla, 5.8 miles east on Texas Highway 97, 1.6 miles southeast on small ranch road, 170 feet northeast in rangeland.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 36 to more than 60 inches. Electrical conductivity ranges from 0.2 to 2.0 dS/m in the A horizon; 1.0 to 4.0 in the upper Bt horizon; and 4.0 to 12.0 in the lower Bt and C horizons. linear extensibility exceed 6 cm. in the majority of pedons. COLE of the control section ranges from 0.07 to 0.09. Reaction is slightly alkaline or moderately alkaline throughout.
The A horizon has hue of 10YR, value of 5 or 6, and chroma of 2 or 3. The A horizon is loam, sandy clay loam, or clay loam. In pedons where the moist value is less than 3.5 the horizon is less than 7 inches thick. In some pedons, the upper 2 to 8 inches is noncalcareous.
The Btk and Btyz horizons have hue of 10YR, value of 6, and chroma of 3 or 4. Texture is clay loam or clay with few to common masses and clusters of salts.
The Byz horizon has hue of 10YR, value of 6 to 8 and chroma of 3 or 4. Texture is clay loam or clay with few to many soft shale fragments and common or many masses and clusters of salts. Soft shale fragments that slake in water comprise 0 to 30 percent by volume in the upper 6 inches and increase with depth. The C horizon where present is similar to the Byz but has higher color values.
COMPETING SERIES: This is the only series in the family. Similar soils are the Aguilares, Denhawken, Garceno, Orla, Pryor, Reeves, and Tonio series. Aguilares, Orla, Reeves, and Tonio soils are in the fine-loamy family. In addition, Aguilares and Tonio soils do not have argillic or gypsic horizons, and Orla and Reeves soils have gypsic mineralogy. Denhawken soils are moist in the control section for longer periods. Garceno soils do not have argillic or gypsic horizons, and do not have vertic properties. Pryor soils have a paralithic contact between 40 and 60 inches.
GEOGRAPHIC SETTING: Altita soils are on nearly level to gently sloping upland plains. These soils occupy the microhighs in complex soil areas. Slopes range from 0 to 2 percent but are mostly less than 0.5 percent. The soil formed in calcareous loamy alluvium over residuum. Mean annual precipitation ranges from 20 to 25 inches, and mean annual air temperature ranges from 70 to 73 degrees F. Frost free days range from 275 to 300 days, and elevation ranges from 400 to 600 feet. Thornthwaite annual P-E index ranges from 25 to 34.
GEOGRAPHICALLY ASSOCIATED SOILS: These include Amphion, Caid, Chacon, Charco, Cotulla, Maverick, and Moglia soils. Amphion, Caid, Divot soils have mollic epipedons. Amphion, Chacon and Divot soils are on lower elevations in the landscape. Caid soils are on landscapes similar to areas of Altita soils. Charco soils have mollic epipedons. Cotulla soils are at lower elevations. Maverick soils are more clayey throughout with C horizons dominated by clay shale. Maverick soils occur at higher elevations.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately slow. Runoff is negligible on slopes less than 1 percent, and very low on 1 to 3 percent.
USE AND VEGETATION: Mainly used as native rangeland and wildlife habitat. The grasses are mainly red grama, curlymesquite, pink pappusgrass, threeawn, bristlegrass, Hall panicum, and lovegrass tridens. Woody plants include mesquite, guayacan, blackbrush, whitebrush, pricklypear, tasajillo, allthorn, lotebush, condalia, and leatherstem.
DISTRIBUTION AND EXTENT: In Northern and Western Rio Grande Plain of Texas. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: La Salle County, Texas; 1988.
REMARKS: Classification change from Ustertic Haplargids to Vertic Argigypsids based on application of the 6th edition of SOIL TAXONOMY.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 18 inches. (A horizon)
Gypsic horizon - 28 to 64 inches. (Btyz, Byz1, and Byz2 horizons)
Argillic horizon - 18 to 38 inches. (Btk and Btyz horizons)
Vertic feature - Linear extensibility of 6 cm or more between the soil surface and 40 inches.
Soil Interpretation Record: TX1043