Zavco soil series
A representative soil profile of Zavco sandy clay loam, 1 to 5 percent slopes. At a depth of about 70 centimeters, calcium carbonate masses have accumulated so thick that it restricts air and water uptake by the plant roots. (Soil Survey of McMullen County, Texas; by Clark K. Harshbarger, Jon Wiedenfeld, and Gary Harris, Natural Resources Conservation Service)
The Zavco series consists of very deep, well drained soils that formed in calcareous loamy residuum from interbedded sandstone and siltstone of the Yegua Formation. These nearly level to gently sloping soils occur on summits, backslopes, and footslopes of interfluves. Slopes range from 0 to 5 percent. Mean annual temperature is about 22.2 degrees C (72 degrees F) and mean annual precipitation is about 610 mm (24 in).
TAXONOMIC CLASS: Fine, mixed, active, hyperthermic Aridic Argiustolls
Soil Moisture: A typic-ustic moisture regime. The soil moisture control section is dry in some or all parts for more than 90 days 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 23.9 degrees C (72 to 75 degrees F)
Depth to argillic: 18 to 55 cm (7 to 22 in)
Depth to secondary forms of calcium carbonate: 25 to 71 cm (10 to 28 in)
Particle size control section (weighted average): clay content: 38 to 55 percent
USE AND VEGETATION: The major use is wildlife habitat. A few acres are cultivated and the principal crops are grain sorghum, small grain, and introduced perennial grasses. Grasses which make up about 70 percent of the plant community under climax conditions are fourflower trichloris, twoflower trichloris, pinhole bluestem, plains bristlegrass, buffalograss, and pink pappusgrass. About 5 percent forbs such as bundleflower and orange zexmenia, and about 5 percent shrubs such as guajillo and guayacan also occur. With retrogression, plants such as pink pappusgrass and buffalograss increase initially. With continued retrogression, increasers and invaders such as curlymesquite, threeawn, Hall's panicum, red grama, mesquite, whitebrush, blackbrush, twisted acacia and Texas persimmon dominate the plant community. The ecological site is Clay Loam, PE 26-36 (R083CY446TX).
DISTRIBUTION AND EXTENT: Northern and Central Rio Grande Plain of Texas. LRR I; MLRA 83A, 83C. The series is of moderate extent.
For additional information about the survey area, visit:
www.nrcs.usda.gov/Internet/FSE_MANUSCRIPTS/texas/mcmullen...
For a detailed soil description, visit:
soilseries.sc.egov.usda.gov/OSD_Docs/Z/ZAVCO.html
For acreage and geographic distribution, visit:
casoilresource.lawr.ucdavis.edu/see/#zavco
Zavco soil series
A representative soil profile of Zavco sandy clay loam, 1 to 5 percent slopes. At a depth of about 70 centimeters, calcium carbonate masses have accumulated so thick that it restricts air and water uptake by the plant roots. (Soil Survey of McMullen County, Texas; by Clark K. Harshbarger, Jon Wiedenfeld, and Gary Harris, Natural Resources Conservation Service)
The Zavco series consists of very deep, well drained soils that formed in calcareous loamy residuum from interbedded sandstone and siltstone of the Yegua Formation. These nearly level to gently sloping soils occur on summits, backslopes, and footslopes of interfluves. Slopes range from 0 to 5 percent. Mean annual temperature is about 22.2 degrees C (72 degrees F) and mean annual precipitation is about 610 mm (24 in).
TAXONOMIC CLASS: Fine, mixed, active, hyperthermic Aridic Argiustolls
Soil Moisture: A typic-ustic moisture regime. The soil moisture control section is dry in some or all parts for more than 90 days 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 23.9 degrees C (72 to 75 degrees F)
Depth to argillic: 18 to 55 cm (7 to 22 in)
Depth to secondary forms of calcium carbonate: 25 to 71 cm (10 to 28 in)
Particle size control section (weighted average): clay content: 38 to 55 percent
USE AND VEGETATION: The major use is wildlife habitat. A few acres are cultivated and the principal crops are grain sorghum, small grain, and introduced perennial grasses. Grasses which make up about 70 percent of the plant community under climax conditions are fourflower trichloris, twoflower trichloris, pinhole bluestem, plains bristlegrass, buffalograss, and pink pappusgrass. About 5 percent forbs such as bundleflower and orange zexmenia, and about 5 percent shrubs such as guajillo and guayacan also occur. With retrogression, plants such as pink pappusgrass and buffalograss increase initially. With continued retrogression, increasers and invaders such as curlymesquite, threeawn, Hall's panicum, red grama, mesquite, whitebrush, blackbrush, twisted acacia and Texas persimmon dominate the plant community. The ecological site is Clay Loam, PE 26-36 (R083CY446TX).
DISTRIBUTION AND EXTENT: Northern and Central Rio Grande Plain of Texas. LRR I; MLRA 83A, 83C. The series is of moderate extent.
For additional information about the survey area, visit:
www.nrcs.usda.gov/Internet/FSE_MANUSCRIPTS/texas/mcmullen...
For a detailed soil description, visit:
soilseries.sc.egov.usda.gov/OSD_Docs/Z/ZAVCO.html
For acreage and geographic distribution, visit:
casoilresource.lawr.ucdavis.edu/see/#zavco