LOCATION ZUNKER TX

Established Series
RM-MLG-JAG
07/2017

ZUNKER SERIES

The Zunker series consists of very deep, well drained, moderately rapid permeable soils that formed in calcareous loamy alluvial deposits. These nearly level soils are on flood plains. Slope ranges from 0 to 1 percent. Mean annual precipitation is about 711 to 813 mm (28 to 32 in) and the mean annual air temperature is about 21 to 23 degrees C (70 to 74 degrees F).

TAXONOMIC CLASS: Coarse-loamy, siliceous, superactive, hyperthermic Fluventic Haplustepts

TYPICAL PEDON: Zunker fine sandy loam occasionally flooded, on a west-facing, 0.5 percent slope in pastureland at an elevation of 72 m (235 ft) (Colors are for dry soil unless otherwise stated.)

Ap--0 to 20 cm (0 to 8 in); grayish brown (10YR 5/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable; common fine roots; few snail shell fragments; about 20 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline; abrupt smooth boundary. [10 to 31 cm (4 to 12 in) thick]

A--20 to 46 cm (8 to 18 in); grayish brown (10YR 5/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable; common fine roots; few snail shell fragments; 25 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline; clear wavy boundary. [10 to 46 cm (4 to 18 in) thick]

Bw1--46 to 104 cm (18 to 41 in); pale brown (10YR 6/3) fine sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable; few fine roots; few snail shell fragments; few strata of loamy fine sand .63 to 8 cm (1/4 to 3 in) thick in upper part; 30 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline; clear wavy boundary. [25 to 94 cm (10 to 37 in) thick]

Bw2--104 to 152 cm (41 to 60 in); very pale brown (10YR 7/3) loamy fine sand, very pale brown (10YR 7/3) moist; weak fine granular structure; loose, very friable; very few fine roots; few snail shell fragments; 20 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline; clear wavy boundary. [20 to 97 cm (8 to 38 in)]

Ab--152 to 203 cm (60 to 80 in); grayish brown (10YR 5/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; slightly hard, friable; very few fine roots in upper part; few snail shell fragments; few thin films and fine threads of calcium carbonate on ped surfaces; 20 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline.

TYPE LOCATION: Karnes County, Texas; from the intersection of Texas Highway 72 and Farm Road 792 in Kenedy, 1.1 mile north on Farm Road 792 to county road; 5 miles east on county road; 23 meters (75 ft) south in pastureland. The latitude is 28 degrees 53 minutes 18 seconds north and the longitude is 97 degrees 47 minutes 08 seconds west; NAD83.

RANGE IN CHARACTERISTICS:

Soil Moisture: An ustic soil moisture regime. The soil moisture control section is dry in some or all parts for more than 90 but less than 180 days in normal years. July through September and January through March are the driest months, while April through June and October through November are the wettest.

Mean annual soil temperature: 22 to 26 degrees C (72 to 78 degrees F).
Depth to secondary calcium carbonate: 0 to 152 cm (0 to 60 in)
Depth to cambic horizon: 10 to 51 cm (4 to 20 in)
Particle-size control section (weighted average)
Clay content: 7 to 18 percent

A Horizon
Hue: 10YR
Value: 4 or 5
Chroma: 2 to 4
Texture: fine sandy loam or loamy fine sand
Clay content: 3 to 20 percent
Effervescence: slight or strong

Bw Horizon
Hue: 10YR
Value: 4 to 7
Chroma: 2 to 4
Texture: fine sandy loam or loamy fine sand, or fine sand that are from 0.6 to 8 cm (1/4 to 3 in) thick and range from a few to many in most pedons.
Iron
Redox concentrations: amount-0 to 2, shades-brown
Coarse fragments: none to few snail shell fragments
Effervescence: slight to violent

Ab Horizon
Hue: 10YR
Value: 3 to 5
Chroma: 1 to 4
Texture: loamy fine sand, fine sandy loam loam or clay loam (Loam or clay loam layers are below the control section.)
Coarse fragments: none to few snail shell fragments
Redox concentrations: amount-0 to 2, shades-brown
Identifiable secondary carbonate: none to few films and threads of calcium carbonate
Effervescence: slight to violent

COMPETING SERIES: There are no competing series in this same family. Similar soils are the Boerne, Conalb, Lagloria, Santo, Yahola and Zavala series.
Boerne and Conalb soils: have carbonatic mineralogy. In addition, Boerne soils have a thermic soil temperature regime.
Lagloria soils: have less than 18 percent coarser than very fine sand.
Zavala soils: are noncalcareous throughout.
Santo and Yahola soils: do not have a cambic horizon. In addition, Santo and Yahola soils have a thermic soil temperature regime.

GEOGRAPHIC SETTING:
Parent material: loamy calcareous sediments derived from recent alluvium
Landform: floodplain
Slope: 0 to 1 percent
Mean annual air temperature range: 21 to 23 degrees C (70 to 74 degrees F).
Mean annual precipitation range: 711 to 813 mm (28 to 32 in)
Precipitation Pattern: Precipitation falls mostly during the months of April through June and October through November. July through September and January through March are the driest months.
Frost-free period: 275 to 290 days
Elevation: 61 to 152 m (200 to 500 ft)
Thornthwaite annual P-E indices: 31 to 44

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Buchel, Odem, and Sinton soils.
The Buchel soils: are clayey throughout.
Odem soils: are noncalcareous, have dark surface layers.
Sinton soils: have dark surface layers.
All of these soils: are on slightly lower flood plain positions.

DRAINAGE AND PERMEABILITY:
Drainage class: well.
Permeability class: moderately rapid.
Runoff: negligible.

USE AND VEGETATION: Most areas of Zunker soils are farmed to grain sorghum, wheat, or corn. Native vegetation is dominantly bluestems, fourflower trichloris, vine mesquite, big sandbur, switchgrass, Texas wintergrass, and hackberry trees. The Ecological Site is Loamy Bottomland (083AY573TX).

DISTRIBUTION AND EXTENT: In the eastern part of the Northern Rio Grande Plain Major Land Resource Area. It is along the San Antonio River and its major tributaries. The series is of minor extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Karnes County, Texas, 1991.

REMARKS: Classification change from Fluventic Ustochrepts to Fluventic Haplustepts based on application of the 2nd edition of Soil Taxonomy, 1999.

Diagnostic horizons and features recognized in this pedon are:

Particle size control section: 25 to 102 cm (10 to 40 in). (A and Bw horizons)

Ochric epipedon: 0 to 46 cm (0 to 18 in). (A horizons)

Cambic horizon: 46 to 152 cm (18 to 60 in). (Bw horizons)

Buried horizon: 152 to 203 cm (60 to 80 in). (Ab horizon)

Fluventic feature: Few thin stratification below 46 cm (18 in). -irregular distribution of organic matter.

ADDITIONAL DATA: Laboratory data exists from the series type location by the MLRA 150 Soil Survey Office.

TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006

National Cooperative Soil Survey
U.S.A.