LOCATION RYDOLPH                 TX

Established Series
SDC-WLM-KBH
09/2015

RYDOLPH SERIES

The Rydolph series consists of deep, somewhat poorly drained soils that formed in clayey and loamy alluvium of Holocene age. These nearly level soils are on flood plains of major streams in the Coast Prairie. Slopes range from 0 to 1 percent. Mean annual precipitation is about 864 mm (34 in) and the mean annual air temperature is about 22 degrees C (72 degrees F).

TAXONOMIC CLASS: Fine-silty, mixed, active, calcareous, hyperthermic Aeric Fluvaquents

TYPICAL PEDON: Rydolph silty clay- on northeast-facing, concave, 0.1 percent slope in rangeland at an elevation of 7.6 m (25 ft) (Colors are for moist soil unless otherwise stated.)

A--0 to 23 cm (0 to 9 in); dark grayish brown (10YR 4/2) silty clay, light brownish gray (10YR 6/2) dry; moderate medium and fine subangular blocky structure; very hard, very firm, sticky and plastic; many fine and medium roots in upper part, and common fine and very fine roots in lower part; few fine pores; few shell fragments less than 10 mm across; slightly effervescent; moderately alkaline; gradual smooth boundary. (15 to 30 cm [6 to 12 in] thick)

C1--23 to 81 cm (9 to 32 in); grayish brown (10YR 5/2) loam, light gray (10YR 7/2) dry; massive; hard, friable, slightly sticky and slightly plastic; many discontinuous strata 2 to 5 mm thick of grayish very fine sand and silt; common fine and very fine roots; few shell fragments less than 10 mm across; common fine distinct yellowish brown (10YR 5/6) masses of oxidized iron; slightly effervescent; moderately alkaline; clear smooth boundary. (25 to 76 cm [10 to 30 in] thick)

C2--81 to 122 cm (32 to 48 in); grayish brown (10YR 5/2) silty clay loam, light gray (10YR 7/2) dry; massive; very hard, firm, sticky and plastic; few discontinuous strata 2 to 10 mm thick of brownish very fine sand and silt; common fine and very fine roots; few shell fragments less than 10 mm across; slightly effervescent; moderately alkaline; clear smooth boundary. (0 to 51 cm [0 to 20 in] thick)

C3--122 to 150 cm (48 to 59 in); brown (10YR 5/3) silt loam, very pale brown (10YR 7/3) dry; massive; hard, friable, slightly sticky and slightly plastic; few discontinuous strata 2 to 10 mm thick of grayish very fine sand and silt; few fine roots; few fine pores; few shell fragments less than 10 mm across; common fine distinct yellowish brown (10YR 5/6) and few fine prominent dark reddish brown masses of oxidized iron; slightly effervescent; moderately alkaline; clear smooth boundary. (15 to 46 cm [6 to 18 in] thick)

C4--150 to 180 cm (59 to 71 in); grayish brown (10YR 5/2) silty clay loam, light gray (10YR 7/2) dry; massive; very hard, firm, sticky and plastic; few discontinuous strata 2 to 10 mm thick of grayish silty clay loam; few fine roots; common medium pores; common shell fragments less than 10 mm across; many fine distinct yellowish brown (10YR 5/6) masses of oxidized iron; slightly effervescent; moderately alkaline; clear smooth boundary. (20 to 51 cm [8 to 20 in] thick)

C5--180 to 203 cm (71 to 80 in); gray (10YR 5/1) loam, light gray (10YR 7/1) dry; massive; hard, friable, slightly sticky and plastic; few fine pores; few shell fragments less than 10 mm across; slightly effervescent; moderately alkaline.

TYPE LOCATION: Victoria County, Texas; from the intersection of Loop 175 and U. S. Highway 77 southwest of Victoria, 11.3 miles south on U. S. Highway 77 to Farm Road 445, 2.5 miles east on Farm Road 445, 1.2 miles south, 1.3 miles east and 50 ft north in rangeland. Bloomington SW USGS quad; Latitude is 28 degrees 31 minutes 31.25 seconds N; 96 degrees 58 minutes 57.7 seconds W; NAD 83

RANGE IN CHARACTERISTICS: This alluvial soil has clayey and loamy sediments more than 80 in thick. The reaction is moderately alkaline and most pedons are slightly effervescent throughout. Few to many shell fragments throughout.

Soil Moisture: An aquic soil moisture regime.

Mean annual soil temperature: 71 to 73 degrees C. (21.7 to 22.8 degrees F).

Particle-size control section (weighted average)
Clay content: 23 to 45 percent
Silicate clay content: 23 to 45 percent
Calcium carbonate equivalent: 20 to 35 percent
Sands larger than very fine sand: less than 15 percent
Strata: amount-few or common; texture-silt loam, silt, very fine sand

A Horizon:
Hue: 10YR
Value: 4 to 6
Chroma: 1 to 3
Texture: silty clay or clay
Clay content: 40 to 50 percent
Redox concentrations: amount-0 to 2 percent, shades-brown or yellow
Redox depletions: amount-0 to 2 percent, shades-gray

C Horizon:
(60 or more of upper C horizons)
Hue: 10YR
Value: 4 or 5
Chroma: 2
Texture: silty clay loam, silt loam, or loam
Clay content: 20 to 40 percent
Redox concentrations: amount-1 to 20 percent, shades-brown or yellow
Redox depletions: amount-1 to 10 percent, shades-gray

C Horizon:
(Lower C horizons)
Value: 4 to 7
Chroma: 1 to 3
Texture: silty clay loam, silt loam, or loam
Clay content: 20 to 40 percent
Redox concentrations: amount-0 to 20 percent, shades-brown or yellow
Redox depletions: amount-0 to 10 percent, shades-gray

COMPETING SERIES: There are no competing series in the same family. Similar series are the Camargo (TX), Commerce (LA), Meguin (TX), Retrop (OK), and Sonoma (NV) series.
Camargo soils: do not have masses of oxidized iron; in a drier climate. Commerce soils: non-acid; in a thermic temperature regime.
Meguin soils: a mollic epipedon; do not have masses of oxidized iron in the control section.
Retrop soils: do not have chroma of 2 or less; in a thermic temperature regime. Sonoma soils: in a mesic temperature regime; and semiarid climate.

GEOGRAPHIC SETTING:
Parent material: clayey and loamy alluvium of recent geologic age
Landscape: flat coastal plains
Landform: flood plain
Slope: 0 to 1 percent
Mean annual air temperature range: 21.7 to 22.8 degrees C (71 to 73 degrees F)
Mean annual precipitation range: 940 to 1041 mm (37 to 41 in)
Precipitation Pattern: Precipitation falls uniformly throughout the year.
Frost-free period: 270 to 300 days
Elevation: 5.3 to 22.9 m (18 to 75 feet)
Thornthwaite annual P-E indices: 46 to 64

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aransas (TX), Austwell (TX), and Trinity (TX) series.

Aransas and Austwell soils: in a fine particle-size family; are saline; on elevations below 5 M (17 ft)
Trinity soils: in a very-fine particle-size family; vertic properties; on a slightly lower position on a similar landform

DRAINAGE AND PERMEABILITY: Somewhat poorly drained; medium runoff; slow permeability. Rydolph soils are saturated or wet for significant periods during the winter and spring months.

USE AND VEGETATION: Used mainly for rangeland. Some occasionally flooded areas are used for growing grain sorghum. Native vegetation is pecan and elm trees with an understory of grasses such as Virginia wildrye, big bluestem, little bluestem, switchgrass, and indiangrass.

DISTRIBUTION AND EXTENT: The soil is mainly along the San Antonio and Guadalupe River in south Texas. The soils are of minor extent.

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

SERIES ESTABLISHED: Victoria County, Texas; l980.

REMARKS: This soil was formerly mapped in the Loire or Meguin series.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon-0 to 23 cm (0 to 9 in) (A horizon)

Aquic conditions-23 to 203 cm (C horizons)

ADDITIONAL DATA: Data from NSSL, sample 79P 188-193.

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

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National Cooperative Soil Survey
U.S.A.