LOCATION NAVIDAD TXEstablished Series
TAXONOMIC CLASS: Coarse-loamy, siliceous, superactive, hyperthermic Cumulic Haplustolls
TYPICAL PEDON: Navidad fine sandy loam--on a nearly level flood plain in pasture. (Colors are for moist soil unless otherwise stated.)
A1--0 to 10 inches; very dark grayish brown (10YR 3/2) fine sandy loam, dark grayish brown (10YR 4/2) dry; moderate fine subangular blocky structure parting to weak fine granular; slightly hard, friable; many very fine and fine roots; slightly effervescent; moderately alkaline; clear wavy boundary. (7 to 14 inches thick)
A2--10 to 33 inches; very dark grayish brown (10YR 3/2) fine sandy loam, dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure; slightly hard, friable; common fine roots; strongly effervescent; moderately alkaline; clear wavy boundary. (13 to 25 inches thick)
C1--33 to 43 inches; dark grayish brown (10YR 4/2) loamy fine sand, grayish brown (10YR 5/2) dry; single grained; loose, very friable; few fine roots; strongly effervescent; moderately alkaline; gradual wavy boundary. (10 to 22 inches thick)
C2--43 to 59 inches; brown (10YR 5/3) fine sand, pale brown (10YR 6/3) dry; single grained; loose, very friable; few fine roots; strongly effervescent; moderately alkaline; abrupt wavy boundary. (20 to 30 inches thick)
C3--59 to 70 inches; dark grayish brown (10YR 4/2) sandy clay loam, grayish brown (10YR 5/2) dry; massive; slightly hard, friable; few fine roots; few fine prominent strong brown (7.5YR 5/6) masses of iron accumulation; strongly effervescent; moderately alkaline; gradual wavy boundary. (8 to 15 inches thick)
C4--70 to 80 inches; dark brown (10YR 4/3) sandy clay loam, brown (10YR 5/3) dry; massive; slightly hard, friable; few fine roots; strongly effervescent; moderately alkaline.
TYPE LOCATION: Jackson County, Texas; from the intersection of U. S. Highway 59 and Farm Road 822 in Edna, 9.6 miles northwest on Farm Road 822 to Robinson Ranch Road, 0.7 miles southwest and 1.9 miles northwest on Robinson Ranch Road, 0.1 mile northeast on a private gravel road, and 60 feet southeast in pasture.
RANGE IN CHARACTERISTICS: This alluvial soil has loamy and sandy sediments more than 80 inches thick. The thickness of the A horizon ranges from 20 to 47 inches. Texture of the control section is fine sandy loam, loamy fine sand, or loam, with weighted average clay content less than 18 percent, and more than 15 percent fine sand. Thin strata and lenses of loam, sandy clay loam or clay loam occur in some pedons. Reaction ranges from neutral to moderately alkaline and most pedons are calcareous throughout.
The A horizon has hue of 10YR, value of 3 and chroma of 1 to 3. Texture is fine sandy loam, sandy clay loam or loam.
The C horizon has hue of 10YR, value of 4 to 7 and chroma of 2 to 4. Yellowish and brownish masses of iron accumulation range from none to a few. Texture ranges from fine sand to sandy clay loam. Thin strata of sandy, loamy or clayey materials range from none to a few.
COMPETING SERIES: There are no competing series. Similar soils are the Asa, Bergstrom, Gowen and Sinton series. Asa and Bergstrom are in the fine-silty family and, in addition, Asa soils receive more precipitation in most years. Gowen and Sinton soils are in the fine-loamy family.
GEOGRAPHIC SETTING: Navidad soils are on nearly level flood plains. Slope gradient is 0 to 2 percent. The soils formed in loamy and sandy alluvium of recent geologic age. The mean annual temperature ranges from 70 to 72 degrees F., and mean annual precipitation ranges from 38 to 44 inches. Frost free days range from 260 to 290 days and elevation ranges from 50 to 550 feet. Thornthwaite annual P-E indices range from 52 to 62.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Meguin, Sinton and Navaca series. Meguin and Sinton soils have more than 18 percent clay in the control section. Navaca soils have more than 35 percent clay in the upper part of the control section. These soils are in slightly lower floodplain positions.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately rapid. Runoff is negligible.
USE AND VEGETATION: Used mainly for pasture and rangeland. Native vegetation includes pecan and elm trees with an understory of grasses such as big bluestem, little bluestem, switchgrass, indiangrass, Texas wintergrass, and wildrye.
DISTRIBUTION AND EXTENT: The soil is mainly along streams in coastal areas of south Texas. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jackson County, Texas; 1986.
REMARKS: Navidad soils were formerly included with the Gowen and Sinton series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 33 inches. (A1 and A2 horizons)
Cumulic feature - Mollic epipedon is thicker than 20 inches.