LOCATION HARGILL TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, hyperthermic Udic Paleustolls
TYPICAL PEDON: Hargill fine sandy loam--cultivated.
(Colors are for dry soil unless otherwise
stated.)
Ap--0 to 8 inches; brown (7.5YR 4/2) fine sandy loam, dark
brown (7.5YR 3/2) moist; massive; slightly hard, friable; few
fine roots; many fine pores; mildly alkaline; abrupt smooth
boundary. (5 to 9 inches thick)
A--8 to 18 inches; brown (7.5YR 4/2) fine sandy loam, dark
brown (7.5YR 3/2) moist; weak fine subangular blocky structure; slightly hard, friable; few fine roots; many fine pores; mildly alkaline; clear smooth boundary. (5 to 11 inches thick)
Bt1--18 to 25 inches; reddish brown (5YR 4/4) sandy clay
loam, dark reddish brown (5YR 3/4) moist; weak coarse prismatic structure parting to weak fine blocky; hard, friable; many fine
roots and pores; thin patchy clay films on faces of peds and in pores; mildly alkaline; gradual smooth boundary. (5 to 20 inches thick)
Bt2--25 to 47 inches; reddish brown (5YR 5/4) sandy clay
loam, reddish brown (5YR 4/4) moist; moderate medium prismatic structure parting to weak fine subangular blocky; hard, friable;
many fine pores; thin patchy clay films on faces of peds; mildly alkaline; gradual smooth boundary. (12 to 20 inches thick)
Bt3--47 to 63 inches; yellowish red (5YR 5/6) sandy clay
loam, yellowish red (5YR 4/6) moist; weak fine subangular blocky structure; hard, friable; thin patchy clay films; mildly
alkaline; gradual smooth boundary. (10 to 18 inches thick)
BC--63 to 71 inches; reddish yellow (7.5YR 7/6) sandy clay
loam, reddish yellow (7.5YR 6/6) moist; weak fine subangular
blocky structure; hard, friable; calcareous in lower part,
moderately alkaline; gradual smooth boundary. (6 to 12 inches
thick)
Ck--71 to 84 inches; reddish yellow (7.5YR 7/6) sandy clay
loam, reddish yellow (7.5YR 6/6) moist; massive; hard, friable;
few threads of calcium carbonate; calcareous, moderately
alkaline.
TYPE LOCATION: Hidalgo County, Texas; 5 miles north and 2.65
miles east of Edinburg, Texas; 2.65 miles east on Farm Road 2812
from its intersection with U.S. Highway 281, then 100 feet north
in cultivated field.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. Depth to calcareous soil ranges from 36 to more
than 60 inches. The mollic epipedon is 12 to 20 inches thick.
The A horizon is brown (7.5YR 5/2, 5/4, 4/2, 4/4; 10YR 5/3, 4/3), grayish brown (10YR 5/2), dark brown (10YR 3/3, 4/3; 7.5YR 4/2,
4/4), and dark grayish brown (10YR 4/2). It is loam or fine
sandy loam with clay content of 10 to 16 percent. It is neutral
or mildly alkaline.
The Bt horizon is reddish brown (5YR 5/3, 5/4, 4/4), yellowish
red (5YR 5/6), brown (7.5YR 5/2, 5/4), reddish yellow (7.5YR
6/5), dark brown (7.5YR 4/2, 4/4), or light brown (7.5YR 6/4).
Clay content ranges from 21 to 33 percent. It has weak or
moderate, fine to coarse prismatic and weak or moderate, fine or medium blocky or subangular blocky structure, and is neutral or mildly alkaline in the upper part and moderately alkaline in the lower part. The BC horizon is pinkish gray (5YR 7/2, 6/2; 7.5YR
7/2, 6/2), pink (5YR 7/3, 7/4; 7.5YR 7/4), or reddish yellow
(7.5YR 7/6). Fine to medium splotches and streaks of uncoated
sand grains range from none to common. When the matrix has
dominant chromas of 4 or less, there are common to many distinct reddish and yellowish mottles with chromas of 6 or 8. The
calcium carbonate equivalent in the BC and C horizons is 3 to 10 percent and remains relatively constant with depth.
The C horizon is pinkish gray (5YR 7/2, 6/2; 7.5YR 7/2, 6/2),
pink (5YR 7/3, 7/4; 7.5YR 7/4), or reddish yellow (7.5YR 7/6). Weakly cemented fragments of sandstone range from 0 to 15 percent
by volume below 60 inches.
COMPETING SERIES: There are no other known soils in the same
family. Similar soils are Brennan, Delfina, Cuero, Duval, and Willacy series. Brennan, Delfina, and Duval soils lack mollic epipedons. Cuero soils have mollic epipedons more than 20 inches thick. Delfina soils have mottles due to wetness in the upper Bt horizon. Duval and Willacy soils have sola less than 60 inches thick. In addition, Willacy soils have hues of 10YR throughout.
GEOGRAPHIC SETTING: Hargill soils are on coastal terraces and
deltas with slopes mostly less than 2 percent, but range up to
about 5 percent along local drainageways. The soil formed in
loamy sediments 10 feet or more thick. The climate is dry
subhumid. Average annual precipitation ranges from 26 to 34
inches and the mean annual temperature ranges from 72 to 74
degrees F. Thornthwaite annual P-E index ranges from 28 to 36.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing
Delfina and
Willacy series, and
Hidalgo series. Delfina soils
occur at similar elevations. Hidalgo soils are calcareous throughout. Hidalgo and Willacy soils occur at slightly lower elevations.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability. Under irrigation a seasonal water table
accumulates 5 to 8 feet below the surface in local areas.
USE AND VEGETATION: Mostly cultivated and mostly irrigated. Few areas in native rangeland. Used for wide variety of vegetables, citrus, cotton, grain sorghum, and flax. In rangeland grasses
are mostly fourflower trichloris, Arizona cottontop, tanglehead, lovegrass tridens, plains bristlegrass, hooded windmillgrass, and hairy grama. Other vegetation consists of mesquite, Texas ebony, spiny hackberry, blackbrush, catclaw, lotebush, and pricklypear cactus.
DISTRIBUTION AND EXTENT: Mainly within the Lower Rio Grande
Valley and Coastal Bend in southern Texas. Possibly in Mexico. Series is of moderate extent, about 25,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Hidalgo County, Texas; 1979.
REMARKS: Hargill series was included in the Duval and Brennan series.