LOCATION BROOME TXEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, thermic Calcidic Paleustalfs
TYPICAL PEDON: Broome silt loam--rangeland.
(Colors are for dry soil unless otherwise
stated.)
A1--0 to 7 inches; brown (7.5YR 5/4) silt loam, brown (7.5YR
4/4) moist; weak fine subangular blocky structure; hard, friable;
few threads and films of calcium carbonate; few fine and medium roots; few insect burrows; calcareous; moderately alkaline; clear wavy boundary. (6 to 12 inches thick)
Btk1--7 to 18 inches; brown (7.5YR 5/4) silty clay loam,
brown (7.5YR 4/4) moist; weak fine subangular blocky structure;
hard, friable; few fine roots; few insect burrows, thin patchy
clay films; few threads and films and few soft bodies of calcium carbonate; calcareous; moderately alkaline; gradual wavy
boundary. (7 to 17 inches thick)
Btk2--18 to 39 inches; light brown (7.5YR 6/4) silty clay
loam, brown (7.5YR 5/4) moist; weak fine subangular blocky
structure; hard, friable; thin patchy clay films; films about 30 percent by volume of soft bodies of calcium carbonate;
calcareous; moderately alkaline; gradual wavy boundary. (10 to
41 inches thick)
Btk3--39 to 84 inches; reddish yellow (5YR 6/6) silty clay
loam, yellowish red (5YR 5/6) moist; weak fine subangular blocky structure; hard, friable; thin patchy clay films; films about 10 percent by volume of soft bodies of calcium carbonate;
calcareous; moderately alkaline.
TYPE LOCATION: Sterling County, Texas; 1 mile west of the
Sterling County Courthouse on U.S. Highway 87, then 135 feet
south to type location in native pasture.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches.
The A horizon has hue of 5YR through 10YR, value of 5 or 6, and chroma of 2 through 4. When moist values and chromas are less
than 3.5, the horizon is less than 7 inches thick. It is silty
clay loam, silt loam, loam, or clay loam.
The Btk1 and Btk2 horizons have hue of 5YR or 7.5YR, value of 5 through 8, and chroma of 4 through 6. The Btk1 has hue of 10YR
in some pedons. The Bt horizon is silt loam, clay loam, silty
clay loam with the content of silicate clay estimated to range
from 18 to 35 percent and it contains 1 to 10 percent sand
coarser than very fine sand. Carbonate clays range from 3 to 15 percent. The Btk1 horizon contains about 5 to 30 percent
carbonates and the carbonates increase to about 25 to 50 percent
in the Btk2 horizon. The calcic horizon begins near the top of
the Bt horizon with the maximum visible calcium carbonate begins
at depths of 13 to 24 inches, with visible calcium carbonate
occuring as concretions, soft bodies and films and threads.
The Btk3 horizon has hue of 5YR or 7.5YR, value of 5 through 7,
and chroma of 6 through 8. Carbonates are concentrated on
vertical faces of peds and range from 5 to 30 percent.
COMPETING SERIES: There are no other series in this family.
Series in closely related families are
Angelo,
Mansker,
Midessa,
Posey,
Reagan,
Tulia, and
Veal series. Angelo and Mansker soils
have mollic epipedons. Midessa, Reagan, and Veal soils lack Bt horizons. Posey and Tulia soils contain more than 15 percent
sand coarser than very fine sand in the control section, in
addition, Tulia soils contain more than 40 percent calcium
carbonate equivalent in the 10- to 40-inch control section.
GEOGRAPHIC SETTING: Broome soils are on nearly level and gently sloping convex surfaces, mainly on broad lower side slopes of
valleys or side slopes of draws, intermittent streams or playas. Slopes range from 0 to 5 percent. These soils have developed in calcareous loamy sediments presumed to be alluvial and eolian in origin and were recalcified by atmospheric dust. The climate is
dry subhumid to semiarid. The mean annual precipitation ranges
from 17 to 22 inches. Mean annual temperature ranges from 60 to
70 degrees F. Thornthwaite P-E indices range from 25 to 31.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing
Angelo and
Reagan series, and
Ector,
Kimbrough,
Mereta, and
Rioconcho series. Ector, Kimbrough, Mereta, and Rioconcho soils
have mollic epipedons, in addition, Ector, Kimbrough, and Mereta soils have sola less than 20 inches thick. Ector soils are carbonatic, and Mereta and Rioconcho soils have more than 35
percent silicate clay in their control sections.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Mostly rangeland. Some areas are farmed
with cotton, wheat, or grain sorghums. Native vegetation is
sideoats grama, buffalograss, tobosa, perennial threeawn, Texas wintergrass, and mesquite.
DISTRIBUTION AND EXTENT: Mainly in the Edwards Plateau of Texas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Sterling County, Texas; 1974.
REMARKS: This soil was formerly included in Mansker, Posey, and Tulia series.
ADDITIONAL DATA: NSSL data on 2 pedons; Sterling County, Texas. Sample number 81P4646-4651; Irion County, Texas; sample number 81P4657-4662.