LOCATION LOU TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, thermic Typic Haplustalfs
TYPICAL PEDON: Lou coarse sandy loam--in rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 7 inches; brown (7.5YR 5/3) coarse sandy loam, dark brown (7.5YR 3/3) moist; weak fine granular structure; very hard, friable; common fine roots; 13 percent granite pebbles; neutral; clear smooth boundary. (3 to 10 inches thick)
A2--7 to 12 inches; brown (7.5YR 5/4) gravelly coarse sandy loam, dark brown (7.5YR 4/4) moist; weak fine and very fine subangular blocky structure; hard, friable; common fine roots; 20 percent granite pebbles; neutral; clear smooth boundary. (0 to 12 inches thick)
Bt1--12 to 20 inches; reddish brown (5YR 5/4) gravelly coarse sandy loam, reddish brown (5YR 4/4) moist; moderate fine subangular blocky structure; hard, firm; common fine roots; some clay bridging of sand grains; 27 percent granite pebbles; neutral; clear smooth boundary. (6 to 24 inches thick)
Bt2--20 to 30 inches; yellowish red (5YR 5/6) gravelly sandy clay loam; yellowish red (5YR 4/6) moist; moderate fine subangular blocky structure; hard, firm; few fine roots; patchy clay films on surface of peds and fragments and in pores; 27 percent granite pebbles; neutral; gradual wavy boundary. (0 to 15 inches thick)
Bt3--30 to 38 inches; yellowish red (5YR 5/6) gravelly sandy clay loam; yellowish red (5YR 4/6) moist; few faint red and reddish brown mottles; moderate fine subangular blocky structure; very hard, firm; few fine roots; patchy clay films on surface of peds and fragments; 30 percent granite pebbles; slightly acid; clear wavy boundary. (0 to 12 inches thick)
Cr--38 to 75 inches; finely fragmented granite grus (saprolite); horizontal and vertical fracture planes contain red clay coatings, but comprise less than 10 percent of the matrix; structure controlled by angular rock fragments; few fine roots in fractures.
TYPE LOCATION: Llano County, Texas. About 15 miles east of Llano Texas. From the intersection of Texas Highway 16 and Texas Highway 29 in Llano, Texas, 15 miles east of Llano on Texas Highway 29 to junction with Ranch Road 1431, 1.6 miles north on Ranch Road 1431, 0.6 mile north on county road and private road, 100 feet east in rangeland.
RANGE IN CHARACTERISTICS: The thickness of the solum and depth to granite grus (paralithic contact) ranges from 20 to 40 inches. Approximately 80 percent of the coarse fragments are between 2 mm and 4 mm, the remaining 20 percent is greater than 4 mm in diameter. Reaction throughout the solum is slightly acid or neutral.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 or 4. Texture is sandy loam, coarse sandy loam, gravelly sandy loam or gravelly coarse sandy loam. Clay content ranges from 10 to 17 percent. Gravel content ranges from 2 to 20 percent. The A horizon is hard and massive when dry.
An E horizon may be present in some pedons.
The Bt horizons are typically 5YR hue but range from 2.5YR to 7.5YR, with value of 4 to 6, and chroma of 4 to 6. Textures are gravelly sandy loam, gravelly sandy clay loam or gravelly coarse sandy loam. Clay content ranges from 18 to 35 percent. Gravel content ranges from 15 to 35 percent. Clay films range from few to common and are faint and patchy. Base saturation ranges from 75 to 100 percent.
The Cr horizon consists of dense, fractured weathered granite saprolite; the upper few inches has clay films in fractures and coating fragments. Some pedons have massive indurated granite below 60 inches.
COMPETING SERIES: These include the Cobb, Grandfield, Grandmore, Honeycreek, Hye, McKnight, Menard, and Rochelle soils. Click soils are similar. Cobb soils are 20 to 40 inches thick over sandstone, are calcareous in the lower Bt and receive less rainfall. Granfield and Grandmore soils are more than 60 inches thick and have developed from loamy material. Honeycreek soils are 40 to 60 inches thick over schist. Hye soils are 20 to 40 inches thick over sandstone and have less than 15 percent gravel in the Bt horizon. McKnight and Menard soils contain secondary carbonates at depths less than 30 inches. Rochelle soils are greater than 60 inches to bedrock. Click soils have more than 35 percent pebbles in the control section.
GEOGRAPHIC SETTING: Lou soils are on gently sloping ridges underlain by fractured granite. Slope ranges from 1 to 5 percent. The climate is dry subhumid. Mean annual precipitation ranges from 24 to 30 inches and mean annual temperature ranges from 65 to 68 degrees F. Frost free days range from 210 to 240 days and elevations range from 800 to 2,200 feet. Thronthwaite P-E indices range from 38 to 44.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Bauman, Castell, Click, Katemcy, Keese, Ligon and Voca soils. Bauman soils are on lower concaved positions and have natric horizons. Castell soils have fine control sections and are 20 to 40 inches thick over gneiss. Katemcy soils have fine control sections and are 20 to 40 inches thick over schists. Keese soils lack Bt horizons and are less than 20 inches thick over bedrock. Ligon soils have red Bt horizons and sola less than 20 inches thick over schists. Voca soils have fine control sections.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium. Permeability is moderate.
USE AND VEGETATION: Used mainly for rangeland. Some areas are used for wildlife land and improved pastures. Vegetation consists of tall and mid grasses. Little bluestem, tall dropseed, Arizona cottontop and sideoats grama are the dominant grasses. Texas persimmon, postoak, and live oak are dominant woody species.
DISTRIBUTION AND EXTENT: In the Central Basin of Texas. This series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES PROPOSED: Llano County, Texas; 1984. Lou is a coined name. Alternate names are Tow and Itz.
REMARKS: This soil was formerly included with the Voca or Click series. Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 12 inches. (A1 and A2 horizons)
Argillic horizon - 12 to 38 inches. (Bt1, Bt2 and Bt3 horizons)
Paralithic contact - 38 inches and below is fractured granite saprolite. It is fractured, but continuous coherent material that excludes roots.
ADDITIONAL DATA: NSSL - S82TX-299-002. (sampled as Voca-like)