LOCATION CARBENGLE TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, carbonatic, thermic Udic Calciustolls
TYPICAL PEDON: Carbengle clay loam, on a convex 5 percent slope, in pasture. (Colors are for dry soil unless otherwise stated.)
A1--0 to 7 inches; very dark gray (10YR 3/1) clay loam, black (10YR 2/1) moist; weak fine granular structure; hard, friable; many fine roots; strongly effervescent; moderately alkaline; clear smooth boundary.
A2--7 to 12 inches; very dark gray (10YR 3/1) clay loam, black (10YR 2/1) moist; weak fine subangular blocky structure; hard, friable; many fine roots; many fine pores; violently effervescent; moderately alkaline; abrupt wavy boundary. (combined thickness of the A horizon is 7 to 18 inches)
Bk1--12 to 23 inches; light gray (10YR 7/2) loam, light gray (10YR 7/2) moist; moderate fine and medium subangular blocky structure; hard, very friable; common fine roots; common fine pores; common masses of calcium carbonate; violenty effervescent; moderately alkaline; clear wavy boundary. (5 to 25 inches thick)
Bk2--23 to 34 inches; white (10YR 8/2) loam, light gray (10YR 7/2) moist; weak fine and medium subangular blocky structure; hard, very friable; 30 percent soft masses of calcium carbonate; common concretions of calcium carbonate; common fine roots; common fine pores; strongly effervescent; moderately alkaline; abrupt wavy boundary. (0 to 17 inches thick)
Cr--34 to 60 inches; violently effervescent; weakly cemented sandstone, interbedded with loamy materials.
TYPE LOCATION: Washington County, Texas; about 2 miles north of William Penn; 0.2 miles west on County Road 73 from its junction with Farm Road 1935, then 250 feet south in a native bluestem meadow.
RANGE IN CHARACTERISTICS: Solum thickness and depth to weathered bedrock ranges from 20 to 40 inches, the lower limits being the depth to weakly to strongly cemented calcareous sandstone interbedded with loamy materials. Secondary carbonates are present throughout the B horizon in the form of soft masses, films, threads, and concretions. Calcium carbonate equivalent ranges from 40 to 65 percent. The average clay content of the 10- to 40- inch particle size control section ranges from 20 to 35 percent. The control section contains more than 15 percent material coarser than very fine sand.
The A or Ap horizon has hue of 10YR or 7.5YR, value of 3 or 4, and chroma of 1 to 3. Texture is loam, sandy clay loam or clay loam.
The Bk1 horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 5 to 7, and chroma of 2 to 6. Texture is loam, clay loam, sandy clay loam or silty clay loam.
The Bk2 or BCk horizons have hue of 7.5YR, 10YR and 2.5Y, value of 6 to 8, and chroma of 2 to 6. Mottles of brownish yellow, light brownish gray, and pale yellow range from none to common. Texture is loam, clay loam, sandy clay loam or silty clay loam.
The Cr horizon ranges from calcareous weakly cemented to strongly cemented sandstone that is interbedded with loamy sediments. It can be cut with a spade or auger. Roots penetrate only in occasional fractures and in loamy interbedded material.
COMPETING SERIES: These are the Bolar, Rumley, Sunev and Topsey series. Similar soils are the Austin, Brenham, Engle, Hidalgo, and Venus series. Bolar soils have a lithic contact within 40 inches of the surface and have fragments of limestone in the control section. Rumley and Sunev soils do not have a paralithic contact within 40 inches of the surface. Topsey soils have sola 20 to 40 inches thick over clayey material and are in a slightly drier climate. Austin and Brenham soils have fine-silty control sections. In addition, Austin soils are underlain by chalk. Engle and Venus soils have less than 40 percent calcium carbonate equivalent. In addition, Venus soils have thicker sola. Hidalgo soils have mean annual soil temperatures greater than 72 degrees F.
GEOGRAPHIC SETTING: Carbengle soils are on very gently sloping to strongly sloping uplands. The soils formed in weakly cemented calcareous sandstones of Miocene age mainly of Fleming and Oakville formations. Slopes are mainly 1 to 6 percent, but range up to 12 percent. Mean annual precipitation ranges from 35 to 45 inches with a summer dry season. Mean annual temperature ranges from 67 to 70 degrees F. Frost free days range from 260 to 290 and elevation ranges from 200 to 550 feet. Thornthwaite annual P-E indices range from 48 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Brenham series and the Cuero, Frelsburg, Klump, Knolle, Latium, and Renish series. Brenham soils are on nearby similar slopes. Cuero soils are on footslopes and concave areas and have mollic epipedons thicker than 20 inches. Frelsburg and Latium soils are on nearby slopes, contain more clay and have intersecting slickensides. Klump and Knolle soils have Bt horizons, have redder hues, and are on nearby slopes. Renish soils have a solum less than 20 inches thick over hard sandstone, and are on nearby ridges and steeper slopes.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is medium on 1 to 5 percent slopes, and high on slopes from 5 to 12 percent.
USE AND VEGETATION: Used mainly for corn and improved pastures. Some areas are used for range. Native grasses are mainly species of little bluestem, indiangrass, sideoats grama, and big bluestem. Pastures now have bermudagrass, Texas grama, buffalograss, and scattered scrubby mesquite and huisache trees.
DISTRIBUTION AND EXTENT: Southeast Central Prairies of Texas. The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Washington County, Texas; 1978.
REMARKS: Diagnostic horizon and features recognized in this pedon are:
Mollic epipedon - 0 to 12 inches. (A1 and A2 horizons)
Calcic horizon - 12 to 34 inches. (Bk1 and Bk2 horizons)
Paralithic contact - at 34 inches contact with weakly cemented sandstone.
Soil Interpretation Record Number: TX0790