LOCATION ROWDEN             TX

ROWDEN SERIES

The Rowden series consists of moderately deep over limestone bedrock, well drained, slowly permeable soils that formed in loamy and clayey residuum from limestone. These soils are on nearly level to gently sloping plains. Slopes range from 0 to 3 percent.

TAXONOMIC CLASS: Fine, mixed, superactive, thermic Typic Argiustolls

TYPICAL PEDON: Rowden clay loam--cropland. (Colors are for dry soil unless otherwise stated.)

Ap--0 to 8 inches; brown (10YR 4/3) clay loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; hard, friable; many very fine roots; common wormcasts; few fine quartz and chert pebbles; slightly effervescent; moderately alkaline; clear smooth boundary. (5 to 12 inches thick)

Bt1--8 to 15 inches; reddish brown (5YR 4/3) clay, dark reddish brown (5YR 3/3) moist; moderate medium angular blocky structure; very hard, firm; common very fine roots; common wormcasts; thin patchy clay films on surfaces of peds; few fine quartz and chert pebbles; matrix is noncalcareous; moderately alkaline; clear wavy boundary. (5 to 12 inches thick)

Bt2--15 to 27 inches; reddish brown (5YR 4/4) clay; dark reddish brown (5YR 3/4) moist; strong medium angular blocky structure; very hard, firm; few very fine roots; few wormcasts; thin patchy clay films on surfaces of peds; few fine quartz and chert pebbles; few threads of films of calcium carbonate in lower 2 inches; strongly effervescent; moderately alkaline; abrupt wavy boundary. (10 to 20 inches thick)

R--27 to 60 inches; indurated, light reddish brown limestone bedrock; coarsely fractured; thin calcium carbonate coating on surface of bedrock and in fractures.

TYPE LOCATION: Callahan County, Texas; from the intersection of Texas Highway 36 and Farm Road 2287 west of Cross Plains, 0.1 mile south and 5.6 miles west on Farm Road 2287; and 10 feet north of road right-of-way in cultivated field. Lat. 32 degrees, 07 feet 33 inches N; Long. 99 degrees, 16 feet 27 inches W.

RANGE IN CHARACTERISTICS: Solum thickness and depth to limestone bedrock ranges from 20 to 40 inches. The lower boundary of the solum either rests abruptly on limestone bedrock or grades into bedded limestones with soil occupying the interstices. Coarse fragments range from 0 to 15 percent in the A and Bt horizons.

The A horizon has hue of 5YR to 10YR, value of 3 to 5, and chroma of 2 or 3. Texture is loam or clay loam with a clay content from 20 to 40 percent. Reaction ranges from neutral to moderately alkaline.

The Bt1 horizon has hue of 5YR or 7.5YR, value of 3 to 5, and chroma of 2 to 3. Texture is clay loam or clay with a clay content of 35 to 60 percent.

The Bt2 horizon has hue of 2.5YR to 7.5YR, value or 4 to 6, and chroma of 3 to 6. Texture is clay loam or clay with a clay content of 35 to 60 percent. Reaction ranges from slightly alkaline to moderately alkaline.

The R horizon of limestone bedrock is gray, white, pink or reddish brown in color and has a hardness from 3 to 4 on Mohs' scale.

COMPETING SERIES: These are the Bexar (TX), Frankirk (TX), Lawton (OK), Luckenbach (TX), Sagerton (TX), and Swenson (TX) series. Similar soils are the Hensley, Lindy, Mingo, Scullin, and Speck series. Bexar soils have 15 to 35 percent coarse fragments in the control section. Frankirk, Lawton, Luckenbach, and Sagerton soils are deeper than 60 inches and are not underlain by bedrock. Swenson soils have a calcic horizon. Hensley and Speck soils have sola less than 20 inches thick. Lindy soils have an ochric epipedon. Mingo soils have a mollic epipedon more than 20 inches thick. Scullin soils are moist in the soil moisture control section for longer periods of time and do not have free carbonates within the solum.

GEOGRAPHIC SETTING: Rowden soils are on upland plains; surfaces are convex to plane. Slope gradients are 0 to 3 percent. The regolith is loamy and clayey materials over thick beds of strongly cemented or indurated limestone. The underlying limestone is typically of the Pennsylvanian and Permian period and mean annual precipitation ranges from 24 to 30 inches, and mean annual temperature ranges from 64 to 66 degrees F. Frost free days range from 210 to 240 days, and elevation ranges from 1,150 to 2,150 feet. Thornthwaite annual P-E indices range from 32 to 44 and

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Hensley, Lindy, and Speck series, and the Callahan, Leeray, Lueders, Palopinto, Set, Throck, and Valera series. Callahan, Set, and Throck soils formed in shaly clay. Lueders and Palopinto soils lack argillic horizons and have sola less than 20 inches thick. Leeray soils lack argillic horizons and have intersecting slickensides. Valera soils lack argillic horizons.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is low on slopes less than 1 percent and medium on 1 to 3 percent slopes.

USE AND VEGETATION: Dominantly used as rangeland, but in some areas sizable amounts are cultivated with small grains as the main crop. The native vegetation is mainly mid and short grasses with scattered live oak trees.

DISTRIBUTION AND EXTENT: Rolling Limestone Prairie and North Central Prairie of Texas. The series is moderately extensive.

MLRA OFFICE RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Callahan County, Texas; 1979.

REMARKS: These soils were formerly included in the Lindy series.

Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - 0 to 15 inches. (A and Bt1 horizons)

Argillic horizon - 8 to 27 inches. (Bt1 and Bt2 horizons)

Lithic contact - limestone bedrock at 27 inches.

Other- the clay increase from the Ap to the Bt1 horizon is insufficient for the Paleustolls great group. Depth to secondary carbonates is 15 inches.