LOCATION PERCILLA TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Aeric Epiaqualfs
TYPICAL PEDON: Percilla clay loam, on a concave 0.5 percent slope in woodland. (Colors are for moist soil unless otherwise stated.)
A--0 to 3 inches; dark grayish brown (10YR 4/2) clay loam, moderate medium granular structure; hard, friable; common fine, medium, and coarse roots; very strongly acid; clear smooth boundary. (2 to 8 inches thick)
BAg--3 to 10 inches; prominently mixed dark gray (10YR 4/1) and yellowish red (5YR 4/6) clay loam; moderate medium subangular blocky structure; very hard, firm; many fine, medium, and coarse roots; common fine vesicular and tubular pores; few light brownish gray loam crayfish krotovina; common fine and medium iron-manganese concretions and ironstone nodules; very strongly acid; clear smooth boundary. (0 to 10 inches thick)
Btg1--10 to 17 inches; prominently mixed 50 percent dark gray (10YR 4/1), 40 yellowish red (5YR 4/6) and 10 percent strong brown (7.5YR 5/6) clay; moderate medium subangular blocky structure; very hard, firm; common fine, medium, and coarse roots; common vesicular and tubular pores; few patchy clay films; few light grayish brown loam crawfish krotovina; common fine and medium iron-manganese concretions and ironstone nodules; very strongly acid; gradual smooth boundary.
Btg2--17 to 35 inches; prominently mixed 60 percent dark gray (10YR 4/1) and 40 percent yellowish red (5YR 5/8) clay; weak coarse prismatic structure parting to weak medium angular blocky; very hard, very firm; common fine and medium roots; common fine vesicular and tubular pores; almost continuous dark gray clay films on surface of prisms; few light brownish gray loam crawfish krotovina; common fine and medium iron-manganese concretions and ironstone nodules; very strongly acid; gradual smooth boundary.
Btg3--35 to 63 inches; prominently mixed 70 percent dark gray (10YR 4/1), 35 percent yellowish red (5YR 5/8) and 25 percent strong brown (7.5YR 5/6) clay; weak coarse prismatic structure parting to weak medium angular blocky; very hard, very firm; common fine and medium roots; many fine vesicular and tubular pores; almost continuous dark gray clay films on surface of prisms; common fine and medium iron-manganese concretions and ironstone nodules; very strongly acid; clear wavy boundary. (combined Bt subhorizons are 46 to 70 inches thick)
C/Btg--63 to 80 inches; yellowish red (5YR 5/6) weathered glauconitic materials with texture of sandy clay loam; massive; extremely hard, firm; few fine and medium roots; common fine tabular pores; about 30 percent dark gray (10YR 4/1) clay Bt materials with few medium distinct brown (10YR 5/3) redox concentrations and few fine iron-manganese concretions; strongly acid.
TYPE LOCATION: Nacogdoches County, Texas; about 5 miles east of Nacogdoches on Texas Highway 7 from the east loop in Nacogdoches to Farm Road 2112; 0.3 mile north on Farm Road 2112; 200 feet east in woodland.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to 80 inches. The weighted average clay content of the particle-size control section ranges from 35 to 45 percent. The base saturation ranges from 35 to 60 percent in the argillic horizon. Some subhorizon has dominant colors with chroma of 3 or more in the upper 30 inches of the solum. Ironstone fragments or nodules and iron-manganese concretions range from few to common in some part of the solum of most pedons. The redox features are mainly contemporary. It is wet for extended periods in the surface and upper part of the argillic horizon. The soil has aquic soil conditions during most years.
The A horizon has colors in shades of brown or gray in hue of 7.5YR or 10YR, value of 3 to 5, and chroma of 1 to 3. Mollic colored horizons are less than 7 inches thick. Texture is loam or clay loam. The reaction ranges from very strongly acid to moderately acid.
The BAg horizon is not diagnostic to the series. When present, it has colors like the argillic horizon and texture like the A horizon.
The Btg horizon has colors in shades of gray and is commonly mixed with colors of brown, red, or yellow. The gray colors have hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 or 2. The other colors have hue of 2.5YR to 10YR, value of 4 to 6, and chroma of 4 to 8. The texture is clay loam or clay. Reaction ranges from very strongly acid to moderately acid.
The C horizon is weathered glauconitic materials, glauconitic marl, or glauconitic greensand or is straitfied with these materials. The texture of these geologic materials is mainly loam, sandy clay loam or clay loam. Reaction ranges from moderately acid to neutral. Clayey Bt soil materials range from none to about 40 percent by volume.
COMPETING SERIES: There are no competing series, similar soils include the Derly, Mollville, and Wrightsville series. Derly, Mollville, and Wrightsville soils have a glossic horizon and classify in Glossaqualfs.
GEOGRAPHIC SETTING: Percilla soils have concave surfaces. They are in depressional areas on uplands. Slopes range from 0 to 1 percent. These soils formed in materials from the Weches Geologic Formation. Mean annual rainfall ranges from 42 to 52 inches and is evenly distributed throughout the year. Mean annual temperature rages from 65 degrees to 68 degrees F. Frost free days range from 235 to 250. The elevation ranges from 300 to 650 feet above sea level. Thornthwaite P-E indices range from 68 to 82.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alto, Attoyac, Chireno, Elrose, Nacogdoches, and Trawick series. Alto, Elrose, Nacogdoches, and Trawick soils are on higher positions in the landscape and are better drained. Alto soils have a brownish argillic horizon. Elrose, Nacogdoches, and Trawick soils have a red argillic horizon. Attoyac and Chireno soils are slightly lower on terrace positions. Attoyac soils have reddish subsoils and are well drained. Chireno soils have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Percilla soils are poorly drained and very slowly permeable. Runoff is negligible. A water table is at or above the surface for periods of 2 to 4 weeks from January to April.
USE AND VEGETATION: Used mainly for woodland. Primary species are water oak and willow oak with a scattering of hickory, red oak, and loblolly pine. Minor areas are used for bahiagrass pastures.
DISTRIBUTION AND EXTENT: Redland belt of East Texas, MLRA 133B. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Cherokee County, Texas; 1958.
REMARKS: These soils were formerly classified in Aeric Ochraqualfs. Classification changed based on Issue NO. 16 a revision to Soil Taxonomy. Changed March, 1994.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--0 to 10 inches.
Argillic horizon--10 to 63 inches, the Btg horizon.
Aquic conditions below th A horizon.
Aeric feature--subhorizon with dominant chroma of 3 or more within 30 inches of the surface (Btg1).
SOIL INTERPRETATION RECORD NUMBER: TX0709.