LOCATION PATILO TXEstablished Series
TAXONOMIC CLASS: Loamy, siliceous, semiactive, thermic Grossarenic Paleustalfs
TYPICAL PEDON: Patilo fine sand--wooded pasture.
(Colors are for dry soil unless otherwise
stated.)
A--0 to 4 inches; light brownish gray (10YR 6/2) fine sand,
dark grayish brown (10YR 4/2) moist; single grained; loose;
common fine roots; neutral; clear smooth boundary. (2 to 20
inches thick)
E--4 to 50 inches; white (10YR 8/2) fine sand, light gray
(10YR 7/2) moist; single grained; loose; common fine roots in
upper part, few in lower part; slightly acid; clear wavy
boundary. (20 to 72 inches thick)
Bt1--50 to 70 inches; light gray (10YR 7/1) sandy clay loam, light gray (10YR 6/1) moist; many coarse and medium prominent red (2.5YR 5/8) and few fine distinct brownish yellow mottles; weak coarse blocky structure; very hard, very firm; few very fine
roots and pores; thin patchy clay films on surfaces of peds;
strongly acid; gradual smooth boundary. (6 to 30 inches thick)
Bt2--70 to 74 inches; white (10YR 8/1) sandy clay loam, light gray (10YR 7/1) moist; many coarse and medium prominent red
(2.5YR 5/8) and few brownish yellow mottles; weak coarse blocky structure; hard, firm; strongly acid.
TYPE LOCATION: Erath County, Texas; about 7.5 miles northeast of Stephenville; 1.1 miles southeast of Pilot Knob Church to intersection of private road and county road; 0.5 mile northeast
of intersection and 40 yards northwest of private road.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 65 to more than 100 inches.
The A and E horizons range from 40 to 80 inches thick. They are fine sand or loamy fine sand and are neutral through medium acid. The A horizon has hue of 10YR, value of 4 through 7, and chroma of 2 through 4.
The E horizon has hue of 7.5YR or 10YR, value of 5 through 8, and chroma of 2 through 6. The boundary between the E and Bt horizon is wavy to irregular. Texture is fine sand or loamy fine sand.
The Bt horizon is dominantly sandy clay loam with clay content of
25 to 35 percent, but the clay content ranges from 18 to 35
percent. Reaction ranges from slightly acid through strongly
acid. Base saturation ranges from 40 to 75 percent throughout
the argillic horizon. These horizons have hue of 5YR through 5Y, value of 5 to 7, and chroma of 1 to 8, with varying sizes and amounts of red, yellow, and gray mottles.
COMPETING SERIES: These include
Catilla,
Desan, and
Padina
series in the same family. Similar soils include
Arenosa,
Eufaula,
Heaton,
Kenney,
Nimrod,
Sarita, and
Silstid series. Catilla soils contain more than 5 percent plinthite in the Bt2 horizons. Desan soils lack mottles with chromas of 2 or less in the Bt1 horizon. Padina soils are moist in the moisture control section for longer periods of time. Arenosa soils lack Bt horizons. Eufaula soils have Bt horizons of loamy fine sand or lamella of fine sandy loam. Heaton, Nimrod, and Silstid soils have A horizons less than 40 inches thick. In addition, Heaton and Silstid soils lack mottles with chromas of 2 or less. Kenney soils are moist for longer periods and have mixed mineralogy. Sarita soils have mixed mineralogy and mean annual soil temperatures of more than 72 degrees F.
GEOGRAPHIC SETTING: Patilo soils are on uplands. Slopes are 0 to 15 percent, with concave and convex surfaces. The soil formed in thick sandy beds that appear to have been reworked somewhat by wind. The mean annual temperature is 66 to 70 degrees F.; average annual precipitation is 26 to 35 inches; Thornthwaite annual P-E indices are 38 to 54.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Arenosa,
Heaton,
Nimrod, and
Silstid series, and the
Chaney,
Selden, and
Windthorst series. Arenosa, Heaton, Nimrod and
Silstid soils are in similar position. Chaney and Selden soils occupy concave swales or slightly higher convex knolls and have
sandy surface layers less than 20 inches thick. Windthorst soils occupy higher ridges and knolls and have surface horizons less
than 20 inches thick.
DRAINAGE AND PERMEABILITY: Moderately well drained; moderately
slow permeability. Perched water tables occur for short periods following periods of heavy rainfall.
USE AND VEGETATION: Mainly brushy rangeland and used for
grazing. A few areas are cultivated to peanuts and watermelons. Native vegetation is a scrub forest of post and blackjack oak
with greenbriers, annual weeds, and grasses in the openings and beneath the trees.
DISTRIBUTION AND EXTENT: Mainly in the sandy timbered areas of central Texas. The soil is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Erath County, Texas; 1970.
REMARKS: These soils were formerly included in the Nimrod
eries. Although colors indicate reduced conditions under the present moisture regime the soils are not saturated to the surface. Some of the gray colors are considered to be inherited from the parent material.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 4 inches, or the A horizon.
Grossarenic feature - fine sand from the surface to 50 inches.
Paleustalf feature - the argillic horizon does not decrease significantly in clay and has many coarse mottles that are 2.5YR 5/8.
Argillic horizon - the zone from 50 to 74 inches.