LOCATION DURALDE LA
Established Series
Rev. BAT:DFS
10/2018
DURALDE SERIES
The Duralde series consists of deep, somewhat poorly drained, slowly permeable soils that formed in thick loess. These soils are on convex, circular mounds and gentle side slopes on terrace uplands. Slopes range from 1 to 5 percent.
TAXONOMIC CLASS: Fine-silty, mixed, active, thermic Fragic Glossudalfs
TYPICAL PEDON: Duralde silt loam--pasture. (Colors are for moist soil.)
A1--0 to 4 inches; dark grayish brown (10YR 4/2) silt loam; few fine faint gray mottles; weak fine granular structure; very friable; many fine roots; many medium soft black bodies; medium acid; clear wavy boundary. (2 to 5 inches thick)
B1--4 to 21 inches; yellowish brown (10YR 5/4) silt loam; common medium faint pale brown (10YR 6/3) mottles; moderate medium subangular blocky structure; friable; few fine roots; few fine
pores lined with white silt; many medium soft black and brown bodies; very strongly acid; clear irregular boundary. (15 to 20 inches thick)
B&A--21 to 25 inches; dark brown (10YR 4/3) silty clay loam; few medium distinct yellowish brown (10YR 5/6) and few fine faint grayish brown mottles; moderate medium subangular blocky
structure; firm; this portion is brittle; few fine roots along surfaces of peds; many fine pores; thin patchy clay films on horizontal surfaces of peds; 20 percent pale brown (10YR 6/3) silt coats and discontinuous silt pockets; many medium soft brown bodies; few fine brown concretions; very strongly acid; clear wavy boundary. (4 to 6 inches thick)
B21t--25 to 36 inches; dark brown (10YR 4/3) silty clay loam; common medium faint grayish brown (10YR 5/2) mottles; weak medium subangular blocky structure; firm; many fine pores; this portion is brittle; thin continuous clay films on surfaces of peds; thin silt coats on vertical surfaces of peds; common medium soft brown bodies; few fine brown concretions; very strongly acid; gradual
wavy boundary. (8 to 16 inches thick)
B22t--36 to 60 inches; yellowish brown (10YR 5/4) silty clay loam; common medium faint yellowish brown (10YR 5/8) mottles; moderate medium subangular blocky structure; firm; few fine roots along surfaces of peds; common fine pores lined with clay; thick continuous clay films on surfaces of peds; common fine soft brown bodies; few fine brown concretions; very strongly acid; gradual wavy boundary. (20 to 30 inches thick)
B23t--60 to 92 inches; yellowish brown (10YR 5/4) silty clay loam; common medium faint yellowish brown (10YR 5/8) mottles; moderate medium subangular blocky structure; firm; few fine pores lined with clay; thin continuous clay films on surfaces of peds; silt coats on vertical surfaces of peds; common medium soft brown bodies; few fine brown concretions; neutral.
TYPE LOCATION: Evangline Parish, Louisiana; about 10 miles north of Ville Platte; 1/2 mile west of Louisiana Highway 3042, 100 yards east of gravel road on a mound in a pasture; sec. 1, T. 3 S., R. 2 E.
RANGE IN CHARACTERISTICS: Solum thickness is more than 60, commonly over 100 inches. Typically these soils have less than 3 percent sand, but range up to 10 percent. Grayish mottles due to wetness occur within 30 inches of the surface.
The A horizon is dark grayish brown (10YR 4/2), brown (10YR 4/3), dark yellowish brown (10YR 4/4), yellowish brown (10YR 5/4), pale brown (10YR 6/3), or light yellowish brown (10YR 6/4). It is silt loam and strongly acid through medium acid.
The B1 horizon is brown (10YR 5/3), yellowish brown (10YR 5/4, 5/6), pale brown (10YR 6/3), or light yellowish brown (10YR 6/4) silt loam. It is very strongly through medium acid.
A pale brown (10YR 6/3) or light gray (10YR 7/2), silt loam, discontinuous A'2 horizon occurs as tongues around peds in the B&A horizon and occupies up to 50 percent of the mass. The Bt horizon
is brown (10YR 4/3, 5/3), yellowish brown (10YR 5/4, 5/6) with few to many gray or grayish brown mottles. It is silty clay loam or silt loam. The brown portions are brittle and dense and are similar to material in fragipans. The B1 and B22t horizons are medium acid through very strongly acid and range to neutral in the B23t horizon.
COMPETING SERIES: There are no other series in this family.
Other similar series are the
Calloway,
Evangeline,
Falkner,
Fred,
Frizzell,
Glenmora,
Grenada,
Leverett,
Messer,
Muskogee,
Tippo,
Vidrine and
Wanilla series. Calloway and Grenada soils are quite similar in texture and horizon sequence but have fragipan horizons. Evangeline and Messer soils lack gray mottles within 30 inches of the surface and in addition the Messer soils have B horizons that average less than 18 percent clay in the upper part and are siliceous. Falkner, Muskogee, and Vidrine soils have more than 35 percent clay in the lower B horizons. Fred soils are more alkaline and have carbonate nodules in the B horizon. Frizzell and Glenmora soils have siliceous mineralogy and in addition the Frizzell soils have less than 18 percent clay in the upper B horizons. Leverett and Tippo soils have coarse-silty control sections. Wanilla soils have coarse-loamy control sections.
GEOGRAPHIC SETTING: Duralde soils are on convex circular mounds and gentle side slopes of nearly level loess covered plains. Circular mounds are about 70 feet in diameter, 20 inches in height and 1 to 4 per acre in number. Slope gradients range from 1 to 5 percent. Mound slope gradients average about 4 percent. Climate is warm and humid. The average air temperature is about 68
degrees F., and the average annual rainfall is about 58 inches. Thornthwaite's P-E index is about 70.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Evangeline soils that occur at lower elevations and the gray
Calhoun and
Tenot soils that occur inthe intermound areas on
nearly level landscape.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow to medium runoff; slow permeability. The water table is perched above the Bt for 2 or 3 months in winter and spring.
USE AND VEGETATION: These soils are used principally as woodland. Native vegetation was loblolly pine and hardwood. Small areas have been cleared and used for row crops and pasture.
DISTRIBUTION AND EXTENT: Pre-Prairie loess area of Louisiana and possibly Arkansas, Mississippi, Tennessee, and Texas. This series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: AUBURN, ALABAMA
SERIES ESTABLISHED: Evangeline Parish, Louisiana; 1970.
REMARKS: These soils were formerly included in the Calloway
series and were formerly classified in Gray-Brown Podzolic great
soil group.
National Cooperative Soil Survey
U.S.A.