LOCATION GURDON AR+LA
Established Series
Rev. LBW, EPM
03/2022
GURDON SERIES
The Gurdon series consists of very deep, somewhat poorly drained, moderately permeable soils that formed in alluvium high in silt. These soils are on Pleistocene terraces in the Western Coastal Plain, MLRA 133B. Slopes range from 0 to 3 percent. Mean annual temperature is about 64 degrees F. and mean annual precipitation is about 1270 mm (50 in).
TAXONOMIC CLASS: Coarse-silty, siliceous, semiactive, thermic Aquic Paleudults
TYPICAL PEDON: Gurdon silt loam, 1 percent slope in woodland. (Colors are for moist soil unless otherwise stated.)
0--3 to 0 cm (1 to 0 in); partially decomposed forest debris.
A--0 to 10 cm (0 to 4 in); dark grayish brown (10YR 4/2) silt loam; moderate medium granular structure; very friable; many fine and medium roots; few orgainic stains on peds; few fine faint pale brown iron accumulations in matrix; few Fe-Mn concretions; very strongly acid; clear smooth boundary. (5 to 20 cm (2 to 8 in) thick)
BA--10 to 25 cm (4 to 10 in); yellowish brown (10YR 5/4) silt loam; moderate medium subangular blocky structure; friable; common fine and medium roots; common fine pores; common fine distinct pale brown (10YR 6/3) iron depletions in matrix; few Fe-Mn concretions; very strongly acid; clear smooth boundary. (10 to 20 cm (4 to 8 in) thick)
Bt--25 to 53 cm (10 to 21 in); yellowish brown (10YR 5/6) silt loam; moderate medium subangular blocky structure; friable; many distinct clay films on faces of peds; common fine and medium roots; few fine pores; common medium distinct light brownish gray (10YR 6/2) iron depletions in matrix; common Fe-Mn concretions; extremely acid; gradual smooth boundary. (20 to 76 cm (8 to 30 in) thick)
Btx1--53 to 76 cm (21 to 30 in); yellowish brown (10YR 5/6) silt loam; moderate medium subangular blocky structure; firm, compact and brittle in 25 percent of soil mass; many distinct clay films on faces of peds; few fine roots; common fine pores; common coarse distinct gray (10YR 6/1) iron depletions in matirx; common Fe-Mn concretions; about 1 percent by volume of plinthite; extremely acid; gradual smooth boundary.
Btx2--76 to 127 cm (30 to 50 in); variegated, yellowish brown (10YR 5/6) and gray (10YR 6/1) silt loam; moderate medium subangular blocky structure; firm, compact and brittle in 25 percent of soil mass; many distinct clay films on faces of peds; common fine roots; few fine pores; common Fe-Mn concretions; about 1 percent by volume of plinthite; very strongly acid; gradual smooth boundary. (Combined thickness of the Btx horizons ranges from 0 to 122 cm (0 to 48 in).)
B't1--127 to 163 cm (50 to 64 in); yellowish brown (10YR 5/6) silt loam; moderate medium subangular blocky structure; firm; common distinct clay films on faces of peds; few fine roots; few fine pores; common coarse distinct gray (10YR 6/1) iron depletions in matrix; common Fe-Mn concretions; very strongly acid; gradual smooth boundary. (0 to 50 cm (0 to 20 in) thick)
B't2--163 to 183 cm (64 to 72 in); yellowish brown (10YR 5/6) silty clay loam; common coarse distinct gray (10YR 6/1) mottles; moderate medium subangular blocky structure; firm; common faint clay films on faces of peds; few fine roots; few fine pores; common coarse distinct gray (10YR 6/1) iron depletions in matrix; common Fe-Mn concretions; very strongly acid.
TYPE LOCATION: Clark County, Arkansas; about 10 miles southeast of Gurdon on a gravel road, then 100 feet west in SW1/4SE1/4SE1/4, sec. 20, T. 10 S., R. 18 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 152 to over 203 cm (60 to over 80 in). Except where the soil has been limed, the reaction ranges from moderately acid to extremely acid throughout the profile. Plinthite content ranges from 0 to 5 percent.
A horizon:
Hue: 10YR
Value: 4 or 5
Chroma: 2 or 3
Redoximorphic features: Iron accumulations and depletions range from none to common in shades of brown or yellow.
Texture: silt lom, very fine sandy loam, loam or fine sandy loam
E horizon (where present):
Hue: 10YR
Value: 5 or 6
Chroma: 3 or 4
Redoximorphic features: Iron accumulations and depletions range from none to common in shades of brown or yellow.
Texture: silt loam, very fine sandy loam, or loam.
BA horizon:
Hue: 10YR
Value: 5
Chroma: 3, 4, or 6
Redoximorphic features: Iron accumulations and depletions range from none to many in shades of brown or yellow.
Texture: silt loam, very fine sandy loam or loam.
Upper Bt horizon:
Hue: 10YR
Value: 5 or 6
Chroma: 4, 6, or 8
Redoximorphic features: Iron accumulations and depletions in shades of gray, brown or yellow.
Texture: silt loam, very fine sandy loam, or loam.
Lower Bt horizon:
Hue: 10YR
Value: 5 or 6
Chroma: 4 or 6
Redoximorphic features: Iron accumulations and depletions in shades of gray, brown or yellow, or are variegated in shades of brown, yellow and gray.
Texture: silt loam, loam, or silty clay loam.
Btx horizon:
Hue: 10YR
Value: 5 or 6
Chroma: 4 or 6
Redoximorphic features: Iron accumulations and depletions in shades of gray, brown or yellow, or is variegated in shades of brown, yellow and gray.
Texture: silt loam, loam, or silty clay loam.
Brittleness: It is compact and brittle in 0 to 30 percent of the soil volume.
Btg horizons (where present) below depths of 40 inches.
Hue: 10YR
Value: 5 or 6
Chroma: 1 or 2
Redoximorphic features: iron accumulations and depletions in shades of brown, yellow, and gray.
Texture: silt loam or silty clay loam.
The BC and C horizons (where present)
Matrix colors ranging from brown with gray and yellow
Redoximorphic features: iron accumulations and depletions to gray with brown and yellow iron accumulations.
Texture: silt loam, silty clay loam, or silty clay.
COMPETING SERIES: Gurdon is the only series in this family.
GEOGRAPHIC SETTING: Gurdon soils are on level to nearly level stream terraces in the Western Coastal Plains. The soil formed in alluvium high in silt. Slopes range from 0 to 3 percent. The mean annual temperature ranges from 60 to 65 degrees F., the mean annual precipitation ranges from 45 to 52 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Amy,
Guyton,
Smithton,
Stough and
Una series.
Amy soils occur on similar landscapes at slightly lower positions; have a fine-silty control section, and are poorly drained.
Guyton soils are on flood plains; have a fine-silty control section, higher base saturation and are poorly drained.
Smithton soils occur on similar landscapes; have a coarse-loamy control section, and are poorly drained.
Stough soils are on similar landscapes at slightly higher positions; have a coarse-loamy control section, and slightly more brittleness in the Bt horizon.
DRAINAGE AND PERMEABILITY: Gurdon soils are somewhat poorly drained. Runoff is slow to medium and permeability is moderate. A perched water table is within 12 to 24 inches of the soil surface from November to April, most years.
USE AND VEGETATION: Most of these soils are used for woodland and pasture with limited use for cultivated crops. Native trees are loblolly pine, shortleaf pine, sweetgum, willow oak, and shumard oak. Soybeans are the main cultivated crop. Common pasture grasses are tall fescue and bermudagrass.
DISTRIBUTION AND EXTENT: Western Coastal Plains in Arkansas, Louisiana and possibly Oklahoma and Texas. This series is of small extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: TEMPLE, TEXAS
SERIES ESTABLISHED: Clark County, Arkansas 1980. The name is from a small community in Clark County.
REMARKS: These soils were formerly included in the Felker series.
Diagnostic horizon and features recognized in this pedon are:
Ochric epipedon-the zone for the surface to a depth of 25 cm (0 to 10 in). (A and BA horizons)
Argillic horizon- zone form 25 to 183 cm (10 to 72 in). (Bt horizon)
Iron depletions with chroma of 2 or less within 76 cm (30 in) of the soil surface.
ADDITIONAL DATA: Laboratory data by University of Arkansas Soil Characterization Laboratory. Pedon number S79AR-059-18.
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National Cooperative Soil Survey
U.S.A.