LOCATION ATWOOD                  MS

Established Series
Rev. WMK-AJT-AMS
09/2016

ATWOOD SERIES

The Atwood series consist of very deep, well drained soils that formed in a mantle of silty material and the underlying loamy sediments of marine origin. Atwood soils are on hills of the Southern Coastal Plain. Slopes range from 0 to 17 percent. Mean annual precipitation is about 142 to 147 centimeters (56 to 58 inches) and the mean annual temperature is 17 degrees C (62 degrees F).

TAXONOMIC CLASS: Fine-silty, mixed, semiactive, thermic Typic Paleudalfs

TYPICAL PEDON: Atwood silt loam - cultivated. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 15 centimeters (0 to 6 inches): brown (7.5YR 4/4) silt loam; weak fine and medium granular structure; friable; common fine roots; few worm casts, some material from B horizon as fillings in worm holes and root channels; neutral; abrupt smooth boundary. [10 to 23 centimeters (4 to 9 inches) thick]

Bt1--15 to 46 centimeters (6 to 18 inches); dark reddish brown (5YR 3/4) silty clay loam; moderate fine and medium subangular blocky structure; friable, slightly plastic; few fine roots; few fine black concretions; few root channels filled with material from Ap horizon; patchy clay films on faces of peds and in root channels; slightly acid; gradual smooth boundary.

Bt2--46 to 79 centimeters (18 to 31 inches): dark reddish brown (2.5YR 3/4) silty clay loam; moderate medium and coarse subangular and angular blocky structure; friable, slightly plastic; few fine roots; common fine and coarse black coatings; many fine black concretions; clay films on faces of peds and lining pores; few root channels and worm holes filled with material from Ap horizon; slightly acid; gradual smooth boundary.

Bt3--79 to 114 centimeters (31 to 45 inches); dark reddish brown (2.5YR 3/4) silty clay loam; moderate medium and coarse subangular and angular blocky structure; friable, slightly plastic; few fine roots; common fine to coarse black coatings; common fine black concretions; clay films on faces of peds and lining pores; few root channels filled with material from Ap horizon; slightly acid; gradual smooth boundary.

Bt4--114 to 145 centimeters (45 to 57 inches); dark reddish brown (2.5YR 3/4) silty clay loam; moderate medium and coarse subangular and angular blocky structure; friable, slightly plastic; few fine roots; common fine black concretions; clay films on faces of peds and in pores; strongly acid; gradual smooth boundary. [Combined thickness of the Bt horizon is 86 to 152 centimeters (34 to 60 inches) or more.]

2Bt--145 to 201 centimeters (57 to 79 inches); dark yellowish brown (10YR 3/6) clay loam; moderate medium and coarse subangular and angular blocky structure; friable, slightly plastic; few fine black coatings; few concretions; patchy clay films on faces of peds and in pores; slightly acid.

TYPE LOCATION: Pontotoc County, Mississippi; about 4.02 kilometers (2.5 miles) south of Pontotoc, on Mississippi State Highway No. 15, then 0.4 kilometers (.25 mi) southwest on gravel road, then 183 m (200 yd) west of gravel road; 360 m south and 411 m west of the northeast corner of sec. 17, T. 10 S., R. 3 E., Chickasaw Principal Meridian; USGS Southwest Pontotoc Quadrangle; Latitude 34 degrees 12 minutes 59.65 seconds N.; Longitude 89 degrees 0 minutes 18.57 seconds W.; UTM 314775.18 meters east, 3788204.71 meters north, zone 16N.

RANGE IN CHARACTERISTICS:
Depth to the base of soil development: > 203 centimeters (> 80 inches)
Depth to argillic horizon: 10 to 23 centimeters (4 to 9 inches)
Depth to lithologic discontinuity: 96 to 175 centimeters (38 to 69 inches)
Particle size control section: 27 to 35 percent clay

A or Ap horizon:
Hue: 10YR, 7.5YR, or 5YR
Value: 4 or 5
Chroma: 2 to 4
Texture: silt loam or loam
Reaction: neutral to slightly acid

Bt horizon:
Hue: 5YR or 2.5YR
Value: 3 to 5
Chroma: 3 to 6
Texture: silty clay loam (sand increases in lower part)
Reaction: strongly acid to slightly acid

2Bt horizon:
Hue: 10R, 2.5YR, or 5YR
Value: 3 to 5
Chroma: 4 to 6
Texture: clay loam, sandy clay loam, or silty clay loam
Ped Void Surface Features: black coatings and concretions, few to common (in lower Bt and 2Bt)
Reaction: strongly acid to slightly acid

COMPETING SERIES:
There are no series in the same family. The following are closely related:
Greenville soils have A horizon moist color values less than 4, and a clayey particle-size control section.
Lexington soils have an active CEC activity class, are bisequums, have clay amount decrease with depth and 2Bt horizon with sandy loam or loam textures.
Lucedale soils have A horizon moist color values less than 4, and a fine-loamy particle-size control section.
Macon soils have a fine-loamy particle-size control section.
Memphis soils have a solum less than 152 centimeters (60 inches) thick, and contain less than 5 % sand to a depth of 122 centimeters (48 inches).
Providence soils are moderately well drained, and have a fragipan.
Sallisaw soils have a fine-loamy particle-size control section.
Tippah soils have mottles with chroma of 2 or less within a depth of 76 centimeters (30 inches) of the surface.

GEOGRAPHIC SETTING:
Parent material: silty material over loamy marine sediments of Ripley formation
Landscape: Coastal Plain
Landform: hillslopes
Hillslope profile position: summit, crest, shoulder, and backslope
Geomorphic Component: sideslope and ridges
Slope: 0 to 17 percent
Elevation: 73 to 190 meters (240 to 623 feet)
Mean annual air temperature: 17 degrees C (62 degrees F)
Mean annual precipitation: 145 centimeters (57 inches)
Frost-free period: 250 to 310 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Adaton soils are poorly drained and are in depressions and broad drainageways.
Bude soils are somewhat poorly drained, have a fragipan, and are near heads of drainageways and in broad depressions.
Henry soils are poorly drained, have a fragipan, and are in depressions and broad drainageways.
Lexington soils are well drained, and are on similar positions.
Ora soils are moderately well drained, on ridgetops, have a fragipan and a fine-loamy particle-size control section.
Providence soils are moderately well drained, and are on similar positions.
Ruston soils are well drained, on ridgetops, bisequum, and have a fine-loamy particle-size control section.
Smithdale soils are well drained, on side slopes, and have a fine-loamy particle-size control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated hydraulic conductivity (Ksat): moderate
Permeability: moderate
Surface runoff: low to medium
Water table: none
Ponding: none
Flooding: none

USE AND VEGETATION:
Atwood soils are mainly used for crop, pasture, and forest. Most areas of this soil are cleared and used for cotton, soybeans, corn, and peach orchards. Some areas of the soil are used for hay and pasture. Native vegetation is cherrybark oak, white oak, sweetgum, and shortleaf pine.

DISTRIBUTION AND EXTENT:
Distribution: Mississippi
Major Land Resource Area (MLRA): Southern Coastal Plain (133A)
Extent: moderate

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Auburn, Alabama

SERIES ESTABLISHED: Franklin County, Alabama; 1927.

REMARKS:
Particle-size control section: 15 to 65 centimeters (6 to 40 inches)
Ochric epipedon: the zone from 0 to 15 centimeters (0 to 6 inches) (Ap horizon)
Argillic horizon: the zone from 15 to 201 centimeters (6 to 79 inches) (Bt1, Bt2, Bt3, Bt4, 2Bt horizons)
Lithologic discontinuity: the zone from 145 to 201 centimeters (57 to 79 inches)
Aquic conditions: none

Soil classified according to the 12th Edition of the Keys to Soil Taxonomy

ADDITIONAL DATA:
Laboratory data for the Official Soil Series Description (OSD) is available on the National Soil Survey website at: http://ncsslabdatamart.sc.egov.usda.gov/rptExecute.aspx?p=4076&r=1
NASIS Pedon ID #: 2016MS115190
KSSL ID number: S1961MS115001
OSD User Site ID: 2016MS115190
OSD User Pedon ID: 2016MS115190

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National Cooperative Soil Survey
U.S.A.