LOCATION MEMPHIS MS+AR KY LA MO TNEstablished Series
The Memphis series consists of very deep, moderately permeable, well drained soils that formed in loess deposits more than 48 inches in thickness. These soils are on terraces and uplands of the Coastal Plain. Slopes range from 0 to 50 percent.
TAXONOMIC CLASS: Fine-silty, mixed, active, thermic Typic Hapludalfs
TYPICAL PEDON: Memphis silt loam on a 2 to 5 percent slope in a wooded area. (Colors are for moist soil unless otherwise stated.)
A--0 to 4 inches; dark grayish brown (10YR 4/2) silt loam; weak fine and medium granular structure; very friable; many fine roots; moderately acid; clear smooth boundary. (2 to 8 inches thick)
E--4 to 9 inches; brown (10YR 4/3) silt loam; weak medium and fine granular structure; friable; many fine and medium roots; few wormcasts, some mixing of material from A horizon; very strongly acid; clear smooth boundary. (0 to 6 inches thick)
Bt1--9 to 23 inches; brown (7.5YR 4/4) silty clay loam; moderate fine and medium subangular blocky structure; firm; slightly sticky, plastic; many fine roots; distinct clay films on peds; few dark coatings on faces of peds in lower part of horizon; very strongly acid; gradual wavy boundary. (10 to 24 inches thick)
Bt2--23 to 41 inches; brown (7.5YR 4/4) silt loam; weak medium subangular blocky structure; friable, slightly sticky, plastic; many fine roots; few faint clay films on peds; few dark coating on faces of peds; few gray silt coatings between peds; strongly acid; clear smooth boundary. (14 to 26 inches thick)
Bt3--41 to 51 inches; brown (7.5YR 4/4) silt loam; weak medium subangular blocky structure; friable, slightly sticky, plastic; few fine roots; few faint clay films on faces of some peds; gray silt coatings on faces of peds and in cracks; strongly acid; clear smooth boundary. (6 to 14 inches thick)
C--51 to 77 inches; brown (7.5YR 4/4) silt loam; massive; friable; few fine roots; gray silt coatings in cracks or crevices; moderately acid.
TYPE LOCATION: Warren County, Mississippi; 2.5 miles southwest of Oak Ridge on paved road; 0.5 mile southeast on gravel road and 15 feet east in woods; NW1/4SW1/4 sec. 17, T. 17 N., R. 5 W.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 32 to more than 80 inches. The soil ranges from moderately through very strongly acid throughout, except where limed. The calcium-magnesium ratio is 1 or more.
The A horizon has hue of 10YR, value 4 or 5, and chroma 1 to 4; or hue 7.5YR, value 4 or 5, and chroma 4. Some pedons have an A horizon up to 4 inches thick that has hue 7.5YR or 10YR, value 3, and chroma 2 or 3. Texture is silt loam or silt.
The E horizon, where present has hue of 10YR, value 4 or 5, and chroma 1 to 3. Texture is silt loam or silt.
The Bt and C horizons are in hue 7.5YR or 10YR, value 4 or 5, and chroma 4 through 6. Texture is silt loam or silty clay loam. Clay content in the upper 20 inches of the Bt horizon typically contains 25 to 30 percent clay and ranges from 20 to 35. To a depth of 48 inches or more, the soil contains less than 5 percent sand. Black coats and stains on faces of peds in the Bt horizon range from few to many. Gray or pale brown silt coatings in cracks or on faces of peds range from none to common.
COMPETING SERIES: These are the
Dubbs,
Gallion,
Rilla, and
Siwell series in the same family and the
Atwood,
Cascilla,
Center,
Dexter,
Kleinpeter,
Lexington,
Loring,
Natchez, and
Tutwiler series in closely related families. Dubbs soils are on natural levee or low terrace positions and have more than 5 percent
sand in the subsoil. Gallion and Rilla soils formed in alluvium on natural levee positions, have redder hue and contain more than 15 percent sand in the subsoil. Siwell soils have a silty mantle about 20 to 40 inches thick over calcareous clay. Atwood soils do not have a significant clay decrease within a depth of 60 inches. Cascilla soils do not have an argillic horizon. Kleinpeter soils have more than 5 percent strippings of albic materials in the lower part of the solum. Center soils have mottles of chroma of 2 or less in the upper 10 inches of the Bt horizon. Lexington soils have more than 15 percent sand in some horizon within 48 inches of the surface. Loring soils have a fragipan. Natchez soils do not have an argillic horizon and have less than 18 percent clay in the 10 to 40 inch control section. Tutwiler soils contain less than 18 percent clay in the upper 20 inches of the argillic horizon.
GEOGRAPHIC SETTING: Memphis soils are on nearly level to very steep uplands and terraces having slopes ranging from 0 to 45 percent. The soils formed in loess more than 4 feet thick. The climate is warm and humid with annual precipitation of about 49 inches and annual temperature of 65 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Lexington, Loring, and Natchez series and the Calloway and Grenada series. Calloway and Grenada soils have a fragipan and are on broader ridgetops, depressions, and heads of drainageways.
DRAINAGE AND PERMEABILITY: Well drained; medium to very high runoff; moderately permeable.
USE AND VEGETATION: Most of Memphis soils are used for woodland of mixed hardwoods and pines. Cleared areas are used for cotton, soybeans, small grains, hay, and pasture.
DISTRIBUTION AND EXTENT: Southern Mississippi Valley Silty Uplands (MLRA 134) in Arkansas, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee. The series is of large extent.
MLRA OFFICE RESPONSIBLE: Little Rock, Arkansas
SERIES ESTABLISHED: Yazoo Area, Mississippi; 1901.
REMARKS: Added silt to range of surface and subsurface horizons based on data from Wilkinson County, Mississippi (5/2001).
Diagnostic horizons and features recognized in the type location pedon include:
Ochric epipedon --- 0 to 9 inches (A and E horizons)
Argillic horizon --- 9 to 51 inches (Bt horizons)