LOCATION GRAMERCY                LA

Established Series
Rev.JDS
10/2018

GRAMERCY SERIES

The Gramercy series consists of very deep, poorly drained, very slowly permeable soils that formed in clayey over fine-silty alluvium. These soils are on alluvial flats and on the lower parts of natural levees on the alluvial plain of the Mississippi River and its distributaries. Mean annual air temperature is 68 degrees F. near the type location, and mean annual rainfall is about 65 inches. Slope is dominantly less than 0.5 percent but ranges to 3 percent.

TAXONOMIC CLASS: Fine, smectitic, hyperthermic Chromic Epiaquerts

TYPICAL PEDON: Gramercy silty clay loam--in cropland. (Colors are for moist soil unless otherwise stated).

Ap1--0 to 6 inches; very dark gray (10YR 3/1) silty clay; weak fine subangular blocky structure; firm, moderately sticky, moderately plastic; slightly acid; clear smooth boundary.

Ap2--6 to 11 inches; very dark gray (10YR 3/1) silty clay; moderate medium angular blocky structure; firm, very sticky, very plastic; many fine roots between peds; common fine low continuity tubular pores; 7 percent prominent very dark gray (10YR 3/1) pressure faces on all faces of peds; 3 percent fine faint threadlike dark grayish brown (10YR 4/2) masses of oxidized iron lining pores; slightly alkaline; abrupt wavy boundary (combined thickness of the Ap horizons is 6 to 12 inches).

Bssg1--11 to 22 inches; gray (10YR 5/1) silty clay; moderate medium prismatic structure parting to moderate medium angular blocky; firm, very sticky, very plastic; many fine roots between peds; common very fine low continuity tubular pores; 25 percent prominent grayish brown (10YR 5/2) pressure faces on all faces of peds and 5 percent faint grayish brown (10YR 5/2) slickensides (pedogenic); 10 percent medium distinct irregular brown (10YR 4/3) masses of oxidized iron on faces of peds; 5 percent medium prominent irregular brown (7.5YR 4/4) masses of oxidized iron on faces of peds; slightly alkaline; gradual smooth boundary.

Bssg2--22 to 36 inches; gray (10YR 5/1) silty clay; moderate medium prismatic structure parting to moderate medium angular blocky; firm, very sticky, very plastic; many fine roots between peds; common very fine low continuity tubular pores; 25 percent prominent gray (10YR 5/1) pressure faces on all faces of peds and 10 percent distinct very dark gray (10YR 3/1) organic stains on all faces of peds and 5 percent faint gray (10YR 5/1) slickensides (pedogenic); 20 percent medium prominent irregular dark yellowish brown (10YR 4/6) masses of oxidized iron on faces of peds; 8 percent medium prominent irregular brown (7.5YR 4/4) masses of oxidized iron on faces of peds; slightly alkaline; clear wavy boundary.

Bssg3--36 to 42 inches; gray (10YR 5/1) clay; weak medium prismatic structure parting to moderate medium angular blocky; firm, very sticky, very plastic; common fine roots between peds; common very fine low continuity tubular pores; 25 percent prominent gray (10YR 5/1) pressure faces on all faces of peds and 5 percent faint gray (10YR 5/1) slickensides (pedogenic); 15 percent medium prominent irregular dark yellowish brown (10YR 4/4) masses of oxidized iron on faces of peds; 1 percent fine distinct irregular light gray (10YR 7/1) barite masses on faces of peds; slightly alkaline; gradual wavy boundary (combined thickness of the Bssg horizons is 18 to 50 inches).

Bg--42 to 48 inches; gray (10YR 5/1) silty clay; moderate medium angular blocky structure; firm, moderately sticky, moderately plastic; common fine roots between peds; common very fine low continuity tubular pores; 15 percent distinct gray (10YR 5/1) pressure faces on all faces of peds; 20 percent medium distinct irregular dark yellowish brown (10YR 4/4) masses of oxidized iron on faces of peds; 10 percent medium distinct irregular brown (10YR 4/3) masses of oxidized iron on faces of peds; neutral; clear wavy boundary.

Ab--48 to 55 inches; dark gray (10YR 4/1) silty clay loam; moderate medium angular blocky structure; firm, moderately sticky, moderately plastic; common fine roots between peds; common very fine low continuity tubular pores; 10 percent faint dark gray (10YR 4/1) pressure faces on all faces of peds; 7 percent fine distinct irregular dark yellowish brown (10YR 4/4) masses of oxidized iron on faces of peds; 1 percent medium prominent cylindrical reddish brown (5YR 4/4) masses of oxidized iron lining pores; slightly alkaline; gradual wavy boundary (0 to 10 inches thick).

Bgb1--55 to 63 inches; gray (10YR 5/1) silty clay loam; moderate medium angular blocky parting to moderate medium prismatic structure; firm, moderately sticky, moderately plastic; common fine roots between peds; common very fine low continuity tubular pores; 25 percent distinct dark gray (10YR 4/1) pressure faces on all faces of peds and 20 percent distinct dark gray (10YR 4/1) organic stains on all faces of peds; 12 percent medium prominent irregular yellowish brown (10YR 5/6) masses of oxidized iron on faces of peds; neutral; gradual wavy boundary.

Bgb2--63 to 80 inches; gray (10YR 5/1) silty clay; moderate medium angular blocky structure; firm, moderately sticky, moderately plastic; few very fine roots between peds; 25 percent distinct gray (10YR 5/1) pressure faces on all faces of peds; 10 percent medium distinct irregular dark yellowish brown (10YR 4/4) masses of oxidized iron on faces of peds; 1 percent fine distinct irregular light gray (10YR 7/1) barite masses on faces of peds; neutral.

TYPE LOCATION: St. John the Baptist Parish, Louisiana; from the intersection of U.S. Highways 51 and 61 in LaPlace, Louisiana, 12.2 miles west on U.S. Highway 51, then 2.4 miles south on La. Highway 641 across bridge at Gramercy, La., then 4.65 miles east on La. Highway 18, then 2200 feet south on farm road across railroad tracks, then 150 feet west into field; 30 degrees, 1 minutes, 26.48 seconds north Latitude; 90 degrees, 36 minutes, 35.89 seconds west Longitude; USGS Reserve, Louisiana 7.5 minute topographic quadrangle, NAD 1983.

RANGE IN CHARACTERISTICS:
Solum thickness: 60 to more than 80 inches
Clay content in the Control Section: 35 to 60 percent. Some pedons have thin layers in the lower part of the control section that have more than 60 percent clay.
Redoximorphic features: Depleted matrix with iron accumulations throughout the solum
Other distinctive soil features: Depth to subsoil layers with less than 40 percent clay ranges from 30 to 60 inches. A clayey discontinuity is at 60 to more than 80 inches deep in some pedons.

Ap horizon:
Color--Hue of 10YR or 2.5Y, value of 3 to 5, and chroma of 1 or 2; or it is neutral with value of 4.
Redoximorphic features--Masses of iron accumulation and iron depletions in shades of brown and gray range from none to common.
Texture--Commonly silty clay loam or silty clay, however some pedons have a surface mantle of recent overwash material that is stratified silt loam.
Reaction--Moderately acid to moderately alkaline

Bssg horizon:
Color--Hue of 10YR to 5Y, value of 4 to 6, and chroma of 1; or it is neutral with value of 4 to 6. Some pedons have value of 3 and chroma of 1 in the upper part of the Bssg horizon within a depth of 12 inches.
Redoximorphic features--Masses of iron accumulation and iron depletions in shades of brown and gray are common. Soft masses of manganese accumulation are none to common.
Texture--Silty clay or clay
Other features=Some pedons have thin lenses or seams of material with hue of 5YR or redder within the horizon.
Reaction--Moderately acid to moderately alkaline

Ab horizon: (where present)
Color--Hue of 10YR or 2.5Y, value of 3 or 4, and chroma of 1 or 2.
Redoximorphic features--Masses of iron accumulation and iron depletions in shades of brown and gray range from none to common.
Texture--Silty clay loam
Reaction--Moderately acid to moderately alkaline

Bg or Bgb horizon:
Color--Hue of 10YR to 5Y, value of 4 to 6, and chroma of 1 or 2; or it is neutral with value of of 4 to 6.
Redoximorphic features--Masses of iron accumulation and iron depletions in shades of brown and gray range from few to common.
Texture--Silty clay loam in the parts within a depth of 40 inches. Texture is silt loam, silty clay loam or very fine sandy loam with or without strata or lenses of clay or silty clay in the parts below 40 inches.
Other features--Some pedons have thin lenses or seams of material with hue of 5YR or redder within the horizon.
Reaction--Moderately acid to moderately alkaline

2BCg or 2Cg horizon: (where present)
Color--Hue of 2.5Y to 5BG, value of 3 to 6, and chroma of 1 or less.
Redoximorphic features--Masses of iron accumulation and iron depletions in shades of brown and gray range from none to common.
Texture--Silty clay, clay, or silty clay loam
Other features=None
Reaction--Moderately acid to moderately alkaline

COMPETING SERIES: There are no other series in the same family.

GEOGRAPHIC SETTING: Gramercy soil are on flood plains of the lower Mississippi River and its distributaries in the Southern Mississippi Valley Alluvium Major Land Resource Area. Slope gradients are generally less than 1 percent, but range up to 2 percent. Elevation ranges from 5 to 20 feet above mean sea level. Mean annual air temperature ranges from 65 to 75 degrees F., and mean annual precipitation is 55 to 70 inches. Annual frost free days range from 235 to 350.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cancienne, Mhoon, and Schriever series. Cancienne and Mhoon soils are on slightly higher natural levee positions and average less than 18 percent clay throughout the 10 to 40 inch control section. Schriever soils are on slightly lower positions and average more than 60 percent clay throughout the 10 to 40 inch control section.

DRAINAGE AND PERMEABILITY: Poorly drained. Runoff is slow. These soils are very slowly permeable in the clayey A and Bssg horizons, and moderately permeable in the loamy 2Bg and 2C horizons. Gramercy soils are wet in the surface layer between 0 and 6 inches, and in the loamy subsoil and substratum layers below the discontinuity during the months of January through April during normal years; and they are moist in the Bg and Bssg horizons. Areas of these soils that are not protected by levees are subject to rare to frequent flooding for brief to long periods.

USE AND VEGETATION: Most areas of Gramercy soils are cultivated to sugarcane, soybeans, cotton, small grains, corn, hay, or pasture. A smaller amount of the total acreage is in bottomland hardwoods. In wooded areas, the overstory generally consists of cherrybark oak, eastern cottonwood, green ash, nuttall oak, sweetgum, American sycamore, elm, water oak, hackberry, pecan, and water hickory.

DISTRIBUTION AND EXTENT: Southern Mississippi Valley Alluvium (MLRA 131) in South-central Louisiana; The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: AUBURN, ALABAMA

SERIES ESTABLISHED: St. John the Baptist Parish, Louisiana, 2004. Gramercy soils formerly were included with the Sharkey, Mhoon, and Tunica series.

REMARKS: Diagnostic horizons and features in this pedon include:

Umbric epipedon-----------0 to 11 inches (Ap & Assg horizon)
Cambic horizon------------11 to 80 inches (Bssg, Ab, and Bg horizons)
Aquic conditions----------0 to 11 inches (episaturation and redoximorphic features in the Ap horizon)
Intersecting slickensides-11 to 35 inches (Bssg horizons)

ADDITIONAL DATA: Characterization data for this pedon were run at the NSSL, Lincoln, Nebraska; Pedon no.S2000LA-095-001

MLRA = 131; Southern Mississippi Valley Alluvium

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National Cooperative Soil Survey
U.S.A.