LOCATION GIGGER LAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, thermic Typic Fragiudalfs
TYPICAL PEDON: Gigger silt loam, crest of convex ridge on 1 percent slope, in cotton field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; brown (10YR 4/3) silt loam; weak medium granular structure; friable; common fine roots; few fine black concretions; medium acid; abrupt smooth boundary. (4 to 9 inches thick)
Bt1--6 to 15 inches; dark brown (7.5YR 4/4) silt loam; moderate medium subangular blocky structure; friable; few fine roots; few fine discontinuous vesicular pores; few faint clay films on faces of peds; strongly acid; clear wavy boundary. (6 to 12 inches thick)
Bt2--15 to 26 inches; brown (7.5YR 5/4) silty clay loam; moderate medium subangular blocky structure; friable; few fine roots; few fine discontinuous vesicular pores; few faint clay films on faces of peds; few distinct pale brown silt coatings on faces of peds; strongly acid; clear wavy boundary. (8 to 14 inches thick)
Btx1--26 to 33 inches; yellowish brown (10YR 5/4) silt loam; common medium distinct strong brown (7.5YR 5/6) and few medium faint gray (10YR 5/1) mottles; weak very coarse prismatic structure parting to moderate medium subangular blocky; firm, compact and slightly brittle; few fine roots between prisms; few fine discontinuous vesicular pores; few faint clay films on faces of peds; common distinct pale brown silt coatings on faces of peds; strongly acid; clear irregular boundary. (4 to 10 inches thick)
2Btx2--33 to 41 inches; yellowish brown (10YR 5/4) silt loam containing noticeable sand; common medium distinct strong brown (7.5YR 5/6) and few medium faint light brownish gray (10YR 6/2) mottles; weak very coarse prismatic structure parting to moderate medium subangular blocky; prisms and peds separated by 0.5 to 3 cm wide wedges of pale brown silt loam; prisms are firm and brittle and comprise about 85 percent of the horizontal cross section; few fine roots between prisms; common fine discontinuous vesicular pores; few faint clay films on faces of peds; few fine dark brown concretions; few medium black stains on faces of peds; strongly acid; clear irregular boundary. (6 to 15 inches thick)
2Btx3--41 to 55 inches; brown (7.5YR 4/4) silt loam; common medium distinct light brownish gray (10YR 6/2) and common medium faint strong brown (7.5YR 5/8) mottles; weak very coarse prismatic structure parting to moderate medium subangular blocky; firm; compact and brittle; common fine discontinuous vesicular pores; few faint clay films on faces of peds; distinct pale brown silt coatings on faces of peds and prisms; strongly acid; gradual wavy boundary. (0 to 15 inches thick)
2Bt--55 to 65 inches; brown (7.5YR 4/4) loam; weak coarse subangular blocky structure; friable; few fine vesicular pores; few faint clay films on faces of peds; few fine black stains on faces of peds; few distinct pale brown silt coatings on faces of peds; strongly acid.
TYPE LOCATION: Franklin Parish, Louisiana; 1 mile southeast of Liddieville; 0.8 mile east of State Highway 135; 300 feet south of equipment shed; northeast 1/4 southeast 1/4, sec. 10, T. 13 N., R. 6 E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to 100 inches. Depth to the fragipan ranges from 18 to 35 inches. Reaction of the A and Bt horizons ranges from medium acid to extremely acid, except for surface layers that have been limed. The Btx, 2Btx, and 2Bt horizons range from medium acid to very strongly acid.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 or 4.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 4 to 6. Texture is silt loam or silty clay loam. The sand content ranges from 5 to 15 percent, dominated by very fine sand.
The Btx and 2Btx horizons have hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 to 6. Mottles are in shades of gray, yellow, or brown. Concretions range from none to common. Texture of the Btx horizon is loam, silt loam, clay loam, or silty clay loam. Texture of the 2Btx horizon is loam, silt loam, clay loam, or silty clay loam, with 15 to 40 percent sand that is dominantly very fine sand.
The 2Bt horizon has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 3 to 6. Texture is fine sandy loam, loam, sandy clay loam, or clay loam.
COMPETING SERIES: These are the Byram, Dulac, Loring, and Providence series in the same family and the Byler, Calloway, Grenada, Libuse, and Necessity series. Byler and Byram soils are underlain by alkaline clays. Calloway, Grenada, and Loring soils have less than 10 percent sand throughout the solum. Dulac soils have clay or silty clay 2B horizons. Libuse soils have siliceous mineralogy. Necessity soils have 1 or 2 chroma mottles in the upper part of the argillic horizon. Providence soils are underlain by siliceous 2B horizons that developed in coastal plain sediment.
GEOGRAPHIC SETTING: Gigger soils are on nearly level to sloping terraces. Slope gradients range from 1 to 8 percent. The soil formed in a thin mantle of loess over loamy Late Pleistocene Age stream terrace sediments. The climate is warm and humid. Average annual precipitation ranges from 45 to 55 inches. Mean annual temperature ranges from 60 to 70 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Necessity series and the Deerford, Dexter, Egypt, Foley and Gilbert series. Deerford and Foley soils are on lower lying areas and have natric horizons. Dexter soils are on higher lying convex ridges and lack fragipans. Egypt and Gilbert soils are on lower lying areas and lack fragipans.
DRAINAGE AND PERMEABILITY: Gigger soils are moderately well drained. Runoff is slow to medium. Permeability is slow. A seasonal high water table is perched above the fragipan for short periods during January through March.
USE AND VEGETATION: Most areas are in cropland or pasture. The main crops are cotton, soybeans, small grains and truck crops. Wooded areas are in oaks, elm, pine, sweetgum, and locust.
DISTRIBUTION AND EXTENT: Louisiana and possibly Arkansas. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Franklin Parish, Louisiana; 1979.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon.........................0 to 6 inches (Ap)
Argillic horizon.......................6 to 65 inches (Bt1,Bt2,Btx1,Btx2,2Btx3,2Bt3)
Fragipan..............................26 to 55 inches (Btx1,2Btx2,2Btx3)
Lithologic discontinuity....................33 inches