LOCATION STUTTGART AR
Established Series
Rev. LBW:MAV
11/2019
STUTTGART SERIES
The Stuttgart series consists of very deep, moderately well to somewhat poorly drained, slowly permeable soils that formed in silty and clayey alluvium. These level to gently sloping soils are on Prairie terraces in the Lower Mississippi Valley, MLRA 131. Slopes are typically less than 3 percent, but range to 5 percent.
TAXONOMIC CLASS: Fine, smectitic, thermic Albaquultic Hapludalfs
TYPICAL PEDON: Stuttgart silt loam - cultivated (Colors are for moist conditions)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam; weak medium granular structure; very friable; common fine and medium roots; common fine pores; few medium faint dark gray (10YR 4/1) iron depletions; common fine faint brown (10YR 4/3) iron accumulations; few fine hard iron-manganese concretions; strongly acid; abrupt smooth boundary. (4 to 7 inches thick)
A--6 to 11 inches; grayish brown (10YR 5/2) silt loam; weak medium subangular blocky structure; friable; common fine and medium roots; few fine pores; common medium distinct brown (7.5YR 4/4) and common fine faint brown (10YR 5/3) iron accumulations; few fine hard iron-manganese concretions; moderately acid; clear smooth boundary. (3 to 7 inches thick)
E--11 to 23 inches; yellowish brown (10YR 5/4) silt loam; weak medium subangular blocky structure; friable; common fine roots; few fine pores; common medium distinct light brownish gray (10YR 6/2) and pale brown (10YR 6/3) iron depletions; common fine hard iron-manganese concretions; very strongly acid; abrupt smooth boundary. (6 to 15 inches thick)
Bt1--23 to 35 inches; red (2.5YR 4/6) silty clay; weak coarse prismatic structure parting to moderate medium subangular blocky structure; firm; few fine roots; few fine pores; many distinct clay films lining pores and on faces of most peds; many medium prominent grayish brown (10YR 5/2) iron depletions; few fine and medium prominent yellowish brown (10YR 5/4) clay depletions on faces of prisms; few fine hard iron-manganese concretions; moderately acid; clear smooth boundary.
Bt2--35 to 46 inches; grayish brown (10YR 5/2) silty clay loam; moderate medium subangular blocky structure; firm; few fine pores; few distinct clay films lining some pores and on faces of some peds; common medium distinct yellowish brown (10YR 5/6) iron acummulations and common medium distinct gray (10YR 6/1) iron depletions; few fine and medium black (10YR 2/1) and very dark brown (10YR 2/2) manganese accumulations on faces of some peds; few fine hard iron-manganese concretions; moderately acid; gradual wavy boundary.
Bt3--46 to 60 inches; light brownish gray (10YR 6/2) silty clay loam; moderate medium subangular blocky structure; firm; few fine pores; few distinct clay films lining some pores and on faces of some peds; common medium distinct strong brown (7.5YR 5/6) iron acummulations and common medium distinct gray (10YR 5/1) iron depletions; common fine and medium black (10YR 2/1) and very dark brown (10YR 2/2) manganese accumulations on faces of some peds; common fine hard iron-manganese concretions; moderately acid; gradual wavy boundary.
Bt4--60 to 80 inches; light brownish gray (10YR 6/2) and gray (10YR 6/1) silty clay loam; weak medium subangular blocky structure; firm; few fine pores; few distinct clay films lining some pores and on faces of some peds; common medium distinct strong brown (7.5YR 5/6) iron acummulations; common fine and medium black (10YR 2/1) and very dark brown (10YR 2/2) manganese accumulations on faces of some peds; few fine hard iron-manganese concretions; moderately acid. (Combined thickness of the Bt horizon ranges from 48 to more than 60 inches.)
TYPE LOCATION: Lonoke County, Arkansas; SE1/4SW1/4SW1/4, Sec. 4, T. 1 N., R. 7 W.
RANGE IN CHARACTERISTICS: Solum thickness is more than 60 to more than 80 inches. There is an abrupt texture change between the ochric epipedon and the underlying argillic horizon. Sodium saturation ranges from 5 to 15 percent in the upper 16 inches of the argillic. It generally increases with depth and may range over 20 percent in the lower part in some pedons.
The A or Ap horizon has hue of 10YR, value of 4 or 5, and chroma of 2 to 4. Iron accumulations and depletions are in shades of gray and brown. Reaction is typically strongly acid or moderately acid, but ranges to neutral where limed or affected by irrigation water
The E horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 3 or 4. Iron accumulations and depletions are in shades of brown, red and gray. Texture is silt loam or silt. Reaction typically ranges from very strongly acid to moderately acid, but areas affected by alkaline irrigation water may range to neutral.
The Bt horizon has hue of 5YR or 2.5YR, value of 4 or 5, and chroma of 4 to 8. Iron accumulations are in shades of brown. Iron and clay depletions are in shades of gray and brown. In some pedons, there is no dominant hue and the horizon is variegated in shades of red, brown and gray. Texture is silty clay loam, silty clay or clay. Reaction ranges from very strongly acid through moderately acid.
The lower Btg horizons, or Btng horizons where present, have hue of 10YR, value of 5 or 6, and chroma of 1 or 2. Iron accumulations and depletions are in shades of brown, yellow, red, or gray. Black to dark brown manganese accumulations are present in some pedons. Texture is silty clay loam or silt loam. Reaction ranges from moderately acid to slightly alkaline.
The BCg, BCtg, BCng, or BCtng horizon, where present, has hue of 10YR, value of 5 or 6, and chroma of 1 or 2. Iron accumulations and depletions are in shades of brown, yellow, red, or gray. Black to dark brown manganese accumulations are present in some pedons. Texture is silty clay loam, silt loam or clay loam. Reaction ranges from moderately acid to slightly alkaline.
COMPETING SERIES: Stuttgart is the only series in this family.
GEOGRAPHIC SETTING: Stuttgart soils are on the Grand Prairie of Arkansas and other similar Prairie terraces in the Lower Mississippi Valley, MLRA 131. The terraces are thought to be made up of sediments from the Arkansas River system with a silty mantle from the Mississippi River system. The upper mantle may be mixed with loess in some places. The average annual air temperature ranges from about 60 to 65 degrees F., and average annual precipitation ranges from about 50 to 55 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Dewitt,
Ethel
Immanuel and
Tichnor series. Dewitt soils, which occur on similar landscapes, have aquic mositure regimes and are poorly drained. Ethel soils, which occur on level to depressional landscapes are in a fine-silty particle-size family, do not have an
abrupt texture change and contain a glossic horizon.
Immanuel soils typically occur on more disected landscapes around the perimeter of the terrace and on escarpments. They are in a fine-silty particle-size family, do not have an abrupt texture change and contain a glossic horizon.
Tichnor soils occur on local floodplains. They are in a fine-silty particle-size family, have ochric epipedons greater than 24 inches thick, do not contain an abrupt texture change and are poorly drained.
DRAINAGE AND PERMEABILITY: Moderately well to somewhat poorly drained. Runoff is negligible to high, depending on slope. Permeability is slow.
USE AND VEGETATION: Most areas are cleared and used for the production of rice, soybeans, small grains and corn. The native vegetation was mainly tall
grasses, with large areas of hardwood forests of oaks, gums and ash with scattered areas of shortleaf pine.
DISTRIBUTION AND EXTENT: Prairie terraces in Arkansas and possibly Louisiana. The series is of large extent with over 150,000 acres mapped.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: TEMPLE, TEXAS
SERIES ESTABLISHED: St. Francis County, Arkansas, 1964.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon..................0 to 23 inches (Ap, A, E)
Abrupt Texture Change............Contact between E and Bt
Argillic horizon................ 23 to 80 inches (Bt1, Bt2, Bt3, Bt4)
ADDITIONAL DATA: The typical pedon was characterized by the University of Arkansas Soil Characterization Laboratory. Pedon S79-085-01.
National Cooperative Soil Survey
U.S.A.