LOCATION BALDWIN LA

Established Series
Rev. JDS
10/2018

BALDWIN SERIES

The Baldwin series consists of deep, poorly drained, very slowly permeable soils that formed in alluvium. These soils are on the middle and lower parts of natural levees on the Mississippi River delta plain and its tributaries. Slopes range from 0 to 3 percent.

TAXONOMIC CLASS: Fine, smectitic, hyperthermic Chromic Vertic Epiaqualfs

TYPICAL PEDON: Baldwin silty clay loam - on a 1 percent slope, in pasture.
(Colors are for moist soil unless otherwise stated.)

Ap--0 to 6 inches; dark grayish brown (2.5Y 4/2) silty clay loam; moderate medium subangular blocky structure parting to weak medium granular; firm, moderately sticky and slightly plastic; many fine roots throughout; many fine continuous tubular pores; few fine prominent cylindrical yellowish brown (10YR 5/8) masses of iron accumulation throughout; moderately acid; clear smooth boundary.

A--6 to 11 inches; dark gray (2.5Y 4/1) silty clay loam; moderate medium subangular blocky structure; firm, moderately sticky and slightly plastic; many fine roots throughout; many fine continuous tubular pores; few fine irregular prominent light olive brown (2.5Y 5/6) masses of iron accumulation between peds; neutral; gradual smooth boundary. (Combined thickness of the A and Ap horizons is 6 to 12 inches)

Btg1--11 to 17 inches; gray (5Y 5/1) silty clay; strong medium subangular blocky structure; very firm, moderately sticky and moderately plastic; many fine roots between peds; many faint continuous very dark gray (5Y 3/1) clay films on faces of peds; many distinct pressure faces on vertical and horizontal faces of peds; many medium irregular prominent olive yellow (2.5Y 6/6) masses of iron accumulation between peds; many medium irregular prominent yellowish brown (10YR 5/8) masses of iron accumulation between peds; slightly alkaline; gradual smooth boundary.

Btg2--17 to 26 inches; olive gray (5Y 5/2) silty clay; strong medium subangular blocky structure; very firm, moderately sticky and moderately plastic; few fine roots between peds; few fine continuous tubular pores; common distinct continuous dark gray (2.5Y 4/1) clay films on faces of peds; common distinct pressure faces on vertical and horizontal faces of peds; common medium irregular prominent dark yellowish brown (10YR 4/6) masses of iron accumulation between peds; slightly alkaline; gradual smooth boundary.

Btg3--26 to 37 inches; dark gray (5Y 4/1) silty clay loam; strong medium subangular blocky structure; firm, moderately sticky and slightly plastic; few fine roots between peds; few fine continuous tubular pores; common faint continuous very dark gray (5Y 3/1) clay films on faces of peds; common distinct pressure faces on vertical and horizontal faces of peds; common medium irregular prominent brownish yellow (10YR 6/8) masses of iron accumulation between peds; slightly alkaline; gradual smooth boundary.

Btg4--37 to 46 inches; olive gray (5Y 5/2) silty clay loam; strong medium angular blocky structure; firm, moderately sticky and slightly plastic; few fine roots between peds; few prominent discontinuous very dark gray (2.5Y 3/1) clay films on faces of peds; few distinct pressure faces on vertical and horizontal faces of peds; many medium irregular prominent olive yellow (2.5Y 6/6) masses of iron accumulation between peds; many medium irregular prominent brownish yellow (10YR 6/8) masses of iron accumulation between peds; few fine rounded iron-manganese nodules throughout; slightly alkaline; abrupt smooth boundary. (Combined thickness of the Btg horizon is 14 to 36 inches)

2ABg--46 to 55 inches; dark gray (5Y 4/1) silty clay; moderate medium wedge-shaped aggregates structure parting to strong medium angular blocky; very firm, very sticky and very plastic; few fine roots between peds; few fine tubular pores; many distinct pressure faces on vertical and horizontal faces of peds; common medium irregular prominent brownish yellow (10YR 6/8) masses of iron accumulation between peds; common fine rounded iron-manganese nodules throughout; slightly alkaline; clear smooth boundary.

2Btg1--55 to 61 inches; grayish brown (2.5Y 5/2) silty clay loam; moderate medium subangular blocky structure; firm, moderately sticky and slightly plastic; few fine roots between peds; many distinct continuous dark gray (5Y 4/1) clay films on faces of peds and in pores; many medium irregular prominent brownish yellow (10YR 6/6) masses of iron accumulation between peds; common medium rounded masses of manganese accumulation throughout; slightly alkaline; gradual smooth boundary.

2Btg2--61 to 71 inches; olive gray (5Y 5/2) silty clay loam; strong medium prismatic structure parting to moderate medium angular blocky; firm, moderately sticky and slightly plastic; few fine tubular pores; common faint continuous dark gray (5Y 4/1) clay films on faces of peds; many medium irregular prominent yellowish brown (10YR 5/8) masses of iron accumulation between peds; common fine rounded manganese nodules throughout; slightly alkaline; gradual smooth boundary.

2Btg3--71 to 87 inches; olive gray (5Y 5/2) silty clay loam; strong medium prismatic structure parting to strong medium angular blocky; firm, moderately sticky and slightly plastic; few fine tubular pores; many distinct pressure faces on vertical and horizontal faces of peds; common distinct discontinuous gray (2.5Y 5/1) clay films on faces of peds; common medium irregular prominent yellowish brown (10YR 5/8) masses of iron accumulation between peds; few fine rounded manganese nodules throughout; slightly alkaline.

TYPE LOCATION: Iberia Parish, Louisiana; 2 miles east of New Iberia on LA. 86, to Justine Antebellum home, .3 miles south on paved road, 250 feet east of fence, 2400 feet southwest of northeast corner of Spanish Land Grant section 8, T.12S., R.7 E.;30 degrees 0 minutes 22.8 seconds N. Latitude; 91 degrees 45 minutes 49.2 seconds W Longitude, USGS St. Martin Quadrangle, Louisiana.

RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to more than 80 inches. These soils form cracks when dry that extend to depths of 20 inches or more and remain open for 10 to 30 days during normal years. PLE calculated from the COLE is 6 to 10 cm. in the upper 40 inches of the solum.

The A horizon has hue of 10YR, value of 3 or 4, and chroma of 1 or 2. Where value is 3, the thickness of the layer is 4 inches or less, and the soil material when mixed to a depth of 7 inches has value of 4. Texture is silt loam or silty clay loam. Reaction ranges from very strongly acid to neutral.

The Btg horizon has hue of 10YR to 5Y, value of 4 to 6, and chroma of 1 or 2. It is clay, silty clay, or silty clay loam. Masses of iron accumulation are in shades of brown or olive. Most peds have dark gray or very dark gray, silty or clayey coatings. Reaction ranges from moderately acid to slightly alkaline. In some pedons, one or more subhorizons of the Bt horizon contain 1 to 5 percent calcium carbonate concretions that are 2 to 20 mm. in diameter.

The 2ABg horizon, where present has hue of 10YR to 5Y, value of 3 or 4, and chroma of 1 or 2. It is clay, silty clay, or silty clay loam. Masses of iron accumulation are in shades of brown or olive. Most peds have dark gray or very dark gray, silty or clayey coatings. Reaction ranges from moderately acid to slightly alkaline.

The 2Btg or BCg horizon has hue of 10YR to 5Y, value of 4 to 6, and chroma of 1 or 2. It is clay, silty clay, or silty clay loam. Masses of iron accumulation are in shades of brown or olive. Reaction ranges from moderately acid to moderately alkaline. In some pedons, the 2Btg or BCg horizon contains 1 to 5 percent calcium carbonate concretions that are 2 to 20 mm. in diameter.

The 2Cg or Cg horizon, where present has hue of 10YR to 5Y, value of 4 to 6, and chroma of 1 or 2. Masses of iron accumulation are in shades of brown or olive. Texture is clay, silty clay, silty clay loam, silt loam, loam, or very fine sandy loam. Reaction ranges from neutral to moderately alkaline.

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

GEOGRAPHIC SETTING: These soils are on the middle and lower parts of natural levees. Slope gradients are 0 to 3 percent. Baldwin soils formed in alluvium from older runs of the Mississippi River where sediments have weathered enough to develop argillic horizons. The climate is humid temperate; mean annual precipitation is 56 inches, and mean annual temperature is 77 degrees F. near the type location.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dundee, Galvez, Iberia, and Loreauville series. Dundee, Galvez, and Loreauville soils are on the higher parts of the natural levee, and have less than 35 percent clay in the subsoil. Iberia soils are on lower, backswamp positions, form slickensides, and have a dark colored surface layer more than 12 inches thick.

DRAINAGE AND PERMEABILITY: Poorly drained; low surface runoff; very slow permeability.

USE AND VEGETATION: Most areas of the soil areas cultivated. Sugarcane is the major crop, and some rice and soybeans are grown. Native vegetation probably was tall grasses.

DISTRIBUTION AND EXTENT: Largely on natural levees bordering Bayou Teche and similar older channels of the Mississippi River in Louisiana. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: AUBURN, ALABAMA

MLRA: Southern Mississippi Valley Alluvium (131).

SERIES ESTABLISHED: St. Mary Parish, Louisiana; 1953.

REMARKS: Diagnostic horizons and features recognized in the type location pedon include:
Ochric epipedon 0 to 11 inches (Ap and A horizons)
Argillic horizon 11 to 46 inches (Btg horizons)
Lithologic discontinuity at 46 inches (top of 2ABg horizon)
PLE = 8.35 0 to 40 inches

LAB DATA: Lab analyses were run by NSSL, Lincoln, Nebraska on samples from the type location pedon (S95LA-045-002).

National Cooperative Soil Survey
U.S.A.