LOCATION PORTAGEVILLE            MO

Established Series
Rev. BLB-RLT
02/2013

PORTAGEVILLE SERIES

The Portageville series consists of very deep, poorly drained, very slowly permeable soils formed in alluvium. These soils are on depressional to level areas of flood plains. Slopes are 0 to 2 percent. Mean annual temperature is about 60 degrees F, and mean annual precipitation is about 48 inches.

TAXONOMIC CLASS: Fine, smectitic, calcareous, thermic Vertic Endoaquolls

TYPICAL PEDON: Portageville clay - on a plane slope in a cultivated field at an elevation of 265 feet. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 6 inches; very dark grayish brown (10YR 3/2) clay, grayish brown (10YR 5/2) dry; few fine prominent dark reddish brown (5YR 3/3) mottles; weak fine and medium granular structure; very firm; neutral; abrupt smooth boundary. (4 to 10 inches thick)

A--6 to 15 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; moderate fine and medium subangular blocky structure; very firm; few fine roots and pores; common medium prominent dark reddish brown (5YR 3/4) masses of iron accumulation; slightly effervescent; mildly alkaline; gradual smooth boundary. (6 to 16 inches thick)

Bg1--15 to 25 inches; dark gray (10YR 4/1) clay; moderate medium angular blocky structure; very firm; few slickensides; common medium prominent reddish brown (5YR 4/3) and few coarse prominent yellowish red (5YR 4/6) masses of iron accumulation; slightly effervescence; moderately alkaline; gradual smooth boundary.

Bg2--25 to 47 inches; gray (5Y 5/1) and dark grayish brown (2.5Y 4/2) clay; weak medium angular blocky structure; very firm; few slickensides; few fine prominent dark reddish brown (2.5YR 2.5/4) and common fine prominent dark reddish brown (5YR 3/4) and yellowish red (5YR 4/8) masses or iron accumulation; strongly effervescent; moderately alkaline; gradual smooth boundary. (Combined thickness of the Bg horizon is 24 to 40 inches)

Cg--47 to 60 inches; gray (5Y 5/1) and dark grayish brown (10YR 4/2) clay; massive; very firm; stratified with strata 1/2 to 2 inches, dark reddish brown (5YR 3/4) and yellowish red (5YR 4/8) colors appear as thin lines between the strata; few thin lenses (about 1/2 inch thick) of very fine sandy loam; common fine prominent dark reddish brown (5YR 3/4) and dark brown (7.5YR 4/4) masses of iron accumulation; strongly effervescent; moderately alkaline.

TYPE LOCATION: Pemiscot County, Missouri; about 2 miles northeast of Concord; 1,200 feet south and 400 feet west of the center of sec. 32, T. 20 N., R. 13 E; USGS Stanley quadrangle, lat. 36 degrees 44 minutes 31 seconds N. and long. 89 degrees 40 minutes 8 seconds W.

RANGE IN CHARACTERISTICS: The mollic epipedon commonly is 10 to 20 inches thick, but ranges to 24 inches. Commonly there is distinct stratification within 48 inches. The particle size control section averages 50 to 60 percent clay and ranges to 65 percent.

The A horizon has hue of 10YR or 2.5Y, value of 2 or 3 and chroma of 1 or 2 or it is neutral with value of 2 or 3. The horizon commonly is mottled. It commonly is clay, but includes silty clay and silty clay loam. It is neutral or mildly alkaline in the Ap and mildly or moderately alkaline in the A horizon.

The Bg and Cg horizons have hue of 10YR to 5Y, value of 4 or 5 and chroma of 1 or 2 or are neutral with value of 4 or 5. They are clay or silty clay. Reaction is mildly or moderately alkaline.

COMPETING SERIES: These are the Dospalos, Gepford, Tinn, and Tulare soils in the same family and the Alligator, Iberia, and Sharkey soils. These soils have a different climate. In addition, Dospalos and Tinn soils have mollic epipedons greater than 24 inches. Gepford soils have higher conductivity. Tulare soils have higher lime content. Alligator and Sharkey soils lack mollic epipedons. Iberia soils are not calcareous.

GEOGRAPHIC SETTING: Portageville soils are on depressional to level areas of the Mississippi River flood plains. Slopes range from 0 to 2 percent. The soils formed in alluvium. Mean annual temperature ranges from 58 to 62 degrees F. Mean annual precipitation ranges from 45 to 50 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Caruthersville, Commerce, Cooter, Crevasse, Hayti, and Sharkey soils. Caruthersville and Commerce soils have less clay and commonly are on higher flood plains or natural levees. Cooter soils are sandy at depths of 12 to 24 inches and in similar positions. Crevasse soils are sandy and are where there have been levee breaks and close to stream channels. Hayti soils have less clay and are in similar positions. Sharkey soils have more clay and are in similar positions.

DRAINAGE AND PERMEABILITY: Poorly drained. Surface runoff is negligible. Permeability is very slow.

USE AND VEGETATION: Most areas are cropped to soybeans and cotton. Native vegetation is water tolerant trees.

DISTRIBUTION AND EXTENT: Mississippi River Delta area (MLRA 131) of southeast Missouri. The series is of moderate extent.

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

SERIES ESTABLISHED: Pemiscot County, Missouri, 1966.

REMARKS: Diagnostic horizons and features in this pedon are:
Mollic epipedon - the zone from the surface of the soil to a depth of 15 inches (Ap and A horizons)

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National Cooperative Soil Survey
U.S.A.