LOCATION ELVIRA                  IA

Established Series


The Elvira series consists of deep, poorly drained soils formed in silty alluvium on flood plains. These soils have moderate permeability in the solum and rapid permeability in the underlying material. The Elvira soils are high in free iron. Slopes range from 0 to 2 percent. Mean annual precipitation is about 34 inches, and mean annual temperature is about 50 degrees F.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Endoaquolls

TYPICAL PEDON: Elvira silty clay loam - on a slope of less than 1 percent in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 7 inches; black (10YR2/1), silty clay loam, very dark gray (10YR3/1) dry; weak medium angular and subangular blocky structure; firm; moderately acid; clear smooth boundary.

A--7 to 15 inches; black (N 2/0) silty clay loam, very dark gray (10YR3/1) dry; moderate medium subangular blocky structure; firm; many worm holes and root channels with dark reddish brown (5YR3/3) stains; common fine soft dark red (2.5YR3/6) Fe and Mn oxides; moderately acid; clear wavy boundary. (Combined thickness of A horizons is 12 to 24 inches.)

Bg1--15 to 21 inches; dark gray (10YR 4/1) silty clay loam; moderate medium subangular blocky structure; firm; common fine soft dark red (2.5YR 3/6) Fe and Mn oxides; many root channels with reddish brown (5YR 4/3) stains; slightly acid; clear wavy boundary.

Bg2--21 to 28 inches; dark gray (5Y 4/1) silty clay loam; moderate fine subangular blocky structure; firm; many fine soft reddish brown (5YR 4/4) and dark red (2.5YR 3/6) Fe and Mn oxides; slightly acid; clear irregular boundary. (Combined thickness of Bg horizons is 10 to 20 inches.)

Bw--28 to 33 inches; yellowish red (5YR 4/6) silty clay loam; moderate very fine subangular blocky structure; firm; sticky when wet; hard when dry; slightly acid; clear irregular boundary. (3 to 8 inches thick)

BCg--33 to 39 inches; mottled gray (5Y 5/1) and yellowish red (5YR 5/6) silty clay loam; weak coarse prismatic structure; firm; black (10YR 2/1) krotovina with common distinct yellowish red (5YR 4/6) mottles; neutral; clear irregular boundary. (0 to 8 inches thick)

Cg1--39 to 48 inches; grayish brown (2.5Y 5/2) silty clay loam; massive; friable; common fine distinct yellowish red (5YR 4/6) and grayish brown (10YR 5/2) mottles; neutral; clear smooth boundary. (5 to 12 inches thick)

2Cg2--48 to 60 inches; grayish brown (2.5Y 5/2) sandy loam; massive; friable; neutral.

TYPE LOCATION: Clinton County, Iowa; about 2 1/2 miles north and 1/2 mile west of town of Elvira; 320 feet south and 1,060 feet west of center of sec. 22, T. 82 N., R. 5 E.

RANGE IN CHARACTERISTICS: Solum thickness ranges from 36 to 60 inches. Depth of free carbonates is greater than 48 inches. Thickness of the mollic epipedon ranges from 12 to 24 inches. The

A horizon typically is black (10YR 2/1 or N 2/0) but ranges to very dark gray (10YR 3/1). Texture of the A horizon commonly is silty clay loam but ranges to include silt loam and clay loam. There are common or many dark red (2.5YR 3/6), dark reddish brown (5YR 3/3 and 3/4) or reddish brown (5YR 4/3 to 5/4) Fe and Mn oxides, oxide stains or mottles in the A horizon. The A horizon ranges from neutral to medium acid. An AB horizon or BA horizon is in some pedons.

The Bg horizon has hue of 2.5Y or 5Y, value of 4 to 6, and chroma of 1 or 2. Colors in the Bwhorizon and the BCg horizon are commonly the same as in the Bg horizon but subhorizons with matrix colors of 7.5YR or 5YR hue, value of 4 or 5, and chroma of 4 to 6 are in the range. In some pedons, these colors are in a mottled matrix with grayer colors. Oxides and mottles in the B horizon are similar to those in the A horizon. The B horizons commonly are silty clay loam, but thin horizons of clay loam are in the range. Clay content of the B horizons ranges from 28 to 35 percent. Reaction ranges from neutral to medium acid.

The Cg horizon has hues of 2.5Y or 5Y with values of 4 to 6 and chromas of 1 or 2. Texture of the Cg horizon commonly is silty clay loam but ranges to clay loam. The Cg horizon ranges from neutral to slightly acid.

The 2C horizon typically is sandy loam or loamy sand, but strata ranging from clay loam to loamy sand are common.

COMPETING SERIES: These are the Chalmer, Dolbee, Drummer, Garwin, Hartsburg, Leshara, Madelia, Marcus, Maxcreek, Maxfield, Ossian, Patton, Pella, Rushmore, Sable, and Wacousta soils in the same family and Ambraw, Bremer, Beaucoup, Colo, Gorham, and Sawmill series. All of these series lack the concentrations of Fe and Mn oxides in the B horizon and Fe and Mn accumulation in the A horizon. Free iron is higher in Elvira than these soils. Also, Beaucoup and Gorham soils are Fluvaquentic, and Colo and Sawmill soils are Cumulic.

GEOGRAPHIC SETTING: Elvira soils are on flood plains and low stream terraces in nearly level and depressional areas and are subject to flooding. Slope gradient is usually less than 1 percent but ranges up to 2 percent for short distances. Elvira soils formed in silty alluvial sediments that commonly overlay stratified loamy or sandy sediments below 40 inches. Mean annual temperature is from about 47 to 52 degreesF, and mean annual precipitation is from 32 to 35 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Ambraw, Colo, and Sawmill soils, and the Calco soils. These soils occur in the same landscape position as the Elvira series but lack high Fe and Mn concentrations in the solum.

DRAINAGE AND PERMEABILITY: Poorly drained. Runoff is slow in level areas and is ponded in depressional areas that are not artificially drained. Permeability is moderate in the solum and rapid in the underlying material. These soils are frequently flooded.

USE AND VEGETATION: Where artificially drained, they are used mainly for corn and soybeans. The native vegetative cover is a herbaceous wetland community commonly inhabited with Prairie Cordgrasses, Bluejoint Grasses, Fox Sedges, Oval Sedges, Inland Rushes, New England Asters, Foxglove Penstemons, Cool Mountain Mints, Prairie Sundrops, Winged Loosestrifes, and Saw-Tooth Sunflowers.

DISTRIBUTION AND EXTENT: Along some of the major streams in eastern Iowa. They are inextensive. Extent in other states is unknown.


SERIES ESTABLISHED: Clinton County, Iowa, 1978.

REMARKS: Elvira soils have a minimum of 2.5 ppm free iron according to laboratory method 6C2a (S.S.I.R. No.1, Rev. April, 1972).

National Cooperative Soil Survey