LOCATION FORNEY IA+NE SD
Established Series
Rev. LEB-BC-PTC-RJB
06/2015
FORNEY SERIES
The Forney series consists of very deep, poorly drained soils formed in clayey alluvium on flood plains. Slope ranges from 0 to 2 percent. Mean annual air temperature is about 10 degrees C (50 degrees F), and mean annual precipitation is about 710 millimeters (28 inches).
TAXONOMIC CLASS: Fine, smectitic, nonacid, mesic Vertic Fluvaquents
TYPICAL PEDON: Forney silty clay with about 1/2 percent slope on a nearly level flood plain - cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 13 centimeters (0 to 5 inches); very dark gray (10YR 3/1) silty clay, dark gray (5Y 4/1) dry; moderate very fine subangular blocky structure; firm; few fine faint very dark grayish brown (10YR 3/2) redox depletions; slightly acid; clear smooth boundary.
A--13 to 20 centimeters (5 to 8 inches); very dark grayish brown (2.5Y 3/2) silty clay, dark grayish brown (2.5Y 4/2) crushed, gray (5Y 5/1) dry; weak fine subangular blocky structure; firm; some very fine blocky peds of black (10YR 2/1) and some black (10YR 2/1) material in channels and voids; few fine distinct brown (10YR 4/3) redox concentrations; neutral; clear smooth boundary. [Combined thickness of the A horizons is 10 to 25 centimeters (4 to 10 inches).]
Cg1--20 to 38 centimeters (8 to 15 inches); dark grayish brown (2.5Y 4/2) silty clay; massive but parts along planes of weakness; firm; few black (10YR 2/1) channel fillings; faces of peds have high sheen; few very fine pores; few fine distinct brown (10YR 4/3) redox concentrations; neutral; gradual smooth boundary.
Cg2--38 to 48 centimeters (15 to 19 inches); dark grayish brown (2.5Y 4/2) silty clay; massive but parts along planes of weakness; firm; some black (10YR 2/1) channel fillings; faces of peds have high sheen; no visible pores; faces of peds dark gray (5Y 4/1) redox depletions; few fine distinct yellowish brown (10YR 5/4) and brown (7.5YR 4/4) redox concentrations; neutral; abrupt smooth boundary. [Combined thickness of the C horizons is 15 to 41 centimeters (6 to 16 inches).]
2Ab--48 to 74 centimeters (19 to 29 inches); black (N 2/0) silty clay, dark gray (5Y 4/1) dry; moderate fine subangular blocky structure; firm; faces of peds smooth and with high sheen; very few very fine pores; few fine distinct olive (5Y 5/3) redox concentrations; neutral; clear smooth boundary. [25 to 51 centimeters (10 to 20 inches) thick]
2Bgb--74 to 86 centimeters (29 to 34 inches); dark gray (5Y 4/1) silty clay, olive gray (5Y 4/2) crushed; moderate fine subangular blocky structure; very firm; some black (5Y 2/1) staining on faces of peds; faces of peds smooth and with high sheen; no visible pores; few fine dark oxides (iron and manganese oxides); few fine faint olive (5Y 5/3) and few fine distinct strong brown (7.5YR 5/6) redox concentrations; slightly alkaline; gradual smooth boundary. [13 to 25 centimeters (5 to 10 inches) thick].
2BCgb--86 to 114 centimeters (34 to 45 inches); gray (5Y 5/1) silty clay; weak fine subangular blocky structure with some vertical cleavage; very firm; few fine dark oxides (iron and manganese oxides); common fine prominent strong brown (7.5YR 5/8) redox concentrations; slightly alkaline; gradual smooth boundary. [0 to 36 centimeters (0 to 14 inches) thick].
2Cg--114 to 152 centimeters (45 to 60 inches); gray (5Y 5/1) silty clay; massive with some vertical cleavage; firm; few fine dark concretions (iron and manganese oxides); slightly alkaline.
TYPE LOCATION: MLRA 107B (Iowa and Missouri Deep Loess Hills, South Part); Harrison County, Iowa subset; about 1.6 kilometers (1 mile) south and 4.8 kilometers (3 miles) west of the town of Missouri Valley; 34 meters (110 feet) south and 625 meters (2,050 feet) east of the NW corner of sec. 19, T. 78 N., R. 44 W. at elevation 305 meters (1000 feet) above mean sea level. U.S.G.S. Missouri Valley, Iowa-Nebr. Topographic Quadrangle; latitude 41 degrees, 32 minutes and 58 seconds N., longitude 95 degrees, 56 minutes, and 59 seconds W.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is moist from November to July; aquic moisture regime.
Mean annual soil temperature: 9 to 14 degrees C (49 to 58 degrees F)
Depth to redox concentrations: 10 to 25 centimeters (4 to 10 inches)
Depth to lithologic discontinuity: 25 to 66 centimeters (10 to 26 inches)
Thickness of the ochric epipedon: less than 25 centimeters (< 10 inches)
Thickness of the solum: less than 25 centimeters (<10 inches)
Particle-size control section (weighted average): silty clay or clay
Clay content: 50 to 60 percent
Sand content: <15 percent
Ap or A horizon:
Hue: 2.5Y, 10YR, or neutral
Value: 3
Chroma: 0 to 2
Texture: clay, silty clay or silty clay loam
Clay content: 27 to 60 percent
Calcium carbonate equivalent: 0 to 15 percent, 0 to 25 percent if silt loam or silty clay loam
Reaction: slightly acid to slightly alkaline; slightly acid to moderately alkaline if silt loam or silty clay loam
Thickness: 10 to 25 centimeters (4 to 10 inches)
Note: Some pedons have silt loam texture in the Ap or A horizon with 20 to 27 percent clay.
Cg horizon:
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
Texture: clay or silty clay
Clay content: 40 to 60 percent
Calcium carbonate equivalent: 0 to 15 percent
Reaction: slightly acid to slightly alkaline
Thickness: 15 to 41 centimeters (6 to 16 inches)
Note: Few or common redox features are in most pedons. Stratification is evident in some pedons.
2Ab horizon:
Hue: 2.5Y, 5Y, or neutral
Value: 3 or less
Chroma: 1 or less
Texture: silty clay or clay
Clay content: 50 to 60 percent
Calcium carbonate equivalent: 0 to 15 percent
Organic Matter: 3 percent
Reaction: slightly acid to slightly alkaline
Thickness: 25 to 51 centimeters (10 to 20 inches)
Note: Thin horizons less than 6 inches thick with lower clay contents are in some pedons.
2Bg horizon:
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
Texture: silty clay or clay
Clay content: 50 to 60 percent
Calcium carbonate equivalent: 0 to 15 percent
Reaction: slightly acid to slightly alkaline
Thickness: 0 to 36 centimeters (0 to 14 inches)
2Cg horizon:
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
Texture: silty clay or clay
Clay content: 50 to 60 percent
Calcium carbonate equivalent: 0 to 15 percent
Reaction: slightly acid to slightly alkaline
Note: The 2Bgb and 2Cg horizons are separated by a 2Ab horizon in some pedons.
COMPETING SERIES: These are the:
Rennie soils lack a 2Ab horizon and receive two to three times the annual precipitation.
Other similar soils are the:
Abbott soils contain free carbonates throughout the control section and lack a buried soil.
Albaton soils contain free carbonates throughout the control section and lack a buried soil.
Cape soils are in the acid family and have more than 890 millimeters (35 inches) of rainfall precipitation.
GEOGRAPHIC SETTING:
Parent material: clayey alluvium over a clayey buried soil
Landform: flood plains and oxbow lakes of the Missouri River
Slopes: 0 to 2 percent
Elevation: 275 to 505 meters (900 to 1650 feet)
Mean annual air temperature: 8 to 13 degrees C (47 to 56 degrees F)
Mean annual precipitation: 510 to 890 millimeters (20 to 35 inches)
Frost-free period: 135 to 165 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are:
Albaton soils on similar landscape positions.
Blencoe soils on similar landscape positions.
Blend soils on similar landscape positions.
Cooper soils at slightly higher elevations on the flood plains.
Luton soils on similar landscape positions.
Moville soils at slightly higher elevations on the flood plains.
Owego soils on similar landscape positions.
DRAINAGE AND PERMEABILITY:
Drainage: the seasonal high water table is at a depth of 0 to 30 centimeters (0 to 1 foot) during November to July in most years. In dry areas, the seasonal high water table is at a depth of 30 to 90 centimeters (1 to 3 feet) for brief periods in most years.
Permeability: very slow
Runoff: very slow
Flooding: these soils are subject to rare or common flooding for brief periods. Flooding is limited where these soils are protected by dams or levees.
USE AND VEGETATION: Most areas of Forney soils are drained by surface ditches or land grading and are cropped to corn and soybeans. Native vegetation was grasses tolerant to wetness. See Additional Data section for native vegetative cover in Iowa.
DISTRIBUTION AND EXTENT: Forney soils are along the intermediate flood plains of the Missouri River Valley and its tributaries in the Major Land Resource Areas 102C (Loess Uplands) and 107B (Iowa and Missouri Deep Loess Hills, South Part) within the Central Feed Grains and Livestock Region (Land Resource Region M). They are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Woodbury County, Iowa, 1971.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 25 to 100 centimeters (10 to 40 inches - Cg1, Cg2, 2Ab, 2Bgb, 2BCgb horizons)
Ochric epipedon: The zone from 0 to 20 centimeters (0 to 8 inches - Ap and A horizons)
Other features: aquic moisture regime.
Remarks: The structure in the C horizons is the result of the high clay content of the strata rather than pedogenesis.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Eighth edition, 1998
ADDITIONAL DATA: Laboratory data are available from Iowa State University Soil Survey Laboratory for this site.
Series T Value: 5
Surface K value: .28
Surface Wind Erodibility Group: 4
Surface Wind Erodibility Index: 86
In Iowa, the native vegetative cover is a herbaceous wetland community commonly inhabited with Rice Cutgrasses, Softstem Bulrushes, Needle Spikerushes, Broadfruit Burreeds, Pickerel Weeds, Broadleaf Cattails, Water Smartweeds, American Water Lilies, Yellow Pond Lilies, American Lotuses, Small Pondweeds, Sago Pondweeds, and Arrowheads. Source: Iowa State Office, Natural Resources Conservation Service, Des Moines, IA.
National Cooperative Soil Survey
U.S.A.