LOCATION BLEND                   IA

Established Series
Rev. CSF-RAL-RJB
06/2015

BLEND SERIES

The Blend series consists of very deep, poorly drained soils on flood plains. These soils formed in clayey alluvium. Slopes range from 0 to 2 percent. Mean annual air temperature is about 51 degrees F. Mean annual precipitation is about 29 inches.

TAXONOMIC CLASS: Fine, smectitic, mesic Fluvaquentic Vertic Endoaquolls

TYPICAL PEDON: Blend silty clay, on a nearly level flood plain, in a cultivated field at elevation 1,005 feet above sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 7 inches; black (10YR 2/1) silty clay, very dark gray (10YR 3/1) dry; strong medium and fine angular blocky structure; firm; very few very fine tubular pores; moderately acid; clear smooth boundary.

A--7 to 14 inches; very dark gray (10YR 3/1) silty clay, dark gray (10YR 4/1) dry, faces of peds black (10YR 2/1); moderate fine and very fine subangular blocky structure; firm; few very fine tubular pores; very few fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; slightly acid; gradual smooth boundary. (Combined thickness of the A horizons is 10 to 18 inches.)

2Bg1--14 to 22 inches; dark grayish brown (10YR 4/2) silty clay loam; moderate fine subangular blocky structure; friable; very few very fine tubular pores; common distinct very dark gray (10YR 3/1) organic coatings on faces of peds; common very fine soft iron and manganese concentrations; common fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; slightly acid; clear smooth boundary.

2Bg2--22 to 32 inches; dark grayish brown (10YR 4/2) and dark gray (10YR 4/1) silty clay loam; very weak fine subangular and angular blocky structure; friable; many very fine tubular pores; common distinct very dark gray (10YR 3/1) organic coatings on surfaces of peds; few very fine soft iron and manganese concentrations; many fine prominent strong brown (7.5YR 5/6) and few fine prominent dark reddish brown (5YR 3/3) redoximorphic concentrations; neutral; clear smooth boundary. (Combined thickness of 2Bg horizons is 8 to 18 inches.)

3Agb--32 to 43 inches; very dark grayish brown (2.5Y 3/2), grayish brown (2.5Y 5/2), and light olive brown (2.5Y 5/4) silty clay; moderate medium subangular blocky structure; firm; very few very fine tubular pores; few distinct dark gray (10YR 4/1) coatings on faces of peds; very few lime concretions in lower part; common fine prominent yellowish brown (10YR 5/6) and few fine prominent dark reddish brown (5YR 3/3) redoximorphic concentrations; slightly acid; gradual smooth boundary. (6 to 12 inches thick)

3Bgb--43 to 60 inches; light brownish gray (2.5Y 6/2) and light olive brown (2.5Y 5/4) silty clay; moderate medium and coarse subangular blocky structure; firm; many very fine tubular pores; few distinct dark gray (10YR 4/1) coatings on faces of peds; few very fine soft iron and manganese concentrations; many lime concretions; few fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; slightly effervescent; slightly alkaline.

TYPE LOCATION: Harrison County, Iowa; about 2 miles east and 1 mile south of Missouri Valley; about 2,190 feet north and 135 feet west of the center of sec. 21, T. 78 N., R. 44 W.; USGS Missouri Valley quadrangle; lat. 41 degrees 32 minutes 27 seconds N. and long. 95 degrees 54 minutes W., NAD 83

RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon--10 to 18 inches
Depth to buried soil--24 to 36 inches
Content of clay in the particle-size control section (weighted average)--40 to 50 percent
Content of sand in the particle-size control section (weighted average)--less than 15 percent

Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silty clay or silty clay loam
Clay content--30 to 60 percent
Sand content--1 to 5 percent
Calcium carbonate equivalent--0 to 5 percent
Reaction--moderately acid to neutral
Moist bulk density--1.30 to 1.35 g/cc

Overwash phases:
Texture--silty clay loam
Clay content--27 to 35 percent
Thickness--7 to 20 inches

Some pedons have Bg horizons with texture of silty clay

2Bg horizon:
Hue--10YR or 2.5Y
Value--4 to 6
Chroma--1 to 4
Texture--silty clay loam
Clay content--30 to 40 percent
Sand content--1 to 5 percent
Calcium carbonate equivalent--0 to 20 percent
Reaction--slightly acid to slightly alkaline
Moist bulk density--1.30 to 1.45 g/cc

Some pedons have thin strata of calcareous silt loam

3Agb horizon:
Hue--10YR or 2.5Y
Value--2 to 5
Chroma--1 to 4
Texture--silty clay or clay
Clay content--45 to 55 percent
Sand content--1 to 5 percent
Calcium carbonate equivalent--0 to 20 percent
Reaction--slightly acid to slightly alkaline
Moist bulk density--1.35 to 1.40 g/cc

3Bgb or 3Bkgb horizon:
Hue--10YR or 2.5Y
Value--3 to 6
Chroma--1 to 4
Texture--silty clay or clay
Clay content--50 to 75 percent
Sand content--1 to 5 percent
Calcium carbonate equivalent--0 to 20 percent
Reaction--slightly alkaline or moderately alkaline
Moist bulk density--1.35 to 1.40 g/cc
Thickness: 20 to 37 inches

3Cgb horizon (if it occurs):
Hue--10YR or 2.5Y
Value--4 to 6
Chroma--1 to 4
Texture--silty clay or clay
Clay content--60 to 75 percent
Sand content--1 to 5 percent
Calcium carbonate equivalent--0 to 20 percent
Reaction--slightly alkaline or moderately alkaline
Moist bulk density--1.35 to 1.40 g/cc

COMPETING SERIES: These are the Darwin, Saddlerock (T), Stillwater, and Waldo series.
Darwin--do not have buried horizons within the series control section and have a reaction range of slightly acid to slightly alkaline in the middle third of the series control section
Saddlerock--are in areas that have mean annual precipitation range of 9 to 16 inches, have one or more buried horizons within the series control section and have a reaction range of slightly alkaline or moderately alkaline throughout the series control section
Stillwater--are in areas that have mean annual precipitation range of 4 to 6 inches, do not have buried horizons within the series control section and have carbonates within depths of 16 to 35 inches
Waldo--do not have buried horizons within the series control section and have a reaction range of strongly acid or moderately acid in the middle third of the series control section

GEOGRAPHIC SETTING:
Parent material--clayey alluvium
Landform--flood plains
Slopes--0 to 2 percent
Elevation--800 to 1,200 feet above sea level
Mean annual air temperature--47 to 56 degrees F.
Mean annual precipitation--26 to 32 inches
Frost-free period--145 to 175 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blencoe, Cooper, Luton, and Woodbury soils.
Blencoe--are in landscape positions similar to those of the Blend soils, have a saturated zone that occurs between depths 1 to 3 feet during April to June in most years, and have a clay content of 18 to 24 percent in the lower third of the particle-size control section
Cooper--are in landscape positions similar to those of the Blend soils, have a saturated zone that occurs between depths of 1 to 3 feet during April to June in most years and have a clay content of 40 to 60 percent in the lower third of the particle-size control section
Luton--are in the slightly lower positions on the landscape, do not have buried horizons within the series control section and have a clay content of 40 to 75 percent throughout the series control section
Woodbury--are in landscape positions similar to those of the Blend soils and have clay content of 20 to 30 percent in the lower third of the series control section

DRAINAGE AND PERMEABILITY:
Drainage--poorly drained--a saturated zone occurs within a depth of 1 foot during March to June in most years and is considered apparent
Permeability--very slow
Surface runoff potential--low or very low
Flooding--rare flooding for brief periods during the months of February to November from precipitation events and snowmelt

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn and soybeans. Nearly all areas of Blend soils are drained by surface ditches. A few areas are land graded. The native vegetative cover is a herbaceous wetland community commonly inhabited with Bluejoint Grasses, White Cutgrasses, Fox Sedges, Oval Sedges, Inland Rushes, Torreys Rushes, Dark Green Bulrushes, Flatstem Spikerushes, Blue Vervains, Indian Hemps, Winged Loosestrifes, Wild Mints, and Water Horehounds.

DISTRIBUTION AND EXTENT:
LRR M, MLRA 107; Blend soils are on the highest level of the Missouri River flood plain in Iowa, commonly in areas that are near or within the backswamps or swales produced by meander scars which border or extend a few miles from upland foot slopes. These soils are of large extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Woodbury County, Iowa, 1971.

REMARKS:
Particle-size control section--the zone from a depth of 10 to 40 inches (A, 2Bg1, 2Bg2, and 3Ab horizons);
series control section--the zone from the surface to a depth of 60 inches (Ap, A, 2Bg1, 2Bg2, 3Ab, and 3Bgb horizons).

Diagnostic horizon and features recognized in this pedon:
mollic epipedon--the zone from the surface to a depth of 14 inches (Ap and A horizons);
cambic horizon--the zone from a depth of 14 to 32 inches (2Bg1 and 2Bg2 horizons);
aquic moisture regime.

Vertic subgroup based on linear extensibility greater than 6.0 cm between the surface and a depth of 39 inches (100 cm). Fluvaquentic subgroup based on an irregular decrease in organic-carbon content within the zone from a depth of 10 (25 cm) to 50 inches (125 cm).

Taxonomy version--second edition, 1999.

Classification was changed from Fluvaquentic Endoaquolls to Fluvaquentic Vertic Endoaquolls in 2002 based on data from the Woodbury County, Iowa soil survey update.

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National Cooperative Soil Survey
U.S.A.