LOCATION ALLENDORF IA

Established Series
Rev. RJV-DJP-AAC
03/2013

ALLENDORF SERIES

The Allendorf series consists of very deep, well drained soils formed in 75 to 100 centimeters of loess or silty and loamy alluvium over sandy sediments. These soils are on treads and risers on stream terraces. Slope ranges from 0 to 9 percent. Mean annual air temperature is about 9 degrees C. Mean annual precipitation is about 710 millimeters.

TAXONOMIC CLASS: Fine-silty over sandy or sandy-skeletal, mixed, superactive, mesic Typic Hapludolls

TYPICAL PEDON: Allendorf silty clay loam, on a 3 percent convex slope, in a cultivated field, at an elevation of about 436 meters above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 23 centimeters; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; weak fine subangular blocky structure parting to weak fine granular; friable; few fine roots; slightly acid; clear smooth boundary.

A--23 to 33 centimeters; very dark grayish brown (10YR 3/2) silty clay loam, dark grayish brown (10YR 4/2) dry; dark brown (10YR 3/3) and black (10YR 2/1) mixings; moderate fine and very fine subangular blocky structure; friable; few very fine roots; slightly acid; clear smooth boundary. (Combined thickness of the A horizon is 25 to 50 centimeters.)

Bw1--33 to 46 centimeters; dark yellowish brown (10YR 4/4) silty clay loam; very dark grayish brown (10YR 3/2) animal mixings; weak medium and fine subangular blocky structure; friable; few very fine roots; dark brown (10YR 3/3) coats on faces of peds; neutral; clear smooth boundary.

Bw2--46 to 69 centimeters; dark yellowish brown (10YR 4/4) silty clay loam; brown (10YR 4/3) animal mixings; weak medium prismatic structure parting to weak medium subangular blocky; friable; few very fine roots; neutral; gradual smooth boundary.

Bw3--69 to 86 centimeters; dark yellowish brown (10YR 4/4) silt loam; weak medium prismatic structure parting to weak medium subangular blocky; friable; few very fine roots; neutral; clear smooth boundary. (Combined thickness of the Bw horizon is 36 to 76 centimeters.)

2BC--86 to 94 centimeters; brown (10YR 4/3) loam; weak medium and fine subangular blocky structure; friable; few very fine roots; about 5 percent rock fragments; neutral; abrupt smooth boundary. (0 to 15 centimeters thick)

2C1--94 to 102 centimeters; brown (10YR 4/3) very gravelly loamy coarse sand; single grain; loose; few very fine roots; few calcium carbonate accumulations; about 50 percent rock fragments; strongly effervescent; moderately alkaline; abrupt smooth boundary.

2C2--102 to 152 centimeters; yellowish brown (10YR 5/4) gravelly sand; single grain; loose; few very fine roots in the upper part; about 30 percent rock fragments; strongly effervescent; moderately alkaline.

TYPE LOCATION: Major Land Resource Area (MLRA) 107-Iowa and Missouri Deep Loess Hills, Osceola County, Iowa subset; about 2.5 miles south of May City; located about 700 feet east and 500 feet south of the northwest corner of section 28, T. 98 N., R. 39 W; USGS May City topographic quadrangle; lat. 43 degrees 16 minutes 59 seconds N. and 95 degrees 27 minutes 53 seconds W., NAD83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 50 centimeters
Thickness of silty material--75 to 100 centimeters
Depth to carbonates--75 to 100 centimeters
Clay content in the upper two thirds of the particle-size control section (weighted average)--27 to 30 percent
Clay content in the lower third of the particle-size control section (weighted average)--2 to 10 percent
Sand content of the upper two thirds of the particle-size control section (weighted average)--5 to 15 percent
Sand content of the lower third of the particle-size control section (weighted average)--80 to 95 percent

Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 to 3
Texture--silty clay loam or silt loam
Clay content--24 to 32 percent
Sand content--5 to 15 percent
Rock fragment content--0 percent
Reaction--moderately acid or slightly acid
Some pedons have an AB or BA horizon

Bw horizon:
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--silty clay loam in the upper part and silty clay loam or silt loam in the lower part
Clay content--27 to 32 percent in the upper part and 24 to 30 percent in the lower part
Sand content--5 to 15 percent
Rock fragment content--0 percent
Reaction--slightly acid or neutral

2BC horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--loam or sandy loam
Clay content--18 to 24 percent
Sand content--45 to 75 percent
Rock fragment content--0 to 10 percent
Calcium carbonate equivalent -- 0 to 20 percent
Reaction--neutral or slightly alkaline

2C horizon:
Hue--10YR or 2.5Y
Value--4 to 6
Chroma--3 to 6
Texture--gravelly loamy coarse sand, very gravelly loamy coarse sand, gravelly sand, loamy sand, or sand
Clay content--less than 10 percent
Sand content--more than 80 percent
Rock fragment content--10 to 60 percent
Calcium carbonate equivalent -- 5 to 30 percent
Reaction--slightly alkaline or moderately alkaline

COMPETING SERIES: These are the Arthur, Baytown, and Waukegan series.
Arthur--do not have rock fragments in the lower third of the series control section
Baytown--have a paralithic contact with sandstone within a depth of 100 centimeters
Waukegan--do not have carbonates within a depth of 100 centimeters

GEOGRAPHIC SETTING:
Parent material--75 to 100 centimeters of loess or silty and loamy alluvium over sandy sediments
Landform--treads and risers on stream terraces
Slope--0 to 9 percent
Elevation--427 to 488 meters above sea level
Mean annual air temperature--7 to 11 degrees C
Mean annual precipitation--660 to 760 millimeters
Frost-free period--140 to 150 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coland, Everly, and Wadena soils.
Coland--are at lower landscape positions on flood plains and are frequently saturated at the soil surface during the wettest periods of normal years
Everly--are at higher landscape positions on ground moraines and till plains and average more than 15 percent sand in the particle-size control section
Wadena--are in landscape positions similar to the Allendorf soils and average more than 25 percent sand in the particle-size control section

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained--a frequently saturated zone does not occur within 1.8 meters in normal years
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second (moderately high) in the silty sediments and 100.00 to 705.00 micrometers per second (very high) in the underlying sandy and gravelly sediments
Surface runoff potential--negligible to medium
Flooding--rarely flooded for brief or very brief duration

USE AND VEGETATION:
Most areas are cultivated. Corn and soybeans are the principal crops. Native vegetation is big bluestem, indiangrass, switchgrass, and other grasses of the tall grass prairie.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs--Iowa and Missouri Deep Loess Hills (107A)
LRR M; western and northwestern Iowa
Extent--small

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

SERIES ESTABLISHED: Osceola County, Iowa, 1985.

REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters;
series control section--the zone from the surface to a depth of 150 centimeters.

Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 33 centimeters (Ap and A horizons);
cambic horizon--the zone from a depth of 33 to 94 centimeters (Bw1, Bw2, Bw3, 2BC horizons);
udic moisture regime.

Cation-exchange class is inferred from lab data for similar soils in the surrounding area.

Taxonomy version--Keys to Soil Taxonomy, eleventh edition, 2010.

ADDITIONAL DATA:

Lab characterization data is available from the Kellogg Soil Survey Laboratory, Lincoln, Nebraska: 1978MN133-004 (3646); Iowa State University: 1983IA035001, 1982IA143001.

National Cooperative Soil Survey
U.S.A.