LOCATION BERTRAM                 IA

Established Series
Rev. EJS-RPD-AAC
07/2013

BERTRAM SERIES

The Bertram series consists of moderately deep, well drained and somewhat excessively drained soils formed in 50 to 100 centimeters of oxidized and leached sandy loam eolian material and in the underlying residuum from limestone. These soils occur on convex summits of interfluves and side slopes on dissected till plains. Slope ranges from 2 to 14 percent. Mean annual air temperature is about 8.3 degrees C (47 fegrees F). Mean annual precipitation is about 890 millimeters (35 inches).

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Hapludolls

TYPICAL PEDON: Bertram sandy loam, on a north-facing slope of 6 percent, in a cultivated field. (All colors are for moist soil unless otherwise noted.)

Ap--0 to 20 centimeters (0 to 8 inches); very dark brown (10YR 2/2) sandy loam; very dark grayish brown (10YR 3/2) dry; weak fine granular structure; very friable; neutral; abrupt smooth boundary.

A--20 to 43 centimeters (8 to 17 inches); very dark brown (10YR 2/2) and very dark grayish brown (10YR 3/2) sandy loam; very dark grayish brown (10YR 3/2) and dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure, very friable; slightly acid; gradual smooth boundary. [Combined thickness of the A horizon is 25 to 50 centimeters (10 to 20 inches).]

Bw1--43 to 69 centimeters (17 to 27 inches); dark yellowish brown (10YR 4/4) sandy loam, kneaded brown (10YR 4/3); weak coarse subangular blocky structure; very friable; many distinct dark brown (10YR 3/3) organic coats on faces of peds; moderately acid; clear smooth boundary.

Bw2--69 to 76 centimeters (27 to 30 inches) ; dark yellowish brown (10YR 4/4) sandy loam; weak medium subangular blocky structure; friable; moderately acid; clear smooth boundary. [Combined thickness of the Bw horizon is 20 to 40 centimeters (8 to 16 inches).]

2Bt--76 to 86 centimeters (30 to 34 inches); dark yellowish brown (10YR 4/4) sandy clay loam; moderate fine subangular blocky structure; firm; common distinct clay films on ped faces; moderately acid; abrupt wavy boundary. [3 to 15 centimeters (1 to 6 inches) thick]

2C--86 to 91 centimeters (34 to 36 inches); dark yellowish brown (10YR 4/4) gravelly loamy sand; single grain; loose; about 20 percent hard limestone fragments 1 to 3 centimeters in diameter; slightly alkaline. [0 to 10 centimeters (0 to 4 inches) thick]

3R--91 centimeters (36 inches); hard limestone bedrock, moderately alkaline.

TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies, Linn County, Iowa subset; about 1.5 miles east of Coggon; located about 2,040 feet east and 380 feet north of the southwest corner of section 1, T. 86 N., R. 6 W; USGS Ryan topographic quadrangle; lat. 42 degrees 17 minutes 00 seconds N. and long. 91 degrees 29 minutes 32 seconds W., WGS 84.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 50 centimeters (10 to 20 inches)
Depth to lithic contact with limestone bedrock--50 to 100 centimeters (20 to 40 inches)
Clay content in the particle-size control section (weighted average)--8 to 16 percent
Sand content in the particle-size control section (weighted average)--60 to 80 percent

Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--2
Texture--sandy loam, fine sandy loam, loamy sand or loamy fine sand
Clay content--2 to 20 percent
Sand content--60 to 80 percent
Reaction--moderately acid to neutral

Bw horizon:
Hue--10YR
Value--3 to 5
Chroma--3 or 4
Texture--sandy loam or fine sandy loam
Clay content--8 to 20 percent
Sand content--60 to 80 percent
Reaction--strongly acid or moderately acid

2Bt horizon:
Hue--10YR
Value--4 or 5
Chroma--4 to 6
Texture--sandy clay loam or clay loam
Clay content--20 to 35 percent
Sand content--40 to 70 percent
Reaction--moderately acid to neutral

2C horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--4 to 6
Texture--loamy sand, gravelly loamy sand, loamy fine sand, gravelly loamy fine sand, sand, fine sand, gravelly sand, or gravelly fine sand
Clay content--less than 10 percent
Sand content--75 to 85 percent
Rock fragment content--0 to 35 percent
Reaction--neutral to moderately alkaline

COMPETING SERIES: These are the Augusta Lake, Aureola, Bolan, Dickinson, Elrick, Etter, Filley, Gardencity, Olin, Ridgeport, Roine, Wadenill, and Zenor series.
None of these series have limestone bedrock within a depth of 100 centimeters (40 inches).

GEOGRAPHIC SETTING:
Parent material--50 to 100 centimeters (20 to 40 inches) of oxidized and leached sandy loam eolian material and in the underlying residuum from limestone
Landform--convex summits of interfluves and convex side slopes on dissected till plains
Slope--2 to 14 percent
Elevation--175 to 300 meters (574 to 1148 feet) above sea level
Mean annual air temperature--7.8 to 9.4 degrees C (46 to 49 degrees F)
Mean annual precipitation--735 to 940 millimeters (34 to 36 inches)
Frost-free period--165 to 205 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dickinson, Flagler, Marshan, and Rockton soils.
Dickinson--are on landscape positions similar to those of the Bertram soils and do not have limestone bedrock within a depth of 100 centimeters
Flagler--are on lower landscape positions on treads and risers on stream terraces and do not have limestone bedrock within a depth of 100 centimeters
Marshan--are on lower landscape positions in drainageways and have a frequently saturated zone within a depth of 0.3 meter when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Rockton--are on landscape positions similar to those of the Bertram soils and have a clay content that averages 24 to 35 percent in the particle-size control section

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained and somewhat excessively drained--a saturated zone does not occur within a depth of 1.8 meters ( 6 feet) when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Saturated hydraulic conductivity--10.00 to 100.00 micrometers per second in the eolian material and 1.00 to 10.00 micrometers per second in the residuum and underlying limestone bedrock

USE AND VEGETATION:
The gently sloping areas are commonly cultivated. The principal crops are corn, soybeans, small grains, and legume hay. The steeper slopes are pastured. The native vegetation is big bluestem, little bluestem, 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
MLRA--Eastern Iowa and Minnesota Till Prairies (104)
LRR M; northeastern Iowa
Extent--small

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

SERIES ESTABLISHED: Linn County, Iowa, 1970.

Remarks:
Particle-size control section--the zone from a depth of 25 to 91 centimeters (10 to 36 inches);
series control section--the zone from the surface to a depth of 91 centimeters (36 inches).

Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 43 centimeters (17 inches) (Ap and A horizons);
cambic horizon--the zone from a depth of 43 centimeters to 86 centimeters ( 17 to 34 inches) (Bw1, Bw2 and 2Bt horizons);
lithic contact--the contact with limestone bedrock at a depth of 91 centimeters (36 inches);
udic moisture regime.

The upper 0.3 to 1.5 meters (1 to 5 feet)of limestone may be significantly fractured and may not be a root restrictive layer.

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

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

Range in characteristics were edited based on available lab data during the Bertram Soil Data Join Recorrelation projects, FY 2013.

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National Cooperative Soil Survey
U.S.A.