LOCATION OLMITZ IA+KS MO NEEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Cumulic Hapludolls
TYPICAL PEDON: Olmitz loam, on a southwest-facing, slope of 3 percent, in a pasture. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 18 centimeters; black (10YR 2/1) loam, very dark brown (10YR 2/2) kneaded, grayish brown (10YR 5/2) dry; moderate fine granular structure; friable; moderately acid; clear smooth boundary.
A1--18 to 38 centimeters; very dark brown (10YR 2/2) clay loam, grayish brown (10YR 5/2) dry; weak very fine and fine subangular blocky and moderate fine granular structure; friable; many worm casts; common very fine tubular pores and root channels; moderately acid; gradual smooth boundary.
A2--38 to 58 centimeters; very dark brown (10YR 2/2) clay loam, very dark grayish brown (10YR 3/2) kneaded, dark grayish brown (10YR 4/2) and grayish brown (10YR 5/2) dry; moderate fine and very fine subangular blocky structure; friable; common very fine tubular pores and root channels; moderately acid; gradual smooth boundary.
A3--58 to 76 centimeters; very dark grayish brown (10YR 3/2) clay loam, very dark grayish brown (10YR 3/2) kneaded, dark grayish brown (10YR 4/2) and grayish brown (10YR 5/2) dry; moderate fine subangular blocky structure with some very fine blocks; friable; common very fine tubular pores and root channels; few very dark brown (10YR 2/2) organic coats on ped faces; few fine rock fragments (2 to 5 millimeters in diameter); moderately acid; gradual smooth boundary. (Combined thickness of the A horizon is 60 to 90 centimeters.)
Bw1--76 to 104 centimeters; dark brown (10YR 3/3) clay loam, brown (10YR 4/3) kneaded; weak coarse prismatic and weak coarse blocky structure parting to weak very fine and fine subangular blocky; friable; common very fine tubular pores; few very dark grayish brown (10YR 3/2) organic coats on ped faces; few fine rock fragments (2 to 5 millimeters in diameter); slightly acid; gradual smooth boundary.
Bw2--104 to 122 centimeters; mostly dark brown (10YR 3/3) with some brown (10YR 4/3) clay loam; weak coarse prismatic and weak coarse blocky structure parting to weak very fine and fine subangular blocky; friable; few to common very fine tubular pores; a few fine dark concretions (oxides); few fine faint yellowish brown (10YR 5/6) redoximorphic concentrations; slightly acid; gradual smooth boundary. (Combined thickness of the Bw horizon is 30 to 60 centimeters.)
BC--122 to 152 centimeters; brown (10YR 4/3) clay loam; weak fine subangular blocky structure; friable; common very fine tubular pores; slightly acid.
TYPE LOCATION: Major Land Resource Area (MLRA) 108D-Iowa and Missouri Deep Loess and Drift, Western Part, Madison County, Iowa subset; about 1 mile west and 7 miles north of Patterson; located about 1,940 feet north and 740 feet east of the southwest corner of section 30, T. 77 N., R. 26 W; USGS Saint Charles NW topographic quadrangle; lat. 41 degrees 26 minutes 12 seconds N. and long. 93 degrees 53 minutes 39 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--60 to 107 centimeters
Depth to redoximorphic concentrations--100 to 150 centimeters
Depth to carbonates--greater than 150 centimeters
Depth to till--greater than 150 centimeters
Clay content in the particle-size control section (weighted average)--28 to 34 percent
Sand content in the particle-size control section (weighted average)--20 to 50 percent
A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--loam or clay loam
Clay content--18 to 34 percent
Rock fragment content--0 to 5 percent
Reaction--moderately acid to neutral
Some pedons have up to 50 centimeters of recently deposited materials
Bw horizon:
Hue--10YR
Value--3 or 4
Chroma--2 or 3
Texture--clay loam
Clay content--22 to 34 percent
Rock fragment content--0 to 5 percent
Reaction--strongly acid to neutral
Redoximorphic concentrations or depletions can be found in the lower portion of this horizon
BC horizon:
Hue--10YR
Value--4
Chroma--2 or 3
Texture--loam or clay loam
Clay content--22 to 34 percent
Rock fragment content--0 to 5 percent
Reaction--strongly acid to neutral
Redoximorphic concentrations or depletions can be present in the BC horizon
COMPETING SERIES: These are the
Dameron,
Deloit,
Du Page,
Fort Dodge,
Racket,
Ross,
Spillco,
Spillville,
Terril, and
Turlin series.
Dameron--have more than 15 percent rock fragments within a depth of 100 centimeters
Deloit--do not have a frequently seasonally saturated zone within a depth of 1.8 meters during the wettest periods of normal years and have a clay content that averages 22 to 30 percent in the particle-size control section
Du Page--have carbonates within a depth of 25 centimeters
Racket--have more than 15 percent rock fragments in the lower third of the series control section
Fort Dodge--have a clay content that averages 18 to 27 percent in the particle-size control section
Ross--have carbonates within a depth of 114 centimeters and have mollic epipedons 60 to 100 centimeters thick
Spillco--have carbonates within a depth 90 centimeters and have a mollic epipedon more than 100 centimeters thick
Spillville--have a frequently saturated zone at a depth of 0.3 meter during the wettest periods of normal years and have a clay content of 5 to 24 percent in the lower third of the series control section
Terril--have a clay content that averages 18 to 27 percent in the particle-size control section
Turlin--have a frequently saturated zone at a depth of 0.3 meter during the wettest periods of normal years and have a clay content of 8 to 18 percent in the lower third of the series control section
GEOGRAPHIC SETTING:
Parent material--loamy local alluvium derived from till of mixed mineralogical composition
Landform--alluvial fans at or near the mouth of upland drainageways and on slightly concave to linear base slopes
Slope--2 to 14 percent
Elevation--180 to 305 meters above sea level
Mean annual air temperature--9 to 12 degrees C
Mean annual precipitation--710 to 860 millimeters
Frost-free period--150 to 180 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are
Ely,
Gara,
Shelby, and
Zook soils.
Ely--are at lower landscape positions and have a frequently saturated zone at a depth of 0.3 meter during the wettest periods of normal years
Gara--are at higher landscape positions on side slopes and have ochric epipedons 15 to 46 centimeters thick
Shelby--are at higher landscape positions on side slopes and have mollic epipedons 25 to 50 centimeters thick
Zook--are in lower landscape positions on floodplains, have mollic epipedons 90 to more than 150 centimeters thick, and are frequently saturated at the soil surface during the wettest periods of normal years
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs at a depth of 1.2 meters during the wettest periods of normal years and is considered apparent
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second
Surface runoff potential--low or medium
USE AND VEGETATION:
Areas adjacent to wide valleys or less sloping uplands are cultivated. Principal crops are corn, soybeans, small grains, and alfalfa. Areas associated with steeply sloping uplands are pastured. The native vegetation is big bluestem, little bluestem, switchgrass, and other grasses of the tall grass prairie.
DISTRIBUTION AND EXTENT:
Physiographic location--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Dissected till plains
MLRAs--Nebraska and Kansas Loess-Drift Hills (106),
Iowa and Missouri Deep Loess Hills (107),
Illinois and Iowa Deep Loess and Drift 108), and
Iowa and Missouri Heavy Till Plain (109)
LRR M; southern Iowa, northeastern Kansas, southeastern Nebraska, and northern Missouri
Extent--moderate
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Lucas County, Iowa, 1940
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (A2, A3, and Bw1 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (Ap, A1, A2, A3, Bw1, Bw2, and BC horizons).
Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 76 centimeters (Ap, A1, A2, and A3 horizons);
cambic horizon--the zone from a depth of 76 to 122 centimeters (Bw1 and Bw2 horizons);
udic moisture regime.
The loamy sediments are 1.8 to 2 meters thick in most areas but depth to clay loam till is as shallow as 100 centimeters in some pedons.
Cation-exchange class is inferred from lab data for similar soils in the surrounding area.
Taxonomy version--Keys to Taxonomy, tenth edition, 2006.
ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska pedon S56IA001003 and S56IA001004 (http://ssldata.sc.egov.usda.gov/).