LOCATION CLARINDA           IA+MO

CLARINDA SERIES

TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Argiaquolls

TYPICAL PEDON: Clarinda silty clay loam, on a south-facing, convex slope of about 8 percent, in a pasture, at an elevation of about 332 meters above sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 13 centimeters; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR 4/1) dry; very fine granular and very fine subangular blocky structure; friable; moderately acid; abrupt smooth boundary.

A--13 to 28 centimeters; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR 4/1) dry; moderate fine subangular blocky structure; friable; many quartz grains; strongly acid; gradual smooth boundary. (Combined thickness of the A horizon is 25 to 41 centimeters thick.)

2Bt--28 to 48 centimeters; very dark gray (10YR 3/1) silty clay, dark gray (10YR 4/1) dry; moderate fine subangular blocky structure; firm; common distinct dark gray (10YR 4/1) clay films on faces of peds; many fine white sand grains on faces of peds; few fine prominent yellowish red (5YR 4/6) redoximorphic concentrations; strongly acid; gradual smooth boundary. (0 to 20 centimeters thick)

2Btg1--48 to 86 centimeters; gray (5Y 5/1) clay; weak medium subangular blocky structure; very firm; many distinct gray (10YR 5/1) clay films on faces of peds; common fine white sand grains on faces of peds; common fine prominent yellowish brown (10YR 5/8) and few fine prominent yellowish red (5YR 5/8) redoximorphic concentrations; strongly acid; gradual boundary.

2Btg2--86 to 119 centimeters; gray (5Y 5/1) clay; weak medium prismatic structure parting to moderate medium and coarse subangular blocky; very firm; many distinct gray (10YR 5/1) clay films; few fine white sand grains on faces of peds; common coarse prominent yellowish brown (10YR 5/8) redoximorphic concentrations; slightly acid; gradual boundary.

2Btg3--119 to 170 centimeters; gray (5Y 5/1) clay; weak medium prismatic structure parting to moderate medium subangular blocky; very firm; many distinct gray (10YR 5/1) clay films; few very dark gray (10YR 3/1) organic stains on peds and on surfaces along pores; few fine and medium sand grains on faces of peds; common coarse prominent yellowish brown (10YR 5/8) redoximorphic concentrations; neutral.

TYPE LOCATION: Major Land Resource Area (MLRA) 109-Iowa and Missouri Heavy Till Plain, Wayne County, Iowa subset; about 1 mile west of Corydon; located about 1,940 feet east and 240 feet south of the northwest corner of section 24, T. 69 N., R. 22 W; USGS Corydon topographic quadrangle; lat. 40 degrees 46 minutes 2.0 seconds N. and long. 93 degrees 20 minutes 20 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 50 centimeters
Depth to carbonates--more than 150 centimeters
Depth to lithic or paralithic contact--more than 200 centimeters
Content of clay in the particle-size control section (weighted average)--40 to 60 percent
Content of sand in the particle-size control section (weighted average)--less than 15 percent
Rock fragment content--0 percent within a depth of 150 centimeters

Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silt loam, silty clay loam, or silty clay
Clay content--25 to 40 percent
Sand content--less than 15 percent
Reaction--strongly acid to neutral

Some pedons have an AB horizon

2Bt horizon (when present):
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silty clay or clay
Clay content--40 to 55 percent
Sand content--less than 15 percent
Reaction--strongly acid to slightly acid

2Btg horizon:
Hue--10YR to 5Y
Value--4 to 6
Chroma--1 or 2
Texture--silty clay or clay
Clay content--40 to 60 percent
Sand content--less than 15 percent
Reaction--strongly acid to moderately alkaline

2C horizon (when present):
Hue--10YR to 5Y
Value--4 to 6
Chroma--1 to 6
Texture--clay loam
Clay content--30 to 40 percent
Sand content--20 to 40 percent
Reaction--moderately acid to slightly alkaline

COMPETING SERIES: These are the Butler, Carbika, Chancellor, Coatsburg, Edinburg, Fosterburg, Haig, Lodgepole, Mazaska, Minnetonka, Sacville, Sampsel, Taintor, Terrabella, Virden, and Worthing series.
Butler--are in areas that average less than 730 millimeters of precipitation
Carbika--have a clay content that averages less than 40 percent in the particle-size control section
Chancellor--have mollic epipedons greater than 61 centimeters thick
Coatsburg--do not have horizons with more than 45 percent clay
Edinburg--have a clay content that averages less than 40 percent in the particle-size control section
Fosterburg--contain concentrations of exchangeable sodium in the subsoil
Haig--have mollic epipedons 50 to 71 centimeters thick
Lodgepole--have mollic epipedons 50 to 127 centimeters thick
Mazaska--have carbonates within a depth of 150 centimeters and have 2 to 8 percent rock fragments in the series control section
Minnetonka--have carbonates within a depth of 132 centimeters
Sacville--have a rock fragment content of 1 to 60 percent in the lower third of the series control section
Sampsel--have a paralithic contact within a depth of 200 centimeters
Taintor--have a clay content that averages less than 42 percent in the particle-size control section
Terrabella--have matrix hues of 5YR or 7.5YR in the middle third of the series control section
Virden--have a clay content of 20 to 32 percent in the lower fourth of the series control section
Worthing--have mollic epipedons greater than 89 centimeters thick

GEOGRAPHIC SETTING:
Parent material--paleosol formed in till, with or without a thin layer of loess on the surface
Landform--side slopes and head slopes on dissected till plains
Slope--5 to 18 percent
Elevation--185 to 475 meters above sea level
Mean annual air temperature--8 to 13 degrees C
Mean annual precipitation--660 to 1,040 millimeters
Frost-free period--155 to 220 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lamoni, Seymour, and Shelby soils.
Lamoni--are on similar landscape positions as the Clarinda soils or at lower elevations on side slopes and have a sand content that averages more than 15 percent in the particle-size control section
Seymour--are at higher landscape positions on side slopes and have a sand content of less than 3 percent throughout the series control section
Shelby--are at lower landscape positions on side slopes and have a sand content that averages 20 to 40 percent in the particle-size control section

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--poorly drained--these soils have a saturated zone between depths of 0.0 to 0.3 meters during March to June when precipitation is within one standard deviation of the 30 year mean of annual precipitation and is considered perched
Saturated hydraulic conductivity--0.01 to 0.10 micrometers per second
Surface runoff potential--very high

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, small grains, and hay. The native vegetation is big bluestem, western wheatgrass, sedges, blue grama and other species of the tall grass prairie that are tolerant of excessive wetness.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs--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 and northern Missouri
Extent--large

MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Taylor County, Iowa, 1954.

REMARKS:
Particle-size control section--the zone from a depth of 28 to 78 centimeters (2Bt and 2Btg1 horizons);
series control section--the zone from the surface to a depth of 170 centimeters (Ap, A, 2Bt, 2Btg1, 2Btg2, and 2Btg3 horizons).

Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 48 centimeters (Ap, A, 2Bt horizons);
argillic horizon--the zone from a depth of 28 to 170 centimeters (2Bt, 2Btg1, 2Btg2, 2Btg3 horizons);
aquic moisture regime.

Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.

ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska, pedons 87IA159005 and 87IA159006 (http://ssldata.sc.egov.usda.gov/).