LOCATION CASTANA                 IA

Established Series
Rev. BCJ-RAL-DJP
08/2017

CASTANA SERIES

The Castana series consists of very deep, well drained soils on footslopes. These soils formed in silty local alluvium and colluvium from loess. Slope ranges from 5 to 30 percent. Mean annual air temperature is about 10 degrees C. Mean annual precipitation is about 740 millimeters.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Entic Hapludolls

TYPICAL PEDON: Castana silt loam, on a southwest-facing slope of about 16 percent in a pasture. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters; very dark grayish brown (10YR 3/2) silt loam, brown (10YR 5/3) dry; weak fine granular structure; friable; many very fine roots; few fine rounded carbonate nodules; strongly effervescent; slightly alkaline; abrupt smooth boundary.

A--20 to 46 centimeters; very dark grayish brown (10YR 3/2) and dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; weak fine and very fine granular structure; friable; many very fine roots; few fine rounded carbonate nodules; strongly effervescent; moderately alkaline; clear smooth boundary. (Combined thickness of the Ap and A horizons is 25 to 61 centimeters.)

AC--46 to 76 centimeters; brown (10YR 4/3) silt loam; weak fine prismatic structure parting to weak fine granular; friable; very dark grayish brown (10YR 3/2) organic coatings on faces of peds; few fine rounded carbonate nodules; strongly effervescent; moderately alkaline; clear smooth boundary. (0 to 51 centimeters thick)

C1--76 to 102 centimeters; brown (10YR 4/3) silt loam; massive; friable; dark brown (10YR 3/3) organic coatings on faces of peds; few fine rounded carbonate nodules; strongly effervescent; moderately alkaline; gradual smooth boundary.

C2--102 to 127 centimeters; brown (10YR 4/3) silt loam; massive, with evidence of parting along planes of weakness; friable; few fine rounded carbonate nodules; strongly effervescent; moderately alkaline; gradual smooth boundary.

C3--127 to 152 centimeters; brown (10YR 4/3) and brown (10YR 5/3) silt loam; massive, with evidence of parting along planes of weakness; friable; few fine rounded carbonate nodules; strongly effervescent; moderately alkaline.

TYPE LOCATION: Land Resource Unit (LRU) 107B - Iowa and Missouri Deep Loess Hills; Monona County, Iowa; about 2 miles northwest of Castana; about 900 feet north and 2,490 feet east of southwest corner sec. 28, T. 84 N., R. 44 W.; USGS Castana topographic quadrangle; lat. 42 degrees 3 minutes 15 seconds N. and long. 95 degrees 58 minutes 23 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Depth to carbonates: 0 to 25 centimeters
Maximum calcium carbonate equivalent: 5 to 30 percent
Content of clay in the particle-size control section (weighted average): 18 to 24 percent
Content of sand in the particle-size control section (weighted average): 1 to 6 percent

A or Ap horizon:
Hue: 10YR
Value: 2 or 3
Chroma: 2 or 3
Texture: silt loam or loam
Reaction: neutral to moderately alkaline

AC horizon (when present):
Hue: 10YR
Value: 4 or 5
Chroma: 3 or 4
Texture: silt loam
Reaction: slightly alkaline or moderately alkaline

C horizon:
Hue: 10YR
Value: 4 or 5
Chroma: 3 or 4
Texture: silt loam
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES:
There are no other series in this family.

GEOGRAPHIC SETTING:
Parent material--silty local alluvium and colluvium from loess
Landform--footslopes
Slopes--5 to 30 percent
Elevation--274 to 366 meters above sea level
Mean annual air temperature--8 to 12 degrees C
Mean annual precipitation--660 to 813 millimeters
Frost-free period--145 to 175 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hamburg, Ida, and Napier soils.
Hamburg--are at higher elevations and do not have a mollic epipedon
Ida--are in landform positions similar to those of the Castana soils or are at higher elevations and do not have a mollic epipedon
Napier--are in slightly lower landscape positions and do not have carbonates within a depth of 91 centimeters

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained--a saturated zone does not occur within a depth of 1.8 meters during April to June in normal years
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second
Surface runoff potential--high
Permeability--moderate

USE AND VEGETATION:
Most areas are cultivated. Corn, soybeans, small grains, and legume hay are the principal crops. The more steeply sloping areas are in pasture or timber and pasture. The native vegetation is tall prairie grasses.

DISTRIBUTION AND EXTENT:
LRR M, MLRA 108; western Iowa and possibly northwestern Missouri, principally along the Missouri River and its tributaries. This series is of moderate extent.

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

SERIES ESTABLISHED: Monona County, Iowa, 1956.

REMARKS:
Diagnostic horizons and features recognized in this pedon:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (A, AC, and C1 horizons).
Series control section--the zone from the surface to a depth of 150 centimeters (Ap, A, AC, C1, C2, and C3 horizons).
Mollic epipedon--from the surface to a depth of 46 centimeters (Ap and A 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, Twelfth Edition, 2014.

Most descriptions available appear to have mollic epipedons less than 61 centimeters thick, although data tends to indicate that organic carbon content of 1 percent extends to depths of 76 centimeters in many pedons.

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National Cooperative Soil Survey
U.S.A.