LOCATION LADOGA IA+KS MOEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Mollic Hapludalfs
TYPICAL PEDON: Ladoga silt loam, on a north-facing slope of 7 percent, in a deciduous forest. (Colors are for moist soil unless otherwise stated.)
A--0 to 18 centimeters; black (10YR 2/1) silt loam, very dark gray (10YR 3/1) kneaded, gray (10YR 5/1) dry; moderate fine granular structure; friable; neutral; clear smooth boundary. (13 to 23 centimeters thick)
E--18 to 25 centimeters; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; weak medium platy structure; friable; few very dark gray (10YR 3/1) organic stains on faces of peds and worm casts; slightly acid; abrupt smooth boundary. (0 to 15 centimeters thick)
BE--25 to 36 centimeters; brown (10YR 4/3) silty clay loam; weak fine subangular blocky structure; friable; common dark grayish brown (10YR 4/2) silt coats on faces of peds; moderately acid; gradual smooth boundary. (0 to 10 centimeters thick)
Bt1--36 to 48 centimeters; brown (10YR 4/3) silty clay loam; weak medium subangular blocky structure parting to moderate and strong fine subangular blocky; friable; common distinct dark yellowish brown (10YR 4/4) clay films on faces of peds; common dark grayish brown (10YR 4/2) silt coats on faces of peds; moderately acid; gradual smooth boundary.
Bt2--48 to 64 centimeters; dark yellowish brown (10YR 4/4) silty clay loam; moderate medium and fine subangular and angular blocky structure; firm; many distinct brown (10YR 4/3) clay films on faces of peds; few distinct dark grayish brown (10YR 4/2) silt coats on faces of peds; strongly acid; gradual smooth boundary.
Bt3--64 to 81 centimeters; dark yellowish brown (10YR 4/4) silty clay loam; moderate fine subangular and angular blocky structure; firm; common distinct brown (10YR 4/3) clay films on faces of peds; few distinct grayish brown (10YR 5/2) silt coats on vertical faces of peds; few fine concretions; strongly acid; gradual smooth boundary.
Bt4--81 to 114 centimeters; brown (10YR 5/3) silty clay loam; weak medium prismatic structure parting to weak fine and medium angular blocky; friable; few distinct brown (10YR 4/3) clay films on faces of peds; common fine concretions; common fine and medium olive gray (5Y 5/2) redoximorphic depletions; strongly acid; gradual smooth boundary.
Bt5--114 to 130 centimeters; brown (10YR 5/3) silty clay loam; weak medium prismatic structure parting to weak medium angular blocky; friable; few distinct brown (10YR 4/3) clay films on faces of peds and on surfaces along pores; common fine and medium olive gray (5Y 5/2) redoximorphic depletions; moderately acid; gradual smooth boundary. (Combined thickness of Bt horizon is 66 to 135 centimeters.)
C--130 to 152 centimeters; brown (10YR 5/3) silt loam; massive; friable; many fine and medium olive gray (5Y 5/2) redoximorphic depletions; slightly acid.
TYPE LOCATION: Major Land Resource Area (MLRA) 108D-Illinois and Iowa Deep Loess and Drift, Western Part, Guthrie County, Iowa subset; about 5 miles south and 3 miles west of Guthrie Center; located about 1,500 feet south and 1,400 feet east of the northwest corner of section 5, T. 78 N., R. 32 W.; USGS Casey topographic quadrangle; lat. 41 degrees 35 minutes 52 seconds N. and long. 94 degrees 33 minutes 48 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Depth to carbonates--more than 150 centimeters
Content of clay in the particle-size control section (weighted average)--35 to 42 percent
Content of sand in the particle-size control section (weighted average)--less than 5 percent
Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--18 to 35 percent
Sand content--less than 5 percent
Reaction--moderately acid to neutral
E horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--2 or 3
Texture--silt loam or silty clay loam
Clay content--15 to 35 percent
Sand content--less than 5 percent
Reaction--moderately acid or slightly acid
BE horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--2 or 3
Texture--silt loam or silty clay loam
Clay content--25 to 35 percent
Sand content--less than 5 percent
Reaction--strongly acid to slightly acid
Bt horizon:
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--silty clay loam or silty clay
Clay content--35 to 42 percent
Sand content--less than 5 percent
Reaction--strongly acid or moderately acid
BC (when present) and C horizon:
Hue--10YR
Value--5
Chroma--2 to 4
Texture--silty clay loam or silt loam
Clay content--24 to 32 percent
Sand content--less than 5 percent
Reaction--moderately acid or slightly acid
COMPETING SERIES: This is the
Armster series.
Armster--have a sand content that averages more than 20 percent in the particle-size control section
GEOGRAPHIC SETTING:
Parent material--loess
Landform--convex summits of interfluves, side slopes, and nose slopes on dissected till plains and treads and risers on stream terraces
Slope--0 to 30 percent
Elevation--210 to 400 meters above sea level
Mean annual air temperature--9 to 12 degrees C
Mean annual precipitation--750 to 870 millimeters
Frost-free period--160 to 180 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Armstrong,
Clinton,
Gara, and
Givin soils.
Armstrong--are at lower landscape positions on side slopes and nose slopes and have a frequently saturated zone within a depth of 0.3 meter during the wettest periods of normal years
Clinton--are in similar landscape positions to those of the Ladoga soils and have a surface layer less than 13 centimeters thick
Gara--are at lower landscape positions on side slopes and have a sand content that averages 25 to 45 percent in the particle-size control section
Givin--are at higher landscape positions on the nearly level summits of interfluves soils and have a frequently saturated zone within a depth of 0.3 meter during the wettest periods of normal years
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs within a depth of 1.2 meters during April to June in normal years and is considered apparent
Saturated hydraulic conductivity--moderately high
Surface runoff potential--negligible to high
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybean, small grain, and grass-legume hay. The native vegetation is mixed big bluestem, little bluestem, switchgrass, other grasses of the tall grass prairie and deciduous trees (oak-hickory).
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs--Iowa and Missouri Deep Loess Hills (107) and Illinois and Iowa Deep Loess and Drift (108)
LRR M; southern Iowa, northern Missouri, and northeastern Kansas
Extent--large
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Taylor County, Iowa, 1948.
REMARKS:
Particle-size control section--the zone from a depth of 36 to 86 centimeters (Bt1, Bt2, Bt3, and Bt4 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (A, E, BE, Bt1, Bt2, Bt3, Bt4, Bt5, and C horizon).
Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface to a depth of 25 centimeters (A and E horizons);
albic horizon--the zone from a depth of 10 to 25 centimeters (E horizon);
argillic horizon--the zone from 36 to 130 centimeters (Bt1, Bt2, Bt3, Bt4, and Bt5 horizons);
udic moisture regime.
Classification changed to Mollic subgroup because the linear extensibility (LE) does not meet the requirements for Vertic subgroup.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.