LOCATION KESWICK IA+MO ILEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aquertic Chromic Hapludalfs
TYPICAL PEDON: Keswick loam, on an east-facing, convex slope of about 11 percent, in a deciduous forest. (Colors are for moist soil unless otherwise stated.)
A--0 to 8 centimeters; very dark gray (10YR 3/1) loam, gray (10YR 6/1) dry; weak fine granular and very fine platy structure; friable; few fine dark brown and black accumulations (oxides); moderately acid; clear smooth boundary. (5 to 13 centimeters thick)
E1--8 to 18 centimeters; grayish brown (10YR 5/2) loam, with some dark grayish brown (10YR 4/2) material, light gray (10YR 7/1) dry; weak fine platy and fine granular structure; friable; few fine dark brown and black accumulations (oxides); strongly acid; clear smooth boundary.
E2--18 to 28 centimeters; brown (10YR 5/3) loam, light brownish gray (10YR 6/2) dry; weak fine subangular blocky structure; friable; common distinct light gray (10YR 7/2) dry silt and very fine sand coats on faces of peds; common fine distinct reddish brown (5YR 4/4) redoximorphic concentrations; strongly acid; clear smooth boundary. (Combined thickness of the E horizon is 0 to 30 centimeters.)
2Bt1--28 to 46 centimeters; about 70 percent reddish brown (5YR 4/4) and about 30 percent brown (7.5YR 5/2) clay loam; moderate fine and very fine subangular blocky structure; firm; few distinct clay films on faces of peds; common distinct gray (10YR 6/1) dry silt and very fine sand coats on faces of peds; few fine distinct red (2.5YR 4/6) redoximorphic concentrations; concentration of rock fragments (2 to 75 millimeters in diameter) in 2 to 8 centimeter thick layer in the at top of horizon; strongly acid; clear smooth boundary.
2Bt2--46 to 58 centimeters; about 50 percent yellowish red (5YR 4/6) and about 50 percent brown (7.5YR 5/3) clay; moderate very fine subangular blocky structure; very firm; common distinct clay films on faces of peds; common fine distinct red (2.5YR 4/6) redoximorphic concentrations; common fine distinct grayish brown (2.5Y 5/2) redoximorphic depletions; strongly acid; clear smooth boundary.
2Bt3--58 to 81 centimeters; about 50 percent brown (10YR 5/3), about 35 percent yellowish red (5YR 4/6), and about 15 percent gray (10YR 5/1) clay; moderate fine subangular blocky structure; very firm; common distinct clay films on faces of peds and along surfaces of pores; moderately acid; gradual smooth boundary.
2Bt4--81 to 109 centimeters; about 70 percent strong brown (7.5YR 5/6) and about 30 percent yellowish brown (10YR 5/6) clay loam; moderate fine prismatic structure parting to weak medium subangular blocky; firm; few distinct clay films on faces of peds and on surfaces along root channels; many distinct gray (10YR 5/1) silt and very fine sand coats on faces of peds; few fine distinct red (2.5YR 4/6) redoximorphic concentrations; few fine distinct grayish brown (10YR 5/2) redoximorphic depletions; moderately acid; gradual smooth boundary. (Combined thickness of the 2Bt horizon is 60 to 100 centimeters.)
2BC--109 to 152 centimeters; yellowish brown (10YR 5/6) clay loam; faces of peds brown (10YR 5/3); weak medium prismatic structure parting to weak medium subangular and angular blocky; firm; few distinct brown (7.5YR 4/2) clay flows on surfaces along root channels; common black stains on prism faces; common fine black accumulations (oxides); many medium prominent gray (5Y 5/1) redoximorphic depletions; moderately acid.
TYPE LOCATION: Major Land Resource Area (MLRA) 109-Iowa and Missouri Heavy Till Plain; Davis County, Iowa subset; about 3 miles west of Ashgrove; located about 200 feet east and 1,940 feet south of the northwest corner of section 17, T. 70 N., R. 15 W.; USGS Paris topographic quadrangle; lat. 40 degrees 51 minutes 57 seconds N. and long. 92 degrees 37 minutes 07 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Depth to carbonates--100 to 190 centimeters
Content of clay in the particle-size control section (weighted average--35 to 55 percent
Content of sand in the particle-size control section (weighted average)--20 to 45 percent
Special feature--some pedons have a stone line or thin layer, 2 to 13 centimeters thick of gravelly and sandy materials at the base of the loess or loamy sediments
A horizon (when present):
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--loam, silt loam, or clay loam
Clay content--15 to 35 percent
Sand content--15 to 40 percent
Rock fragment content--0 to 10 percent
Reaction--moderately acid or slightly acid
Ap horizon (when present):
Hue--10YR
Value--4
Chroma--2 or 3
Texture--loam, silt loam, or clay loam
Clay content--15 to 35 percent
Sand content--15 to 40 percent
Rock fragment content--0 to 10 percent
Reaction--moderately acid or slightly acid
E horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--2 or 3
Texture--loam, silt loam, or clay loam
Clay content--15 to 30 percent
Sand content--15 to 40 percent
Rock fragment content--0 to 10 percent
Reaction--very strongly acid to slightly acid
BE horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--loam, silt loam, or clay loam
Clay content--20 to 30 percent
Sand content--20 to 35 percent
Rock fragment content--0 to 10 percent
Reaction--very strongly acid to slightly acid
Some pedons have a Bt horizon
Some pedons have a Btg horizon
2Bt horizon (upper part):
Hue--5YR or 7.5YR
Value--4 or 5
Chroma--2 to 6
Texture--clay or clay loam
Clay content--35 to 55 percent
Sand content--20 to 45 percent
Rock fragment content--2 to 15 percent
Reaction--very strongly acid to moderately acid
2Bt (lower part) and 2BC horizon:
Hue--7.5YR, 10YR, or 5Y
Value--4 or 5
Chroma--1 to 6
Texture--clay loam or clay
Clay content--28 to 50 percent
Sand content--20 to 45 percent
Rock fragment content--2 to 15 percent
Reaction--moderately acid to slightly alkaline
Some pedons have 2C horizons
COMPETING SERIES: These are the
Colp,
Galland,
Gorin,
Marion, and
Weller series.
Colp--have a sand content that averages less than 15 percent in the particle-size control section
Galland--do not have rock fragments in the upper half of the series control section and have a sand content of more than 45 percent in the lower third of the series control section
Gorin--have a sand content that averages less than 20 percent in the particle-size control section
Marion--have a sand content that averages less than 10 percent in the particle-size control section
Weller--have a sand content that averages less than 10 percent in the particle-size control section
GEOGRAPHIC SETTING:
Parent material--25 to 50 centimeters of loess or loamy sediments and in the underlying paleosol weathered from glacial till
Landform--convex summits of interfluves, convex side slopes, shoulders of side slopes on till plains
Slope--5 to 25 percent
Elevation--213 to 396 meters above sea level
Mean annual air temperature--10 to 12 degrees C
Mean annual precipitation--780 to 900 millimeters
Frost-free period--165 to 180 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Clinton,
Ladoga,
Lindley, and
Olmitz soils.
Clinton--are at higher landscape positions on side slopes and interfluves and have a sand content that averages less than 5 percent in the particle-size control section
Ladoga--are at higher landscape positions on side slopes and interfluves and have a sand content that averages less than 5 percent in the particle-size control section
Lindley--are at lower landscape positions on side slopes and have a clay content that averages 25 to 35 percent in the particle-size control section
Olmitz--are at lower landscape positions on base slopes and have mollic epipedons 60 to 100 centimeters thick
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a frequently saturated zone occurs at a depth of 0.3 meter during April to June in normal years and is considered perched
Saturated hydraulic conductivity--0.01 to 1.00 micrometers per second (moderately low)
Surface runoff potential--medium to very high
USE AND VEGETATION:
Most areas are pastured or forested. Some areas are cultivated. The principal crops are corn, oats, and meadow. The native vegetation is deciduous trees.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Dissected till plains, Till plains
MLRAs--Illinois and Iowa Deep Loess and Drift (108),
Iowa and Missouri Heavy Till Plain (109),
Central Claypan Area (113), and
Central Mississippi Valley Wooded Slopes (115)
LRR M; southern Iowa, northern Missouri, and west central Illinois
Extent--large
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Iowa County, Iowa, 1961
REMARKS:
Particle-size control section--the zone from a depth of 28 to 78 centimeters (2Bt1, 2Bt2, and 2Bt3 horizons);
series control section--the zone from the surface to a depth of 152 centimeters (A, E1, E2, 2Bt1, 2Bt2, 2Bt3, 2Bt4, and 2BC horizons).
Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface to a depth of 28 centimeters (A, E1, and E2 horizons);
albic horizon-- the zone from a depth of 8 to 18 centimeters (E1 horizon);
argillic horizon--the zone from a depth of 28 to 109 centimeters (2Bt1, 2Bt2, 2Bt3, and 2Bt4 horizons);
udic moisture regime.
Where more permeable soils formed in loess are upslope, Keswick soils commonly have seepy spots in wet seasons, but in years of average rainfall this is not a hazard to use of the soil.
The color and pattern appear to be inherited from the Late Sangamon paleosol.
Aquertic subgroup based on redoximorphic depletions within the upper 25 centimeters of the argillic horizon and linear extensibility greater than 6.0 centimeters between the surface and a depth of 100 centimeters.
Chromic subgroup based on color value, moist, of 4 or more and color value, dry, of 6 or more after mixing the surface materials to a depth of 18 centimeters.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.
ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska--user pedon id number 95IA051001 (http://ssldata.sc.egov.usda.gov/).