LOCATION HARCOT                  IA+MN

Established Series
Rev. RLB-JDH-RJB
06/2015

HARCOT SERIES

The Harcot series consists of very deep, poorly drained soils formed in 50 to 100 centimeters of alluvium and in the underlying sandy and gravelly outwash. These soils are on slightly concave to slightly convex positions on treads on stream terraces and on flood plains in river valleys and on outwash plains. Slope ranges from 0 to 2 percent. Mean annual precipitation is about 740 millimeters. Mean annual air temperature is about 8 degrees C.

TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Typic Calciaquolls

TYPICAL PEDON: Harcot loam, on a nearly level slope, in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Apk--0 to 20 centimeters; black (10YR 2/1) loam, dark gray (10YR 4/1) dry; weak very fine granular structure; friable; violently effervescent, moderately alkaline; clear smooth boundary.

Ak--20 to 36 centimeters; black (N 2/0) loam, dark gray (10YR 4/1) dry; weak fine granular structure; friable; violently effervescent; moderately alkaline; clear smooth boundary

ABk--36 to 51 centimeters; very dark gray (10YR 3/1) loam, gray (10YR 5/1) dry; weak medium subangular blocky structure; friable; few fine prominent brown (7.5YR 4/4) iron concentrations; violently effervescent; moderately alkaline; clear smooth boundary.

Bkg--51 to 61 centimeters; gray (10YR 5/1) loam; weak medium subangular blocky structure; friable; few dark reddish brown (5YR 2/2) concretions (oxides); common fine prominent strong brown (7.5YR 5/6) iron concentrations; violently effervescent; moderately alkaline; clear wavy boundary.

BC--61 to 74 centimeters; mixed strong brown (7.5YR 5/6), reddish brown (2.5YR 5/4) and light brownish gray (2.5Y 6/2) loam; weak coarse subangular blocky structure; friable; few dark reddish brown (5YR 2/2) concretions (oxides); strongly effervescent; slightly alkaline; clear smooth boundary.

2C1--74 to 102 centimeters; pale brown (10YR 6/3) fine sand; single grain; loose; few fine prominent yellowish brown (10YR 5/8) iron concentrations; slightly effervescent; slightly alkaline; gradual smooth boundary.

2C2--102 to 142 centimeters; light brownish gray (2.5Y 6/2) fine sand; single grain; loose; few fine prominent yellowish brown (10YR 5/6) iron concentrations; slightly effervescent; slightly alkaline; gradual smooth boundary.

2C3--142 to 200 centimeters; light brownish gray (2.5Y 6/2) fine sand; single grain; loose; few fine distinct yellowish brown (10YR 5/6) iron concentrations; about 5 percent gravel; slightly effervescent; slightly alkaline

TYPE LOCATION: Major Land Resource Area (MLRA) 103-Central Iowa and Minnesota Till Prairies, Worth County, Iowa subset; about 4 miles west and 3 miles north of Northwood; located about 160 feet north and 85 feet west of the southeast corner of section 11, T. 100 N., R. 21 W.; USGS Fertile NE topographic quadrangle; lat. 43 degrees 29 minutes 17.8 seconds N. and long. 93 degrees 16 minutes 51.1 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 60 centimeters
Depth to coarse textured material--50 to 100 centimeters
Clay content of the upper part of the particle-size control section (weighted average)--20 to 27 percent
Clay content of the lower part of the particle-size control section (weighted average)--less than 10 percent
Sand content of the upper part of the particle-size control section (weighted average)--35 to 50 percent
Sand content of the lower part of the particle-size control section (weighted average)--more than 75 percent
Rock fragment content (upper mantle)--0 to 5 percent
Rock fragment content (underlying material)--0 to 25 percent

Apk or Ak horizon:
Hue--10YR or neutral
Value--2 or 3
Chroma--0 to 2
Texture--loam, clay loam, and silt loam
Clay content--18 to 30 percent
Sand content--25 to 50 percent
Reaction--pH 7.4 to 8.4
Thickness--30 to 45 centimeters

ABk horizon:
Hue--10YR to 5Y or neutral
Value--3
Chroma--0 to 3
Texture--loam, clay loam, and silt loam
Clay content--18 to 30 percent
Sand content--25 to 50 percent
Reaction--pH 7.9 to 8.4
Thickness--0 to 20 centimeters

Bkg horizon:
Hue--10YR to 5Y
Value--4 or 5
Chroma--1 or 2
Texture--loam, clay loam, and sandy clay loam
Clay content--18 to 30 percent
Sand content--40 to 55 percent
Reaction--pH 7.9 to 8.4
Thickness--15 to 35 centimeters

BC horizon:
Hue--7.5YR to 5Y
Value--4 to 6
Chroma--2 to 6
Texture--loam, sandy clay loam, and sandy loam
Clay content--18 to 25 percent
Sand content--40 to 60 percent
Reaction--pH 7.4 to 8.4
Thickness--0 to 20 centimeters

BC horizons with texture of sandy loam are less than 13 centimeters thick

2C horizon:
Hue--10YR to 5Y
Value--5 or 6
Chroma--1 to 6
Texture--loamy fine sand, fine sand, sand, loamy sand, and their gravelly analogues
Clay content--less than 10 percent
Sand content--more than 80 percent
Reaction--pH 6.6 to 7.8
Note--In some pedons, the upper 10 to 30 centimeters of the 2C horizon contains over 35 percent gravel and cobbles

COMPETING SERIES: This is the Arlo series.
Arlo--are in areas that receive less rainfall and are drier in the soil moisture control section, see remarks

GEOGRAPHIC SETTING:
Parent material--50 to 100 centimeters of alluvium and in the underlying sandy and gravelly outwash
Landform--slightly concave to slightly convex positions on treads on stream terraces and on flood plains in river valleys, and on outwash plains
Slope--0 to 2 percent
Elevation--300 to 400 meters above mean sea level
Mean annual air temperature--6 to 10 degrees C
Mean annual precipitation--585 to 890 millimeters
Frost-free period--155 to 200 days

GEOGRAPHICALLY ASSOCIATED SOILS: Near the type location, these are the Coland, Dickinson, Lawler, and Marshan soils.
Coland--are in slightly lower landscape positions on floodplains and have a sand content that averages less than 15 to 30 percent in the particle-size control section
Dickinson--are on higher landscape positions and are not frequently saturated within a depth of 1.8 meters during the wettest periods of years when the precipitation is within one standard deviation of the 30 year mean of annual precipitation
Lawler--are on slightly higher landscape positions and do not have carbonates in the series control section
Marshan--are on landscape positions similar to those of the Harcot soils and do not have carbonates within a depth of 100 centimeters

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--poorly drained--these soils have a frequently saturated zone from the surface of the soil to a depth of 0.3 meter during the wettest periods of years when the precipitation is within one standard deviation of the 30 year mean of annual precipitation and this saturation is considered apparent
Saturated hydraulic conductivity--1.0 to 10.0 micrometers per second in the alluvium and 100 to 705 micrometers per second in the underlying outwash
Flooding--not flooded to rarely flooded for brief duration

USE AND VEGETATION:
Where artificially drained, Harcot soils are cultivated. The principal crops are corn and soybeans. Undrained areas are pastured or wildlife land. The native vegetative cover is a herbaceous wetland community commonly inhabited with Bluejoint Grasses, Fowl Bluegrasses, Green Muhlies, Fox Sedges, Field Sedges, Dudleys Rushes, Torreys Rushes, Swamp Milkweeds, False Sneezeweeds, False Asters, New England Asters, White Panicled Asters, and Wild Mints.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic Section--Western Lake section
MLRA--Central Iowa and Minnesota Till Prairies (103)
LRR M; central and north-central Iowa and southern Minnesota
Extent--moderate

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

SERIES ESTABLISHED: Worth County, Iowa, 1972.

REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters;
series control section--the zone from the surface of the soil to a depth of 150 centimeters.

Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface of the soil to a depth of 51 centimeters (Apk, Ak, and ABk horizons);
calcic horizon--the zone from the surface to a depth of 61 centimeters (Apk, Ak, ABk, and Bkg horizons);
aquic moisture regime.

Aquic subgroup based on low chroma matrix of the zone from a depth of 51 to 61 centimeters (Bkg horizon).

Differentia between Harcot series and Arlo series needs further study.

Cation-exchange class is inferred from lab data from similar soils in the surrounding area.

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

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National Cooperative Soil Survey
U.S.A.