LOCATION ROUNDHEAD OH+MI

Established Series
Rev. RAR-JAG
11/2021

ROUNDHEAD SERIES

The Roundhead series consists of very deep, very poorly drained soils formed in a thin layer of organic material and in the underlying silty glaciolacustrine sediments. These soils are on lake plains. Slopes are less than 1 percent. Mean annual precipitation is about 889 mm (35 inches), and mean annual air temperature is about 10 degrees C (50 degrees F).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Histic Humaquepts

TYPICAL PEDON: Roundhead muck, on a broad nearly level area in a cultivated field at an elevation of 295 meters (969 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Oap--0 to 25 cm (0 to 10 inches); black (10YR 2/1) broken face and rubbed muck with very little fiber, very dark gray (10YR 3/1) dry; moderate fine and medium granular structure; very friable; few fine roots; neutral; abrupt smooth boundary. [20 to 38 cm (8 to 15 inches) thick]

Bg1--25 to 41 cm (10 to 16 inches); dark grayish brown (2.5Y 4/2) silt loam; weak coarse prismatic structure parting to moderate medium subangular blocky; friable; few fine roots; black (10YR 2/1) worm casts and common distinct black (10YR 2/1) organic coatings on vertical faces of peds; common medium faint gray (5Y 5/1) iron depletions in the matrix; common medium prominent white (10YR 8/1) aquatic shells in the matrix; strongly effervescent; slightly alkaline; gradual smooth boundary.

Bg2--41 to 58 cm (16 to 23 inches); grayish brown (2.5Y 5/2) silt loam with thin strata of silt and very fine sand; weak coarse prismatic structure parting to weak medium subangular blocky; friable; common prominent yellowish brown (10YR 5/6) iron oxide coatings in old root channels; common medium distinct light olive brown (2.5Y 5/4) masses of iron accumulation in the matrix; common medium distinct light gray (10YR 7/2) gypsum crystals (CaSO4) in old root channels; strongly effervescent; slightly alkaline; gradual smooth boundary.

Bg3--58 to 94 cm (23 to 37 inches); gray (5Y 5/1) silty clay loam; weak medium and coarse subangular blocky structure; firm; common prominent yellowish brown (10YR 5/4) iron oxide coatings in old root channels; common medium prominent olive brown (2.5Y 4/4) and common medium faint dark grayish brown (2.5Y 4/2) masses of iron accumulation in the matrix; common medium prominent light gray (10YR 7/2) gypsum crystals (CaSO4) in old root channels; strongly effervescent; slightly alkaline; gradual smooth boundary. [Combined thickness of the Bg horizon is 15 to 81 cm (6 to 32 inches).]

Cg--94 to 152 cm (37 to 60 inches); gray (5Y 5/1) silty clay loam with strata of silt loam; massive; weakly laminated; firm; common medium prominent yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; strongly effervescent; slightly alkaline.

TYPE LOCATION: Hardin County, Ohio; about 2 1/2 miles south of McGuffey, in McDonald Township; 4370 feet south of the intersection of State Route 195 and County Road 65, then 165 feet east; USGS Alger, Ohio topographic quadrangle; lat. 40 degrees 38 minutes 09.4 seconds N. and long. 83 degrees 47 minutes 18.5 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
Thickness of the histic epipedon: 20 to 38 cm (8 to 15 inches)
Depth to carbonates: 20 to 38 cm (8 to 15 inches)
Thickness of the solum: 38 to 102 cm (15 to 40 inches)
Particle-size control section: averages 18 to 35 percent clay
Rock fragment content: typically absent

Oap horizon:
Hue: 7.5YR, 10YR, or is neutral
Value: 2, 2.5 or 3
Chroma: 0 to 2
Reaction: strongly acid to slightly alkaline

Some pedons have an Oa horizon.

Bg horizon:
Hue: 10YR, 2.5Y, 5Y, or is neutral
Value: 4 to 6
Chroma: 0 to 2
Texture: typically silt loam or silty clay loam, but thin strata or lenses of silty clay, clay loam, loam, or fine sandy loam are common
Reaction: slightly alkaline or moderately alkaline

Cg horizon:
Hue: 10YR, 2.5Y, or 5Y
Value: 4 to 6
Chroma: 1 or 2
Texture: typically silt loam or silty clay loam, but thin strata of silty clay, clay loam, loam, or fine sandy loam are in some pedons
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: There are no other series in this family. The McGuffey and Olentangy soils are in closely related families. McGuffey soils have illitic clay mineralogy and average more than 35 percent clay in the particle-size control section. Olentangy soils are formed in coprogenous earth, and do not have carbonates in the upper part of the series control section.

GEOGRAPHIC SETTING: Roundhead soils typically are on broad, nearly level areas or in depressions associated with Wisconsin age lake plains. Slope gradients are less than 1 percent. The soils formed in organic plant material in former marshes and bogs and in the underlying silty glaciolacustrine sediments. However, drainage of the marshes, subsidence, and loss of surface has nearly depleted the organic soil material. Mean annual precipitation ranges from 686 to 1067 mm (27 to 42 inches). Mean annual air temperature ranges from 7 to 13 degrees C (45 to 55 degrees F). Frost-free period is 150 to 180 days. Elevation is 274 to 305 meters (900 to 1000 feet) above mean sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carlisle, Linwood, McGuffey, Milford, Montgomery, Patton, and Willette soils. Carlisle, Linwood, and Willette soils have surface layers of sapric material more than 41 cm (16 inches) thick. Carlisle soils are in the deepest part of the lake basin or upper end of drainage systems where organic materials have accumulated to the greatest depth. Linwood and Willette soils are in landscape positions between Roundhead and Carlisle soils. McGuffey soils are on similar landscape positions as Roundhead soils. Milford, Montgomery, and Patton soils are very poorly drained mineral soils on the perimeter of the lake plain.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained. The depth to the top of an intermittent apparent high water table ranges from 30 cm (1 foot) above the surface to 30 cm (1 foot) below the surface between December and June in normal years. The potential for surface runoff is negligible. Saturated hydraulic conductivity is moderately high or high in the organic material and moderately high or moderately low in the underlying glaciolacustrine material. Permeability is moderate or moderately rapid in the organic material and slow or moderately slow in the underlying glaciolacustrine material.

USE AND VEGETATION: Most areas are cultivated. Principal crops are corn and soybeans and specialty crops such as potatoes and carrots. Native vegetation is wet prairie grasses, reeds, and sedges with some shrubs and scattered hardwoods.

DISTRIBUTION AND EXTENT: Northwest Ohio and central Michigan, and possibly Indiana; MLRAs 99 and 111B. The type location is in MLRA 111B. The series is of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: AMHERST, MASSACHUSETTS

SERIES ESTABLISHED: Hardin County, Ohio, 1987.

REMARKS: The Roundhead series were originally identified as Carlisle or Linwood series, but with continued subsidence and loss of surface by soil blowing these soils no longer qualify as Histosols.

A loamy substratum phase has been recognized. This phase should be investigated during MLRA update activities to determine if sufficient acreage exists to warrant the development of a new series.

Diagnostic horizons and features recognized in this pedon are:
Histic epipedon: from the surface to a depth of 25 cm (Oap horizon).
Cambic horizon: from a depth of 25 to 94 cm (Bg horizon).
Aquic conditions: from the surface to a depth of 152 cm.

ADDITIONAL DATA: Laboratory characterization data is available from The Ohio State University Soil Characterization Laboratory for HD-23, the typical pedon.

National Cooperative Soil Survey
U.S.A.