LOCATION HECLA SD+MN ND

Established Series
LDS-CJH-ARG
02/2014

HECLA SERIES

The Hecla series consists of very deep, moderately well drained soils formed in sandy sediments on lake plains and glacial outwash plains. Permeability is moderately rapid or rapid. Slopes range from 0 to 6 percent. Mean annual precipitation is about 19 inches, and mean annual air temperature is about 43 degrees F.

TAXONOMIC CLASS: Sandy, mixed, frigid Oxyaquic Hapludolls

TYPICAL PEDON: Hecla loamy fine sand - on a plane slope of 2 percent in native grass. When described the soil was dry to 30 inches and moist below. (Colors are for dry soil unless otherwise stated)

A1--0 to 6 inches; dark gray (10YR 4/1) loamy fine sand, black (10YR 2/1) moist; weak fine granular structure; soft, very friable; many fine and medium roots; neutral; clear smooth boundary.

A2--6 to 20 inches; dark gray (10YR 4/1) fine sand, very dark gray (10YR 3/1) moist; single grain; loose; common fine and medium roots; neutral; clear wavy boundary. (Combined A horizons 16 to 30 inches thick)

AC--20 to 30 inches; dark gray (10YR 4/1) fine sand, very dark gray (10YR 3/1) moist; weak medium subangular blocky structure; loose, very friable; few fine and medium roots; neutral; gradual wavy boundary. (0 to 15 inches thick)

C1--30 to 46 inches; grayish brown (10YR 5/2) fine sand, dark grayish brown (10YR 4/2) moist; few fine distinct dark yellowish brown (10YR 4/4) moist redoximorphic concentrations; single grain; loose; few very fine bands of very dark grayish brown (10YR 3/2) moist; few fine and medium roots; slightly alkaline; gradual wavy boundary. (8 to 20 inches thick)

C2--46 to 54 inches; grayish brown (2.5Y 5/2) fine sand, dark grayish brown (2.5Y 4/2) moist; common fine distinct yellowish brown (10YR 5/6) and dark yellowish brown (10YR 4/4) moist redoximorphic concentrations; single grain; few fine and medium roots; slightly alkaline; clear wavy boundary. (6 to 12 inches thick)

2Ab--54 to 62 inches; very dark gray (10YR 3/1) fine sandy loam, black (10YR 2/1) moist, common fine prominent dark yellowish brown (10YR 4/4) moist redoximorphic concentrations; massive; soft, very friable; few fine and medium roots; slightly alkaline; clear wavy boundary. (0 to 10 inches thick)

2C--62 to 72 inches; light brownish gray (2.5Y 6/2) loamy fine sand, grayish brown (2.5Y 5/2) moist; common fine prominent yellowish brown (10YR 5/6) and dark yellowish brown (10YR 4/4) moist redoximorphic concentrations; single grain; loose; few medium roots; slightly alkaline.

TYPE LOCATION: Brown County, South Dakota; about 8 miles south and 2 miles east of Hecla; 510 feet west and 130 feet north of the southeast corner of sec. 36, T. 127 N., R. 61 W.

RANGE IN CHARACTERISTICS: The mollic epipedon is 10 to 20 inches thick. Mollic colors extend to depths of more than 18 inches, however horizons with mollic colors below depths of 20 inches and extending to depths of 40 inches contain less than .6 percent organic carbon. Typically, a few faint or distinct redoximorphic features are below the lower part of the A horizon or the AC horizon and distinct or prominent redoximorphic features are in the lower part of the C horizon. Buried horizons are below depths of 30 inches in most pedons. Depth to carbonates ranges from 20 to 80 inches or more. The particle-size control section averages more than 45 percent fine sand and very fine sand, less than 35 percent medium and coarser sand, and less than 15 percent coarse and very coarse sand.

The A horizon has value of 3 or 4 and 2 or 3 moist, and chroma of 1 or 2. It is loamy fine sand, loamy sand, sandy loam, or fine sandy loam in the upper part and loamy fine sand, loamy sand, or fine sand in the lower part. It is slightly acid to slightly alkaline.

The AC horizon has value of 3 to 5 and 2 or 3 moist, and chroma of 1 or 2. It is loamy fine sand, fine sand, or loamy sand. It ranges from slightly acid to slightly alkaline. Some pedons have a Bw horizon.

The C horizon has hue of 10YR, 2.5Y, or 5Y; value of 4 to 7 and 3 to 5 moist; and chroma of 2 to 4. The C horizon is loamy fine sand, loamy sand, or fine sand. It ranges from slightly acid to moderately alkaline. Clay loam or loam till is between depths of 40 and 60 inches in some pedons. Very fine sandy loam, loamy very fine sand, silty clay loam, silty clay or silt loam material is between depths of 40 and 60 inches in some pedons.

COMPETING SERIES: These are the Duelm, Falsen, Flaming, Radium and Walum series in the same family. Duelm soils have less than 40 percent fine and very fine sand. Falsen soils have a particle-size control section that averages less than 45 percent fine sand and very fine sand, more than 35 percent medium and coarser sand, and more than 15 percent coarse and very coarse sand. Flaming soils have mollic colors less than 18 inches thick. Radium soils have more than 10 percent rock fragments. Walum soils contain more than 50 percent sand size shale fragments.

GEOGRAPHIC SETTING: Hecla soils are on plane and convex surfaces of sandy lacustrine and glacial outwash plains and nearby sand-mantled till plains. Slope gradients typically are less than 3 percent and range from 0 to 6 percent. Hecla soils formed in reworked sands. Mean annual temperature ranges from 34 to 48 degrees F, and mean annual precipitation from 14 to 24 inches. Growing season is about 110 to 140 days; average growing season precipitation ranges from 13 to 18 inches; and growing degree days are about 2500 to 3000.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fossum, Garborg, Hamar, Ulen, Venlo and Maddock soils. Fossum, Garborg, Hamar and Venlo soils have an aquic soil moisture regime. Garborg and Ulen and soils are somewhat poorly drained. Garborg soils are in shallow depressions and Ulen soils are on flats. In addition, the Ulen soils have a calcic horizon within depths of 16 inches. Fossum, Hamar, and Venlo soils are in the lower, wetter positions. Maddock soils do not have redoximorphic features within depths of 40 inches and typically are on slightly steeper slopes at higher elevations.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. Surface runoff is very low. Saturated hydraulic conductivity is high. A seasonal water table is at depths of 2.5 to 5 feet.

USE AND VEGETATION: Most areas cropped to corn, alfalfa, and small grains. Some areas are in tame pasture. Native grasses are big bluestem, prairie sandreed, little bluestem, needleandthread, switchgrass, forbs, and sedges.

DISTRIBUTION AND EXTENT: Northeastern South Dakota, eastern North Dakota, and western Minnesota. The soil is extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Brown and Marshall Counties (Brown-Marshall S and WCD), South Dakota, 1940.

REMARKS: Diagnostic horizons and feature recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of about 20 inches (A1 and A2 horizons). The AC horizon has the color, but not the organic carbon content to be mollic.

The zone immediately below the mollic epipedon (AC horizon) meets the color requirement for the aquic subgroup, but does not have aquic conditions.

The pedon meets the color requirement for the aquic subgroup in the horizon immediately below the mollic epipedon (AC horizon), however the soil does not have aquic conditions immediately below the mollic epipedon and does not meet the subgroup criteria. Saturation does not occur shallower than 2.5 feet.

ADDITIONAL DATA: Laboratory data for the typical pedon of Hecla loamy fine sand is No. 74L1051-74L1059.

National Cooperative Soil Survey
U.S.A.