Wisconsin State Soil: Antigo Silt Loam

Adopted on September 14, 1983

An official state soil was created by 1983 Wisconsin Act 33 to remind Wisconsinites of their soil stewardship responsibilities. Thus, Antigo Silt Loam was declared the official state Soil in 1983.This soil occurs only in Wisconsin, across the north central part of the state. It is a versatile and productive soil and is representative of the many
silty soils that cover nearly half of the state. It is named after the city of Antigo in Langlade County. Professor Francis D. Hole, a UW-Madison soil scientist was behind the drive to declare an official state soil. It was done to remind the people of Wisconsin of their soil stewardship responsibilities. Antigo Silt Loam was selected to represent more than 500 major soil types in Wisconsin.

About 11,000 years ago, near the end of the last Ice Age, glacial meltwaters deposited the sand and gravel outwash that forms the lower subsoil and substratum of the Antigo soil. Strong winds and glacial meltwaters then deposited 2 to 3 feet of silty loess and loamy outwash on top of the sand and gravel. Soil development, under northern hardwood forests, produced an organic enriched surface layer and a clay enriched
subsoil.

The soil stores water for use by plants and filters our ground water and surface water. We depend on the soil to provide us with food and fiber. Soils play a major role in recycling carbon and nitrogen. Without soils neither we or the ecosystems in which we live could exist. The quality of our soil resources directly affects our quality of life. Good conservation practices allow us to use the soil while protecting the environment and keeping the soil healthy for future generations.

The Antigo series consists of very deep well, drained soils which are moderately deep to sandy outwash. These soils formed mostly in loess or silty alluvium and in loamy alluvium underlain by stratified sandy outwash. Typically these soils are on outwash plains, stream terraces, outwash terraces, kames, eskers, glacial lake plains, glacial drainageways, and outwash areas of moraines. Permeability is moderate in the silty and loamy layers and rapid or very rapid in the sandy outwash. Slopes range from 0 to 30 percent. Mean annual precipitation is about 30 inches. Mean annual air temperature is about 42 degrees F.

TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Haplic Glossudalfs

TYPICAL PEDON: Antigo silt loam - on a plane slope of less than 1 percent in a cultivated field at an elevation of about 1520 feet. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 9 inches; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; weak fine subangular blocky structure; very friable; many fine roots; about 6 percent gravel and 2 percent cobbles; neutral; abrupt smooth boundary. (5 to 12 inches thick)

E--9 to 12 inches; brown (10YR 5/3) silt loam, very pale brown (10YR 7/3) dry; weak thin platy structure; very friable; common fine roots; about 1 percent gravel and 1 percent cobbles; slightly acid; clear wavy boundary. (0 to 10 inches thick)

B/E--12 to 19 inches; 70 percent dark yellowish brown (10YR 4/4) silt loam (Bt); moderate very fine angular blocky structure; friable; few distinct brown (7.5YR 4/4) clay films on faces of peds; penetrated by brown (10YR 5/3) silt loam (E), very pale brown (10YR 7/3) dry; weak thin platy structure; very friable; common fine roots; very strongly acid; clear irregular boundary. (0 to 19 inches thick)

Bt1--19 to 28 inches; dark yellowish brown (10YR 4/4) silt loam; moderate fine angular blocky structure; friable; common fine roots; common distinct brown (7.5YR 4/4) clay films on faces of peds; common coatings of pale brown (10YR 6/3) clean silt and very fine sand grains on vertical faces of peds; about 1 percent gravel and cobbles; very strongly acid; abrupt wavy boundary. (0 to 20 inches thick)

2Bt2--28 to 31 inches; brown (7.5YR 4/4) loam; moderate medium subangular blocky structure; friable; common fine roots; common prominent dark reddish brown (5YR 3/4) clay films on faces of peds and in pores; common coatings of pale brown (10YR 6/3) clean silt and sand grains primarily on vertical faces of peds; about 11 percent gravel and 2 percent cobbles; very strongly acid; abrupt wavy boundary.

2Bt3--31 to 33 inches; brown (7.5YR 4/4) very gravelly sandy loam; weak coarse subangular blocky structure; friable; few fine roots; few distinct dark reddish brown (5YR 3/4) clay bridges between mineral grains; about 34 percent gravel and 2 percent cobbles; very strongly acid; abrupt wavy boundary. (Combined thickness of the 2Bt horizon is 0 to 10 inches)

3C--33 to 60 inches; brown (7.5YR 5/4) stratified sand and gravelly sand; single grain; loose; about 16 percent gravel and 2 percent cobbles; few fine roots; strongly acid.

TYPE LOCATION: Langlade County, Wisconsin; about 2 miles northeast of Antigo; 1270 feet west and 345 feet north of the southeast corner of sec. 16, T. 31 N., R. 11 E.

RANGE IN CHARACTERISTICS: Depth to stratified sandy outwash ranges from 20 to 40 inches. Thickness of the silty mantle ranges from 12 to 40 inches. The coarse-loamy part of the particle-size control section averages 8 to 17 percent clay and 15 to 50 percent fine sand or coarser. Volume of gravel ranges from 0 to 10 percent in the silty mantle and from 0 to 40 percent in the loamy subsoil. Volume of gravel in the sandy outwash ranges from 3 to 45 percent as a weighted average but ranges from 0 to 65 percent in individual strata. Volume of cobbles ranges from 0 to 5 percent throughout. A few stones are on the surface or in the solum in some areas. Reaction typically ranges from very strongly acid to slightly acid in the solum but it ranges to neutral in the upper part, where the soil is limed. It ranges from strongly acid to slightly acid in the substratum. Free carbonates are absent to depths of more than 5 feet.

The Ap horizon has hue of 7.5YR or 10YR, value of 3 to 5, and chroma of 2 or 3. Where the value moist is 3, the value dry is 6 or more. Uncultivated areas have an A horizon 1 to 5 inches thick with hue of 7.5YR or 10YR, value of 2 or 3, and chroma of 1 or 2.

The E horizon has hue of 5YR, 7.5YR, or 10YR; value of 4 to 6; and chroma of 2 or 3. Colors of 4/3 or 5/3 have value, dry of 7 or more.

Some pedons have a Bw horizon below the A or E horizon with hue of 10YR, value of 3 to 6, and chroma of 4 to 6.

Antigo soils have a glossic horizon (E/B or B/E horizons, or both). Horizonation has a wide range depending on the thickness of the silty mantle and the degree to which eluviation has occurred. Therefore, there can be E/B, B/E, 2E/B, or 2B/E horizons, singly or in combination, with or without Bt or 2Bt horizons.

The E part of the E/B or B/E horizons has color and texture like the E horizon described above. The Bt part has hue of 7.5YR or 10YR and value of 3 to 5.

The Bt horizon has color and texture like the Bt part described above.

The 2E part of the 2E/B or 2B/E horizons has hue of 5YR, 7.5YR, or 10YR; value of 4 to 6; and chroma of 2 or 3. It is loam, sandy loam, fine sandy loam, or the gravelly or very gravelly analogs. These horizons have less than 50 percent fine sand or coarser or are less than 5 inches thick.

The 2Bt part of the 2E/B or 2B/E horizons has hue of 5YR, 7.5YR, or 10YR; value of 3 to 6; and chroma of 4 to 6. It has textures like the 2E part described above.

The 2Bt horizon has color and texture like the 2Bt part described above. 2Bt horizons with 50 percent or more of fine sand or coarser are less than 5 inches thick.

Some pedons have a 3Bt horizon with color like the 2Bt part described above. It is sand, coarse sand, loamy sand, loamy coarse sand, or the gravelly or very gravelly analogs.

The 3C horizon has hue of 5YR, 7.5YR, or 10YR; value of 4 to 6; and chroma of 3 to 6. It is typically stratified sand, coarse sand, or the gravelly or very gravelly analogs, but some individual strata may be extremely gravelly.

COMPETING SERIES: This is the Sconsin series. A similar soil is the Anigon series. Sconsin soils have a zone of near saturation with redox concentrations above the sandy outwash within the series control section. Anigon soils average 18 to 27 percent clay and less than 15 percent fin sand or coarser in the argillic horizon.

GEOGRAPHIC SETTING: These soils are typically on glacial outwash plains and stream terraces, but in some places they are on eskers and kames or on glacial lake plains and moraines. Slope gradients range from 0 to 30 percent. The soils formed mostly in 20 to 40 inches of loess or water laid silty deposits and in loamy alluvium or sandy outwash or both, underlain by stratified sandy outwash. Mean annual temperature ranges from 39 to 45 degrees F. Mean annual precipitation ranges from 28 to 33 inches. The frost free period is estimated to range from 120 to 135 days. Elevation ranges from 800 to 1,950 feet.
Parent material: Formed in 20 to 40 inches of loess or silty alluvium and loamy alluvium underlain by stratified sandy outwash.
Landform: Outwash plains, stream terraces, outwash terraces, kames, eskers, glacial lake plains, glacial drainageways, and outwash areas of moraines.
Slope: 0 to 30 percent.
Elevation: 800 to 1950 feet.
Mean annual air temperature: 39 to 45 degrees F.
Mean annual precipitation: 28 to 33 inches.
Frost-free days: 120 to 135 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Billyboy(T), Langlade, Minocqua, Ossmer, and Sconsin soils. The moderately well drained Billyboy(T) and Sconsin soils, the somewhat poorly drained Ossmer soils, and the poorly drained Minocqua soils form a drainage sequence with Antigo soils. Sconsin soils are on more level landscape positions. Billyboy(T) and Ossmer soils are on lower landscape positions associated with apparent water tables, or are adjacent to moraines. Minocqua soils are in depressions and drainageways. The well drained Langlade soils are on similar landscape positions as Antigo soils where the loamy mantle is more than 40 inches thick.

DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is low to very high. Permeability is moderate in the silty and loamy layers and rapid or very rapid in the sandy outwash.

USE AND VEGETATION: Most areas of this soil are used for cropland. Common crops are corn, small grains, and hay. In some places, potatoes and snap beans are important crops and some areas are used for pastureland. Some areas remain in woodland. Timber stands are mostly American basswood, sugar maple, yellow birch, white ash, big tooth aspen, quaking aspen, and black cherry.

DISTRIBUTION AND EXTENT: Northern Wisconsin. LRR K, MLRA 90A, and MLRA 90B. This soil is of large extent.

MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Langlade County, Wisconsin, l947.

REMARKS: Diagnostic horizons and features recognized in this pedon: ochric epipedon - from 0 to 12 inches (Ap,E); albic horizon - from 9 to 12 inches (E); glossic horizon - from 12 to 19 inches (B/E); argillic horizon - from 12 to 33 inches (B/E, Bt1, 2Bt2, 2Bt3).
Particle size control section - the zone from 12 to 40 inches.
Ochric epipedon - the zone from 0 to 12 inches (Ap, E).
Albic horizon - the zone from 9 to 12 inches (E).
Glossic horizon - the zone from 12 to 19 inches (B/E).
Argillic horizon - the zone from 12 to 33 inches (B/E, Bt1, 2Bt2, 2Bt3).
Lithologic discontinuity - at the upper boundary of the 2Bt2 horizon at 28 inches and at the upper boundary of the 3C horizon at 33 inches.

ADDITIONAL DATA: Former Soil Interpretation Record - WI0142. Refer to soil survey sample number S79WI-067-088 for data on typical pedon. Refer to soil survey sample number S81WI-069-001 for data on another pedon.


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National Cooperative Soil Survey
U.S.A.