LOCATION PERSHING IA+MOEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Epiaqualfs
TYPICAL PEDON: Pershing silt loam on a convex slope of about 5 percent - cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; weak fine granular structure; friable; common fine dark reddish brown (5YR 2/2) and dark brown (7.5YR 3/2) soft accumulations (iron and manganese oxides); neutral; abrupt smooth boundary. (6 to 10 inches thick)
E--6 to 9 inches; dark grayish brown (2.5Y 4/2) silt loam, faces of peds very dark grayish brown (2.5Y 3/2), dark grayish brown (2.5Y 4/2) kneaded, grayish brown (2.5Y 5/2) dry; common fine distinct light olive brown (2.5Y 5/4) mottles; weak medium platy structure; friable; discontinuous streaks of very dark gray (10YR 3/1) on faces of peds; common fine dark reddish brown (5YR 2/2) and dark brown (7.5YR 3/2) soft accumulations (iron and manganese oxides); medium acid; clear smooth boundary. (0 to 6 inches thick)
BE--9 to 13 inches; mottled grayish brown (2.5Y 5/2) and yellowish brown (10YR 5/4) silty clay loam, faces of peds dark gray (10YR 4/1) and grayish brown (2.5Y 5/2), dark grayish brown (2.5Y 4/2) and olive brown (2.5Y 4/4) kneaded; weak very fine subangular blocky structure; friable; discontinuous light gray (10YR 7/1) dry silt coats; strongly acid; clear smooth boundary. (2 to 6 inches thick)
Bt1--13 to 17 inches; mottled yellowish brown (10YR 5/4) and grayish brown (2.5Y 5/2) silty clay, faces of peds dark gray (10YR 4/1) and grayish brown (2.5Y 5/2), light olive brown (2.5Y 5/4) kneaded; few fine faint yellowish brown (10YR 5/6) mottles; moderate fine subangular blocky structure; firm; thin discontinuous dark grayish brown (10YR 4/2) clay films; few thin patchy gray (10YR 6/1) silt coats; few fine dark reddish brown (5YR 2/2) concretions (iron oxides); strongly acid; clear smooth boundary.
Bt2--17 to 26 inches; mottled grayish brown (2.5Y 5/2) and yellowish brown (10YR 5/6) silty clay, light olive brown (2.5Y 5/4) kneaded; strong fine subangular blocky structure; very firm; discontinuous dark gray (10YR 4/1) coatings, few black (10YR 2/1) streaks; thick continuous dark grayish brown (2.5Y 4/2) clay films; few fine dark reddish brown (5YR 2/2) and dark brown (7.5YR 3/2) concretions (iron and manganese oxides); strongly acid; gradual smooth boundary.
Bt3--26 to 37 inches; mottled grayish brown (2.5Y 5/2) and yellowish brown (10YR 5/6) silty clay in upper part, silty clay loam in lower part; weak fine prismatic structure parting to moderate and strong fine subangular blocky; firm; few discontinuous dark gray (10YR 4/1) coatings mainly on vertical ped faces; thin discontinuous dark grayish brown (2.5Y 4/2) clay films; few fine dark reddish brown (5YR 2/2) and dark brown (7.5YR 3/2) soft concretions (iron and manganese oxides); medium acid; gradual smooth boundary.
Bt4--37 to 46 inches; mottled grayish brown (2.5Y 5/2) and yellowish brown (10YR 5/6) silty clay loam; few fine distinct strong brown (7.5YR 5/6) mottles; weak fine prismatic structure parting to weak fine subangular blocky; firm; thin discontinuous dark grayish brown (2.5Y 4/2) clay films; few dark gray (10YR 4/1) clay flows on prism faces and in old channels; common fine dark reddish brown (5YR 3/2) concretions (iron oxides); medium acid; gradual smooth boundary.
Bt5--46 to 60 inches; mottled yellowish brown (10YR 5/6), gray (5Y 6/1), and grayish brown (2.5Y 5/2) silty clay loam; weak fine prismatic structure; friable; few dark gray (10YR 4/1) clay flows on prism faces and in old channels; common fine dark reddish brown (5YR 3/2) concretions (iron oxides); medium acid; gradual smooth boundary. (Combined thickness of the Bt horizons is 28 to 54 inches.)
BC--60 to 72 inches; mottled yellowish brown (10YR 5/4) and gray (5Y 6/1) silty clay loam; weak medium prismatic structure; friable; few dark gray (10YR 4/1) clay films on prism faces; many fine dark reddish brown (5YR 3/2) soft concretions (iron oxides); medium acid.
TYPE LOCATION: Monroe County, Iowa; about 9 miles west and 3 miles north of Albia; 2,100 feet south and 80 feet west of the northeast corner of sec. 6, T. 72 N., R. 18 W.
RANGE IN CHARACTERISTICS: Solum thickness typically is 6 feet or more but ranges from 4 to 8 feet. In general, free carbonates are lacking to depths of 10 feet or more.
The A or Ap horizon typically has hue of 10YR, value of 3, and chroma of 1 or 2. It is silt loam or silty clay loam.
The E horizon typically has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2. In many pedons, the E horizon is mixed in the Ap horizon.
The BE horizon has 2.5Y or 10YR hue, value of 4 or 5, and chroma of 2 through 4. Reaction of the E and BE horizons typically is medium acid or strongly acid but ranges to very strongly acid in the E horizons of some pedons.
The Bt1, Bt2 and Bt3 horizons have hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2 through 8. These horizons are silty clay or silty clay loam. The finest part of these horizons generally contains between 42 and 48 percent clay. The upper boundary of the finest part of the Bt horizon commonly is within depths of 14 to 20 inches below the surface. The upper part of the Bt horizon has thin, discontinuous silt coats, but they are lacking in the lower part. Reaction of the Bt1, Bt2, and Bt3 horizons ranges from medium acid to strongly acid.
The Bt4 and Bt5 horizons range from slightly acid to strongly acid. The Bt4 and Bt5 horizons have hue of 10YR, 2.5Y, or 5Y; value of 4 through 6; and chroma of 1 through 6. Silty clay loam textures commonly extend to depths of 5 feet or more, but some pedons are silt loam in the lower part of the sola. In some pedons, on uplands, the lower part of the sola formed in paleosols.
COMPETING SERIES: These are the Armstrong, Hoyleton, Mystic, and Sunbury series of the same family and the Atterberry, Belinda, Givin, Hedrick, Kniffin, Ladoga, Mexico, and Weller series. Armstrong and Hoyleton soils have 2B horizons that contain more sand and coarse fragments. Mystic soils contain more sand throughout the solum. Sunbury soils have 2B horizons and have free carbonates above depths of 60 inches. Atterberry soils are fine-silty. Belinda soils have thicker E horizons and have an abrupt change in texture from the E horizon to the B horizon. Givin and Hedrick soils have less clay in the Bt horizons. Kniffin soils are shallower to the horizon highest in clay and contain more clay in the finest part. Ladoga soils have less clay in the B horizons and are deeper to mottles or colors of low chroma. Mexico soils have a thinner solum and have more clay in at least part of the B horizon. In addition, Mexico soils have common or many red mottles. Weller soils have lighter colored or thinner A horizons or both and the upper part of the B horizon commonly has redder hue and higher value and chroma.
GEOGRAPHIC SETTING: Pershing soils typically are on convex slopes bordering the flat interstream divides in the loess-covered Kansan and Nebraskan till plain. They also are on benches in a few places. On uplands, these soils are underlain by paleosols at depths of 6 to 10 feet. On benches, they are underlain below depths of 4 or more feet by alluvium of Wisconsin or pre-Wisconsin age. Slopes range from 2 to 14 percent. These soils formed in loess that contains less than 5 percent sand and is of Wisconsin age. Mean annual temperature ranges from about 50 to 57 degrees F, and mean annual precipitation ranges from about 32 to 36 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Belinda and Weller soils and the Adair, Gara, and Grundy soils. Belinda soils are on nearly level interfluves. Weller soils are on similar landscape positions as the Pershing soils. Adair and Gara soils are on the more sloping parts of the landscape at slightly lower elevations. These soils have more coarse fragments in their sola, and Gara soils are lower in clay. Grundy soils are on similar slopes and have mollic epipedons. In some places, soils formed in residuum weathered from shale are on nearby lower slopes.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained and moderately well drained. Runoff is medium, and permeability is slow.
USE AND VEGETATION: Most of these soils are cultivated to corn, hay, or oats or are in pasture. Some areas are in woodland. Native vegetation was mixed grasses and deciduous trees.
DISTRIBUTION AND EXTENT: Southern Iowa and northern Missouri. The soil is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Lucas County, Iowa, 1940.
REMARKS: Classification only was updated for final correlations in Iowa. Changes include proposals made in Amendment 17 to Soil Taxonomy. Competing series and other updates will be made later. Diagnostic horizons and features recognized in this pedon are: ochric epipedon - zone from the surface to a depth of approximately 9 inches (Ap and E horizons); argillic horizon - zone from approximately 13 to 60 inches (Bt1, Bt2, Bt3, Bt4, and Bt5 horizons); udic moisture regime.