LOCATION TOOLESBORO IA
The Toolesboro series consists of deep, somewhat poorly drained and poorly drained soils formed in loamy and sandy alluvial sediments on bottomlands. They are moderate or moderately rapidly permeable in the solum and very rapidly permeable in the substratum. Slope ranges from 0 to 2 percent. Mean annual temperature is about 50 degrees F, and mean annual precipitation is about 34 inches.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Endoaquolls
TYPICAL PEDON: Toolesboro loam, with a slope of about 1 percent on a nearly level flood plain - cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; very dark grayish brown (10YR 3/2) loam (about 26 percent clay), dark grayish brown (10YR 4/2) dry; weak very fine granular structure; friable; common fine roots; some undercomposed plant material; neutral; abrupt smooth boundary.
A--9 to 13 inches; dark brown (10YR 3/3) loam (about 21 percent clay), brown (10YR 5/3) dry; brown (7.5YR 4/2) coats on faces of peds; many fine faint brown (7.5YR 4/4), few fine prominent reddish brown (5YR 4/4), and few fine faint brown (7.5YR 4/2) mottles; weak fine granular structure; friable; very dark grayish brown (10YR 3/2) fills in old root channels; few fine roots; moderately acid; clear wavy boundary. (Combined thickness of the A horizons is 10 to 15 inches.)
Bw1--13 to 20 inches; dark brown (7.5YR 3/4) sandy loam (about 10 percent clay); common fine faint strong brown (7.5YR 4/6) and few fine faint brown (7.5YR 4/2) mottles; weak fine subangular blocky structure; very friable; very dark grayish brown (10YR 3/2) fills in old root channels; slightly acid; clear wavy boundary.
Bw2--20 to 30 inches; brown (7.5YR 4/4) sandy loam (about 9 percent clay); few fine faint brown (7.5YR 4/2) and few fine faint strong brown (7.5YR 4/6) mottles; weak medium subangular blocky structure; very friable; neutral; gradual wavy boundary.
Bw3--30 to 36 inches; dark yellowish brown (10YR 4/4) loamy sand (about 5 percent clay); few medium faint brown (7.5YR 4/4) mottles; weak coarse prismatic structure; very friable; neutral; clear wavy boundary. (Combined thickness of the Bw horizons is 20 to 35 inches.)
C--36 to 60 inches; dark yellowish brown (10YR 4/4) loamy sand (about 3 percent clay); massive; very friable; neutral.
TYPE LOCATION: Louisa County, Iowa; about 1 mile south and 4 miles east of Grandview; 675 feet east and 160 feet south of the northwest corner of sec. 29, T. 75 N., R. 2 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from about 30 to 50 inches. Carbonates are not present in the solum and typically are lacking to depths of several feet. The control section averages about 8 to 18 percent clay and 65 to 80 percent total sand. The sand fraction is more than 50 percent medium sand or coarser. Gravel content ranges from 0 to 5 percent by volume. The gravel typically is less than 1 cm in diameter.
The Ap or A horizon has hue of 7.5YR or 10YR, value of 2 or 3, and chroma of 1, 2, or 3. It is clay loam, loam, sandy clay loam, or sandy loam. Reaction ranges from medium acid to neutral. A BA horizon is in some pedons.
The Bw horizon ranges from loam to sandy loam in the upper part grading to loamy sand or sand in the lower part. It has hue of 5YR through 10YR with value of 3, 4, or 5 and chroma of 1 through 4. Mottles of high and low chroma are present. The upper part of the Bw horizon ranges from slightly acid to strongly acid while the lower part ranges from neutral to medium acid. A BC horizon is in some pedons.
The C horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 1 through 6. It is loamy sand, coarse sand, or sand. Reaction ranges from neutral to medium acid.
COMPETING SERIES: These are the
Lyles soils in the same family and the
Shaffton series. Corunna soils have loamy or silty calcareous 2C horizons above 40 inches. Darfur soils are higher in fine and very fine sand, are shallower to carbonates, and lack hues of 7.5YR or redder. Dassel soils have distinct textural stratification in the Bw horizons and are shallower to free carbonates. Gilford soils have free carbonates in the 2C horizon and are in areas receiving greater rainfall. Hanska soils are shallower to carbonates and have 2.5Y or 5Y hues in the Bw horizon. Jubilee soils have cooler temperatures and mean annual precipitation less than 15 inches. Lyles soils are stratified in the lower part of the solum and lack hues of 7.5YR or redder. Ambraw and Shaffton soils are fine-loamy. Gannett soils typically have free carbonates in the surface and have a thinner solum. Granby soils average more sand in the control section.
GEOGRAPHIC SETTING: The Toolesboro soils are on nearly level flood plains which are subject to flooding unless protected by levees. Slope gradients are from 0 to 2 percent. They formed in loamy and sandy alluvium. Mean annual temperature ranges from about 47 to 54 degrees F, and mean annual precipitation ranges from about 31 to 34 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Ambraw soils and the
Fruitfield soils. Elrick and Fruitfield soils are slightly higher on the landscape and lack the lower chroma mottles in the B horizon. Ambraw soils are slightly lower on the landscape.
DRAINAGE AND PERMEABILITY: Somewhat poorly and poorly drained. Permeability is moderate or moderately rapid in the solum and very rapid in the substratum. Runoff is slow.
USE AND VEGETATION: The Toolesboro soils are commonly drained and cropped to corn and soybeans. A few areas are used for potatoes or tomatoes. Some areas are in timber. The native vegetative cover is a herbaceous wetland community commonly inhabited with Bluejoint Grasses, White Cutgrasses, Fox Sedges, Oval Sedges, Inland Rushes, Torreys Rushes, Dark Green Bulrushes, Flatstem Spikerushes, Blue Vervains, Indian Hemps, Winged Loosestrifes, Wild Mints, and Water Horehounds.
DISTRIBUTION AND EXTENT: Mississippi River bottom lands in southeastern Iowa and possibly adjoining states. They are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Louisa County, 1984.
REMARKS: Even though the chroma in the upper part of the B horizon is more than 2, this soil is wet and has an aquic moisture regime. Drainage is necessary before the soil can be cultivated.
National Cooperative Soil Survey