LOCATION DERRYNANE MNEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Cumulic Vertic Endoaquolls
TYPICAL PEDON: Derrynane clay loam, on a 1 percent concave slope, in a cultivated field. (Colors are for moist soil unless otherwise noted).
Ap--0 to 9 inches; black (10YR 2/1) clay loam, very dark gray (10YR 3/1) dry; moderate fine subangular blocky structure parting to moderate fine granular; friable; neutral; abrupt smooth boundary.
A1--9 to 19 inches; very dark gray (10YR 3/1) silty clay loam, dark gray 10YR (4/1) dry; moderate fine subangular blocky structure; friable; few fine prominent reddish brown (5YR 4/3) Fe concentrations; neutral; clear smooth boundary.
A2--19 to 39 inches; black (N 2/0) silty clay, very dark gray (10YR 3/1) dry; moderate medium prismatic structure parting to strong medium subangular blocky; firm; few fine prominent reddish brown (5YR 4/3) Fe concentrations; slightly acid; clear wavy boundary. (Combined thickness of the A horizon is 24 to 48 inches.)
Btg--39 to 42 inches; very dark gray (5Y 3/1) clay loam, dark gray (5Y 4/1) dry; moderate medium subangular blocky structure; firm; few fine prominent reddish brown (5YR 4/3) Fe concentrations; common distinct black (10YR 2/1) organic coats and clay films on ped faces; slightly acid; clear wavy boundary. (0 to 24 inches thick)
2Bg--42 to 47 inches; olive gray (5Y 4/2) clay loam; weak medium subangular blocky structure; friable; few medium prominent yellowish brown (10YR 5/8) Fe concentrations; about 3 percent gravel; neutral; clear wavy boundary. (6 to 20 inches thick)
2BCg--47 to 65 inches; olive gray (5Y 4/2) clay loam; weak fine subangular blocky structure; friable; common medium prominent yellowish brown (10YR 5/6) Fe concentrations; about 4 percent gravel; neutral.
2Cg--65 to 80 inches; olive gray (5Y 5/2) loam; massive; friable; common medium prominent yellowish brown (10YR 5/6) and common medium prominent strong brown (7.5YR 4/6) Fe concentrations; about 5 percent gravel; slightly effervescent; slightly alkaline
TYPE LOCATION: Le Sueur County, Minnesota; about 1 1/2 miles east of Cordova; about 1,850 feet south and 400 feet east of the northwest corner of section 18, T. 110 N., R. 23 W.; USGS Cordova quadrangle; lat. 44 degrees 20 minutes 09 seconds N and long. 93 degrees 38 minutes 43 seconds W., NAD83.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 24 to 60 inches thick. Depth to calcium carbonates ranges from 40 to 80 inches. The 10 to 40 inch particle size control section averages 35 to 45 percent clay. A clay increase is typical in the B horizons but the B/A clay ratio is less than 1.2. The mantle of colluvial and glacio-lacustrine sediment typically ranges from 30 to 50 inches but some pedons range as thick as 70 inches. The lacustrine mantle typically does not have coarse fragments, but may contain up to 2 percent coarse fragments in some pedons. The underlying glacial till contains 2 to 8 percent coarse fragments, by volume, of mixed lithology. The sand content ranges from 30 to 45 percent and the clay content ranges from 18 to 32 percent in the glacial till.
The Ap and A horizons have a hue of 10YR or are neutral, value of 2 in the upper part and 2 or 3 in the lower part, with a chroma of 0 to 2. They are silty clay loam, clay loam or silty clay. Reaction is slightly acid to neutral.
The Bg or Btg horizon has hue of 10YR, 2.5Y, or 5Y, values of 2 or 3 in the upper part, 4 in the lower part, and chroma of 1 or 2. It is silty clay loam, clay loam or silty clay. Reaction is slightly acid or neutral.
Some pedons may have a Bkg horizon.
The 2Bg or 2Btg horizon has hue of 2.5Y or 5Y, value of 3 to 5 and chroma of 1 to 3. It is loam or clay loam. Reaction is slightly acid or neutral.
The 2BCg horizon has a hue of 2.5Y or 5Y, value of 4 or 5, chroma of 1 to 3. It is loam or clay loam. Reaction is slightly acid or neutral.
The 2Cg has hue of 2.5Y or 5Y, value of 4 or 5 and chroma of 1 to 3. It is loam or clay loam. Reaction is slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Clamo, Okoboji, Wabash, Zoe and Zook series. Clamo soils have free carbonates within 30 inches. Okoboji soils are saturated in the upper one fourth of the series control section for more than half of the 120 days following the summer solstice in an undrained condition. Wabash soils average more than 46 percent clay in the 10 to 40 inch particle size control section. Zoe soils have higher soluble salt concentrations and 4 to 8 millimhos/cm electrical conductivity below a depth of 12 inches. Zook soils have less than 30 percent sand in the lower one fourth of the series control section.
GEOGRAPHIC SETTING: Derrynane soils are on plane to slightly concave positions on footslopes or toeslopes on moraines. Slopes range from 1 to 4 percent. They formed in 30 to 50 inches of silty and/or clayey colluvium and glacio-lacustrine sediment and the underlying calcareous, loamy, friable glacial till of Late Wisconsin age. Mean annual air temperature ranges from 45 to 48 degrees F. Mean annual precipitation ranges from 26 to 32 inches. Frost-free period ranges from 145 to 170 days. Elevation ranges from 1,000 to 1,250 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Erin, Kilkenny, Lerdal, Mazaska, Okoboji, Rolfe, and Shields soils that are in a hydrosequence with Derrynane soils. The moderately well drained Erin and Kilkenny soils are on shoulder and backslope positions. The somewhat poorly drained Lerdal soils are on summits and gently sloping backslopes. The poorly drained Mazaska and Shields soils are on summits and swales. The very poorly drained Okoboji soils formed in similar sediment as Derrynane and are in closed depressions. The very poorly drained Rolfe soils are in slightly concave depressions on summits.
DRAINAGE AND PERMEABILITY: Poorly drained and somewhat poorly drained. Surface runoff is low. Permeability is slow. The apparent seasonal high water table is as high as 0.5 to 1.5 feet for the poorly drained phase and 1.5 to 2.5 feet for the somewhat poorly drained phase in spring in normal years.
USE AND VEGETATION: Commonly drained and cropped to corn and soybeans, though many areas are in hayland or pasture. Native vegetation is mixed wet prairie grasses and deciduous forest.
DISTRIBUTION AND EXTENT: South Central to southeastern Minnesota. MLRA 103.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Rice County, Minnesota, 1996.
REMARKS: Diagnostic horizons and features recognized in this pedon: mollic epipedon - zone from the surface to 42 inches (Ap, A1, A2, Bg horizons); cambic horizon - zone from 42 to 47 inches (2Bg horizon).
A somewhat poorly drained overwash phase is recognized that has 8 to 20 inches of colluvium overlying the original dark colored surface layer.
ADDITIONAL DATA: Soil Interpretation Record Number MN0782.