LOCATION COMFREY MN+IL INEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Cumulic Endoaquolls
TYPICAL PEDON: Comfrey clay loam with a plane slope of less than 1 percent on a flood plain in a cultivated field. (Colors are for moist soils.)
Ap--0 to 25 centimeters (0 to 10 inches); black (10YR 2/1) clay loam; very dark gray (10YR 3/1) dry; moderate very fine granular structure; friable; neutral; abrupt smooth boundary.
A1--25 to 66 centimeters (10 to 26 inches); black (10YR 2/1) clay loam, very dark gray (10YR 3/1) dry; weak coarse prismatic structure parting to weak very fine granular; friable; neutral; gradual smooth boundary.
Bg--66 to 89 centimeters (26 to 35 inches); very dark gray (10YR 3/1) clay loam, dark grayish brown (10YR 4/2) dry; weak coarse prismatic structure parting to weak medium subangular blocky; friable; neutral; gradual wavy boundary.
BCg--89 to 97 centimeters (35 to 38 inches); dark gray (10YR 4/1) clay loam; common fine distinct yellowish brown (10YR 5/8) and strong brown (7.5YR 5/8) redoximorphic concentrations; weak medium subangular blocky structure; friable; slightly effervescent; slightly alkaline; gradual wavy boundary.
Cg1--97 to 152 centimeters (38 to 60 inches); dark gray (5Y 4/1) clay loam; few fine distinct yellowish brown (10YR 5/6) redoximorphic concentrations; massive; friable; slightly effervescent; slightly alkaline.
Cg2--152 to 203 centimeters (60 to 80 inches); olive gray (5Y 4/2) clay loam; many medium distinct yellowish brown (10YR 5/6) redoximorphic concentrations; massive; friable; slightly effervescent; slightly alkaline.
TYPE LOCATION: Rock County, Minnesota; 2600 feet west and 200 feet south of the northeast corner of sec. 20, T. 102 N., R. 44 W. USGS Luverne quadrangle; lat. 43 degrees 37 minutes 51 seconds N.; long. 96 degrees 8 minutes 39 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 61 to 91 centimeters (24 to 36 inches) in thickness. Depth to free carbonates ranges from 46 to 152 centimeters (18 to 60 inches) or more. The control section has between 18 and 35 percent clay and 15 to 35 percent of fine sand and coarser. A small amount of gypsum is in some pedons.
The A horizon has hue of 10YR or 2.5Y, value of 2 or 3, and chroma of 1 or is neutral with value of 2 or 3. It has redoximorphic features in some pedons. It is loam, clay loam, silt loam, or silty clay loam. It has weak or moderate granular or subangular blocky structure. It typically is neutral or mildly alkaline but ranges to moderately acid in subhorizons in some pedons.
The Bg horizon has hue of 10YR or 2.5Y, value of 3 or 4, and chroma of 1 or 2. It is clay loam or loam. It is neutral or mildly alkaline.
The BCg and Cg horizons have hue of 10YR, 2.5Y, or 5Y, value of 4 or 5, and chroma of 1 or 2. They have faint through distinct redoximorphic features in some to all parts. They typically are loam or clay loam, but have subhorizons of silt loam or silty clay loam in some pedons. Also, they have coarser textured subhorizons below depths of 40 inches in some pedons. They are neutral or mildly alkaline in the upper part and mildly or moderately alkaline in the lower part.
COMPETING SERIES: These are the Coland, Delft, Excello, Giglow, Gus, Glencoe, James Canyon, Keddie, Kimmerling, Konner, Lundlake, McClave, Pech, Romnell, Shandep, and Wenas soils in the same family. Coland soils have a thicker mollic epipedon and have free carbonates beginning at greater depths. Delft and Glencoe soils have more coarse fragments and are on upland. James Canyon, Kimmerling, McClave, Pech, and Wenas are in drier climates. Konner soils are in a drier climate and lack free carbonates within a depth of 60 inches. Romnell soils have gypsum throughout their sola. Shandep soils have a coarse-textured substratum. Excello and Cielow soils have a mean annual soil temperature of greater than 12 degrees C. Gus and Keddie soils do not have carbonates in the series control section. Lundlake soils have rock fragments in the series control section.
GEOGRAPHIC SETTING: Comfrey soils have plane or concave slopes with gradient of less than 2 percent on flood plains and alluvial fans. They formed in loamy post glacial alluvium. Mean annual air temperature ranges from 8 to 11 degrees C (46 to 52 degrees F) and the mean annual precipitation ranges from 560 to 810 millimeters (22 to 32 inches). Annual frost free days are 150 to 180. Elevation ranges from 350 to 549 meters (1150 to 1800 feet) above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: The main ones are the Chaska, Millington, and Oshawa soils. The poorly drained Chaska soils are calcareous and are associates along larger streams. The very poorly drained Oshawa soils are in old meander channels. Poorly drained calcareous Millington soils are common associates in some places.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly and very poorly drained. Surface runoff is slow. Saturated hydraulic conductivity is moderate. The apparent seasonal high saturation is at a depth of 15 to 45 centimeters (6 to 18 inches) at some time from March to June in normal years.
USE AND VEGETATION: Small acreage is in cropland, but most areas are used for growing pasture. The original vegetation is wet prairie grasses.
DISTRIBUTION AND EXTENT: Southern Minnesota, western Illinois, and possibly north-central Iowa. Moderately extensive.
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Faribault County, Minnesota, 1951.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 89 centimeters (35 inches).
ADDITIONAL DATA: Refer to Minnesota Agricultural Experiment Station Central File Code No. 959 for results of some laboratory analyses of the typical pedon.
With this revision, the typical pedon was moved from Watonwan County, Minnesota to Rock County, Minnesota to better characterize the series.