LOCATION PECATONICA IL+WI
Established Series
Rev. LJB-HRM-DEC
02/2011
PECATONICA SERIES
The Pecatonica series consists of well drained soils on till plains and moraines. They formed in a thin layer of loess or silty material and the underlying reddish paleosol that formed in loamy till. Slope ranges from 0 to 30 percent. Mean annual temperature is about 8.9 degrees C (48 degrees F), and mean annual precipitation is about 889 mm (35 inches).
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Hapludalfs
TYPICAL PEDON: Pecatonica silt loam at an elevation of 244 meters (800 feet) above mean sea level. (Colors are for moist soil unless otherwise noted.)
A--0 to 8 cm (0 to 3 inches); very dark brown (10YR 2/2) silt loam, grayish brown (10YR 5/2) dry; weak fine and medium granular structure; friable; common very fine roots; slightly acid; abrupt smooth boundary. [5 to 13 cm (2 to 5 inches) thick]
E1--8 to 13 cm (3 to 5 inches); dark grayish brown (10YR 4/2) silt loam; moderate thin platy structure; friable; common very fine roots; common distinct very dark grayish brown (10YR 3/2) organic coatings on faces of peds and worm channel linings; slightly acid; clear smooth boundary.
E2--13 to 25 cm (5 to 10 inches); yellowish brown (10YR 5/4) silt loam; moderate medium platy structure; friable; common very fine roots; few distinct light gray (10YR 7/1) dry, silt coatings and dark brown (10YR 3/3) organic coatings on faces of peds; moderately acid; clear smooth boundary. [Combined thickness of the E horizons is 10 to 25 cm (4 to 10 inches).]
BE--25 to 46 cm (10 to 18 inches); brown (7.5YR 4/4) silt loam; moderate fine and medium subangular blocky structure; friable; common very fine roots; common distinct light gray (10YR 7/1) dry, silt coatings on faces of peds; strongly acid; clear smooth boundary. [10 to 18 cm (4 to 7 inches) thick]
2Bt1--46 to 66 cm (18 to 26 inches); brown (7.5YR 4/4) clay loam; moderate fine and medium subangular blocky structure; firm; few very fine roots; common distinct reddish brown (5YR 4/4) clay films on faces of peds; few distinct light gray (10YR 7/1) dry, silt coatings on faces of peds; 10 percent pebbles; strongly acid; clear smooth boundary.
2Bt2--66 to 117 cm (26 to 46 inches); red (2.5YR 4/6) sandy clay loam; moderate medium and coarse angular blocky structure; firm; few very fine roots; common distinct dark reddish brown (2.5YR 3/4) clay films on faces of peds; 6 percent pebbles; strongly acid; clear smooth boundary.
2Bt3--117 to 163 cm (46 to 64 inches); 65 percent red (2.5YR 4/6), 30 percent dark reddish brown (2.5YR 3/4) and a few pockets (5 percent) of yellowish brown (10YR 5/4) sandy clay loam; weak coarse angular blocky structure; firm; common distinct dark reddish brown (2.5YR 3/4) clay films on faces of peds; 6 percent pebbles; moderately acid; clear smooth boundary.
2Bt4--163 to 173 cm (64 to 68 inches); brown (7.5YR 4/4) sandy clay loam; weak coarse angular blocky structure; firm; few very fine roots; common distinct dark brown (7.5YR 3/2) clay films on faces of peds; 6 percent pebbles; slightly acid; clear smooth boundary. [Combined thickness of the 2Bt horizons is 89 to 188 cm (35 to 74 inches).]
2C--173 to 203 cm (68 to 80 inches); yellowish brown (10YR 5/4) loam; massive; friable; few very fine roots; 8 percent pebbles; strongly effervescent; moderately alkaline.
TYPE LOCATION: Winnebago County, Illinois; about 3 miles (4.8 km) southwest of Rockford, 50 feet (15 m) west and 800 feet (244 m) north of the southeast corner of Sec. 25, T. 26, N., R. 11 E. USGS, Kishwaukee, IL topographic quadrangle: lat. 42 degrees 13 minutes 15 seconds N and long. 89 degrees 10 minutes 24 seconds W, NAD 27; UTM Zone 16, 320629 easting and 4676582 northing, NAD 83.
RANGE IN CHARACTERISTICS: Depth to the base of soil development ranges from 4 feet (1.2 m) to more than 8 feet (2.4 m) depending upon the amount of truncation of the paleosol before the loess was deposited. The soil formed in 15 to 25 inches (38 to 64 cm) of loess or silty material and in the underlying paleosol which formed in loamy till. Many of the properties of the 2BC horizon are assumed to have been inherited from an earlier soil forming regime. Where sola are more than 5 feet (1.5 m) thick, chroma is either less than 5 and hue is 7.5YR or redder, or clay content decreases more than 20 percent within depths of 60 inches (152 cm). The particle-size control section averages 27 to 35 percent clay and 15 to 35 percent fine or coarser sand. Mineralogy of the particle-size control section is mixed, but the dominant clay mineral in the 2C horizon is illite, and illite is an important constituent in the clay fraction of the 2Bt horizon.
The Ap horizon has hue of 10YR, value of 4, and chroma of 2 or 3. In uncultivated areas, A horizons less than 5 inches (13 cm) thick have hue of 10YR, value of 2 to 3, and chroma of 1 or 2. Texture is silt loam. Reaction ranges from strongly acid to neutral.
The E horizon has hue of 10YR, value of 4 to 6, and chroma of 2 to 4. It is silt loam. Reaction ranges from very strongly acid to neutral.
The BE or Bt horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 3 to 6. It is silty clay loam or silt loam. Reaction is very strongly acid to neutral.
The 2Bt horizon has hue of 2.5YR, 5YR, or 7.5YR, value of 4 or 5, and chroma of 4 to 6. Hue of 5YR or redder is on faces of peds or in the matrix in some part of the 2Bt horizon. Texture is clay loam, sandy clay loam, loam, sandy loam, or the gravelly analogs of these textures. Reaction ranges from moderately acid to very strongly acid except that in the lower part, the range includes slightly acid.
The 2C horizon, where present, has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 4 to 6. It ranges from gravelly sandy loam to sandy loam or loam. Reaction ranges from moderately acid to moderately alkaline.
COMPETING SERIES: These are the
Bluemount,
Douds,
Grellton,
Kendallville,
Kliever,
Letort,
Lindley,
Mandeville,
Mchenry,
Mifflin,
Nodine,
Norden,
Ott,
Plumcreek,
Renova,
Rockbridge,
Theresa,
Westville,
Whalan, and
Wykoff soils. Bluemont, Mandeville, Mifflin, Norden, Ott, and Whalan soils have a lithic or paralithic contact within a depth of 60 inches. Douds and Westville soils average more than 15 percent sand in the upper one-fourth of the series control section. Grellton, Kliever, Letort, Lindley, McHenry, and Renova soils lack hue as red as 5YR in the matrix or on faces of peds in some subhorizon in the middle part of the series control section. Nodine and Plumcreek soils have a poorly graded sand fraction in the lower one-half of the series control section. Kendallville, Theresa, and Wykoff soils are less than 40 inches (102 cm) to the base of soil development. Rockbridge soils average more than 35 percent rock fragments in some subhorizon in the lower one-half of the series control section.
GEOGRAPHIC SETTING: Pecatonica soils are on till plains and moraines. Slope gradients range from 0 to 30 percent. The sola formed in 15 to 25 inches (38 to 64 cm) of loess or silty material and in late Sangamon reddish paleosols formed in glacial drift of Illinoian Age. Summers are hot and winters are cold. Mean annual temperature ranges from 45 to 52 degrees F. (7 to 11 degrees C), and mean annual precipitation from 28 to 40 inches (711 to 1016 mm).
GEOGRAPHICALLY ASSOCIATED SOILS:
Argyle soils which have thicker A horizons and
Durand soils which have mollic epipedons are on the same landscape but are farther from drainageways.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. The potential for surface runoff is low to high. Saturated hydraulic conductivity is moderately high or high (4.23 to 14.11 micrometers per second). Permeability is moderate.
USE AND VEGETATION: Pecatonica soils are used for growing cultivated crops, pasture and woodland. Major crops are corn, soybeans, small grain and meadow. Native vegetation was hardwood trees.
DISTRIBUTION AND EXTENT: Northwestern and north central Illinois and south central Wisconsin. The extent is moderate.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Carroll County, Illinois, 1967.
REMARKS: A moderately well drained phase is recognized. This soil will be investigated during MLRA update activities. Possibly a new series will be developed.
Diagnostic horizons recognized in this pedon are: ochric epipedon - the zone from the surface to a depth of 19 inches (48 cm) (A, E1, E2, and BA horizons); argillic horizon - the zone from 19 to 58 inches (48 to 147 cm) (2Bt1, 2Bt2, 2Bt3, and 2Bt4 horizons.); udic moisture regime.
National Cooperative Soil Survey
U.S.A.