Soil Survey of McHenry County, Illinois Part I - Soil Data Mart

McHenry County, Illinois—Part I 119
Management
For general and detailed information about
managing this map unit, see the following sections in
Part II of this publication:
• “Agronomy” section
• “Wildlife Habitat” section
• “Engineering” section
• “Soil Properties” section
Rodman Series
Drainage class: Excessively drained
Permeability: Very rapid
Landform: Stream terraces, kames, outwash plains,
and moraines
Parent material: Gravelly drift
Slope range: 12 to 30 percent
Taxonomic classification: Sandy-skeletal, mixed,
mesic Typic Hapludolls
Typical Pedon for MLRA 95B
Typical pedon of Rodman gravelly loam, in an area of
Casco-Rodman complex, 20 to 30 percent slopes, 500
feet south and 2,600 feet east of the northwest corner
of sec. 7, T. 44 N., R. 9 E.
A—0 to 11 inches; very dark gray (10YR 3/1) gravelly
loam, dark grayish brown (10YR 4/2) dry; strong
fine and medium granular structure; friable; many
very fine and fine roots; 17 percent gravel; neutral;
clear wavy boundary.
Bw—11 to 14 inches; 50 percent dark brown (10YR
3/3) and 50 percent brown (10YR 4/3) gravelly
loam; weak fine granular structure; friable;
common very fine roots; common distinct very
dark grayish brown (10YR 3/2) organic coatings
on faces of peds; 25 percent gravel; strongly
effervescent; slightly alkaline; abrupt wavy
boundary.
C—14 to 60 inches; dark yellowish brown (10YR 4/4)
very gravelly sand and very gravelly loamy sand;
single grain; loose; common very fine roots; 50
percent gravel; strongly effervescent; moderately
alkaline.
MLRA Series Range in Characteristics
Thickness of the mollic epipedon: 4 to 12 inches
Depth to carbonates: 10 to 15 inches
Thickness of the solum: 10 to 15 inches
A or Ap horizon:
Hue—7.5YR or 10YR
Value—2 or 3
Chroma—1 or 2
Texture—loam, sandy loam, or the gravelly
analogs of these textures
Content of gravel—10 to 35 percent
Bw horizon:
Hue—7.5YR or 10YR
Value—3 to 5
Chroma—3 or 4
Texture—gravelly loam or gravelly sandy loam
Content of gravel—15 to 35 percent
C horizon:
Hue—10YR
Value—4 or 5
Chroma—2 to 4
Texture—the very gravelly or extremely gravelly
analogs of sand, loamy sand, coarse sand, or
loamy coarse sand
Content of gravel—35 to 75 percent
969E2—Casco-Rodman complex, 12 to 20
percent slopes, eroded
Setting
Landform: Stream terraces, kames, outwash plains,
and moraines
Position on the landform: Backslopes
Slope range: 12 to 20 percent
Typical soil series descriptions with range in
characteristics are included, in alphabetical order, in
this section. Additional information specific to this map
unit, such as horizon depth and textures, is available
in the “Soil Properties” section in Part II of this
publication.
Composition
Casco and similar soils: 50 percent
Rodman and similar soils: 40 percent
Dissimilar soils: 10 percent
Similar soils:
• soils that are slightly eroded
• soils that contain sandy and gravelly deposits at a
depth of more than 20 inches
• soils that contain carbonates at or near the surface
• soils that have slopes of less than 12 percent or
more than 20 percent
• soils that contain loamy till in the lower part of the
profile
Dissimilar soils:
• the somewhat poorly drained Kane soils in the
lower positions on the landform