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

McHenry County, Illinois—Part I 109
Slope range: 5 to 10 percent
A typical soil series description with range in
characteristics is 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
Parr and similar soils: 85 percent
Dissimilar soils: 15 percent
Similar soils:
• soils that have a seasonal high water table at a
depth of more than 3.5 feet
• soils that contain carbonates at a depth of less than
20 inches or more than 40 inches
• soils that contain less sand in the upper one-half of
the subsoil
• soils that have slopes of less than 5 percent
Dissimilar soils:
• the somewhat poorly drained Lisbon soils in the
lower positions on the landform
• the poorly drained Pella soils in drainageways
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
Pella Series
Drainage class: Poorly drained
Permeability: Moderate
Landform: Moraines, till plains, and outwash plains
Parent material: Silty material and the underlying
loamy outwash
Slope range: 0 to 2 percent
Taxonomic classification: Fine-silty, mixed, mesic
Typic Endoaquolls
Typical Pedon for MLRA 95B
Typical pedon of Pella silty clay loam, 0 to 2 percent
slopes, 314 feet north and 2,430 feet east of the
southwest corner of sec. 7, T. 45 N., R. 7 E.
Ap—0 to 5 inches; black (N 2.5/0) silty clay loam, dark
gray (2.5Y 4/1) dry; weak fine subangular blocky
structure parting to moderate fine granular; friable;
many very fine roots; slightly acid; clear smooth
boundary.
A—5 to 14 inches; black (N 2.5/0) silty clay loam, dark
gray (10YR 4/1) dry; weak fine and medium
subangular blocky structure; friable; common very
fine roots; slightly acid; clear smooth boundary.
AB—14 to 18 inches; very dark gray (10YR 3/1) silty
clay loam, dark grayish brown (10YR 4/2) dry;
weak fine and medium subangular blocky
structure; friable; common very fine roots; few
distinct black (10YR 2/1) organic coatings on
faces of peds; few fine dark reddish brown (5YR
3/3) very weakly cemented iron oxide concretions
throughout; neutral; clear smooth boundary.
Bg—18 to 22 inches; dark grayish brown (2.5Y 4/2)
silty clay loam; weak fine and medium subangular
blocky structure; friable; common very fine roots;
common distinct black (10YR 2/1) organic
coatings on faces of peds and in pores; few fine
dark reddish brown (5YR 3/3) very weakly
cemented iron oxide concretions throughout;
common fine distinct olive brown (2.5Y 4/4)
masses of iron accumulation in the matrix; neutral;
clear smooth boundary.
Btg1—22 to 29 inches; grayish brown (2.5Y 5/2) silty
clay loam; moderate fine and medium subangular
blocky structure; firm; common very fine roots; few
distinct dark grayish brown (2.5Y 4/2) clay films on
faces of peds; few distinct black (10YR 2/1)
organic coatings on faces of peds and in pores;
common fine strong brown (7.5YR 5/6) very
weakly cemented iron oxide concretions
throughout; common fine and medium prominent
yellowish brown (10YR 5/4 and 5/6) masses of
iron accumulation in the matrix; neutral; gradual
smooth boundary.
Btg2—29 to 39 inches; light brownish gray (2.5Y 6/2)
silty clay loam; weak medium prismatic structure
parting to weak medium subangular blocky; firm;
common very fine roots; few distinct grayish
brown (2.5Y 5/2) clay films on faces of peds; very
few distinct dark grayish brown (2.5Y 4/2) clay
films and black (10YR 2/1) organic coatings on
faces of peds and in pores; common fine brown
(7.5YR 4/4) very weakly cemented iron oxide
concretions throughout; common medium
prominent yellowish brown (10YR 5/6) masses of
iron accumulation in the matrix; 1 percent gravel;
slightly effervescent; slightly alkaline; clear smooth
boundary.
2BCtg—39 to 50 inches; light brownish gray (2.5Y 6/2)
clay loam; weak medium and coarse subangular
blocky structure; firm; few very fine roots; very few
distinct dark grayish brown (2.5Y 4/2) clay films on