The Soils of The Regional Municipality of Ottawa=Carleton

The imperfectly drained Vinette series (Gleyed Dystric
Brunisol subgroup) is also subject to water saturation for short
periods during the growing season . Profile characteristics are
similar to the Achigan series with the exception of the upper B
horizons, which are Bm or Bfj horizons rather than Bf horizons
.
The poorly drained Cheney series (Orthic Humic Gleysol
subgroup) is found on level to depressional sites which are subject
to water saturation for much of the growing season . The
very dark brown to black LFH and Ah horizons at the surface
are usually thicker and have a higher organic matter content
than those occurring in the better drained members ofthe association
. The underlying subsoil is light olive brown to dark
grayish brown in color which grades to olive gray or grayish
brown in the parent material . In the B horizons and parent
material, low chromas of the matrix colors and prominent
strong brown mottles are both indicative of the poor drainage
conditions . Structure throughout the profile is single grain .
Mapped Soil Combinations St . Thomas soils were most
often mapped as the dominant soil in combination with either
soils of other associations or miscellaneous land units .
Approximately 700 ha were mapped in this way. The combination
of St . Thomas-Rockland land unit is the most extensive
but is limited in occurrence. Only two combinations of this
type were mapped, with the largest occurring north of the village
of Galetta in West Carleton Township . Smaller combinations
ofSt . Thomas-Manotick and Manotick-St . Thomas were
mapped in areas where level marine clay plains occur adjacent
to deeper marine or fluvial sand deposits . The St . Thomas-
Rockland, St . Thomas-Manotick, and Manotick-St . Thomas
combinations account for approximately 55% of all St .
Thomas soils mapped in combinations .
General Land Use Woodland is the dominant land use found
on St . Thomas soils . Occasionally, small areas may be used for
growing cereal grains and hay in rotation . More often, however,
agricultural use is limited to small areas used for
improved pasture or grazing purposes .
Correlation to Ottawa Urban Fringe The St . Thomas soil
association was not mapped in the Ottawa Urban Fringe. Soils
of the association were included in the Uplands soil association
in the Ottawa Urban Fringe for two main reasons . First, extensive
areas ofSt . Thomas soils do not occur inthe Ottawa Urban
Fringe. Secondly, St . Thomas soils are similar to Uplands soils
in many soil characteristics . The high proportion of fine sand
in St . Thomas soils is the main differentiating soil characteristic
.
Due to extensive occurrences of St . Thomas soil materials
in the survey area as well as a difference in mode of deposition
fromUplands soils mapped inthe OttawaUrban Fringe survey,
it was decided that a new association was warranted to characterize
these soils. Interpretations made for either St . Thomas
or Uplands soils, however, generally are not significantly different
.
UPLANDS (U)
Location and Extent Soils ofthe Uplands association are not
widely distributed across the survey area, and most occur in
Osgoode Township . A few small areas also occur in West
Carleton Township . In Osgoode township, most Uplands soils
are found on or in close proximity to the fluvioglacial ridge
that begins at South Gloucester in the north, and extends
southward through the township. Approximately 2,000 ha of
Uplands soils were mapped, with approximately 50% of that
total mapped incombination with soils ofother associations.
Landform and Topography Uplands soils have developed in a
blanket of coarse textured marine or eolian material which is
usually deeper than 2 m . The majority of Uplands soils in the
regional municipality including the Urban Fringe area are of
deltaic origin, and are found in Gloucester township centred
around the Ottawa Airport . In Osgoode township, however,
Uplands soils have developed in nearshore, shallow water
marine deposits found on or adjacent tothe fluvioglacial ridge
which extends from South Gloucester southward through the
township. Duringthe recession ofthe Champlain Sea, the original
more steeply sloping glaciofluvial ridge was extensively
modifiedby marine wave action and longshore drift . The result
was long, elevated sand plains along or near the ridge which
have nearly level to very gently sloping or undulating topography.
Modification of the original marine deposits by wind
resulting in dune formation is quite common in some areas .
Slopes range from0 to 5% .
Soil Material Uplands soils have parent materials consisting
of noncalcareous medium sand, which in well or imperfectly
drained conditions ranges in color from light olive brown to
pale yellow. Under poorly drained conditions, the color of the
parent material tends to be grayer. Soil reaction of the parent
material is usually medium to very strongly acid . Weathered
subsoil overlying the parent material also has medium sand
textures and tends to be slightly more acidic in reaction than
the parent material . Horizons enriched with iron and aluminum
combined with organic matter(Bf and Bfj horizons) commonly
occur in the upper portion of the weathered subsoil .
These enriched horizons are usually easily recognized by their
reddish brownto strong brown colors .
A thin eluvial horizon (Ae or Aej horizon) quite often
overlies the weathered B horizons . It is variable in thickness,
but is usually less than 15 cm thick . Texture ofthese horizons is
loamy sand or sand . The lighter color exhibited by these horizons
is the result ofthe removal of iron, aluminum, and organic
matter which have been transported downward in the profile .
Although often present, many Uplands soils do not have eluvial
horizons .
Under non-forested conditions, adark yellowish brown to
black surface A horizon occurs which is usually 10 to 20 cm
thick . Most commonly the texture is loamy sand, with sand
and sandy loam textures less frequent . Soil reaction tends to be
slightly more acidic than the parent material . Under forested
conditions, a layer ofaccumulated organic matter (LFH horizon)
is usually present at the surface. It is generally less than 5
cm thick, and isverydark brown to blackin color. This surface
organic layer is composed of leaves and twigs, most of which
has undergone little decomposition .
The sand content of the parent material in Uplands soils
ranges from 91 to 98%, and the combined silt and clay content
seldom exceeds 5% . Uplands soil materials are differentiated
from soil materials ofthe Jockvale and St . Thomas soil associations
on the basis of texture and mode of deposition . The
medium sand fraction, although variable, generally is higher in
Uplands soils resulting in sand rather than fine sand textures .
Of the total sand content, the medium sand fraction ranges
from 21 to 83%, with the mean medium sand content being
51% . Significant amounts of coarse and very coarse sand as
well as some gravel size particles are present in some Uplands
soil materials . Coarse and very coarse sand content in the parent
material is generally less than 25%, and gravel content
when present is usually less than 5 O/o .
Soil Moisture Characteristics Uplands soils are excessive to
well-drained on the very gently sloping or undulating land-