The Soils of The Regional Municipality of Ottawa=Carleton

Taxonomic Components The well-drained Farmington series
(Orthic Melanic Brunisol subgroup) has dark brown to black
colored surface A horizons and dark yellowish brown to olive
colored B and C horizons . Soil structure is generally granular
at the surface, and either granular or subangular blocky at
depth. Texture and the amount of coarse fragments are quite
variable . Surface texture is dominantly sandy loam or loam,
with lesser occurrences of silt loam or fine sandy loam. Texture
oftheB and C horizons is dominantly sandy loam, but coarser
textures are common in areas that have been highly reworked
or wave washed.
The Franktown series (Gleyed Melanic Brunisol subgroup)
consists of imperfectly drained soils which are subject
to water saturation for short periods during the growing sea
son . Distinct dark yellowish brown to yellowish brown mottles
are present in the subsoil which reflect the restricted drainage.
Other than the presenceofmottles, these soils are similar to the
Farmington series in other profile characteristics.
The Brooke series (Orthic Humic Gleysol subgroup) consists
of poorly drained soils which remain saturated for long
periods during the growing season . They are generally located
in depressional sites, and are subject to periodic ponding . SurfaceAhorizons
are slightlythicker and higher in organic matter
content than the better drained soils of the association .
Underlying B and C horizons are more grayish in color thanthe
better drained series, and have prominent dark yellowish
brown mottles. Other profile characteristics are similar to the
better drained series ofthe association.
Mapped Soil Combinations Less than 2001o of the Farmington
soils occurring in the survey area were mapped in
combination with either soils ofother associations or miscellaneous
land units . Approximately 5,100 ha were mapped in
combinations in which they were the dominant component,
and 1,700ha were mapped in combinations in which they were
the significant component . When mapped as the dominant
component, the most extensive combinations were with soils of
the Grenville, Oka, and Greely associations . The Farmington-
Grenville combination was the most extensive of the three,
accounting for approximately 1, 800 ha of all Farmington soils
mapped . In that combination the Grenville soils were most
commonly mapped as a shallow phase. When mapped as the
significant member, the Oka-Farmington combination was the
most extensive. Approximately 700 ha of Farmington soils
were mapped with Oka soils as the dominant member.
Mapped soil combinations in which soils of the Oka association
are either dominant or significant members occur
mainly onthe bedrock plains in Goulbourn and West Carleton
Townships . The relatively small areas of individual beach
deposits in these areas necessitated the use of compound map
units in order to accurately represent soil variability which
occurs. In Farmington-Grenville (shallow) soil combinations,
the majority occur in Rideau and Goulbourn Townships and
represent shallow to bedrock areas in which the depth of some
soils is 50 to 100 cm . These areas could not be mapped separately.
General Land Use Farmington soils are not suitable for
annual cultivationdue to shallowness to bedrock, surface stoniness,
and bedrock outcropping in most areas . When surface
stoniness and bedrock outcrops are not extensive, perennial
forage crops which can withstand droughty conditions may
potentially be grown on some Farmington soils .
The majority of Farmington soils remain under forest
cover. Less extensive areas of abandoned farmland and scrubland
are also commonly found on these soils . Agricultural land
use is mainly confined to thegrazingofsheep and beef cattle.
Correlation to Ottawa Urban Fringe Most Farmington soils
in the area are similar to those mapped in the Ottawa Urban
Fringe. Some soils, however, have been highly reworked by
water action and are coarser textured than those characterized
inthe OttawaUrban Fringe report .
GOULBOURN (GB)
Location and Extent Soils of the Goulbourn association
occur mainly in Osgoode and Rideau Townships . Less extensive
areas also occur in West Carleton and Cumberland Townships.
In all areas they occur in low lying depressional
landscape positions, and frequently are found adjacent to or
are intersected by rivers or streams . Approximately 3,500 ha of
Goulbourn soils were mapped, with an estimated 1,100 ha of
that total having been mapped in combination with soils of
other associations .
Landform and Topography The Goulbourn association is
composed of organic soils which are found inhorizontal basin
or peat margin swamps . The topography is level or depressional,
and slopes are usually 1%or less .
Soil Material Soils of the association consist of 40 to 160 cm
of moderately to well decomposed organic material which is
underlain bymineral material . Most oftenthe organic material
is uniformly woody forest peat which is black in color. Soil
reaction ranges from neutral at the surface to medium acid at
depth . Occasionally, a layer of dark reddish brown to black
sedge fen peat which is variable in thickness may underlay the
woody forest peat . Soil reaction in this instance is more acidic,
ranging from medium acid at the surface to strongly acid at
depth .
The woody forest peat comprising all or part of the
organic material is primarily moderately decomposed or mesic
in terms of its degree of decomposition . Rubbed fibre content
generally ranges from 12to 16 014, In some profiles, a significant
layer of well-decomposed humi.- peat is also present which is
25 cm or more thick and has a rubbed fibre content of less than
10010 . Either type ofmaterial is derived mainly from forest vegetation,
particularly coniferous and deciduous tree species .
Primary components include leaf and needle material as well
as varying amounts of woody debris in the form of stems,
branches, and roots.
When present, the layer of sedge fen peat at depth is most
often moderately decomposed or mesic . It is dominantly composed
of sedge material, with some cotton grass remnants also
present .Asignificant amount of the material is very fine roots
ofthe two previously mentioned plant types .
The underlying mineral material or substratum is quite
variable. Sandy loam textures are most common, but sandy
and clayey textures occur as well . Color of the substratum
ranges from gray to dark greenish gray. The upper portion of
the substratum is usually neutral in reaction and noncalcareous,
although the presence of carbonates and a higher pH can
be expected forsome types of substratums at greater depths .
Soil Moisture Characteristics Goulbourn soils are poorly to
very poorly drained, with the water table at or near the surface
for most ofthe year. Standing ; water atthe surface is acommon
occurrence. Due to the nutrient-rich nature of the mineral substratum
and the surrounding mineral soils, the groundwater
which saturates these soils is also nutrient-rich .