The Soils of The Regional Municipality of Ottawa=Carleton

ial which extends in a northwest-southeast direction through
the village of Stittsville . Less extensive areas also occur in
Cumberland Township near the village of Sarsfield, and in
West Carleton Township near the village of Galetta . Approximately
2,900 ha of Kars soilswere mapped .
Landform and Topography Most of the soils of the association
havedeveloped on ridges ofmarine modified glaciofluvial
material which are fairly low in relief. The original ridges of
glaciofluvial material deposited during glaciation were subsequently
reworked to varying degrees by marine wave action
duringthe ChamplainSeainundation . The result in most cases
was a smoothing of the landscape. Shore formations such as
strandlines, gently sloping beaches, and occasional stone and
boulder pavements indicate that marine modification has been
extensive in some areas . Materials of these formations have
been derived mostly from the original ice contact glaciofluvial
deposits . Slopes rangefrom 2 to 901o in most landscapes.
SoilMaterials Kars soil materials are quite thick and they are
commonly mined for aggregate to depths exceeding 5 m . At
the surface they are moderately coarse to coarse textured, and
in the underlying weathered subsoil and parent material they
are coarse textured . A considerable coarse fragment content
occurs throughout, with the volume often exceeding 50% in
the parent material at depth . Although primarily of Paleozoic
sedimentary bedrock origin, a significant portion ofthe coarse
fragments have also originated from Precambrian igneous and
metamorphic bedrock .
The parent materials of the association consist of coarse
sand and loamy coarse sand matrix material with rounded cobble
and gravel sized coarse fragments . Coarse fragment con
tent usually exceeds 20% by volume. Some soils included in the
association, however, have parent materials which have a low
coarse fragment content and are predominantly coarse sand or
loamy coarse sand . Coarse fragment content in these soils is
less than 20% by volume . The K3, K4, and K5 soil landscape
units represent soils with this material variation . In all soils
comprising the association, the parent material has a coarse
sand or loamycoarse sand matrix which is moderately calcareous,
dark brown to dark yellowish brown in color, and neutral
to mildly alkaline in reaction . Materials at the surface commonly
have a coarse sandy loam or loamy coarse sand matrix
and similar sized coarse fragments .
Surface stoniness is usually present to some extent on the
majority of Kars association soils . Surfaces are most often
slightly to moderately stony, with less than 3% surface cover
age by stones having a diameter of 15 cm or more. Less frequently,
very stonysurface conditions occur in which stones of
similar size cover 3 to 15% ofthe surface.
Soil Moisture Characteristics Approximately 80% of all
Kars soils are rapidly to well-drained . These soils are rapidly
permeable and as a result there is virtually no surface water
runoff. Water holding capacity is low contributing to draughtiness
. Imperfectly or poorlydrained soils constitute theremaining
portion of the soils in the association . Although highly
permeable, these soils remain saturated for significant periods
during the growing season due to high water tables influenced
by surface runoff and groundwater discharge from surrounding
soils .
Soil Landscape Units Five units were identified in the Kars
association . They are described as follows :
Recognized Recognized
Subgroups Series
K1 : Dominantlyrapidly Eluviated Kars
to well-drained Melanic
soils found on very gen- Brunisols
tly to gently sloping
topography. Slopes
range from 2 to 9% .
K2 : Dominantly imper- Gleyed Eluviated
fectly to poorly Melanic Brunisols
drained soils found (Imperfect)
on level to nearly Orthic Humic
level topography. Gleysols (Poor)
Slopes range from
Oto2% .
K3 : Dominantly rapidly Eluviated Melanic
to well-drained Brunisols
soils found on very gently
to gently sloping
topography. Slopes
range from 2 to 9% .
Parent materials are
predominantly mildly
alkaline coarse sands .
K4 : Dominantly imper- Gleyed Eluviated
fectly to poorly Melanic Brunisols
drained soils found (Imperfect)
on nearly level to Orthic Humic
verygently sloping Gleysols (Poor)
topography. Slopes
range from 1 to 3%.
Parent materials are
predominantly mildly
alkaline coarse sands.
K5 : Dominantly rapidly Eluviated Melanic
to well-drained Brunisols
soils found on verygently
to gently sloping
topography. Slopes
range from 2 to 9% .
Parent materials are
mildly alkalinecoarse
sand interbedded with
layers ofgravel having
variable thickness .
Taxonomic Components The rapidly to well-drained Kars
series (Eluviated Melanic Brunisol subgroup) has a high gravel
content and constitutes the K1 soil landscape unit . These soils
have avery dark grayish brown Ap horizon, 15 to 25 cm thick,
withweak granular structure . The underlying Bm and Btj horizons
are strong brown to dark brown in color and have weak
granular structure. The illuvial Btj horizons have a slightly
higher clay content but are not easily recognizable . Well
defined lighter colored Ae horizons are seldom present inthese
soils . Texture ofthe upper A and B horizons is commonlygravelly
coarse sandyloam . Reaction in these horizons is neutral to
mildly alkaline and they are also weakly calcareous . The
underlying parent material or Ck horizons range from yellowish
brown to gray in color and they are also neutral to mildly
alkaline in reaction . Coarser textures and higher gravel con-