Soils of the - Agriculture and Agri-Food Canada

McELVEE SOILS (ME)
Location and Extent : McElvee soils occur in scattered locations throughout the map area ; the largest areas ,
however, occur on the lowlands in the eastern half . There are about 260 ha of pure map units and 340 ha of soi l
complexes dominated by McElvee soils . Most complexes are with Hopedale and Bates soils .
Topography and Elevation : Topographically, McElvee soils are gently undulating, undulating or gentl y
sloping with slopes from 1 to 4 percent . In complexes with better drained soils, they usually occupy lower o r
depressional landscape positions . Elevations generally lie between 5 and 20 m above sea level .
Parent Material and Texture : McElvee soils have developed from medium-textured, stone-free, loca l
stream deposits at least 50 cm deep, which overlie coarse-textured (sandy) sediments . Surface textures are
usually silt loam, varying in a few areas to loam . Subsurface and upper subsoil textures are also mostly silt loa m
with some loam or silty clay loam and sometimes, thin, sandy bands . The lower subsoil grades to medium o r
coarse sand .
Soil Moisture Characteristics : McElvee soils are poorly drained . They-are moderately pervious and have
high to moderate water holding capacity and slow surface runoff . Watertables are near the surface during mos t
the winter and after heavy, prolonged rains . Seepage from adjacent streams and higher land is common an d
temporary .surface ponding occurs in some areas .
General Soil Description : McElvee soils have dark grayish brown to grayish-brown, friable, silty, cultivated
surfaces about 20 cm thick . Underlying this is 30 cm or more of massive, grayish-brown, firm, silty materia l
containing common to many, yellowish or reddish mottles and, sometimes, thin, sandy lenses . This then eithe r
changes abruptly or gradually grades to loose, coarse sand . Soil reaction is usually medium acid throughou t
(1 :1 H2 O). Soil classification is mostly Rego Gleysolwith some inclusions of Orthic Gleysol where small amounts
of eluviated clay have accumulated in the subsurface .
Commonly Associated Soils : Hopedale, Bates and Sim soils often are closely associated with McElve e
soils . Hopedale soils are similar to McElvee soils except that the underlying sand is encountered between 2 0
and 50 cm of the surface . Bates soils have textures similar to McElvee soils but usually occupy slightly highe r
landscape positions and are imperfectly drained . Sim soils differ by having black surfaces in contrast to th e
grayish colours of McElvee soils .
Vegetation : Most areas of McElvee soils are cleared and cultivated . Uncleared areas support, among others ,
black cottonwood, western red cedar, red alder, willow, vine and bigleaf maple, salmonberry, thimbleberry ,
blackberry, sedges and grass . Rooting depth is usually restricted to about 75 cm by high watertables .
General Land Use Comments : (1) Poor drainage, the main agricultural limitation of McElvee soils, limit s
the overwintering of most perennial crops . Annual crops are usually less affected but wet soil conditions ca n
retard planting times . Artificial drainage is beneficial for good production of all crops . (2) McElvee soils are
poorly suited for most urban or related uses . Variable soil bearing strengths may cause uneven subsidence i f
heavy structures are erected and basements or other excavations are likely to contain water for at least part o f
the year. Septic tank effluent disposal is severely impeded by the high watertables . (3) McElvee soils appea r
well suited for forest crops such as black cottonwood . Potential annual wood production by this species i s
estimated at 12 to 15 m 3/ha .
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