Soils of the - Agriculture and Agri-Food Canada

DIXON SOILS .
(DX)
Location and Extent : Dixon soils occur only in the eastern part of Sumas Municipality, mainly on the floor o r
along the margins of former Sumas Lake which was drained in the 1920's . About 1100 ha of Dixon soils ar e
classified as well as 20 ha of Dixon-Vye soil complex .
Topography and Elevation : The topography is nearly level to gently undulating with slope gradients les s
than 2 percent . Elevations lie between 8 and 12 m above sea level .
Parent Material and Texture : The parent material of Dixon soils is 50 cm or more of moderately fine to fine -
textured lacustrine sediments overlying coarse-textured (sandy) lacustrine deposits . Surface textures are
mostly silty clay loam and some clay loam . Subsurfaces are silty clay loam or silty clay changing abruptly t o
medium or coarse sand in the subsoil .
Soil Moisture Characteristics : Dixon soils are poorly to very poorly drained and are slowly pervious .
Surface runoff is slow and frequent surface ponding occurs during heavy rain . Water holding capacity is high .
The watertable is at or near the surface for most of the winter and recedes somewhat during the summe r
because of artificial drainage and pumping during the growing season . Some growing-season subsoil irrigatio n
is provided by controlling water levels in ditches .
General Soil Description : Dixon soils generally have a dark grayish brown to grayish-brown, cloddy ,
cultivated clayey surface layer about 20 cm thick which is low in organic matter (usually less than 4 percent) .
The surface layer is underlain by about 40 cm or more of gray, massive, clayey material containing widel y
spaced, vertical cracks and common to few, strong brown to reddish-brown mottles . This in turn, is underlain by
loose, very dark gray or gray sand below about 80 cm . Soil reaction is medium acid throughout . Soi l
classification is Rego Gleysol.
Commonly Associated Soils : Sumas and Vedder soils commonly occur in close association with Dixo n
soils . Sumas soils differ from Dixon soils by being sandy in texture . Vedder soils are somewhat siltier and les s
poorly drained than Dixon soils as well as having a well-structured subsurface layer. Significant areas of Dixo n
soils :shallow variant have been classified . These soils are similar to Dixon soils except that the underlying san d
occurs within 15 to 50 cm of the surface rather than below 50 cm as is the usual case . Dixon soils :shallow varian t
are gradational between the Dixon soils and the sandy Sumas soils .
Vegetation : Dixon soils are essentially all cleared and cultivated . Scattered trees along fence lines are mainl y
black cottonwood and willow . Rooting is partly restricted by the clayey subsurface layers and is severely
restricted below 50 cm by high watertables .
General Land Use Comments : (1) High watertables and poor drainage presently limit Dixon soils t o
forage, pasture, cereal grains and some vegetables . Improved drainage will widen the range of possible crop s
and also assist in improving productivity of individual crops . Organic matter additions to the surface will improve
soil structure and decrease susceptibility to puddling . (2) Dixon soils are unsuited for urban or simila r
construction . Generally low soil bearing strengths lead to subsidence problems if heavy structures are erecte d
and high watertables preclude basements or other excavations . High watertables severely limit the operation of
septic tank disposal fields .
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