Soils of the - Agriculture and Agri-Food Canada

DURIEU SOILS (DU)
Location and Extent : Durieu soils are almost exclusively restricted to the uplands in the northern part o f
Hatzic Valley. There are about 850 ha of pure map units and a further 290 ha of soil complexes dominated b y
Durieu soils . The complexes are mainly with Scat soils .
Topography and Elevation : Durieu soils occupy the slopes and ridge tops of the undulating to gentl y
rolling topography. Slope gradients vary between 5 and 15 percent . Elevations range between 50 and 100 m
above sea level .
Parent Material and Texture : The parent material of Durieu soils is moderately fine textured glaciomarin e
deposits (a few, small areas of glacial till are also included) . A shallow capping (up to 20 cm thick) of medium -
textured, eolian material usually occurs on, or is mixed into the surface . Surface and subsurface textures ar e
mostly silt loam but sometimes vary to loam . These grade to compact, weakly stratified silty clay loam or cla y
loam in the subsoil . Occasional stones and gravel and a few boulders are usually present .
Soil Moisture Characteristics : Durieu soils are moderately well drained : They are moderately pervious i n
the surface and subsurface but become slowly pervious in the compact subsoil . Water holding capacity is hig h
and surface runoff is moderate to slow. Variable amounts of lateral seepage develop along the surface of th e
dense subsoil during periods of heavy prolonged precipitation .
General Soil Description : Durieu soils generally have about 5 to 10 cm of organic forest litter on the soi l
surface, the lower half of which is black, well-decomposed (humic) and friable . This is underlain by a thin (les s
than 2 cm), grayish, discontinuous, leached, silty layer which, in turn, is underlain by about 15 cm of friable ,
weakly structured, dark reddish brown, silty material usually containing between 10 and 15 percent organi c
matter. Under this is about 50 cm of friable, weakly structured, silty material which grades in colour fro m
reddish-brown in the upper part to yellow-brown near the bottom . Below about 70 cm, unweathered, olive o r
olive-gray, clayey glaciomarine sediments occur which are massive, hard, and contain common, dark brown o r
dark yellowish brown mottles . Soil reaction varies from extremely acid near the surface to strongly acid in th e
upper part of the soil parent material . Soil classification is Orthic Ferro-Humic Podzol.
Commonly Associated Soils : Scat and Judson soils usually occur in close assocation with Durieu soils .
They generally occupy the depressional landscape positions in the areas of Durieu soils and are poorly drained .
Additionally, the Judson soils are organic in the upper 50 to 150 cm .
Vegetation : Small areas of Durieu soils have been cleared for pasture or building sites . The majority, howeve r
is in second-growth forest, mostly coast Douglas-fir, western hemlock, western red cedar, red alder, and vin e
maple . Rooting depth is generally restricted by the dense, compact subsoil to the upper 80 cm or so of soil .
General Land Use Comments : (1) Durieu soils are moderately suited for a variety of agricultural crop s
although presently cleared areas are mainly used only for hay and pasture . The variable topography restricts the
range of crops and crops sensitive to "wet-feet" may suffer during extended periods of heavy rainfall . (2 )
Variable bearing strengths may cause differential subsidence if heavy structures are erected . Septic tan k
effluent disposal is limited by the slowly permeable subsoil ; lateral seepage is likely to occur along the surface
of this zone and accumulate in depressional areas . (3) Durieu soils are well suited for growth of coniferous forest .
Coast Douglas-fir is estimated to have the potential of producing between 9 and 12 m 3 of wood/ha/yr.
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