Soils of the - Agriculture and Agri-Food Canada

SURREY SOILS (SU )
Location and Extent : Surrey soils are relatively uncommon and occur mainly on the uplands of Surrey an d
Delta Municipalities . About 120 ha of pure map units and 310 ha of Surrey-Boosey soil complex are mapped .
Topography and Elevation : Surrey soils are generally undulating to gently rolling with slopes ranging fro m
4 to 10 percent . Elevations range from about 20 to 100 m above sea level .
Parent Material and Texture : The parent material of Surrey soils is moderately coarse textured, compact ,
stony glacial till . Surface, subsurface and subsoil textures are usually sandy loam or gravelly sandy loam wit h
occasional variation to gravelly loamy sand or loam . The subsoil is strongly cemented .
Soil Moisture Characteristics : Surrey soils are moderately well to well drained and have low water holdin g
capacity and slow surface runoff. They are rapidly pervious in the upper part but this decreases to slowl y
pervious in the cemented subsoil . During heavy, prolonged rain, a temporary, perched watertable develop s
above the cemented subsoil and lateral telluric seepage occurs .
General Soil Description : Surrey soils generally have up to 10 cm of raw to well-decomposed, organi c
forest litter on the soil surface . Under this is up to 4 cm of gray to grayish-brown, weakly structured, friable ,
strongly leached, sandy material . In cultivated areas the surface is usually about 15 to 20 cm of friable, dar k
brown to dark reddish brown sandy material . The leached zone is underlain by about 40 cm of weakl y
structured, friable, sandy material which is dark reddish brown in the upper part and dark brown or yellowish -
brown in the lower part and contains variable amounts of hard, spherical concretions, stones and gravel . Thi s
zone grades to about 15 cm of brown or yellowish-brown, moderately structured, friable to firm, sandy materia l
which contains common, reddish mottles . Under this, usually abruptly, is grayish-brown, massive, very firm ,
strongly cemented, sandy material from 20 to 50 cm thick and containing common to few, reddish mottles . Th e
upper part of this zone sometimes tends to break horizontally into coarse, plate-like pieces . Below about 12 0
cm depth, gradation to unweathered, gray, massive, compact glacial till occurs . Soil reactions grade from very
strongly or extremely acid at the surface to medium or slightly acid in the upper part of the unweathered glacia l
till (1 :1 H2O). Soil classification is Duric Humo-Ferric Podzol.
Commonly Associated Soils : Bose, Boosey, Heron and Sunshine soils usually occur in close associatio n
with Surrey soils . Bose and Boosey soils differ from Surrey soils by having developed from up to 150 cm o f
gravelly material (of littoral or glaciofluvial origin) over glacial till ; additionally, Boosey soils are poorly drained .
Heron and Sunshine soils differ by consisting of up to 150 cm of sandy material overlying the glacial till . I n
addition, Heron soils are poorly drained .
Vegetation : Cleared areas of Surrey soils are mainly developed for urban uses or are used for pasture an d
forage crops . Uncleared areas support a second-growth forest consisting of, among others, coast Douglas-fir ,
western hemlock, western red cedar, red alder and birch understoried by blackberry, salai, elderberry, vine
maple, dogwood and willow. Rooting is unrestricted in the surface and subsurface but is severely limited in th e
cemented subsoil (usually 60 to 100 cm from the surface) . A thin layer of concentrated roots usually occur s
immediately above the cemented zone .
General Land Use Comments : (1) Agriculturally, Surrey soils are limited by low moisture holding capacit y
which causes droughty conditions during most summers . Deep rooting is restricted by the cemented subsoi l
and susceptible perennial crops may be adversely affected by perched watertables during the winter. (2) Most
areas of Surrey soils are presently developed for urban uses for which they are moderately suited . Soil bearin g
strengths are high but septic tank effluent disposal is impeded by the slowly permeable subsoil . Excavation s
may be difficult to construct due to the compact, cemented, stony nature of the subsoil .
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