Soils of the - Agriculture and Agri-Food Canada

RICHMOND SOILS (RC)
Location and Extent : Richmond soils are common in the Serpentine-Nicomekl Valley and also occur on th e
lowlands of Richmond and Delta Municipalities . About 300 ha of pure map units and 1390 ha of soil complexe s
dominated by Richmond soils are mapped ; the complexes are mainly with Vinod, Lulu, and Annacis soils .
Topography and Elevation : The topography of Richmond soils is level to gently undulating . Slop e
gradients are less than 2 percent and elevations lie below 3 m above sea level .
Parent Material and Texture : Richmond soils have developed from 40 to 160 cm of mainly well-decomposed
organic material that overlies moderately fine and medium-textured deltaic deposits . Included are som e
areas from which once deeper peat deposits have been mined . Surfaces vary from moderately to well -
decomposed, depending on the length of time they have been cultivated . The subsurface organic material i s
well-decomposed (humic) while the underlying mineral soil is silt loam or silty clay loam and usually salin e
(except for some locations close to the Fraser River) . The mineral soil generally contains substantial amounts o f
compounds high in sulphur .
Soil Moisture Relationships : Richmond soils are very poorly drained . They are moderately pervious an d
have very high water holding capacity and slow surface runoff. The groundwater tables are near, or sometime s
at the soil surface during most of the winter and early spring but usually recede somewhat during the growin g
season . Surface ponding during heavy, prolonged rains is common, due in part to accumulation of runoff fro m
adjacent soils at higher elevations .
General Soil Description : Richmond soils generally have a cultivated surface layer about 20 cm thic k
which is black to dark reddish brown, friable, somewhat granular and well to moderately well decomposed . It i s
underlain by between 30 and 100 cm of black, brownish-black or dark reddish brown, massive (when wet), well -
decomposed organic material which is friable when moist and hard when dry ; vertical cracks develop o n
drying . The organic material is underlain by gray to olive-gray, massive, silty material, often containing th e
vertical remains of old plant stems and roots . Yellowish mottles are common, particularly where the material i s
saline . Soil reaction is extremely acid throughout and soil classification is Terric Humisol.
Commonly Associated Soils : Vinod, Lumbum, Lulu, Annis, Blundell, Goudy and Sandel soils are all ofte n
closely associated with Richmond soils . Vinod and Annis soils differ from Richmond soils by having onl y
between 15 and 40 cm of organic material over clayey mineral soil ; Vinod soils are also strongly saline in th e
mineral underlay. Lulu and Goudy soils have depths of organic material similar to Richmond soils but in Lul u
soils, the organic material is partially (mesic) rather than well-decomposed while Goudy soils are strongly salin e
within 50 cm of the surface . Lumbum soils differ by consisting of more than 160 cm of partially-decompose d
organic material . Sande) soils differ by being silty to the surface while Blundell soils consist of 15 to 40 cm of
well-decomposed organic soil over silty mineral material .
Vegetation : Most areas of Richmond soils are cleared and cultivated . The few, remaining uncleared areas
support moisture tolerant vegetation that includes sedges, reeds, western red cedar, birch, red alder, blackbe -
rry, hardhack, moss and grass . Rooting is mostly restricted to the upper 50 cm by the high groundwater table s
and where the organic material is shallow, by the saline subsoils .
General Land Use Comments : (1) Agriculturally, Richmond soils are limited mainly by high watertable s
(especially during the winter) and very acid soil conditions . The acid conditions can be improved by liming o r
similar soil amendments while artificial drainage is required to control the high watertables . Watertable contro l
sufficient only to meet the crop requirements is usually best . Overdraining accelerates the subsidence an d
decomposition of the organic material and eventually will bring the saline subsoil into the range of crop roots . (2)
Urban or similar uss are not suited for Richmond soils . Low bearing strengths require special foundatio n
considerations while high watertables preclude basements and other excavations as well as severely limitin g
septic tank effluent disposal . Underground utility and other installations are likely to corrode rapidly if not
adequately protected .
156