Soils of the - Agriculture and Agri-Food Canada

NICOMEKL SOILS (NK)
Location and Extent : Nicomekl soils occur only on the lowlands of Surrey Municipality near Mud Bay and i n
the Serpentine-Nicomekl valley. About 30 ha of pure map units and 150 ha of soil complexes dominated b y
Nicomekl soils are mapped . The complexes are mostly with Sandel and Goudy soils .
Topography and Elevation : Nicomekl soils are gently undulating to undulating with slopes less than 5
percent . They usually occupy slightly higher topographic positions when compared to adjacent soils but all li e
less than 3 m above sea level .
Parent Material and Texture : The parent material of Nicomekl soils are medium to moderately fine texture d
local stream deposits, mainly from the Nicomekl and Serpentine rivers, that are mixed with some deltai c
deposits . Surface and subsurface textures are mostly silt loam with some loam or silty clay loam inclusions .
Subsoil textures are similar in the upper part but grade to loam or fine sandy loam and sometimes sand at depth .
Saline conditions and compounds high in sulphur are usually present below 100 cm depth .
Soil Moisture Characteristics : Nicomekl soils are poorly drained . They are moderately pervious and hav e
high water holding capacity and slow surface runoff . The groundwater table is near the soil surface for most o f
the winter, after prolonged heavy rain and during other periods when the water levels in the adjacent rivers ar e
high .
General Soil Description : Nicomekl soils generally have a black, friable, granular, cultivated silty surfac e
layer about 20 cm deep which contains between 15 and 25 percent organic matter . The surface layer i s
underlain by grayish-brown to gray, silty material about 30 cm thick which is firm when moist, very hard when dr y
and contains vertical cracks between 10 and 20 cm apart . Common, reddish mottles are also present . This laye r
then grades to massive, dark gray to gray, silty material 50 cm or more thick . Common, reddish mottles are usua l
in the upper part ; these change to yellowish below about 1 m and at this depth, compounds high in sulphur ar e
also present . Soil reaction grades from strongly acid in the surface to extremely acid in the subsoil (1 :1 H 2 0) . Soi l
classification is Orthic Humic Gleysol.
Commonly Associated Soils : Sandel, Embree, Kitter and Goudy soils are usually closely associated wit h
Nicomekl soils . Sandel soils differ from Nicomekl soils by lacking the dark coloured surface layer and bein g
saline within 100 cm of the surface . Embree soils also differ by being saline within 1 m of the surface in additio n
to containing an organic band, usually 10 to 40 cm thick, in the subsurface . Kitter soils are somewhat bette r
drained than Nicomekl soils and lack a black surface layer . Goudy soils have organic surface and subsurfac e
layers as well as being saline below about 50 cm .
Vegetation : Nicomekl soils are essentially all cleared and cultivated . A few, relatively natural, uncleared area s
such as those along fence lines support mostly deciduous species including willow, blackberry, sedges, reeds
as well as some western red cedar. Rooting depth is usually restricted to the upper 60 cm by high groundwate r
tables and relatively dense subsoil layers .
General Land Use Comments : (1) Nicomekl soils are used mainly for agricultural crops . High watertables
and poor drainage limit production and perennials suffer during the winter months . Artificial drainage i s
required for good watertable control and improved productivity . (2) Urban and similar uses are generally no t
suited for Nicomekl soils . Variable, usually low, soil bearing strengths often require that special foundations b e
considered while excavations such as basements will contain water for large portions of the year. Septic tan k
effluent disposal fields are inefficient due to high watertables and saline subsoil conditions will likely caus e
severe corrosion of unprotected, underground installations .
144