Soils of the - Agriculture and Agri-Food Canada

CALKINS SOILS (CN)
Location and Extent : Calkins soils occupy small, scattered upland areas in the eastern part of the map area ,
particularly in the vicinities of Abbotsford, Mission and Peardonville . There are about 360 ha of pure map unit s
and an additional 210 ha of soil complexes dominated by Calkins soils . The complexes are mainly with Lonz o
Creek, Ryder and Judson soils .
Topography and Elevation : Calkins soils are level to gently undulating and usually depressional in relatio n
to adjacent land . Slope gradients are less than 3 percent and elevations range between 30 and 125 m abov e
sea level .
Parent Material and Texture : The parent material of Calkins soils consists of medium-textured eolia n
deposits, 20 to 75 cm thick, overlying mostly glacial till and some glaciofluvial deposits . Surface and subsurface
textures are silt loam or sometimes silty clay loam . Subsoils are gravelly sandy loam in glacial till areas o r
sand to gravel where glacial outwash is present . Up to 15 cm of organic accumulation is present on the surfac e
in some areas .
Soil Moisture Characteristics : Calkins soils are poorly to very poorly drained . They are moderatel y
pervious in the surface and subsurface, however this changes to slowly pervious in the compact glacial til l
subsoil . A perched watertable is usually present above the restricting subsoil and substantial seepage an d
some runoff from adjacent, higher areas is usual . Water holding capacity of Calkins soils is moderate to hig h
(depending on the depth of the silty capping) and surface runoff is slow . Surface ponding is usual after heavy ,
prolonged rain .
General Soil Description : Calkins soils have a surface consisting of about 20 cm of black or very dar k
brown, friable, silty material (sometimes capped by a thin layer of black organic material) . This grades to 30 c m
or more of olive to olive-gray, massive, silty material containing common, reddish and brownish mottles .
Underlying the silty material is grayish-brown to olive-brown, compact, glacial till or cemented, sandy to gravell y
glacial outwash . Soil reaction is very acid throughout (1 :1 HAD) . Soil classification is Rego Humic Gleysol .
Commonly Associated Soils : Ryder, Lonzo Creek, Abbotsford, Marble Hill and Judson soils often occur i n
close association with Calkins soils . Ryder and Lonzo Creek soils differ from Calkins soils by being well o r
moderately well drained and reddish brown in colour. They consist, however, as do Calkins soils, of silty eolia n
cappings over glacial till . Abbotsford and Marble Hill soils are also well or moderately well drained but ar e
composed of silty eolian cappings over glacial outwash . Judson soils are organic, between 40 and 160 c m
deep.
Vegetation : Uncleared areas of Calkins soils support a variety of moisture tolerant species, mainly wester n
red cedar with some red alder and willow understoried by various shrubs, skunk cabbage, .sedges an d
grasses . Rooting depth is usually limited to about 50 cm by the high, perched watertables .
General Land Use Comments : (1) Undrained areas are mainly suited for forage or pasture production ;
artificial drainage will improve the range of crops possible . The depressional nature of Calkins soils, however ,
often makes drainage outlets difficult to locate and install . (2) High watertables, restricted subsoil permeabilit y
and potential for surface ponding make Calkins soils generally unsuitable for urban use . (3) Calkins soils seem
to be well suited for trees such as black cottonwood . Productivity of this species is estimated to be about 12 to
15 m 3/ha/yr.
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