Soils of the - Agriculture and Agri-Food Canada

JUDSON SOILS (JN)
Location and Extent : Judson soils occupy scattered locations throughout the uplands of the map area .
There are about 910 ha of pure map units and 560 ha of soil complexes dominated by Judson soils . Th e
complexes are mainly with Heron, Scat, Calkins and Ross soils .
Topography and Elevation : Topographically, Judson soils range from slightly depressional to level o r
gently undulating with slopes less than 2 percent . They mostly lie at elevations between 15 and 100 m abov e
sea level .
Parent Material and Texture : Judson soils have developed from 40 to 160 cm of mostly well-decompose d
organic material overlying either glaciomarine or glacial till deposits . The organic material is usually well -
decomposed (humic), containing, sometimes, partly-decomposed strata . The mineral subsoil textures var y
from silty clay loam or silty clay in glaciomarine areas to sandy loam or loam where the underlay is glacial till .
Soil Moisture Characteristics : Judson soils are very poorly to poorly drained . They are moderatel y
pervious in the organic material but this decreases to slowly pervious in the compact mineral underlay . Wate r
holding capacity is very high and surface runoff is slow . Judson soils are accumulation areas for seepage an d
runoff from adjacent, higher soils and they have a more or less permanent, perched watertable . They are also
susceptible to flooding during periods of heavy rainfall .
General Soil Description : Judson soils generally have about 5 cm of undecomposed forest litter on the soi l
surface . This is underlain by between 50 and 120 cm of mainly black to reddish-brown, friable, weakly stratified ,
well-decomposed organic material, sometimes containing partially-decomposed strata and old tree roots .
Underlying this is massive, compact, gray to olive-gray, glaciomarine or glacial till material . Soil reaction i s
generally extremely to very strongly acid throughout . Soil classification is usually Terric Humisol with a few
inclusions of Terric Mesisol where the organic material is only partly-decomposed (mesic) rather than well -
decomposed .
Commonly Associated Soils : Scat, Glen Valley, Heron, Calkins and Ross soils often are closely associ -
ated with Judson soils . Scat, Heron, Calkins and Ross soils all differ from Judson soils by being mineral i n
texture, rather than organic . All are poorly drained, however . Glen Valley soils differ by consisting of deep, mostl y
undecomposed organic material mainly of sedge, reed and grass origin .
Vegetation : Some Judson soil areas are cleared and used mostly for pasture and forage . Uncleared area s
support, among others, western red cedar, western hemlock, willow, red alder, bog birch, lodgepole pine ,
hardhack, Labrador tea, sedges and various mosses . Rooting depth is restricted to the upper 50 to 75 cm b y
the high watertables .
General Land Use Comments : (1) Agriculturally, Judson soils are mainly limited by poor drainage ,
particularily during the winter and early parts of the growing season . Adequate watertable control will allow a
relatively wide range of crops to be grown . Adequate outlets for artificial drainage are sometimes difficult t o
locate due to the often depressional nature of Judson soils . Overdraining can cause rapid subsidence of th e
organic material ; the best watertable control is one which allows progressive lowering of the watertable a s
required by the crop . (2) Urban and similar uses are unsuited for Judson soils . Low soil bearing strengths an d
high watertables preclude most construction . Excavations generally contain water and septic tank operation i s
severely impeded .
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