Soils of the - Agriculture and Agri-Food Canada

ANNACIS SOILS (AS)
Location and Extent : Annacis soils occur only along the southern margin of Burns Bog and in a small are a
south of the Pitt Meadows upland . There are about 130 ha of pure map units and a further 260 ha of soi l
complexes dominated by Annacis soils . The complexes are mainly with Richmond and Lumbum soils .
Topography and Elevation : Level to gently undulating with slopes less than 2 percent is the usua l
topography. All areas lie less than 5 m above sea level .
Parent Material and Texture : Annacis soils have developed from deep organic accumulations whic h
overlie silty deltaic or floodplain sediments . Texturally, the surfaces consist of 40 cm or less of partiall y
decomposed (mesic) organic material . This is underlain by at least 120 cm of well-decomposed (humic )
organic material . The underlying mineral material is silty clay loam or silty clay and, in the Delta area, is usually
saline and high in sulphur compounds .
Soil Moisture Characteristics : Annacis soils are very poorly drained . They are moderately to rapidly
pervious and have very high water holding capacity and slow surface runoff . The watertable is at or near th e
surface for most of the wet winter months but retreats somewhat during the summer .
General Soil Description : The surface of Annacis soils generally consists of about 10 to 30 cm of reddish -
brown to black, partially-decomposed, matted reed, sedge and woody plant remains . This overlies at least 130
cm of black to dark reddish brown, weakly stratified, well-decomposed organic material . The mineral underla y
(which occurs at depths below 150 cm) is massive, gray to greenish-gray, silty clay loam or silty clay and i s
usually water saturated and sometimes saline . Soil reaction is extremely acid throughout . Soil classification i s
Typic Humisol.
Commonly Associated Soils : Lumbum, Richmond and Glen Valley soils usually occur in close association
with Annacis soils . They differ from Annacis soils in that Lumbum soils are composed of deep, partially -
decomposed organic material while Glen Valley soils consist of deep, undecomposed or only slightly decom -
posed organic deposits . Richmond soils are similar in decomposition to Annacis soils but the underlyin g
mineral material occurs between 40 and 160 cm of the soil surface .
Vegetation : Small areas are cleared . Uncleared areas support mainly western red cedar, red alder and birch ,
understoried by a variety of ericaceous shrubs and sedges . Moss is usually present on the soil surface . Rootin g
is mostly restricted to the upper 50 cm by high watertables .
General Land Use Comments : (1) If groundwater levels are adequately controlled and maintained ,
Annacis soils have good potential for a variety of agricultural crops, including forages, annual root crops an d
blueberries . Excessive subsidence of the organic material can be controlled by lowering groundwater level s
only sufficiently for the requirements of the crops grown . Acid soil characteristics can be controlled by liming .
(2) Very low bearing capacities and high watertables make road and building construction and maintenanc e
difficult and costly. Septic tanks effluent disposal is poor due to the high watertables .
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