Response of plants to oil sand tailings

A greenhouse experiment was conducted to evaluate the response of five agronomic species on initially high water content composite tailings (CT) from Alberta oil sands operated by Syncrude Canada Ltd. The CT mixture having an initial solids content of approximately 65% was placed in lysimeters with no drainage at the bottom to prevent water loss other than via evapotranspiration. The species selected for testing were Altai wildrye (Elymus angustus), Creeping foxtail (Alopecurus arundinaceus), Red top (Agostis stolonifera), Reed canarygrass (Phalaris arundinacea), and Streambank wheatgrass (Agopyron riparian). The electrical conductivity, pH and sodium adsorption ratio of the CT mixture were 3.1 dS/m, 7.7 and 8.2, respectively. All plants survived after an eleven-week period. The six grasses used in the experiment are recommended for revegetation of CT.