Revegetation of Oil Sands Tailings: Growth Improvement of Silver-berry and Buffalo-berry by Inoculation with Mycorrhizal Fungi and N2-Fixing Bacteria

Authors
Robert Danielson
Suzanne Visser
Resource Date:
1988
Page Length
98

The ability of actinorhizal shrubs to tolerate inhospitable conditions while improving soil fertility and organic matter status has led to increased usage of these plants for land reclamation and amenity planting purposes. Silver-berry and buffalo-berry are two such shrubs which are being tested as potential candidates for the revegetation of the oil sands tailings in northeastern Alberta. Associated with the roots of silver-berry and buffalo-berry are two symbionts the N2-fixing actinomycete, Frankia, and the vesicular-arbuscular mycorrhizal (VAM) fungi. Numerous studies have demonstrated that, particularly in nutrient limited conditions, mycorrhization and nodulation can result in significantly better plant performance as a consequence of improved N and P nutrition. The benefits conferred on the host by the symbionts may assume even greater importance in the revegetation of mine tailings which are notoriously nutrient-poor. In addition to reducing soil fertility, the upheaval and mixing of soil during the mining process can lower Frankia and VAM inoculum levels. Both soil fertility and symbiont inoculum potential can be improved by introducing an organic amendment to the minespoil. Soil reconstruction on the oil sands tailings is facilitated by the application of muskeg peat which is stockpiled on the site for reclamation purposes. Alternatively, if woody plants are raised as containerized seedlings they can be inoculated with both their N2-fixing and mycorrhizal symbionts prior to being outplanted. However, before embarking on a large-scale inoculation program which will ultimately raise the cost of producing a seedling, factors such as plant dependency on the symbionts, the level of and mycorrhizal inoculums in the outplanting soil and the nodule/mycorrhizal status of containerized seedlings leaving commercial greenhouses should be considered.