The potential of rock dust nanoparticles to improve seed germination and seedling vigor of native species: A review

Land degradation as a result of unregulated mineral exploration and mining, negatively impacts local communities and vulnerable ecosystems. Phytoremediation is used as a progressive rehabilitation strategy to stabilize tailings sites, reduce soil erosion and immobilize heavy metal contaminants. However, in order to develop successful and sustainable phytoremediation methods, native plants must overcome several abiotic stressors. This review examines publicly available literature to determine the potential of repurposed tailings materials, in the form of rock dust nanoparticles (RDNPs), as a nanopriming agent to improve seed germination and seedling vigor of native boreal forest species, for mine reclamation purposes. The review of literature on the effects of nanopriming with metal-and non-metal-based nanoparticles (NPs) on germination percentage (GP) and seedling vigor index (SVI), suggests that nanopriming techniques could be a useful strategy to improve GP and SVI. Overall, the majority of the literature reported an equal or increased GP and an increase in SVI in nanoprimed seeds. Most of the literature employs the use of nanopriming techniques in agricultural practices, which creates an opportunity to expand on nanotechnologies for land reclamation purposes using native boreal forest species. A review of literature on RD application as a soil amendment, reveals the discrepancies in results regarding plant growth and development, likely due to the variability in mineral composition and stability between RD sources. However, by utilizing RDNPs as a seed priming agent, essential or beneficial elements may become more readily available for seedling uptake. The availability of essential and beneficial nutrients at functional concentrations indicates that RD from Pine Cove Mine in Newfoundland, Canada could potentially be utilized as RDNPs as a seed priming agent. Further research is required to determine the effects of RDNPs as a seed priming agent in improving GP and SVI of native boreal forest species for mine reclamation purposes. (C) 2021 Published by Elsevier B.V.