A case study of seed-use technology development for Pilbara mine site rehabilitation

Abstract

Mine rehabilitation is not just earthworks. Mine rehabilitation is a complex, integrated process that involves multiple stakeholders, long-term commitment, and a comprehensive understanding of site-specific conditions. When it comes to the re-introduction of vegetation, increasing the likelihood of successful plant establishment requires the proper implementation of many components including growth media movement, land forming, seedbed preparation, and seed delivery. \nFrom a perspective of initiating plant recruitment, best practice use of native seeds is fundamental, and seed technologies can also be coupled with the invention, development and modification of the seeding equipment needed to deliver seeds at scale. Improving seed-use efficiency through seed-enhancement technologies is one approach that has gained recent attention in dryland rehabilitation. Techniques including precision flash flaming, priming, polymer-based seed coating, and extruded seed pelleting all aim to improve the germination and establishment potential of seeds under suboptimal conditions. Along with modifications to existing mechanical seeders or with new builds, these technologies are one potential solution to overcome inefficiencies in dryland seeding efforts. For instance, through the fabrication and engineering of new parts fitted to existing seed-coating equipment, ‘flash flaming’ is a technique that removes unwanted hairs and appendages off bulky and fluffy seed batches (e.g. spinifex or Triodia species). After removal, seed batch volume is significantly reduced, while the flow properties of seeds through cleaning equipment and mechanised seeders are vastly improved. \nIn this paper, we highlight some key examples of recent approaches to addressing shortfalls in seedling establishment in the mining-intensive Pilbara region of Western Australia. We detail research findings that highlight the benefits of flash flaming of seeds for Australian and American species, the application of polymer-based seed coatings and seed priming, and discuss how collaborations between environmental scientists and mechanical engineers have progressed the application of seed-based technologies for rehabilitation across large-scale, high-impact mining scenarios. Outcomes of these programs are applicable to degraded lands requiring rehabilitation across Australia, the United States of America, and other dryland regions.