Restoration engineering is a swiftly developing field that partners biological research with innovative ecologically-guided engineering solutions. From a plant recruitment perspective, best-practice use of seeds can be coupled with the invention and modification of seeding equipment needed to deliver native seeds at scale. Improving seed use efficiency through seed enhancement technologies is one approach that has gained recent attention in dryland restoration. Techniques including precision flash flaming, hydro- and osmo-priming, polymer-based seed coating, and extruded seed pelleting, all aim to improve the germination and establishment potential of seeds under sub-optimal conditions. When combined with modifications to existing mechanical seeders or with new-builds, these technologies are one potential solution to overcome major inefficiencies in dryland seeding efforts (i.e. >90% of seeds failing to establish).
For instance, ‘flash flaming’ is a technique that removes unwanted hairs and appendages of bulky and fluffy seed batches (e.g. Winterfat / Krascheninnikovia lanata). After removal, seed batch volume is vastly reduced, while the flow properties of seeds through cleaning equipment and mechanised seeders are vastly improved. This recent Australian invention allows many species that are historically hard-to-handle, and/or deliberately avoided, to be used in large scale restoration programs.
Continued research aims to: (1) advance the application of flash-flaming technology to remove unwanted seed appendages to a wider range of species, (2) combine the optimised flash-flaming treatments with additional seed enhancement technologies (priming, pelleting, and coating), (3) critically evaluate the limitations of current mechanised seeding techniques used in rehabilitation (e.g. mining operations) and large-scale cropping to guide engineering modifications or new designs to improve precision-delivery of native seeds in adverse rocky, uneven and sloped landforms, and (4) design, construct, and test a prototype direct seeding machine(s) that can accommodate and efficiently deliver a wide range of seeds that differ in shape, size, and weight, at the scale required.
Results/Conclusions
In this presentation we will highlight some key findings for a selection of our restoration engineering approaches that include the benefits of flash flaming in Australian and US species, polymer-based seed coating combined with priming of seeds, and discuss the modes of treatment applications across large-scale, high-impact mine restoration scenarios. For instance, some of our combined treatments can now achieve up to 40% seedling establishment for key species of Australian desert grasses. Outcomes of these programs are applicable to degraded lands requiring restoration across the United States, Australia, and other semi-arid global regions.