Aeolian dust in contemporary Australia – a fertiliser, a contaminator or just an occasionally spectacular nuisance?

Summary

Aeolian dust usually receives little popular attention in Australia until a massive, rolling dust storm blows out of the arid interior and reduces visibility and air quality across the eastern states. Researchers have estimated that such storms can entrain and transport up to 5 million tonnes of topsoil from arid source areas to more humid sink areas, including the eastern highlands of NSW, the Tasman Sea and New Zealand. But apart from being a spectacular indication that episodic wind erosion is occurring in arid parts of Australia, are there other consequences of aeolian dust transport in eastern Australia? Does aeolian dust deposited on topsoil across eastern NSW contain large concentrations of plant nutrients, soluble salts, or other contaminants such as heavy metals? How much organic carbon is transported and deposited with aeolian dust? Although deep soil profiles derived exclusively from aeolian dust are not common in Australia, it is likely that aeolian dust has played, and still is playing, an important role in soil profile modification in many locations. A possible flow-on effect of climate change in southern Australia is that dust-mediated topsoil modification may increase markedly in some locations.

Supervisor(s)

Associate Professor Stephen Cattle

Research Location

Agriculture and Environment - Camperdown Campus

Program Type

PHD

Synopsis

This research project will investigate the importance of contemporary aeolian dust as a modifier of topsoil chemical properties. Initially, the project will involve the establishment of a network of dust traps in a range of locations across agriculturally significant parts of New South Wales. Deposited dust collected in these traps will be analysed for a range of chemical and physical attributes, including total elemental composition, macronutrients, soluble salts, heavy metals, organic carbon and particle size distribution. Topsoil attributes for the dust trap sites will also be characterised in order to elucidate the cumulative effect of ongoing aeolian dust deposition on topsoil character. Estimations will be made of the likely effect of these dust additions on crop production.

Additional Information

I am seeking a PhD candidate to work on this project – competitive scholarships are available from the Faculty of Agriculture, Food & Natural Resources and the University. International students would require an IPRS scholarship. A student interested in this project should have a background in soil science or geography, and a preparedness to carry out field sampling of dust and soil, and laboratory analyses of the collected samples. Experience and familiarity with high resolution particle-size analysis, scanning electron microscopy and light microscopy would be advantageous.

Keywords

Dust, loess, wind, contaminants, topsoil

Opportunity ID

The opportunity ID for this research opportunity is: 1065