Prospects for Coal-ash in the Management of Australian Soils

Many agricultural soils in Australia have inherent structural and nutritional limitations that pose major constraints to crop productivity. These soils are still productive due to intensive management that involves routine treatments with lime and gypsum at significant costs both to the farmer and the environment. There is therefore an opportunity to explore the use of the 13 million tonnes of coal-ash produced annually in Australia for soil management; at present most of the ash is disposed in landfills. In this paper we briefly describe examples of studies that showed beneficial use of coal-ash for crop production including our ongoing glasshouse study in which fly-ash increased early growth vigour and seed yield by 20% for canola ('Brassica napus'). There are several issues, including costs and regulation, and knowledge-gaps that need to be addressed before adoption of coal-as for routine soil management.