An assessment of Tarong bottom ash for use on agricultural soils

Coal combustion by-products (CCBs), including fly ash and bottom ash, present a waste disposal problem in Australia due to a continuing demand for coal-fired power. Pozzolanic Enterprises handle ash produced by the Tarong Energy coal-fired power station in South West Queensland, which produces approximately 1,200,000 tonnes per annum of CCB's. This comprises roughly 1,100,000 tonnes of fly ash and 100,000 tonnes of furnace bottom ash. The volume and unique properties of the Tarong bottom ash present a significant opportunity for agronomic use. Of particular interest is the ability of Tarong bottom ash to markedly improve the water-holding capacity of soils. Given that Australia's rural environment is currently enduring a 'one-in-one-hundred-year ' drought a study of the ability of Tarong bottom ash to improve water holding capacity is timely. This paper details physical and chemical properties relevant to agronomic use, and water-holding capacity of ash/soil blends, along with experiences in its field use in crop production.