'Mineral-eating' fungus may boost crops

By Dr Steven Wakelin, CSIRO Land and Water

The CSIRO has discovered an Australian strain of a “mineral-eating” fungus that promises to release nutrients from soil minerals and boost crop yields. These new strains of the Penicillium bilaiae fungus are undergoing rigorous testing in the GRDC inoculant evaluation program.

In the first phase of field trials, conducted by the Mingenew Irwin Group in Western Australia, both P. bilaiae and P. radicum increased lentil yield by 10 percent on a cracking clay soil. Soon we hope to have a range of Penicillium inoculants available for Australian farmers to match their agro-ecological conditions.

This new research follows worldwide interest in developing these “mineral eating” fungi into microbial inoculants. Penicillium fungi are commonly found in agricultural soils throughout the world. Most species are integral to the fundamental ecosystem services we take for granted, such as organic matter breakdown and nutrient recycling.

However, the strains that have now been discovered can release nutrients from soil minerals. As well as increasing crop production, these inoculants could potentially increase fertiliser efficiency in an environmentally friendly way.

Such opportunities are being heralded overseas with the highly successful introduction of a strain of mineral-solubilising Penicillium bilaiae to the Canadian and American markets. Results of more than 400 field trials have shown that seed inoculation with P. bilaiae increases average yield by 7.6 percent.

So why are Australian farmers missing out on technology that is proven to increase yields? To date, the major limitation has been the identification and development of strains of Penicillium suited to local soils and environmental conditions.

Research between Charles Sturt University and Australia Seed Inoculants Ltd led to the discovery of an Australian-native fungus called Penicillium radicum. This fungus has also been found to solubilise soil minerals and increase plant growth.

It is now marketed as Pr70Release™ by Bio-Care Technology Pty Ltd, Somersby, NSW.

Much of this work is being conducted by CSIRO Land and Water in Adelaide. With support from the GRDC, trials have been conducted to determine the best opportunities for use of Pr70Release™ in Australia.

For more information:
Dr Maarten Ryder, 08 8303 8534, maarten.ryder@csiro.au
Dr Steven Wakelin, 08 8303 8708, steven.wakelin@csiro.au
Bio-Care Technology, 02 4340 2246

GRDC RESEARCH CODE CSO223, program 4