Thesis: Interactions between microorganisms and rock mineral fertilisers in organic pastures.
I am investigating interactions between minerals and microorganisms in soil.
In my first experiment I proved the hypothesis that changing the mineral composition of a soil alters the structure of the microbial community (FEMS Microbiology Ecology 61: 414-423). In my second experiment I tested the hypothesis that different minerals in soil support microbial communities with different structure.
A third experiment is planned that will investigate the relationship between the pores size distribution of soil and the structure of the microbial community.
I am also investigating the use of ground rocks as fertilisers for organic beef pastures in Western Australia and have published a review covering this and other issues in the management of soil fertility in organic farming systems (Organic Agriculture: A Global Perspective, CSIRO). I am investigating the ability of ground rock fertilisers to provide phosphorus (P) and potassium (K) to beef pastures in a field trial.
Why my research is important
Research on the use of silicate minerals and rock phosphate as fertilisers for pastures will benefit the emerging organic beef industry in Australia. Organic farming systems are attracting interest world-wide for the potential environmental benefits and the increasing market share of organic food products.
Australia’s share of export markets for organic produce is lagging behind other countries. In 2000, the Clean Agriculture Project identified organic beef as having the potential for immediate production and export. However, information on organic beef production methods for farmers wishing to convert is lacking because very little research has been carried out in Australia.
Research to date has caused concern that organic farming in Australia might be unable to maintain adequate levels of nutrients in soil, especially P and K. Rock phosphate and silicate minerals are two of the few sources of P and K acceptable under organic certification standards.