7. Dr Bill Bowden: The Truth About Soil Fertility

Dr Bill Bowden has spent more than five decades shaping the way Western Australia understands soil, fertiliser strategy and plant nutrition. In this episode, he joins host Bill Crabtree for a candid conversation about the science, history and hard-won lessons behind modern cropping systems. From the early days of superphosphate to the complexities of trace elements, root development, pH buffering and nutrient availability, Bill breaks down how WA’s most infertile soils became productive and what farmers must keep in mind as systems evolve. Together they unpack: • The rise of phosphorus use and the foundations of soil testing in WA • Copper, zinc, manganese and why positional availability still matters • Root biology and the shift from input-focused thinking to system understanding • No-till, deep ripping and the long-running debate around disturbance • Rock phosphate, calcination and the realities of using alternative P sources • The biological engine driving soils from microbes to termites A must-listen for growers, agronomists, researchers and anyone working to improve soil fertility and system resilience across Australian agriculture.