Sustainable phosphorus strategies for Eyre Peninsula

Phosphorus (P) is essential for maintaining crop productivity, particularly due to the vital role it plays in regulating crop physiological responses and tolerance to abiotic stressors like heat and drought. Managing P in different soil types is challenging and our understanding of the long-term effects of P applications is limited.

AIR EP is leading a new project, with co-investment by SAGIT, aimed at improving P fertiliser applications in variable paddocks/landscapes and refining long-term management strategies on highly P responsive soils. The overall aim is to increase profitability from P fertiliser applications and determine sustainable P fertiliser strategies for EP.

Single year spatial sites investigating P agronomy will be run at three locations on EP in 2025 and 2026 to generate crop response curves to P at sites with various levels of P responsiveness.

A long-term P agronomy trial has also been established at an Innovator Site near Minnipa to investigate high rates of MAP fertiliser and organic matter on a highly P responsive soil. The trial will evaluate how residual P influences crop growth and identify benefits and limitations; examine whether P applications in year one provide sustained benefits; and compare different P formulations and application methods to determine the most efficient options for improving nutrient uptake and crop yield.

Very clear plant growth responses to phosphorus have already been observed this season and we look forward to insights from the first year of these trials.