To investigate the comparative efficacy of fluid forms of Phosphorus (P) fertiliser compared to the current granular forms for application to grain crops grown on alkaline soils of Victoria.

• Fluid forms of Phosphorus such as Ammonium Polyphosphate (APP) and Phosphoric Acid have been shown to significantly increase the growth and grain yield of crops on highly calcareous soil on the Eyre Peninsula of SA compared to granular fertiliser forms such as DAP and Triple Super.
• Field trials conducted at three sites in 2003 in Victoria on alkaline soils (central and southern Mallee and Wimmera Plains) demonstrated that fluid forms of P fertiliser promoted the growth of wheat more than granular forms at all sites but this was translated to a yield response at only one site (Birchip).
• There is no reliable diagnostic tool however presently available for predicting under what circumstances fluid forms will outperform granular forms of P.
• Experimentation will continue at the same sites in 2004.