To discuss fluid phosphorus fertilisers: how did they fare in Victoria in 2005?

• Field trials were conducted at two sites (comprising Sodosol and Calcarosol soil types) in the southern Mallee and one in the Wimmera (Vertosol soil) to assess the responsiveness of wheat to fluid forms of phosphorus (P) fertilisers.
• Fluid P forms (APP and phosphoric acid) generally produced greater growth during vegetative stages of crop growth compared to granular forms (DAP and Triple Super) at all three sites.
• However, in a season characterised by a late break and dry conditions prior to flowering, early growth responses to P fertiliser (regardless of form) translated to grain yield responses at only one Mallee site. In contrast there was significant grain yield responses to fluid P at Dooen (Wimmera).
• At this site, fluid P forms produced 0.24 t/ha (or nearly 10%) more grain on average than granular forms at commercially applicable rates (4 to 12 kg P/ha).