Sum15-27 Potassium Sources and placement in wheat, Gibson


To assess the relative value of banding and topdressing K at seeding time or topdressing after emergence on growth and yield of wheat in the Esperance area.

For further detaqils contact your local Area Manager or the Summit Research Team

Table 1: Soil Analysis
Fig 1: Yield
Fig 2: Response to K
Fig 3: Response to source and placement


  • Differences in yield between treatments were significant.
  • Treatments clearly demonstrated advantages of banding K fertiliser over topdressing.
  • Sulphate of potash, and SOP-based K products such as the Gusto range, displayed yield advantages over muriate of potash, possibly due to additional S.
    However, price differentials need to be taken into account if increasing K application rates is desired.
  • Early strong growth of Gusto Gold plots emphasizes the benefits of a full-compound product containing N, P, S and K plus trace elements.
  • In a high yielding year, a Gusto-based fertiliser program may need to be supplemented with additional K to maximise yield and returns.
    This will be addressed in future trials.
  • No toxicity was observed in any MOP application up to 50 kg/ha drilled with seed.