SUM19-08: N x P +/- K in Mace Wheat, South Burracoppin


To evaluate local wheat response to nitrogen (N), phosphorus (P) and potassium (K) fertilizer application.

Trial Details

Location: Warakirri Mawarra, South Burracoppin.

Trial Size: 36 treatments x 3 reps = 108 plots.

Soil Type: Sandy Clay Loam.

Crop Sown: Mace Wheat, 82kg/ha, 15/05/2019.

Table 1: Soil test analysis.


Figure 1. Individual treatment yield presented as the mean across 4 replicates. There is a significant increase in yield with applied N and P.  
Figure 2. Returns additional to average gross margin from control (N0 P0). Data shows addition of P increasing profits to approximately 40% by 12 kg P/ha application, with positive return from N only at 20 kg/ha and K being cost only in 2019.

Key Notes

  • South Burracoppin experienced a below average growing season rainfall in 2019 with significant dry periods during early April to mid-June, most of July and all September. Following a very dry summer this rainfall patter heavily impacted the yield potential.
  • The importance of adequate P nutrition, regardless of rainfall conditions, for crop production was demonstrated.
  • Yield trends suggest P had a greater influence on yield than N, with grain quality impacts resulting from the sharp season finish in September.
  • Gross margin returns were maximised at $440/ha from a 1.6 t/ha yield where P 12, N 20 kg/ha and nil K were applied.

Contact your local Area Manager Kobus Marais for more details on this trial, 0427 766 508.