SUM19-02: N x P +/- K in Scepter Wheat, Esperance


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

Trial Details

Location: Hill Plains Farm, Mount Ney, Esperance region.

Trial Size: 44 treatments x 3 replicates = 132 plots.

Soil Type: Loamy sand over loam with carbonaceous rock inclusions.

Crop Sown: Scepter Wheat, 90 kg/ha, 30/04/2019.

Table 1: Pre-trial soil nutrient analysis.


Figure 1: Mean P and N response curves with and without additional K.
Figure 2. Grain quality was characterised by high protein across the site shown here for non-limiting P applied (24 kg/ha).

Key Notes

  • Mount Ney experienced a decile 4 growing season rainfall in 2019. Nearby Beaumont fell 77mm below the 30-year average for the growing season, punctuated by very dry July and September months.
  • Applying P and N increased yields but K was ineffective at the site.
  • Establishment P rate has a strong influence on the ability of a crop to respond to in-season nitrogen application. Inadequate P = decreased N use efficiency.
  • Under the 2019 seasonal conditions, applying P at 24 kg/ha and N at 100 - 120 kg/ha represented the best strategy to optimise profit from Scepter wheat.

Contact your local Area Manager Nick Donkin for more details on this trial, 0428 715 045.