SUM19-03: Nutrition for high-end wheat production on ameliorated soil east of Esperance


To investigate high-end cereal nutrient growth responsecapacity after removal of soil constraints. Particularly evaluating how wheatresponds to nitrogen (N), phosphorus (P) and potassium (K) fertilizerapplication.

Trial Details

Location: Warakirri Lobethal, Boyatup, Esperance Region.

Trial Size: 44 trts x 3 reps = 132 plots.

Soil Type: Sand

Amelioration History: 2018 –2t/ha lime, canola crop.

                                     2017 – Ripped 550-600mm, spaded 250-275mm, 2t/ha lime & 2t/ha gypsum

Crop Sown: Scepter Wheat, 90kg/ha,  17/04/2019

Table 1. Soil nutrient analysis


Figure 1. All yield response to P rate applicationswith and without K. Mitscherlich function is fitted to all graphs.
Figure 2. All yield response to N rate applicationswith and without K. Mitscherlich function is fitted to all graphs.

Key Notes

  • Boyatup experienced a decile 4 growing season rainfall in 2019, despite falling 40mm below the 30 year average, the consistent rainfall was beneficial in producing the high yields.
  • Plant emergence averaged 131 plants/m2 and was significantly influenced by establishment P rates.
  • Plant growth and yield responded strongly to P and N application but not K despite low soil K analysis.
  • Applying ProBoost at10 and 20 kg N/ha late in the season – bringing total N to 90 and 100kg N/ha – did not increase yield, but did increase protein to levels higher than applying 120 or 160kg N/ha.
  • The most profitable treatment under 2019 conditions was $1927/ha when 120kg N/ha, 8kg P/ha and 25kg K/ha was applied.
  • ProBoost late in season increased returns from from 25% to 32% additional to nil control.
  • Capitalising on removal of soil constraints by appropriate nutrition inputs can vastly improve profitability and return on amelioration investment.

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