SUM19-04: Nutrition for high-end canola production on ameliorated soil, east of Esperance


To determine high-end nutrient-growth response capacityafter removal of soil constraints. Particularly evaluating how canola respondsto nitrogen (N), phosphorus (P) and potassium (K) fertilizer application.

Trial Details

Location: Warakirri Lobethal, Boyatup, Esperance Region.

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

Soil Type: Sand over sandy loam.

Amelioration History: 2018 – Lime 2t/ha and deep ripped to 500mm, barley crop (6t/ha).

                                            2017 – Lime 2t/ha, gypsum 2t/ha, ripped 600mm, spaded to 275mm, canola crop.

Crop Sown: Canola InVigor T4510, 4kg/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 graph.

Figure 2. All yield response to N rate applicationswith and without K. Mitscherlich function is fitted to graph.

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.
  • Increasing rates of N and P significantly increased production, with yield increases up to 1.5t/ha,
  • Oil content ranged between 42.2-46.2%, indicating CAG1 delivery grade across the board.
  • Yield response curves for N rates show yield was not maximised at 160kg N/ha, and high-end production driven by N must be supported by adequate P at establishment.
  • Under 2019 growing season conditions the most profitable treatment was $1573/ha when 160kg N/ha, 24kg P/ha and no K was applied.
  • Nutrient application in line with both genetic potential and site potential post-amelioration supports improved profitability and return on an expensive amelioration operation investment

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