Field Research & Agronomy

SUM20.32: Apex Yield Series - Strategic Nitrogen Rates & Timing for Wheat on Sandy Soil, Mingenew

Aim

Managing wheat nutrition in the Mingenew area has implications for sustainable and profitable production. This trial assesses a number of nitrogen application strategies with increasing rates to match site conditions and Scepter wheat yield potential at a sandy site south west of Mingenew.

Trial Details

Location: Mingenew

Trial Size: 1.61m x 10m, 13 treatments x 3 reps = 39 plots

Soil Type: Sand.

Crop Sown: Scepter Wheat, sown 08/06/2020 at 100kg/ha

Season Rainfall: 246 mm, Mingenew DPIRD, 86 mm below long-term average.

Results

**Figure 1.** Harvest yield (bar) and grain protein (line) showed higher protein in early application, but higher yield in late N applications.The fuel gauge treatments indicate higher protein as the rate of N applied increased.

**Figure 2:** Under 2020 growing season conditions the most profitable treatment was applying 15kg N/ha upfront with a return of $225/ha.

Key Messages

Plant biomass responded strongly to increasing N. Differences became greater as the season progressed.
Plant tillers were collected at Z61 and Z99. Early counts showed maximum tiller numbers at 100kg N/ha, whereas late counts showed higher tiller numbers at 55kg N/ha.
There was higher N uptake in early N application treatments than in the later applications.
Close to nil rainfall outside a 25 May – 17 August period, meant biomass growth differences from N were unable to support grain production and the site average yield was only 1.1 t/ha.
Under 2020 growing season conditions the most profitable treatment was applying 15kg N/ha upfront with a return of $225/ha.

For further information about this trial please get in touch with local Area Manager Juliet McDonald, jmcdonald@summitfertz.com.au.

Wheat