Field Research & Agronomy

SUM19-25: Nitrogen x Phosphorus Rates, Goomalling.

Aim

This trial investigates the response of wheat to applied nitrogen (N) and phosphorus (P) ratesto determine a recommended fertilizer regime for local growers that maximises yield and profitability

Trial Details

Location: Haywood Bird Farms, Goomalling

Trial Size: 17 trts x 3 reps = 51 plots.

Soil Type: Gravelly sandy loam.

Crop Sown: Scepter Wheat, dry sown 90kg/ha, 13/05/2019.

Table 1: Pre-trial soil nutrient analysis

Results

**Figure 1:** Grain yield and protein response. Yield (bars) increased with applied N and P. Protein (lines) increased with applied N. Data presented as the treatment mean across the 3 replicates.

**Figure 2:** Gross Margins. Protein content limited grain segregation and harvest yield drove profits. Clear jump in gross margins from applying 0 N to 40 kg N/ha. Individual gross margins presented as the treatment mean of the 3 replicates.

Key Notes

When P supply is limited, plants are unable to utilise additional N for plant growth and yield.
Harvest yield increased with applied N and P to trial maximum of 2.4 t/ha at 24kg P/ha and 120kg N/ha.
Grain protein content increased with applied N, with majority of treatments graded as ASW1.
Economic analysis showed the appropriate recommended fertilizer application rates under decile 5 rainfall conditions on gravelly sandy loam in the Goomalling area are 12kg P/ha and 80-100kg N/ha.

Contact local Area Manager, Brayden Noble bnoble@summitfertz.com.au 0417 490 047 for more details about this trial.

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Wheat