To determine optimum nutrient management for hyper-yielding Wheat by subjecting RGT Accroc feed red wheat to 10 nutrition treatments of varying nitrogen and manure rates.

• Following six years of pasture legume 2013-18 inc. (Fescue/Lucerne/Clover) and three years of cropping (canola 2019 (cut for forage), grazing wheat 2020 and canola 2021, there was no yield response to applied nitrogen (80-280kg N/ha).
• With 142kg N/ha in the soil 0 – 60cm on 2 June the zero N treatment (only 12kg N/ha MAP applied) yielded 9.26 t/ha with a protein of 9.5% indicating the presence of 154kg N/ha in grain.
• If 75% of the N is assumed to be in the grain and 25% in the straw residue, then the total N uptake at harvest in zero N plots would be 205kg N/ha indicating approximately 63kg N/ha coming from the soil via 163mineralization.
• If straw residue was returned to the paddock the nitrogen balance would indicate that 142 kg N/ha was available in the soil in the winter (12N from MAP) and 142kg N/ha removed in the grain at harvest.
• All N applications as urea applied as 2 or 3 split applications only served to increase protein but not yield.
• Despite the application of a PGR at GS31 (Moddus/Errex), increasing N served to increase head number and lodging pressure.
• Applying N as a three split at 200kg N/ha applied moderated the lodging pressure slightly but the difference was not significant.
• Applying manure or the equivalent macro nutrients carried in the manure on top of 160kg N/ha gave no yield benefit, and where the equivalent macro nutrients were applied, significantly reduced yield as a result of increased crop lodging.
• There were no significant differences in harvest dry matter as a result of N application.
• The zero N treatment had the highest test weight and lowest screening.

Trial design: Factorial (Nutrition)