To better understand relationships between grain yield, grain quality and nitrogen, a field trial was established at Hart, SA in 2024 to investigate wheat and barley variety response to increasing rates of nitrogen.

• Seasonal conditions at Hart in 2024 were dry, reducing water availability and nitrogen (N) uptake of crops.
• There is a strong correlation showing that increased biomass contributed to reduced grain yield (t/ha) for Compass barley (up to 61%). This result indicates a haying-off effect in dry seasonal conditions for this variety. No yield penalty was observed for Maximus CL, although biomass increased with application of N.
• Maximus CL had a slight reduction in retention when N was applied, however rates from 30-180 kg N/ha still exceeded minimum receival standards (70%). Screenings slightly increased as nitrogen rates increased, however differences were small, and all treatments achieved <7% screenings.
• No differences were observed for screenings and retention across N rate for Compass barley.
• There was no yield differences observed for any wheat variety or nitrogen rate.
• A minimum application of 30 kg N/ha was required for wheat varieties to meet a minimum protein threshold of 13%. All wheat varieties and N rates met minimum receival standards for H1 (76 kg/hL), however higher N did contribute to lower test weights. No differences were observed for wheat screenings.

The trial was a two-way factorial with two varieties, seven nitrogen rates and three replicates.

The trial was a two-way factorial with two varieties, seven nitrogen rates and three replicates.