To evaluate nitrogen (N) use efficiency in winter barley under different rates and timings of applied N fertiliser applied as in crop urea (46% N) grown on surface irrigation

• There was no interaction between nitrogen rates and nitrogen timing in this trial.
• With moderately high soil fertility following canola (146 kg N/ha available mineral N (0-90cm)) there was no significant difference in grain yield at N rates between 80 – 240kg N/ha (identical result to Trial 1).
• Delaying nitrogen application to GS32 (second node) and GS37 (flag leaf visible) gave a significantly higher yield (9.95 t/ha) than applying nitrogen at sowing and GS30 application (9.37 t/ha).

• Delaying the nitrogen applications to the development window GS32-GS37 increased protein slightly and although the effect was not statistically significant the risk of not achieving malt quality is increased at higher N levels.
• Grain protein increased as higher rates of N were applied, at 160 - 240 kg N/ha, protein was above the maximum 12% required to achieve malt quality irrespective of N timing.
• There was no significant differences in test weight (data not shown), although it was a factor in some treatments not achieving a malt quality grade.
• N uptake in the crop at harvest indicated that over 200kg N/ha had been taken up in the crop.