Miller Magazine Issue: 125 May 2020

90 ARTICLE MILLER / MAY 2020 Blue Low Yield + High Protein Green High Yield + High Protein Yellow High Yield + Low Protein Red Low Yield + Low Protein The Protein/Nitrogen/Yield Balance curve shows that a positive yield response can be achieved by applying more nitrogen fertilizer in the zones where the protein is low, i.e., the Red and Yellow zones. The Protein/Yield Correlation Qu- adrant map shows that approxi- mately 87% of Mr. Hill’s field was under fertilized. The prote- in map shows that the protein content in these zones ranged from 8.5 to 10.5%. The far- mer’s strip trials showed that he should apply between 100 and 330 litres of Flexi-N to increase the protein and thereby increa- se the yield across the field. Based on these maps the lost yield across this field in the 2016 harvest was: Field size: 137.5 ha Red Zone: 41.5 ha Yellow Zone: 78.2 ha Yield Increase in Red Zone: 74.7 T Yield Increase in Yellow Zone: 70.4 T Total Lost Yield: 145.1 T Lost Income @ A$300/T: A$43,530 SUMMARY Nitrogen availability and up- take is the missing layer of in- formation that can provide farmers with a simple means of increasing yield (quantity) and protein(quality)through variable rate nitrogen fertilization applications. Measuring nitrogen in soil and then in the crop during biomass pro- duction do not provide a reli- able means of determining how much and where the nitrogen has been used by the plant. The only direct measurement of nitrogen availability and uptake is when protein and yield are measured in the grains during harvest. By combining protein, yield and GPS coordinates off a combine harvester a new analy- tical tool, the Protein/Yield Cor- relation Quadrant Map, can be generated. These maps provide a simple means of determining where and how much additio- nal nitrogen fertilizer will pro- duce a positive yield response. ABARES data shows that in Australia, the average protein content of wheat is 9.5% and the average yield is 1.7T/ha. If all Australian wheat fields could be mapped with the Protein/ Yield Correlation Quadrant Maps, then it could be possible to increase the average yield to 3.4T/ha which would increase the Australi- an wheat crop by approxima- tely 25 million tonne with an increase in crop payments of $9.3 billion. If the same tech- nology was applied across the world for wheat crops only, then the potential increase in wheat production could be 228,000,000tonne at a value of A$68.4.billion.