Miller Magazine Issue: 125 May 2020

88 MILLER / MAY 2020 The implication of the Protein/Nitrogen/Yield Balance is that farmers have the potential to increase yield and thereby increase their productivity and profitability by applying nitrogen fertilizer into those zones in the field where the protein is low. Till now farmers have been able to measure yield but not protein. The CropScan 3300H On Combine NIR Grain Analyser provides the protein layer necessary to understand the availability and uptake of nitrogen across the field. Closing the yield gap Agronomists and ag scientists around the wor- ld have known for more than 50 years that yield and protein in cereal grains are closely related. Applying more nitrogen to wheat or barley crops will produce a positive response in yield when the protein content is less than 11.5%. So what does this mean? Both yield and protein vary considerably ac- ross fields. For wheat, yield can vary from 0.5 to 12+ T/ha and protein can vary from 6 to 18%. However when the final grains contain less than 11.5% (approximately) then the full yield poten- tial was not achieved. If more nitrogen fertilizer had been applied into the field zones where the protein is less than 11.5%, then the yield would have been higher. The graph 1 shows the response of yield and protein to adding nitrogen fertilizer onto strip trials of 10 varieties of wheat at Trangie, NSW, in 2012. The plot shows that at approximately 90kg/ha additional nitrogen the yield reaches a maximum. Adding more nitrogen increases the protein content but does not increase the yield. When the full yield potential is achieved and the protein content is optimized for the use of the grain, then this is the “Sweet Spot” in how much fertilizer should be added. The implication of the Protein/Nitrogen/Yield Balance is that farmers have the potential to Phillip Clancy CEO Next Instruments