Miller Magazine Issue:114 June 2019

83 ARTICLE JUNE 2019 Protein/Yield Correlation: • Low Yield + High Protein • High Yield + High Protein • Low Yield + Low Protein • High Yield + Low Protein The possible explanation for these scenarios are: • Low Yield + Low Protein = In- sufficient Nitrogen throughout all • growth stages • Low Yield + High Protein = In- sufficient Nitrogen in the Tillering • stage but sufficient Nitrogen in the Flowering and Filling • stages. However there may be some other issues limiting yield • apart from Nitrogen. • High Yield + Low Protein = Sufficient Nitrogen in the Tillering and Stem Elongation stages but • insufficient Nitrogen in the Filling stages • High Yield + High Protein = Sufficient Nitrogen throughout all growth stages. This is the “Sweet Spot” where there has been sufficient Nitrogen available at the Tillering stage as well as the Flowering and Filling stages. Based on these four scenarios, a field can be mapped by the cor- relation between Protein and Yield. Figure 6 shows the Protein and Yield maps for a wheat field from Broden Holland’s farm in Young NSW. Figure 7 shows the Protein/Yield Correlation map which plo- ts the correlation between Protein and Yield within a 25m radius. The plot has four colours, i.e. Blue: Low Yield/High Protein, Red: Low Yield/Low Protein, Green: High Yield/High Protein, Yellow: High Yield/Low Protein. The Green areas in the Correlation map are the “Sweet Spots”, i.e. High Yield and High Protein. However the Red, Blue and Yellow areas have performed poorly. According to the experts referenced above, the Yellow and Red areas would most likely have responded to additional Nitrogen fertilizer being added. Wherever the Protein levels in the finished grain were below 11.5%, then the crop did not reach its full Yield Potential. For the following crop, 2017, the farmer applied a simple Variable Rate Fertilization strategy as follows: Protein < 11.5% = 120kg/ha Protein 11.5 – 12.5% = 80kg/ha Protein > 12.5% = 60kg/ha Figure 8 shows the Protein and Yield maps for the 2017 wheat crop. It can be seen that the majority of the crop had jumped a Protein grade, i.e., APW to H2 and H2 to H1. The farmer calculated that the Yield variation had been reduced by 40% across the field as compared with 2016, and that his Yield was 0.4Ton- ne/ha more than the local average. Based on the increase in Protein pay- ments and Yield, the farmer reported that he made an additional $2482 or $13.61/ha in this field alone through the use of the CropScan On Combine Analyser and the subsequent VRF stra- tegy from the 2016 maps. Discussion: If the drawback for VRF techno- logy lies in the complexity of the maps and the interpretation of the many layers of data, then On the Go Protein analysis using an On Combine NIR Analyser provides a very simple means for farmers and their agronomists to capture 20-30% Yield improve- ments. The “Low hanging fruit”, i.e., the first 20-30% Yield im- provements are not the end of the story. Protein plus Yield tells the complete story as to the availability and uptake of nutrients inclu- ding Nitrogen, Sulphur, Potassium and Phosphorus. The CropScan 3300H On Combine Analyser adds several layers of agronomic data that has been missing from the PA puzzle. Michael Eryes, Field Systems Australia, SA, states: “The Yield map correlates directly to soil performance and the Protein map is a very good proxy for plant performance. The Nitrogen data is what makes everything else fit together, i.e., productivity and performance. The on combi- ne protein analyser is a tool of exceptional value whose true value is only just starting to be well enough understood” Grain yield (t/ha) and protein concentration (%) from 10 wheat varieties with 0, 30, 60, 90 and 120 kg/ha applied nitrogen in a trial at Parkes in 2011. (Brill et al, 2012, Comparison-of-grain-yield- and-grain-protein-concentration-of- commercial-wheat-varieties) Figure 8. Protein and Yield Maps, 2017