WITHIN BLOCK SPATIAL VARIATION IN CCS—ANOTHER POTENTIALLY IMPORTANT CONSIDERATION IN THE APPLICATION OF PRECISION AGRICULTURE TO SUGARCANE PRODUCTION

GROWERS ADOPTING PRECISION Agriculture approaches to sugar cane production have been predominantly focussed on the use of variable rate management of fertilisers and soil amendments (VRT) to optimise yield. However, cane yield is only one component of the sugar production system; CCS (Commercial Cane Sugar) is also important. Clearly, growers using VRT to optimise yield will not want the benefit of doing so to be offset by a possible consequent CCS penalty. We collected cane stalk samples from 202 geo-referenced locations in a 6.8 ha block of cane in the Bundaberg district during the 2011 harvest and analysed them in the laboratory for brix, pol and CCS. CCS varied from 13.29 to 16.84 with a mean of 15.73 and median of 15.80; the coefficient of variation (CV) was only 3.5%. However, the variation in CCS was spatially structured: that is, it was not random. Brix and pol followed the same patterns of variation. Future work will seek to characterise CCS variation in potentially more variable blocks and explore the drivers of CCS variation. Nevertheless, the present results suggest that spatial variation in CCS is something that adopters of PA should consider, alongside variation in yield and soil properties. They also lend weight to the need for a harvestermounted on-the-go sensor for CSS determination as a complement to yield monitoring technology.