Chris Norris1, Troy Jensen2,3 and Cam Whiting4
1Norris Energy Crop Technology, Brisbane, Australia; chris@norrisect.com
2University of Southern Queensland – Centre for Agricultural Engineering, Toowoomba, Australia
3 University of Florida – IFAS, Everglades Research and Education Centre, Belle Glade, USA
4 Previously Sugar Research Australia
Since mechanised harvesting of sugarcane became established in the 1970s, farmers, manufacturers and researchers have been attempting to improve harvester performance and optimise harvest efficiency. The move to green-cane harvesting and the introduction of pneumatic extractor systems on sugarcane harvesters both increased cane loss significantly. Protocols were developed for measuring actual extractor losses. Whilst “averaged” actual extractor losses are typically close to 10% of the crop yield, machine settings, field conditions and varietal characteristics give high variability in cane loss at nominal machine settings. Field and workshop trials demonstrate that, with modern harvesters, the visible recovered cane pieces, “shrapnel”, is often much less than 10% of the actual cane lost through the extractors in normal operation. Outside the Australian industry, the typical protocol to determine losses through the extractors is to collect and weigh this cane “shrapnel” after harvest and assume this represents 100% of the loss. When compared with the visible losses associated with gathering, pickup, basecutting and spillage losses, shrapnel extractor losses are usually considered minimal. In over 30 peer-reviewed papers published over the last decade, reported (visible) extractor losses seldom exceeded 1.5% of yield and were considered of little concern relative to other visible losses. Significantly, manufacturers use visible losses in discussion of cane loss and cane-loss monitors fitted to some harvesters are calibrated against these shrapnel measurements. This monitoring of visible losses then drives an “alternative reality”, where harvester extractor losses are considered to be low, but are actually highly variable and often much greater than all other harvesting losses combined, with an associated impact on industry profitability. In the papers reviewed, the key drivers of cane loss and the lack of understanding of the interactions within the cleaning system were alarming; fundamental parameters were not recorded, with many researchers and reviewers showing little understanding of the cane loss process or parameters that impact on cane loss. International standards must be developed for the measurement of actual cane loss, and both commercial and research communities must use these standards in monitoring cane loss; “visible loss” data is of no technical value and is a dangerously irrelevant measurement. More research is warranted into accurately measuring and managing true cane loss and ensuring commercial cane loss systems display actual cane loss rather than an irrelevant surrogate.