IN-FIELD MEASUREMENT OF SUGARCANE COMPOSITION FOR DRYING-OFF ON THE TABELANDS

AN IN-FIELD method to directly measure sugarcane crop parameters: moisture, Brix and CCS, is presented and illustrated with an example of crop moisture changes during ‘drying off’. The sugarcane measurement method is composed of sampling Brix measurements at five positions along the millable cane stalk then interpolating across the entire cane stalk to derive the stalk Brix. Brix measurements are collected on a representative number of stalks in an area then input into a sugarcane compositional model (ternary growth model) to derive estimates of crop parameters such as crop moisture and CCS. This technique was trialled for two consecutive seasons in SRDC project BSS304, with an accuracy of ± 0.90 Brix units and ± 0.79 units of CCS. Changes in soil moisture during drying off were monitored with an EnviroSCAN® probe to identify trends with changes in crop characteristics and soil moisture. Crop parameters did not track with changes in soil moisture, but changes in crop parameters could be adequately modelled by the passage of time.