Statewide adoption of best irrigation practices for supplementary and full irrigation districts : SRDC Final report BS183S

Abstract

Project BS183S has researched and identified a number of means by which on-farm water use efficiency may be improved. These include the use of irrigation scheduling devices, improved furrow irrigation design and management, and use of modelling tools by local extension staff.Field trials demonstrated that deep drainage losses associated with furrow irrigation can be reduced by the use of surge irrigation and improved furrow irrigation management. Use of the furrow irrigation simulation model SIRMOD has enabled advisory staff to measure and optimise furrow irrigation events under typical sugar growing conditions. Difficulties however remain with deep drainage losses from furrow irrigation under trash blankets. Capacitance soil moisture meters and tensiometers were demonstrated to be effective tools for scheduling sugarcane irrigation. These devices enable growers to time irrigations to minimise crop water stress. APSFront~Sugar was developed in conjunction with APRSU to enable local advisory staff to investigate a range of issues related to sugarcane production. Despite difficulties with high rainfall, field trials demonstrated that in the absence of watertables APSIM produced reasonable predictions of crop yield. APSIM was employed to determine effective rainfall, crop response to irrigation, water use efficiency and irrigation requirement for the Mackay, Bundaberg, Mareeba, Proserpine, Atherton, Childers, and Sarina districts. APSIM was also able to identify a number of improved strategies for the use of limited allocation in supplementary irrigation districts. Project BS183S provided considerable training and support to research and extension staff.