By Burnett Mary Regional Group
To irrigate … or not to irrigate? This critical question is asked by cane growers every day of the growing season. Now, thanks to a Cane Innovation project funded by the Australian Government and the Burnett Mary Regional Group and delivered in partnership with Reef Trust Phase III, the answer should become a little clearer. The project will be jointly undertaken by Bundaberg CANEGROWERS Ltd, Bundaberg Sugar Services Limited (BSSL) and Bundaberg Sugar Ltd.
With the ever-increasing cost of water, fertiliser and electricity, knowing “when and how much” to irrigate is critical to optimising crop yields. Studies conducted by Bundaberg Sugar Services Ltd (BSSL) indicate that a crop that is under moisture stress exhibits a productivity loss of 0.7 tonnes of cane per hectare per day. Improved timing of fertiliser application also reduces the potential for nitrogen losses from large rainfall / runoff events.
The purpose of an optimal irrigation regime is to apply the right amount of water at the right time to replenish soil moisture to the right level to achieve maximum crop yield. Accurate weather forecasting and soil moisture monitoring are therefore integral parts of a successful irrigation schedule.
Current weather forecasts provided by the Bureau of Meteorology are region-wide and do not account for localised differences within the Bundaberg Sugar supply area. Nine industry owned weather stations throughout the area currently monitor a range of parameters including rainfall, temperature, relative humidity and wind speed. There are also 36 soil moisture monitoring probes installed throughout the area owned by Bundaberg Sugar, industry or growers. Data recorded by these probes presents a visual representation of soil moisture levels and indicate when a plant is suffering stress. This information is available on the Bundaberg CANEGROWERS website(http://www/bdbcanegrowers.com.au/irrigation.php). It has been demonstrated that growers who apply this information to their irrigation schedule achieve, on average, 10 per cent greater productivity than the district seasonal average.
The proposal is to integrate data from the nine existing weather stations into a transmission network to generate customised local weather observations and forecasts. This information will be presented in a readily accessible and easily understood visual format on Bundaberg CANEGROWERS’ website to assist growers in making informed irrigation decisions.
The improved weather forecasting will also assist growers in decisions about fertiliser application. Whether the application process involves nitrogen-fortified dunder mix or granular fertiliser on top of the trash blanket, irrigators will be able to determine the timing of application with greater accuracy. This accuracy will reduce the potential for nitrogen loss either as deep drainage, denitrification or runoff.
During implementation of the project, BSSL extension officers will be available to discuss and demonstrate localised weather forecasting to growers who choose to apply this information to their irrigation scheduling. An evaluation and monitoring program will also be established to determine the expected productivity gains from improved decision making.
This project is the first of its kind within the sugar industry. Bundaberg CANEGROWERS, BSSL and Bundaberg Sugar are looking forward to working with growers to improve irrigation practices and achieve greater efficiencies and productivity.