The Reef Water Quality Science Program aims to help producers better manage cane growing and grazing lands in the Wet Tropics, Burdekin Dry Tropics and Mackay Whitsunday catchments, and minimise the impacts upon the health of the Great Barrier Reef.
A suite of science projects were developed to deliver valuable, knowledge-based and practical tools for landholders. One project was funded in the Mackay Whitsunday region – Validation and extension of the water quality, productivity and economic benefits of adopting improved nutrient and chemical management in sugarcane in the Central region. One component of this project, a rainfall simulation study, forms part of an ongoing effort to improve our understanding of the water quality implications of improved sugarcane farming practices in the Mackay Whitsunday region. The study has added to a body of knowledge developed through trial work and paddock scale water quality monitoring conducted over the previous three years, namely;
- Runoff was similar across all 1.8 m solid plant treatments, but reduced in the skip configuration;
- Sediment concentrations and loads were similar across all cane rows, but higher in the skip area;
- No nitrogen treatment effect evident prior to application, but N concentrations and loads increased in line with increasing N rates after application; and
- Annual applications of phosphorus doubled runoff concentrations and loads six months after the previous application.
In summary, results from this rainfall simulation study support those observed in other studies. All of these practices, which result in improved water quality of runoff, have had little/no impact on crop productivity.
Client – Queensland Government
The complete Catchment Solutions Rainfall Simulation Report is available here.