Contents
Contents ................................................................................................................................................... i
List of acronyms ...................................................................................................................................... iii Glossary .................................................................................................................................................. iv Acknowledgements ................................................................................................................................. vi Summary and highlights of this document .............................................................................................. vii Introduction ............................................................................................................................................ 1
1 Purpose and background ......................................................................................................................... 1 1.1 Purpose ............................................................................................................................................ 1 1.2 Background ...................................................................................................................................... 2
Part I : Recommended approach for improved sugarcane irrigation management in the Lower Burdekin for better water quality outcomes ................................................................................................................. 5
2 Proposed Implementation Plan , 2018-2023 ........................................................................................... 5 2.1 Principles and suggested themes of the proposed Implementation Plan ...................................... 5 2.2 Guidance for actions in the Implementation Plan ........................................................................... 7 2.3 Recommended approach to program design .................................................................................. 8
PART II : Synthesis of the current understanding of water quality outcomes from irrigation management in sugarcane in the Lower Burdekin ............................................................................................................ 10
3 Water quality issues in the Lower Burdekin sugarcane area ................................................................ 10 3.1 Description of the area .................................................................................................................. 10 3.2 Priority pollutants .......................................................................................................................... 11 3.2.1 Dissolved inorganic nitrogen ................................................................................................. 12 3.2.2 PSII herbicides ........................................................................................................................ 12 3.3 Timing of pollutant losses related to environmental impact ........................................................ 15 3.4 Management targets and objectives ............................................................................................. 16
4 Defining best management practice for nutrient , pesticide and irrigation management in the Lower Burdekin ........................................................................................................................................................ 21
4.1 Paddock to Reef Water Quality Risk Framework .......................................................................... 21
4.2 Principles for improving water quality from sugarcane areas ...................................................... 22 4.2.1 Reducing nutrient losses ....................................................................................................... 22 4.2.2 Reducing PSII herbicide losses ............................................................................................... 24 4.2.3 Increasing irrigation efficiency and reducing runoff ............................................................. 26
5 Modelling pollutant loads from irrigated sugarcane ............................................................................. 32 5.1 Model assumptions ....................................................................................................................... 33 5.2 Deriving pollutant load estimates for the 2016 Report Card ( released in 2017 ) .......................... 37
6 Current adoption of management practices for improving water quality from Lower Burdekin sugarcane ...................................................................................................................................................... 37
6.1 Current adoption of sugarcane management practices ................................................................ 37 6.1.1 Irrigation management .......................................................................................................... 38 6.1.2 Nutrient management ........................................................................................................... 40 6.1.3 Herbicide management ......................................................................................................... 42 i