In conclusion , the results from economic case studies and bioeconomic modelling to date confirm that while adoption of better management practices in sugarcane is sometimes profitable , there are large variations in net costs and benefits within regions , and that private incentives to improve management practices are unlikely to deliver major reductions in pollutant delivery . Priorities for future research include more robust costing studies for different nutrient , pesticide and irrigation management options ; the relationship between costs , adoption success and practice efficiency ; and analysis to reconcile some of the large variations in cost estimates .
6.4 Delivery options for sugarcane irrigation management to contribute to the load reduction targets
6.4.1 GBR scale
Several mechanisms are available to achieve practice change , which can be summarised into information and persuasion mechanisms , extension , incentives , property rights ( including land retirement ), market-based instruments , and regulation . Historically most programs in the GBR catchments have focused on relatively simple grant programs , which are positive incentive mechanisms , although these have also included ( i ) elements of information and persuasion mechanisms through communication and stakeholder engagement , and ( ii ) education mechanisms through extension elements ( GBRWST , 2016 ).
Previous evidence has shown that grant programs have not been particularly efficient in achieving water quality outcomes ( Eberhard et al ., 2017 ). For example , Rolfe and Windle ( 2011 ) identified that the costs of pollutant reductions can vary by more than 100 times between different projects , and Rolfe and Windle ( 2011 ) and Star et al . ( 2013 ) demonstrated that a simple focus on management actions that achieve the largest reductions is not efficient , and that selection mechanisms should compare additional benefits to project costs .
In recent years , there has been some focus on improving mechanism design , through greater adoption of market-based instruments such as reverse auctions , stewardship payments , temporary land retirement and trading systems ( GBRWST , 2016 ). For example , Smart et al . ( 2016 ) explored the potential for a tradeable permit scheme to be introduced for nitrogen run-off in sugarcane regions . Other examples include the application of reverse tenders to improve nitrogen use efficiency in the Wet Tropics and Burdekin regions ( e . g . www . environment . gov . au / marine / gbr / reef-trust / reef-trust-tender ) and improvements in selection processes through the Water Quality Improvement Plans .
Kroon et al . ( 2016 ) conclude that the mix of mechanisms that have been applied to reduce land-based pollution are unlikely to be sufficient to achieve change in the desired time frames . They argue that standard approaches to incremental mechanism change and adoption improvement are not achieving the necessary scale of change , and that transformational change is required in at least some parts of the Great Barrier Reef catchments and industries .
Great Barrier Reef Water Science Taskforce ( GBRWST , 2016 ) and Alluvium ( 2016 ) identified that priorities may be ordered to a large extent by mechanism design or by the interaction between mechanism design and private net costs , as shown in Figure 6.2 .
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