Great Barrier Reef case study
With polluted water one of the largest threats to the health of the Great Barrier Reef, a partnership of sugar-cane farmers, natural resource management groups and industry has formed to tackle the problem.
The Great Barrier Reef catchment area covers 423 000 square kilometres, with beef grazing and sugarcane, horticulture, cotton and grain farming making up the area’s agricultural industries.
Nutrients from farm fertilizers, particularly nitrogen, enter the Great Barrier Reef in runoff from agricultural lands through flood plumes during major flood events.
High levels of nutrients encourage algae growth, and can change the mix of animals and plants found along inshore reefs. Nitrogen is also linked to outbreaks of the crown-of-thorns starfish. When the conditions are right the crown-of-thorns multiply and the starfish can reach plague proportions, devastating the hard coral population. Each starfish can eat up to one square metre of coral per month.
Herbicides from farm water runoff are also a concern due to their potential impact on a range of marine plant species such as corals, sea-grass and macro-algae.
Sugar cane harvester
(Photo: Commonwealth of Australia (GBRMPA))
A major initiative, ‘Fast tracking adoption of game changing sugarcane nutrient and pesticide management practices’ (known as Game Changer), is reducing the footprint that sugarcane production has on freshwater quality.
Game Changer, funded through the Australian Government’s Reef Programme, supports sustainable farming practices that are good for farmers and good for the reef, by reducing the amount of nitrogen and residual herbicides leaving sugarcane farms in run off. The program is run across catchment areas with participation spread from Cairns in the north to Sarina in the south.
`There are many sugarcane farmers looking for resources and support to trial new and improved farming practices,’ Belinda Billing, Reef Catchments Sustainable Agriculture Project Officer, and programme leader, said.
`The Game Changer programme equips sugarcane farmers with whole of farm planning,’ Belinda said. `The program works via an active learning approach, partnering sugarcane farmers with agronomists and economists to run on-farm demonstration trials over three years'.
There are now 70 farmers directly involved in the Game Changer programme and the networks supported through the programme are helping others adopt the changes promoted through the demonstration trials. Participants range from large enterprises, to multi-generational family farms and smaller individual properties.
Regular cross regional and smaller local events bring networks together for open and frank discussions. `It’s vital for landholders to talk openly and ask questions about the trials,’ Belinda said.
For cane grower David Ellwood, Game Changer means sharing information and learning from others’ experiences. `We’re always thinking about how we can do things better, more effectively and minimise the impact we have on our land. I'll trial things myself with simple designs and if they look like they'll work, take them to the next step,’ he said.
David is involved in a Game Changer demonstration trial to showcase variable rate nitrogen application. With this trial David uses verified EM mapping of his sugarcane block paired with yield maps to identify zones that can be managed differently. In zones with poorer soil the sugarcane yield is low, therefore a lower nitrogen rate can be applied, as the cane is not able to take up a higher rate. Where he has good soil he has a naturally higher yield; in these zones he can apply a higher nitrogen rate, as the larger crop will use the full application.
This has the potential to limit the potential for nitrogen losses, improve efficiency produce higher yields and deliver environmental benefits by reducing run-off.
`We’ve got to maintain the land in a productive state. You should be able to farm with minimal impact,’ David said.
`One old fellow told me that he wanted to pass his land on to the next generation in the same state as he bought it. I thought that was a good philosophy to share.’
For more information on Game Changer, visit http://reefcatchments.com.au/introducing-the-game-changer-program/