An innovative Reef water quality project based in the Wet Tropics region is now a finalist in the Agriculture and Regional Development category of the Banksia National Sustainability Awards.  

Established 33 years ago, the awards recognise individuals, communities, businesses and government for innovation and excellence in environmental and social stewardship. 

The Wet Tropics Major Integrated Project has been described as a blueprint to accelerate progress towards achieving Reef 2050 water quality targets. 

The four-year project, funded by the Queensland Government’s Queensland Reef Water Quality Program and delivered by natural resource management body Terrain NRM resulted in 23,966 hectares of agricultural land undergoing confirmed practice changes in the Tully and Innisfail region. It also prevented an estimated 73 tonnes of dissolved inorganic nitrogen from flowing to the Great Barrier Reef.  

Terrain NRM CEO Stewart Christie said his organisation had worked in collaboration with farmers and the agricultural industry for over 10 years on water quality programs but the Wet Tropics Major Integrated Project stood out for its grass-roots collaborative approach and the high level of uptake from landholders. 

“We know we can only achieve long-term transformational by tailoring our approach to individual farmers needs and empowering them to be in the driver’s seat,” he said.  

“This was a truly collaborative effort which succeeded because of strong relationships between the delivery team, landholders, scientists, Traditional Owners, government agencies, and industry groups – namely Tully & Innisfail Canegrowers and the Australian Banana Growers Council.” 

A new reef water quality program has been announced to reduce the runoff of dissolved inorganic nitrogen (DIN) from farms in the Tully and Johnstone catchments. The $10.7 million program will deliver a range of projects – from helping farmers with nutrient management planning, installing constructed wetlands and expanding local scale water quality monitoring.

The program is being managed by Terrain NRM and funded by the partnership between the Great Barrier Reef Foundation and the Australian Government’s Reef Trust.

Charles Hammond, Waterway Health Leader at Terrain NRM, said the Tully and Johnstone catchments are priorities for DIN runoff due to high rainfall, intensive agriculture on the coastal plain and short sharp rivers.

“There has been significant investment in these catchments previously and farmers have been working hard to improve water quality,’’ he said. “This program will continue to support farmers to make changes to land management and farm practices.

Mr Hammond said four organisations would be delivering on-ground projects.

A partnership led by Canegrowers Innisfail is addressing nitrogen losses by providing extension support to farmers to develop nutrient management plans, identify crop constraints, improve nutrient use efficiency and refine nitrogen inputs.

A boggy spot on a Mourilyan cane farm has been converted into a high-performing “constructed” wetland, removing more than 90 per cent of nitrate from water in the system. 

The Wet Tropics Major Integrated Project team has worked closely with wetlands experts and a third-generation cane farmer to transform the low-lying and unusable strip of land into a water treatment system on his 101-hectare property. 

The 1.2 hectare wetland is proving that, with some remediation and construction, low-lying wet areas can effectively remove high levels of dissolved inorganic nitrogen from the water. 

Acting Project Manager Fiona George said this wetland shows the potential of wet areas on farms to improve the quality of farm run-off water. 

“This constructed wetland is evidence that a wet piece of marginally productive land can yield excellent water quality outcomes with the help of a tailored design and relatively minimal earthworks,” Ms George said. 

“We enhanced existing features that helped it to perform as a denitrifying wetland.” 

Vegetation uptake has been a key factor, with a thriving ecosystem of plant life establishing itself in a short timeframe and enabling the denitrification process to occur. 

The Wet Tropics Major Integrated Project has trialled a range of catchment repair systems in the Tully-Innisfail area, including seven different bioreactor designs, a landscape wetland, three in-drain wetlands, a high-efficiency sediment basin, three constructed wetlands and a riparian revegetation site. 

The constructed wetlands are yielding the best results, proving that, with improved hydrology and the appropriate amount of vegetation, they have high potential to reduce nitrate levels.  

Australia’s first international Bioreactor Forum was held in the Wet Tropics last month.

Interest in these innovative water treatment systems has spiked over the last two years, with the Wet Tropics Major Integrated Project (MIP) installing seven across the Tully and Johnstone basins.

The two-day event brought together researchers, technical specialists, extension officers, growers and funding bodies from Australia and abroad.

Day one included a visit to bioreactor trial sites on farms, where attendees interacted with landholders and delivery teams involved in the research, design and installation of the treatment systems.

Day two involved focused discussion on the role of denitrifying bioreactors in sustainable food production and potential strategies to enhance their performance.

The MIP’s place-based approach has modified traditional “textbook” wall and bed bioreactor designs and is trialling three other designs (in-drain, ag pipe and partial in-drain bioreactors), which were developed to suit the unique nature of Wet Tropics landscapes.

MIP Catchment Repair Coordinator Suzette Argent presented at the forum on designing bioreactors to fit within the Wet Tropics landscape.

“The input we receive from landholders has been a crucial part of the process,” she said.

They’ve not only provided us with sites to implement trials, but invaluable knowledge on the lay of their land.”

“Farming is full of science and it’s rewarding to work alongside our farming community to trial water treatment systems that can improve sustainability, profitability and the quality of water flowing to the Reef.”

Ms Argent hosted forum delegates at a MIP bioreactor site on a Mourilyan cane farm.

“The field trip was a highlight for attendees because they could see firsthand how bioreactors can be implemented to complement farming operations and improve water quality entering adjoining waterways,” Ms Argent said.

Department of Agriculture and Fisheries Research Agronomist Rhianna Robinson coordinated the event and said they were pleased with the interest generated and contributions of everyone who attended.

“It was a networking and learning opportunity with local, interstate and international speakers sharing their experiences in installing bioreactors on farms,” she said.

Cane, banana and tropical fruit producers shared sustainable farming practices with a crowd of more than 100 people recently.

Guest speakers at the Tully Sustainable Farming Day spoke about challenges across the industries and opportunities now and into the future.

Wet Tropics Sugar Industry Partnership’s Alex Lindsay said an all-Tully cast of speakers – including cane farmers Jamie Dore and Graham Maifredi, banana grower Leon Collins and tropical fruit producer Peter Salleras – shared their experiences on topics ranging from feral pig control to crop diversification and farm management changes.

The morning also included one-on-one talks with agribusinesses, farming extension officers and representatives from government departments.

“There is a lot of good news to share locally and that’s what this event was all about,’’ Mr Lindsay said.

There were 24 information booths at the event, a new one for the Tully region. Lucky door prizes included GIS and crop monitoring services, metagenomics soil testing and a tonne of fertiliser that was coated to resist leaching.

The Wet Tropics Major Integrated Project’s Fiona George said there had been good feedback from participants.

Local farmers are setting paddocks aside for farm demo sites to show the water quality benefits possible when soil health is improved through different farming practices.

Farmers are seeing evidence that healthy soil stores nutrients more efficiently, saving them money and improving the quality of water flowing to the Great Barrier Reef.

The demonstration sites are being closely monitored as part of the Wet Tropics Major Integrated Project (MIP). A recent field day reported initial findings back to farmers.

Fiona George is responsible for managing the project’s on-ground activities and says that nitrogen use in the Wet Tropics is critical for crop growth, but comes with some issues.

“We live in a high-rainfall area and our agriculture is close to the coast, so when nitrogen and sediment is lost from our farming systems it doesn’t have far to travel before it impacts the marine ecosystem,” Ms George said.

“Agricultural industries around the world are working to manage nitrogen better”.

Tully Sugar Limited is hosting a side-by-side demonstration site comparing how much nitrogen and sediment reduction can be achieved by improving soil carbon with a range of strategies.

An ‘industry standard’ or control paddock sits next to a comparison paddock with a multi-species cover crop fallow, added organic matter (compost), 1.9m dual row planting and controlled traffic.

These practices are addressing soil constraints by improving soil organic matter and soil biological activity, through reducing tillage and paddock disturbance.

Water coming from both paddocks is monitored. Sophisticated equipment samples surface runoff, as well as water from below the crop’s root zone, to give a more comprehensive picture of how nitrogen is moving through the landscape.

Ms George said they hope to work out how much of a reduction in nitrogen input can be achieved, without affecting productivity.

“We’re all trying to get plants to function in the most efficient way possible, in this case by starting with the soil. Every farm is different, but we can show farmers the results and then support them to make decisions about what will work best for them in their circumstances,” Ms George said.

At the recent field day to the demonstration site, visiting growers saw constraint mapping results done via drone and electro-magnetic induction, the condition of soil at plant after cover cropping, and innovative machinery for minimum tillage and planting with minimal disturbance.

Tully Sugar Limited CEO, Shunjie Guo, said the company’s involvement in the MIP is an opportunity to contribute to a growing understanding of nitrogen losses.

“It’s important to us that we’re not just talking about doing the right thing, but actually doing it.”

“Sugar cane is an important rural industry for the Wet Tropics, and Australia. We see it as our responsibility to show leadership and take steps that ensure its viability into the future.”

“Both corporate and family farms depend on the land. We’re very happy to be part of a project that’s getting relevant data back to farmers.”

“Nobody wants to be losing nitrogen. It’s not just a loss to waterways, it’s a financial loss. Farmers are very interested in maximising efficiencies and we hope demonstration days like this will show which practices could have application to the broader Tully cane industry.”

The Wet Tropics Major Integrated Project is funded by the Queensland Government through the Queensland Reef Water Quality Program.