Water quality benefits demonstrated

July 23, 2019

Local farmers are setting paddocks aside to demonstrate 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.