NESP TWQ Hub’s pilot project south of Cairns “Project 25” is enabling farmers and marine scientists to cooperate and work more closely together to protect the long-term health of the Great Barrier Reef. The project is yielding major dividends and practical solutions with a number of farmers now looking to use the catchment’s existing farm drainage infrastructure in an innovative way to reduce nitrogen runoff.
Being able to correctly determine the source and amounts of dissolved inorganic nitrogen, sediment and other pollutants in river systems that flow onto the Great Barrier Reef has been the biggest challenge in implementing management actions to reduce their levels and meet water quality targets set under the Reef 2050 Plan.
“You can’t control what you can’t measure, and you can’t expect farmers to change their practices and behaviour unless they trust the data, are fully informed and understand what the issues are and their impact on the Reef,” says Sheriden Morris of the Cairns-based Reef and Rainforest Research Centre, who is involved in the project.
Technology utilised by the project has allowed accurate and real-time measurements of nitrate concentrations in local waterways throughout the year to be gathered – rather than the modelling-based data used previously – with the critical information immediately fed back to local canegrowers via CSIRO’s specially-developed mobile phone app 1622.
A key feature of Project 25 has been regular meetings between scientists and local farmers to keep them abreast of the water quality outcomes, and to discuss practical management options for reducing the impacts of nitrogen runoff. In recent years some Queensland canegrowers have questioned the science and data being used in reef policy, but the two-way co-operation and improved trust and understanding facilitated through Project 25 is now leading to improved environmental outcomes for the Great Barrier Reef.
Analyses of wet season data from the study showed that the first big flushes of rain were responsible for a significant proportion of the contaminants that end up flowing onto the Reef from that catchment. The addition of gates or baffles to the drainage channel network currently linking sugarcane farms to rivers can slow and filter this first flush of water runoff after the early wet season rains, effectively reducing the amount of damaging nitrates that end up on the Great Barrier Reef.
“This is a real step forward; both the relationship and trust built up between growers and scientists through Project 25, and the plan to use the drainage channels to hold back the first flush of runoffs so the nitrates are naturally dissipated,” says Mr Steve Calcagno, who is also Chairman of the Canegrowers Association for the Cairns region.
“All we ever used to hear was the simplistic argument that growers should use less nitrogen and less fertiliser, but that would make the industry unviable because it reduces yields and that affects not just growers but the mills, jobs and all the sugar towns down the coast that rely on cane production.
“Instead, by working together and having real figures and nitrogen data we can rely on and trust, we can now say – both scientists and growers – that besides improving on-farm practices, another part of the solution involves slowing the early rain flush down by using our drains, channels and natural wetlands differently; I see this as the start of really exciting new chapter.”.
Mr Calcagno says local growers are already thinking differently about how and when they apply their urea (nitrogen) fertilisers after seeing from sensor data how significantly nitrate levels in the rivers close to their farms can vary during the year.
Some are now applying fertilisers after cane harvest earlier than before to avoid coinciding with the first rains of the wet season; others are experimenting with lower rates later in the year, or delaying putting on fertilisers if heavy rain is forecast.
An added bonus of Project 25, with its hi-tech sensors, sophisticated data logging machines, satellite Internet-of-Things connectivity and phone app capability, has been to engage a younger generation of canegrowers.
They are already adept at changing their management practices and timeliness of farming decisions based on the real time data being supplied to their mobile phones – be it about weather, cane prices, river heights or water nitrate levels – with Mr Calcagno predicting this new generation of farmers can only lead to even better outcomes for the Great Barrier Reef.
“Scientists and Reef decision-makers are smart people but too often they have forgotten to involve farmers and local communities; Project 25 has shown the benefits for the Reef, North Queensland and Australia if you take the time and make the effort to bring everyone along with you.”
More information on Project 25 can be found on the Hub website.
Photo: : Reef and Rainforest Research Centre