THE sugar industry has been putting a lot of attention and effort into the underground placement of fertilisers in recent years - so the potential of nutrients being lost into the environment is minimised and their impact on the crop is maximised.
Stacey Hadlow is a fourth generation Proserpine grower who believes the benefits of dunder as a liquid fertiliser could be enhanced, and its potential environmental impacts reduced, by putting the product underground where usually it’s sprayed onto the surface.
But to do that, Stacey needed to build a one-off applicator.
“But this home farm is 283 hectares and it is flood irrigated,” he explains. “We want to be able to put the fertiliser on straight after the harvester to get the cane away as quickly as possible.
“But if we flood the rattoons then it’ll be washed away or leached out so instead of surface application, we’re putting it through the stool splitter.”
Biodunder is a liquid by-product of ethanol production being sold by Wilmar AgServices. It contains organic compounds and trace elements.
The company says the dunder contains nitrogen (N), phosphorus (P), potassium (K), sulphur (S), magnesium (Mg) and sodium (Na) and the organic carbon it contains may act as a soil conditioner and contribute to soil microbial activity.
Stacey built his dunder applicator from a three row stool splitter which he widened to do five rows with one on-board tank and another following behind.
Injector nozzles sit adjacent to the stool splitter discs and deliver the pumped dunder straight into the cut stool. The widened implement folds to fit down the road.
“The applicator has double disc openers and the yellow hose applies the dunder while the blue one puts the cane grub treatment in,” he says.
““We’re trying to get it 4-6 inches into the ground – depending on the hilling up of the row.”
“The whole project has cost around $100,000 but close to half of that was for the GPS gear and the rate controller.
“It means that if you’re driving a bit faster or slower, the crop is getting the same amount,” he says.
The Australian Government Reef Program has funded a third of the cost of the project with that money going towards the variable rate application technology and the stool splitter.
Two 13,000 litre tanks take an entire truck-load of the dunder product, sold under the name of Liquid One Shot.
“We only started working with the machine at the end of August last year and we did about 500 hectares,” he says.
“It means we’ve had time to iron out the bugs before this season when people will be relying on us.”