Flood slows to a trickle

By Kathy Cogo, NQ Dry Tropics

It’s a radically different way to water cane and has neighbours looking over the fence. It uses far less water, increases yield and really improves the quality of water that runs off farms.

Paul Villis grows cane near Ayr and he’s trialing trickle, or drip, irrigation on part of his farm. Trickle irrigation comprises rows of plastic tape buried underground that delivers water directly to the roots of the plant through tiny drippers that regulate water flow.

Paul Villis checking out his trickle infrastructure.

Ayr is in the heart of the Burdekin region and all sugar grown here is irrigated. Most farms are irrigated by flooding the inter-rows which is labour intensive but, from an infrastructure point of view it’s cheap.

Not all irrigation systems in the Burdekin are metered, making water quite inexpensive for some growers. Paul’s channel water is metered. Burdekin farmers are under increasing pressure to improve the quality of water running off farms and into lagoons, creeks and into the water table. There are some sugar growing areas that aren’t viable anymore because of salinity.

The trickle block is using a lot less water than the flood blocks but they don’t know how much less at this stage.

Paul’s comfortable with the idea of trickle irrigation because he used to grow corn and beans in Bowen. Most of his cane blocks are flood irrigated but he installed trickle on a small area because the shape and form of the blocks weren’t suited to flooding – he was getting unreliable watering. He has seven hectares under trickle with potentially more to come.

Trickle irrigation is a lot more expensive than flood infrastructure. Paul weighed up spending the money laser leveling the problem blocks or installing trickle, both costs were comparable.

Trickle tape costs $3,500 a hectare alone. Other infrastructure, like pumps, filters and computerised timers, is on top of that. Paul says, “It’s a 10 year project really. You’ve got to look at the life of it. The life of the tape is 10 years plus.”

Funding through the Australian Government’s Reef Rescue program made the conversion much more affordable.

Paul Villis says they’re not rushing in to convert other blocks to trickle unless there are good incentives to do so like water restrictions or price increases in future. He says they’ll be the driving influences as to whether trickle is affordable.

“Trickle has the potential to deliver the best water quality outcome in the area. Everyone’s sitting on the fence waiting to see if it works or not.” He says.