Banana farming at Bartle Frere: minimising sediment and nutrient runoff into the Russell River

With the magnificent Mount Bartle Frere, Queensland’s highest mountain, in the background, the banana farm Brad Finch manages near Mirriwinni in Far North Queensland is a particularly striking property.   A banana farm for the last thirty years and a cane farm for an even longer period before that, the issue of sediment and nutrient runoff has long been a concern.  With the Russell River bordering a significant section of the 70 hectare farm, sediment and nutrient runoff makes its way in to the river and possibly downstream, in to the Great Barrier Reef lagoon.

Brad Finch made the decision to change his lifestyle two years ago, swapping commercial fishing off the coast for banana farming.  As soon as he began managing this farm, Brad started planning to upgrade to farming practices that help prevent erosion and better manage the health of the soil.  One of the changes he was keen to make was to carry out contouring of the rows of banana plants.

The next innovation – Brad in a crop of canola, which he plans to use as fallow crop

“This farm has a few slopes on it so contouring is very important,” says Brad. “By curving it around, you follow the gradients, keeping them between 1% and 4%.  This slows down the rate at which the water runs and prevents erosion. If you go over 4% gradients, the water rushes too fast.”

With a Reef Rescue grant administered by Terrain NRM, Brad hired a contouring professional to map and design a contour plan specific to the property. “Obviously, the hill is not the same grade all over,” says Brad.  “Contouring gets the right gradient over the entire paddock.  This stops the erosion and keeps your fertiliser in the paddock rather than running down the road.”

Also interested in upgrading the farm’s irrigation system, Brad employed an irrigation expert to design and supply a fully automated irrigation system over the whole farm.  The idea was to change to a full automated undertree micro-sprinkler system incorporating fertigation.

“We’ve upgraded a lot of the sprinklers.  The watering system that was here was mainly just for the dry period. So we put in self-regulating sprinklers,” he explains.

This system works by putting out the exact same amount of water through each sprinkler, thus distributing an even supply of water.  It’s also a valuable system in fertigating the crop, evenly distributing fertilizer and minimizing the loss of nutrients further down the line.

“If you use the old sprinklers you end up with 20% more fertiliser in one spot than in another spot,” Brad says.  “It’s especially important in hill bocks like this because you can have different pressures between the top of the block and the bottom of the block.”

These changes are not the end for Brad; he is now looking at using canola as fallow crop on the farm, to reduce the level of damaging nematodes in the soil.  The uptake of these improved land management practices was always planned for this farm, but the Reef Rescue grant made it happen a lot faster.

Having swapped fishing for coral trout on the reef for growing bananas 20km inland from the coast, improved farming practices is a no-brainer for Brad.

“It’s common sense really,” he says.  “From a financial point of view too.  You’re going to grow a better crop if you make the changes.  And really, in the scheme of things, it’s not a big thing to change.”