Finding the ‘sweet spot’ for fertiliser

Forty-one growers from Mareeba to Ingham have trialled changes to their cane-growing practices across 10,000 hectares of land to find the ‘sweet spot’ for productivity and sustainable agriculture.

Changes have ranged from using enhanced efficiency nitrogen fertiliser and applying fertiliser at variable rates to improving soil health through compost production, mill mud application and planting legumes fallow crops. They have also included upgrading soil and yield mapping to better understand each cane block.

The Wet Tropics Reef Trust IV Repeated Tender program is funded by the Australian Government and delivered by Terrain NRM in partnership with Cairns Canegrowers, Herbert Cane Productivity Services and Tully Canegrowers.

Hear from Abergowrie grower Andrew Vella:

Andrew Vella – Abergowrie

Abergowrie cane grower Andrew Vella’s change to enhanced efficiency liquid nitrogen fertiliser has enabled him to average 140kg per hectare on the family’s farms, which collectively have 300 hectares under cane.

Application is down to between 80 and 100kg per hectare on plant blocks – depending on whether he can get a legume crop in or not – so that rates can remain higher on ratoons.

“With the rising cost of fertiliser, you don’t want to waste it. But when you’re cutting back on nitrogen you want to still be able to maximise your production. You want the plant to use the whole lot. It’s a challenge because our growing season varies every year. Sometimes we get a lot of late growth.”

Enhanced efficiency fertilisers

He believes new products, like enhanced efficiency fertiliser, are the key to dropping nitrogen fertiliser rates because “you’re not losing as much nitrogen to volatility or leaching”. But they are currently a more expensive option – and that’s where the Wet Tropics Reef Trust IV Repeated Tender program has helped.