Bundaberg macadamia farm deemed carbon positive after neutralising its emissions

Clayton Mattiazi at Hinkler Park Plantations' composting site. (ABC Wide Bay: Johanna Marie)

A Queensland macadamia farm that is leading the charge towards a net-zero future has been declared "carbon positive" by neutralising its own emissions.

Hinkler Park Plantations, a 3,000-hectare macadamia farm based in Bundaberg, removed an estimated 17,670 tonnes of carbon dioxide from the atmosphere in 2021.

That is the equivalent to offsetting the emissions from 4,236 passenger vehicles for an entire year.

Hinkler Park Plantations' general manager and Marquis Macadamias' director, Clayton Mattiazi, said the journey began five years ago when they established a large composting regime to improve their soil.

Hinkler Park Plantations uses excess farm waste to produce large volumes of compost. (Supplied: Hinkler Park Plantations)

"We improved our process to in-situ composting, where we gathered the leaf, grass clippings, canopy management grindings and nut husks from the inter-row (the strip of soil between the crop rows), up underneath the tree, and utilised some microbes through our irrigation system to compost that down," Mr Mattiazi said.

An audit conducted by sustainable food certifier Carbon Friendly found the greenhouse gas (GHG) emissions intensity of macadamia nuts produced at Hinkler Park Plantations reduced from 302 to -2,816 kg CO2 equivalent per tonne between 2019 and 2021.

"They did over 700 soil tests per year for these assessments, and we issued a very detailed report," said Carbon Friendly founder Francois Visser.

Mr Mattiazi said improving soil health had flow-on effects for yield and nut quality. (Supplied: Hinkler Park Plantations)

Carbon reductions refer to a decrease in GHG emissions by using less fertiliser, chemicals, or energy to produce the crop relative to the base year. 

Carbon removals relate to the capture and storage of CO2 from the atmosphere through practices including soil carbon sequestration.

Financial benefits

Mr Visser said Carbon Friendly was working with other large macadamia producers in the Bundaberg region to achieve the same status.

"It's a great opportunity now for farmers to actually get that recognition," he said.

Farmers are being encouraged to reduce emissions by using less fertiliser, chemicals, or energy to produce their crop. (Supplied: Hinkler Park Plantations)

"Then they can invest even further into their sustainability."

Mr Mattiazi has encouraged others in the horticulture industry to determine their carbon footprint and start recording their improvements.

"You need to take significant soil tests and bulk density tests to establish your carbon level, and from there you can measure yourself off that benchmark," he said.