Hinkler Park Plantations, a 3,000-hectare macadamia farm based in Bundaberg, Queensland, has achieved total greenhouse gas (GHG) reductions and removals of 20,207.7 t of carbon dioxide equivalent (CO2e) in 2021 across its entire macadamia production system through carbon sequestration and cutting energy and fertiliser use.

The totals included 26.8 and 20,180.8 t CO2e of reductions and removals, respectively.

In a first for the macadamia industry, Marquis Macadamias shareholder/supplier Hinkler Park Plantations has demonstrated that practices to promote soil health and fertility can significantly reduce greenhouse gas (GHG) emissions and increase GHG removal via soil organic carbon (SOC) improvement.

These practices include replacing some synthetic fertiliser inputs with composts and other organic amendments.

Hinkler Park Plantations Queensland General Manager and Marquis Macadamias Director Clayton Mattiazzi said by going back to basics, Hinkler Park Plantations has completely revolutionised its farming operations.

“This time eight years ago, we were struggling with soil health, tree heath and yields. By implementing biological farming practices, we have completely reinvigorated the health of our farm and quality of our macadamias,” Clayton said.

“We did this by creating a media of nutrient rich material to optimise growing conditions for our macadamia trees.

“The key to this was repurposing the excess organic matter within the farm: prunings, inter-row grass clippings and nut husk were all moved back under the tree into soil to compost this material into food for our trees. This activity is supported with large anaerobic composted mulch that is made from excess farm waste.

“What we have created now is a farm that sequesters more carbon than it produces, preparing us for climate change by building a biologically healthy and more robust farming system.”

An independent audit conducted by sustainable food certifier Carbon Friendly found the GHG emissions intensity of macadamia nuts produced at Hinkler Park reduced from 937 to -2,239 kg CO2e per tonne of macadamia between 2020 and 2021.

The Greenhouse Gas Emission Reductions & Removal Enhancements Report found that soil carbon improvement contributed to the removal of 2,935 kg CO2e per tonne of macadamia nuts during this period.

Marquis Macadamias CEO Larry McHugh said growers across the global macadamia industry were taking advantage of the macadamia tree’s natural resilience to improve sustainable growing practices and productivity. 

“It is vital that Marquis Macadamias and our growers work together to not only meet the needs of the present but preserve the land for future generations,” Mr McHugh said. 

“The initiatives focus on ensuring healthy land and soils, optimising water, energy and electricity usage, waste management, and orchard management.

“Not only do macadamias taste good and have a multitude of health benefits, but their sustainable production can also have positive impacts on the environment. As strong advocates for the sustainable production of macadamias, our facilities and growers are leaders in setting industry standards.”

Marquis Macadamias growers’ on-farm sustainability initiatives include: 

• Water use efficiency – Macadamia farms in sub-tropical regions rely heavily on the region’s natural rainfall. In the Bundaberg region, growers supplement the rainfall with irrigation sourced from dams and bores, using the latest in monitoring systems to apply the right amount of water when needed.
• Healthy soils on farms – Compost, woodchip and woodchip manure blends are used to improve soil health and structure on macadamia farms. Trees are pruned to promote grass growth between the trees on the orchard floor to reduce erosion. 
• Waste minimisation – Marquis Macadamias ensures the whole nut is used in production. On farm, growers add the macadamia husk under trees to improve soil health and to compost mixes. When pruning, growers chip branches to use as mulch. All macadamia shell from the factories is used either as renewable fuel to provide energy to dry nut-in-shell or is milled into stockfeed.
• Integrated Pest and Disease Management (IPDM) – IPDM is central to successful and sustainable pest and disease management. IPDM involves careful monitoring of crops to identify areas of pest and/or disease activity. If monitoring finds that pest and/or pressure is above critical thresholds, these areas are targeted with various control strategies. Marquis growers focus on maximising the use of cultural and biological control agents, where appropriate, to minimise the use of pesticides.
• Integrated Orchard Management (IOM) – On farm, Marquis Macadamias growers use IOM, which combines three fundamental pillars of orchard management: drainage, orchard floor management and canopy management. These pillars work together to minimise soil erosion, build soil health, reduce orchard suitability for pests, increase biodiversity and habitat for beneficial insects, and ensure healthy and productive trees.
• Self-Audit System – Marquis Macadamias has a self-audited quality improvement system in place that all Marquis Macadamias growers must complete at the start of each year.