New trial explores almond orchard recycling in Australia

Scientists are working with a Victorian almond grower to trial an orchard redevelopment practice that is reducing the industry’s carbon footprint in the United States. ‘Whole Orchard Recycling’ involves chipping trees and incorporating them into the orchard soil prior to planting new trees. It replaces the traditional practice of burning the trees once they have been removed from the orchard. 

The work, which is being delivered through Hort Innovation and led by the South Australian Research and Development Institute (SARDI) the research arm of the Department of Primary Industries and Regions (PIRSA), aims to identify whether Whole Orchard Recycling can achieve similar environmental gains under Australian growing conditions.

The trial is taking place on a farm in Merebin, Victoria, where Whole Orchard Recycling has been applied to close to three hectares of 30-year-old trees. At this age, the orchard’s productivity begins to decline which is a signal to the grower that it needs to be redeveloped.

SARDI Principal Scientist Paul Petrie said almond tree trunks, branches and roots accumulate significant amounts of carbon during their lifecycle, and through this project, his team will be looking at ways to harness that carbon.

“We aim to quantify the impact of Whole Orchard Recycling on the carbon footprint of an Australian almond orchard, including the impact on carbon storage and turnover in the soil, soil greenhouse gas emissions and any impacts on the newly planted trees,” he said.

Dr Petrie said researchers will also assess any co-benefits from orchard recycling such as more rapid orchard tree growth, and improved irrigation-use efficiency and soil health.

Trial site owner and long-time almond grower, Neale Bennett, said he had been eyeing the emergence of Whole Orchard Recycling in California, and is keen to test the practice here in Australia.

“There is no doubt that we have an obligation to grow as sustainably as possible and while there is always room for improvement,” he said. “We all want sustainable business models and if that means doing things differently, then I think our industry has a great record for embracing change and innovation.”

Almond Board of Australia (ABA) CEO Tim Jackson said the Orchard Recycling trial will add scientific rigour to the benefits Whole Orchard Recycling in Australian conditions. He said it will help with orchard re-development programs and help quantify expectations around carbon farming, changes in soil health, irrigation use efficiency and productivity improvements. 

“The recycling results on Californian soils have been widely embraced and are contributing to longer-term aspirations for the industry to become at least carbon neutral,” he said. “Almond growers are all about embracing the most sustainable practices available and this trial is yet another example of that commitment.” 

Hort Innovation Head of Research and Development (R&D) Byron de Kock said a reduction in farm and production waste and boosting potential water and nutrient use efficiency have been identified as R&D priorities for the Australian almond industry.

“Almonds are one of Australia’s most lucrative and popular exports with markets in regions such as Asia, Europe and the Middle East,” he said. “Increasingly, sustainability is at the forefront of horticultural business practice as consumers and investors like to see the sustainability credentials of the products they are buying and investing in, and the almond industry is no exception.”