Pathway to carbon neutral – whole orchard recycling in almond orchards (AL21000)

This project is quantifying the impact of whole orchard recycling on the carbon footprint of almond orchards. It will measure how whole orchard recycling influences carbon storage and turnover in the soil, soil greenhouse gas emissions, and carbon accumulation in newly planted trees. The project will also evaluate the potential benefits of whole orchard recycling, such as faster orchard establishment, improved irrigation efficiency, and enhanced soil health, while identifying any possible risks, including increased soil pathogen pressure and nitrogen drawdown. 

Challenge  

Almond trees capture and store significant amounts of carbon in their trunks, branches, and roots throughout their lifecycle. However, when an orchard reaches the end of its commercial life, conventional redevelopment practices often involve burning the old trees. While this method quickly clears debris and can reduce pathogen loads, it also releases large amounts of carbon that could otherwise be sequestered or reintegrated into the soil to enhance organic matter, fertility, and support the establishment of the next orchard. 

With increasing global and domestic emphasis on sustainable production practices, finding alternatives to burning is critical to improving environmental outcomes and strengthening the almond industry’s sustainability credentials.  

Response  

This project will test whole orchard recycling as an alternative to burning prior to replanting. Whole orchard recycling involves mulching the existing almond trees, spreading the mulch across the orchard, and incorporating it into the soil.  

Throughout the trial, researchers will conduct assessments at planting and key phenological stages each year, including:  

At conclusion of the trial, researchers will also conduct a soil pathogen assessment, soil carbon and nitrogen assessment, and a yield assessment (in year three of orchard establishment). 

Data will be collected in a manner to allow it to inform the Australian Life Cycle Assessment and support approved Carbon Market methodology for the industry. 

Benefit  

Insights gained from this project will help almond growers confidently integrate whole orchard recycling into their redevelopment programs, with clear expectations around carbon sequestration, changes in soil health, irrigation use efficiency, and longterm productivity gains.  

Beyond individual growers, the broader almond industry will also benefit from strengthened sustainability credentials, with the potential for whole orchard recycling to underpin practices that allow the production of carbon neutral almonds.