Improved Australian apple and pear orchard soil health and plant nutrition (AP19006)

What was it all about?

From 2020 to 2023, this investment worked to optimise soil health, driving productivity through enhanced nutrient availability and uptake and resilience to climate variability. The desired outcome was an apple and pear orchard production system that maximises quality and yield with high nutrient use efficiency under increasingly variable climates.

Two intensive research trials were established in Tasmania, trial sites with limited data collection were established in New South Wales, South Australia and Western Australia. A further site in Victorian was established and shared as part of project Strengthening cultural and biological management of pests and diseases in apple and pear orchards (AP19002). All sites were used as demonstration sites to facilitate communication and adoption of research findings.

This project has shown that it is possible to move towards a more regenerative approach in orchards by working with natural systems and processes to build optimum soil and plant health, without the need to discard the best of conventional farming methods, to maintain or improve production levels and quality. Natural systems allow for an increase in biodiversity, providing natural control of pests, and building soil health. It is evident that biodiversity, both above and below ground, is the key in the development of ecosystem services that enable a move away from reliance on synthetic fertilisers and pesticides.

The orchard floor is a complex environment that has a major influence on crop productivity and quality. The plants of the orchard floor provide a home and food source for pollinators, predators, and other beneficial insects above ground, and strongly influence the diversity of arthropods (insects, millipedes, spiders, and earth worms) and microbes at the soil boundary and below. Soil biology (macro- and meso-arthropods and micro-organisms) is the key to nutrient cycling, in addition to influencing soil physical properties such as aggregation and water infiltration. A diverse orchard floor can give the orchard resilience and balance both above and below ground, allowing the orchard to resist or rebound rapidly from disturbances or the impact of climatic events such as high rainfall or drought.

Species selected for the orchard floor, whether in the inter-row or tree-line, need to be robust and resilient to traffic, but not invasive or competitive, and provide shelter and a food source for beneficial arthropods without creating an environment conducive to pest species and disease. Understanding the importance and complexity of the interrelationships that occur within the orchard floor, both above and below ground, and nurturing these relationships will increase orchard resilience and long-term productivity.

The research team partnered with SWAN Systems (Scheduling Water and Nutrients) who provide a web-based irrigation and nutrient management program that includes water and nutrients pre-season planning tools, and live data collection from in-field devices to track in-season weather, soil moisture, water use, and drainage. The research team investigated the synergies between SWAN Systems and the SINATA tool (developed in a previous iteration of PIPS) by installing the SWAN platform in five trial orchards, one in each growing region. Each grower reported that SWAN represented an accurate model of the irrigation requirements for their blocks and that seeing SWAN’s outputs gave them confidence in the decisions they were making.

This project was part of the PIPS3 program for the apple and pear industry (the third iteration of the Productivity, Irrigation, Pests and Soils program). The other investments that made up this scope of work were:

• Strengthening cultural and biological management of pests and diseases in apple and pear orchards (AP19002)
• Advancing sustainable and technology driven apple orchard production systems (AP19003)
• Developing smarter and sustainable pear orchards to maximise fruit quality, yield and labour efficiency (AP19005)
• Independent program coordination for apple and pear productivity, irrigation, pests and soils program (PIPS3) (AP19007)

The work done through this project, and the PIPS3 program, was communicated to industry extensively through the levy-funded National apple and pear industry communications program (AP18000) and Future Orchards program Delivery of apple and pear Future Orchards extension program (AP15005). You can sign up to receive industry communications at www.apal.org.au.