Good management of nutrition and soil health in macadamia orchards is crucial for sustaining productive capacity and increasing fertility over time.

NSW DPI’s handy Macadamia Grower's Guide project co-written by Jeremy Bright NSW DPI development officer macadamia in conjunction with principal consultant Stephanie Alt at Give Soil a Chance, divides this management approach into two parts:

Part 1: The Foundations

The Foundations serve as a fundamental framework for every macadamia orchard and focus on the following key aspects:

1. Correcting pH: Monitoring soil pH is essential as it directly affects nutrient availability to the macadamia trees. If the pH is not within the optimal range, corrective measures should be taken to adjust it to the appropriate level

2. Building up organic matter: Organic matter in the soil enhances its fertility and structure, supporting better nutrient retention and water-holding capacity. Incorporating organic matter into the soil is vital for the long-term health of the orchard

3. Implementing effective drainage: Proper drainage is necessary to prevent waterlogging, which can lead to root health issues and nutrient imbalances. Good drainage ensures that the macadamia trees receive the right amount of water without being waterlogged.

4. Replacing nutrients and correcting imbalances: Regular monitoring of soil and tree nutrient levels allows growers to identify deficiencies or imbalances in essential nutrients. By replacing lacking nutrients and correcting imbalances, the orchard's overall nutrition can be optimised.

Part 2: The Next Level

The Next Level of the module provides more detailed support to growers, building on the foundational practices established in Part 1. This section includes the following aspects:

1. Refining foundation practices: Growers can further enhance their practices based on the knowledge gained from the foundational approach. Fine-tuning these practices ensures more efficient and effective management of nutrition and soil health

2. Making more use of monitoring information: Regular monitoring of soil and tree health provides valuable data. In Part 2, growers are encouraged to make even more use of this information to make informed decisions about their orchard management

3. Investigating the causes of nutrient disorders in trees: If nutrient disorders or deficiencies arise in the macadamia trees, it is essential to investigate the root causes behind them. Understanding the underlying issues helps in implementing targeted solutions

4. Positively managing nutrition and soil health: Part 2 emphasises a proactive approach to nutrition and soil health management. By staying ahead of potential problems and continuously optimizing practices, growers can achieve better outcomes

5. Increasing fertility and productivity over the life of the orchard: The ultimate goal is to maintain and improve fertility and productivity throughout the orchard's lifespan. This involves consistent care and application of best practices based on monitoring and data-driven decisions.

By following the guidelines presented in both parts of the module, Mr Bright said macadamia growers can optimise their orchard's nutrition and soil health, leading to increased yields and overall sustainability of their operations.

This project has been funded by Hort Innovation using the macadamia research and development levy and contributions from the Australian Government and co-investment from NSW DPI.

Download the ‘Macadamia Grower guide’ and other macadamia related resources from the NSW DPI website, or simply scan the QR code below.