- Project number: PNC478-1819
- Read a summary of this and 2 other FWPA nutrition projects via this link.
Field research during recent decades and literature reviews have provided insights into nutrition dynamics and other factors that affect the productivity of forest plantations. Key issues for nutrient management are harvest residues, fertilisers and weeds. Managers generally use adequate levels of weed control in plantations, which has a strong evidence-base in research. However, there remains a lack of reliable predictors for responsiveness to harvest residue retention or nutrient application across a variety of multi-rotation hardwood sites.
Process-based modelling can help in understanding these issues, but onerous input requirements and a lack of validation of these models in real-world situations, have meant that there is low industry confidence in using them to drive fertiliser use decisions. More recently, the development of ProFert, an empirically-based decision-making tool in the softwood industry, has led to its use by several companies, but it has not been calibrated for hardwoods or residue management.
Hardwood plantation managers are seeking:
- Clearly articulated operational level fertiliser guidelines on the timing and application of nutrients to maximise growth and clarity on the best approach in different situations.
- Site indicators predicting potential growth responses to nutrient or harvest residue management.
- Access to growth and economic modelling tools such as Profert.
- An understanding of the economics of harvest residue retention on different sites and the potential of fertiliser applied at establishment to ameliorate the effects of harvest residue removal on soil nutrients and site productivity across different sites.
This project proposed to:
- Establish a nutrition trial network designed to address the gaps in nutrition response knowledge consisting of:
1) fertiliser rate experiments and larger scale with and without fertiliser responsiveness trials in mid-rotation stands (2-6 years);
2) harvest residue retention compared to removal experiments, both with and without fertiliser, at sites harvested prior to replanting; and
3) Use results from the proposed nutrition trial network combined with data from past experiments to develop tools that allow hardwood plantation managers to better target their fertiliser management on a site-specific basis, by:
- Develop a site screening tool to assist managers in identifying sites that are likely to be responsive to nutrient management.
- Adapt the ProFert tool for use in hardwood plantations to help optimise multi-rotation nutrient management based on site diagnostics and the economics of fertiliser application.
The trials were established in 2019. This report summarises three years of data, of an expected ten-year rotation targeting pulpwood production. Further research commenced mid-2022 for a three year period as Project VNC590 2223 ‘Enhancing the knowledge base for hardwood plantation management‘.
