Remote sensing and AI to cost-effectively and accurately measure nutritional deficiencies and responses to fertiliser at an individual tree level and predict growth response.
Foliar and/or soil sampling are the primary operational methods used to assess stand nutrient deficiencies and develop suitable fertiliser strategies in both softwood and hardwood plantations.
Foliar and soil sampling results provide the key inputs for the fertiliser response prediction tool ProFert. Collection and analysis of soil and foliar samples is expensive and time consuming.
This constrains the number of samples a plantation manager can take to determine fertiliser requirements and necessarily limits the accuracy of predictions extrapolated across the whole of a plantation from a limited number of sample points. Should remotely sensed measures of foliar nutrients prove accurate, there is potential to replace a slow, inaccurate and expensive method with one that is faster, potentially cheaper and comprehensive.
As the land base for plantations is constrained and land becomes more expensive, plantation managers need to maximize productivity while, at the same time minimizing costs. This project in conjunction with the use of ProFert has the potential to assist land managers develop bespoke fertilizer prescriptions for individual stands, ensuring only the amount of fertilizer required is used, tailored to site specific measures to optimize return on their investment. By enabling managers to identify nutrient deficient stands and determine the type and level of deficiency, the project will also help reduce fertiliser wastage, reducing unnecessary emissions and improving environmental outcomes.
To minimise costs, the project will utilize existing technologies available from ArborCarbon as well as freely available satellite data. It will also use existing foliar data from established fertilizer experiments in hardwood plantations. A limited number of new operational trials will be established to allow pre vs post fertilizer aerial data to be collected and compared with measured foliar nutrient concentrations.
Finally, past foliar data, collected as part of operational nutrient monitoring programs will be sourced from participating companies which can be used to validate
any relationships developed from satellite imagery.
As the project will be collecting digital aerial imagery (DAP) and delineating crowns in areas with existing measurement plots, an investigation will be made into the ability of tree height and crown width (estimated from the imagery) to predict tree and plot volume. As eucalypts do not have a linear relationship between height and diameter, canopy width may be used to estimate diameter. If successful, the additional value of collecting DAP would help make the cost justifiable to forest managers.
Program:
Plantation Nutrition Investment Plan and Resource Modelling & Remote Sensing Investment Plan (further detail available here)
Research Organisation:
Industry Plantation Management Group – IPMG (Dr Danielle Wiseman)
