WA RESEARCHERS are employing Unmanned Aerial Vehicles to get new insights into oil mallee trees, which could become the primary resource for the stateâs growing biofuels industry.
Researchers with the Future Farm Industries Cooperative research Centre are employing the UAV to take photos of mallee trees at their trial site in Narrogin, as part of the new Woody Crop Industries program focusing on mallee trees as a source of biomass.
CSIROâs Richard Bennett says the images produced from the UAV will enable researchers to estimate the biomass yield from a plot of trees as well as test variables such as soil and irrigation to maximise production.
âThe traditional way of doing things is to measure each tree for its length, width and height, then cut that plot down, weight it, and from that determine the ratio between a treeâs measurements and its biomass yield. With that ratio, we can determine the biomass yield for any given plot of trees that we have taken measurements for,â Mr Bennett says.
âItâs very labour intensive, requiring about two days to measure 1500 trees.
âWhat we do with the UAV, is take an aerial image of the plot and work out how many pixels have tree leaves in them. Once we know that number of pixels of the plot and have measured the trees, we can determine the ratio between how many pixels in an aerial shot and what amount of biomass will be produced.â
Mr Bennett says the UAV technology will also allow researchers to record the impacts of variables on the biomass yield, such as different fertlisers and irrigation techniques.
âWe need to know the biomass of the trees as well as how fast theyâre growing under certain conditions. For example, whether they grow faster when you put fertiliser on them, or with differing levels of access to water,â he says.
Using that information we should be able to engineer a way of trapping water so the trees get a little bit extra when needed.
âWith the UAV, we can regularly compare the images with the previous time we flew and determine how fast the trees are growing and whether any of our interventions have had an effect on that growth rate.â
Mr Bennett says researchers made only basic modifications to the UAV, including a customised mount to carry a camera.
Video footage of the UAV in action can be viewed on YouTube .