Drone technology facilitates precision agriculture

Engineers at Monash University have developed a soil moisture mapping system using autonomous drone technology to improve paddock irrigation practices, reduce water use and maximise crop harvests.

The Autonomous Drones for Soil Moisture Mapping project led by Professor Jeff Walker is part of Monash University’s expanding interdisciplinary focus on the use of data and technology to solve real-world problems for today and in the future.

Equipped with optical mapping as a proof of concept, the Monash drone has now advanced to passive microwave sensing technology using L-band waves, with further research being conducted on the potential for using P-band waves. P-band waves are expected to be able to measure up to 15 cm into the soil unimpeded by vegetation and tillage features. Testing has taken place across two farms in regional Victoria and Tasmania, one a dairy farm using a centre pivot irrigator and the other a crop farm using a linear shift irrigator.

Professor Walker said the farming industry has welcomed smarter and more automated practices, but there are few tools available to make the already difficult workloads of farmers more manageable. “At best, farmers might have a single soil moisture sensor in a paddock, but this doesn’t allow for the optimal application of water, especially as this resource becomes scarcer. Plus it won’t take into account moisture variation levels across the individual paddocks,” Professor Walker said.

Discussing the impact of severe drought and the nation’s water security, Professor Walker commented, “We need to produce 60% more food with the same amount of land and water and we can only achieve this by being more efficient with the water we use through irrigation. We need to know how much the crop needs, how much moisture is already there and apply just the right amounts of water in the correct places to avoid wastage while keeping the crop at its peak growth. If the soil is too dry crops can fail due to a lack of water, but if the soil is too wet, crops can not only fail but pests and diseases can flourish,” Professor Walker continued.

Good soil moisture optimises crop growth and yields, and more broadly regulates weather, climate and flooding. Water levels in the soil control evaporation over land and, as a result, energy fluxes into the atmosphere. This drives the atmospheric circulation, which in turn drives climate.