Unpacking wheat’s water use for drought research

Researchers at The University of Queensland have developed a way to quantify how wheat varieties capture and convert soil water.

Dr Raul Gimenez from the Queensland Alliance for Agriculture and Food Innovation said the technique could be used to identify drought-tolerant crops. 

“Climate-resilient cropping systems require both better-adapted varieties and appropriate crop management,” Dr Gimenez said. 

“Although there has been substantial progress on identifying crop structures and traits to increase solar radiation capture and convert it to biomass and yield, less progress has occurred on the crops’ ability to capture and convert soil resources, particularly water. 

“This is what we set out to investigate.” 

Experiments in 2024 and 2025 at UQ Gatton assessed water use by 36 wheat varieties planted at different densities. 

The research team used technologies including electromagnetic induction sensors on an autonomous high-clearance robot - The RootBot - and drone sensing systems.

“We found cultivars differed in their total water use, when they used water, and the depth they took it from,” Dr Gimenez said.

“We also found that an increase in plant density typically resulted in higher water use, radiation capture and canopy development early in the season. 

“But this may affect water availability for later stages of the plant’s development which are more relevant for yield.

“One of the big takeaways was the development of a system that can measure soil moisture at depth and in time, creating a better understanding of water use dynamics.” 

New information on the link between plant roots and yield could also help identify ways to boost productivity and improve drought resilience by combining varieties with management techniques to suit specific scenarios.

Dr Gimenez said similar trials had been conducted with research partners at Agriculture Victoria, the Department of Energy, Environment and Climate Action of Victoria and the Western Australia Department of Primary Industries and Regional Development. 

“We expect cultivar performance and key water-use traits to vary across these sites, given their contrasting soil profiles and climate patterns,” he said.

“Beyond wheat, we have deployed this technology in sorghum, chickpea, and barley, with plans to expand into canola and maize. 

“We also aim to adapt the system to evaluate nitrogen-use efficiency by matching active root distribution with soil water and nitrogen availability.”

Dr Gimenez said the team will now focus on simplifying the tool for breeders and industry agronomists.

Dr Gimenez presented his findings at the Agronomy Australian Conference in Darwin and the ACB Breeders Week at the Gold Coast. 

Collaboration and acknowledgements