Lethbridge Polytechnic researchers are helping farmers manage their water use.
Dr. Michael Kehoe is a research scientist with the Mueller Irrigation Research Group at the polytechnic’s Centre for Applied Research, Innovation and Entrepreneurship. Originally from Australia, he has been with the local post-secondary since 2020.
At the polytechnic, he leads a team that develops software tools to help irrigators make better-informed decisions about when they should water their crops, and how much water should be used.
“Our group is looking at improving water use efficiency [on] the field scale,” Kehoe says.
“There’s been a lot of improvements at the district level in terms of conveyance [carrying water] over the last couple of decades, and the [switch] from hand-wheel movement to centre pivot has reduced water use quite a bit.”
He explains that his group works with farmers to try and improve their irrigation management, “in the sense of improving their productivity per drop of water, so how much yield [they are] getting per drop of water”.
Kehoe says his team’s current work is particularly topical amid concerns of drought and dry summer conditions in recent years.
“We do need to come up with ways of being more efficient with water so that we can free it up for other uses,” he says.
SENSORS
Kehoe notes a three-year project his team has recently started aims to determine what types of sensors best improve irrigation management.
“We’re going to look at the four main types, and we deploy those at our demonstration farm here at the Polytechnic, and they measure the water cycle, so they measure everything going in and out of the field and what’s going on in the soil,” he explains.
“We use that with models to develop forecasting tools to [determine] irrigation decisions, so the farmer can say, ‘what’s my irrigation water demand going to be next Thursday’, and then they can order that water ahead of time.”
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He adds it is important for irrigators to know how much water they need ahead of time.
Kehoe says their work involves various crops, such as canola, potatoes, and sugar beets.
“We would like to get into corn as well, we haven’t got that currently, but we are trying to cover as many as possible because the principles are more or less general.”
KEY TAKEAWAYS
Kehoe explains that last summer, his team compared Subsurface Drip Irrigation to Centre Pivot systems. He says with SDI, lines are buried under fields, with water emitted and transferred directly to the roots of crops, while the Centre Pivot method sees water drip down to the ground from above.
“We expected a big difference in the water usage between the two groups and what it came out as, it was almost identical but the efficiency was far greater on the SDI, so it was really a proof of concept that SDI is more efficient at using water, at least in that season, so it would be nice to see some more work in that area,” Kehoe remarks.
He adds with the Centre Pivot system, “You get a lot of evaporation losses from the surface, and it doesn’t actually get to the plant”.
“So, the idea of Subsurface Drip Irrigation is you’re giving the roots the water where they need it.” Kehoe notes this type of system can be valuable in drier conditions like Alberta.
VARIED RESEARCH
Kehoe says expanding research fields and studying different methods of effectively managing irrigation is vital to the region.
“Southern Alberta depends on irrigation. The economy here – it’s not just farmers and irrigators – it’s everyone. We all depend on that water, and this region would be a lot different without it,” he states.
Kehoe adds his team is also focused on helping farmers determine what type of technology they can and want to implement for their operation.
He says one of his team’s biggest adages is, “You can’t manage what you don’t measure”.
“Currently, a lot of irrigators are sort of flying blind, and they’ve got a lot of experience, so they’re doing a reasonably good job. We just think there’s a lot of potential through measurement to improve irrigation management.”
More on the agricultural work being done in the region is available at the Lethbridge Polytechnic website.
