Variable-rate irrigation on the rise in Alberta

Not everyone is convinced the technology is where it needs to be, but advocates say ‘interest is growing exponentially’

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Southern Alberta’s irrigation system is on the cusp of going very high tech.

Now that crop yield monitoring is commonplace and variable-rate crop-input technology making inroads, ag equipment companies and early adopters of advanced technology are setting their sights on micromanaging irrigation.

“Variable-rate irrigation (VRI) is certainly here to stay,” said Jeff Bronsch, president of Sunrise Ag, an agronomic consulting firm in Taber focusing on data-driven agriculture.

“Multiple companies now offer platforms, and interest is growing exponentially among growers. Right now, there are about 50 to 60 VRI systems in place in Alberta. But like any new technology, once it’s out there and guys can see the benefits, uptake is going to increase.”

The goal is the same as in any variable-rate technology — applying different amounts of water to different areas of a field based on topography, soil variability, and other factors to maximize yield and quality while making the most efficient use of all inputs.

“If you don’t irrigate optimally, you can’t achieve optimal yield or minimize losses,” said Bronsch. “If you fertilize a hilltop to grow 20 tonnes of potatoes, but can only irrigate it to achieve 15 tonnes, you’re wasting the money you invested in fertilizer.”

And providing the right amount of water to each part of a field means it produces better uniformity, consistency, maturity, and size — and that’s especially important in a high-value crop like potatoes, he added.

“Water is a pretty cheap input but it has a very big impact on a crop’s outcome.”

In 2014, Bronsch conducted a side-by-side comparison of two fields, both with the same soil types, topographical challenges, planting and harvesting dates. The field with variable irrigation was harvested down to the very last acre, whereas the field with traditional irrigation was left with approximately eight acres of low-quality, undersized, unharvestable potatoes.

While his study is hardly of a large enough scale to be considered scientific, the results are still turning heads.

Flattening the field

“I call VRI the flattening out of the field,” said Bronsch. “You use VRI to eliminate topographical challenges and improve the maturity and size profile. In our side-by-side comparison, the grower saw a gross revenue increase of $70,000 off the field with VRI compared to the field without.

“The investment in the VRI system for this field was about $50,000, which is a bit higher than a standard pivot because this pivot had a corner arm. So he essentially paid for the system in one year and put $20,000 in his jeans.”

That said, a study conducted by Alberta Agriculture and Rural Development researcher Ted Harms in 2012 and 2013 showed less stellar results. Although the concept makes sense, implementing variable rate was a challenge, he found.

“It was just way too much work with the instrumentation we had,” Harms said in the study. “It could take you most of your day to manage two pivots, (the test areas) have 19. We need to have some kind of a program or computer modelling to make this work. If we got to that point, variable-rate irrigation could have very real possibilities for many fields.”

While there may still be a debate over whether the technology is ready now for implementation, one thing is certain: How we use water will be an increasing focus over the coming years.

With aquifer levels dropping precariously low in many parts of the U.S., water demand growing, and drought seeming to be increasingly common in many areas, experts say water will not be cheap and easily accessible for long.

“Thinking about water as an important commodity is sound and rational, but no one seems to be recognizing that yet,” said Bronsch. “People aren’t rewarded in society for being conservationists with water. Water use is usually tied to some economic number. But I really think growers who use less water should be rewarded or awarded — recognized for doing something above and beyond.

“Their efforts to conserve water by investing in technology need to be recognized.”

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