USask researchers develop a nutrient calculator

Farmers and agronomists have a new tool to calculate nutrient requirements of crops, thanks to the University of Saskatchewan.

The Prairie Nutrient Removal Calculator is an online tool, USask says in a news release, that provides a critical piece of information to help make on-farm fertilizer decisions.

It was developed by Two USask soil scientists – Dr. Fran Walley (PhD) and Dr. Rich Farrell (PhD) – both of whom led a 3-year project that drew collaboration from numerous producer groups and industry.

“We know how valuable nutrient removal guidelines are, but the most recent guidelines available are from 2001,” said Walley, associate dean (academic) and professor in the College of Agriculture and Bioresources. “A lot has changed in the last few decades—different crops, genetics, management strategies and crop rotations—and so we set about to revise the existing guidelines to ensure the information was more relevant and reflective for today.”

The calculator uses local data collected from commercial farms in Manitoba, Saskatchewan, and Alberta, gathering more than 2,200 grain and biomass samples representing 14 different crops.

“We really wanted to get a handle on what the nutrient uptake and removal was for commonly grown crops in commercial fields,” added Walley.

USask says “the calculator focuses on nutrient removal as a more relevant number for farmers and agronomists than nutrient uptake. Users choose from the list of crops and add in known yield from the previous year or expected yield for the upcoming year, to find a nutrient removal value.”

“We wanted the tool to be easy to use and be readily adaptable to be used on any device,” said Farrell, associate professor in the College of Agriculture and Bioresources and the Ministry of Agriculture Strategic Research Program (SRP) Chair in Soil Biological Processes.

Funding for this project was provided by the Western Grains Research Foundation, Alberta Wheat Commission, Prairie Oat Growers Association, Saskatchewan Canola Development Commission, Saskatchewan Flax Development Commission, Saskatchewan Wheat Development Commission, with logistical support provided by Nutrien Ag Solutions, and Manitoba Agriculture and Resource Development.

The online calculator is now available at

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