A new online tool is available for farmers focusing on the nutrient requirements of key crops grown in Western Canada.

University of Saskatchewan scientists Dr Fran Walley and Dr Rich Farrell worked with a team across the prairies to collect data focusing on the nutrient uptake and removal for commonly grown crops.

Walley says we know how valuable nutrient removal guidelines are, but the most recent guidelines available were from 2001.

"A lot has changed in the last few decade, 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."

Farrell says the updated data is part of the new Prairie Nutrient Removal Calculator.

"If you want to keep from depleting the nutrients in your soil,  or even to maybe build some nutrients in your soil it's a good idea to know how much is coming off. This in conjunction with soil testing can give you an idea of how much to add back to the soil so that you can produce the crop."

He says the research team collected from over 2200 grain and biomass samples over the last three years representing various crops types.

"What the calculator reports is the data like removal out of pounds per acre basis, but we also calculated data on a pounds per bushel basis. And when you compare the wet and the dry year the pounds per bushel is about the same. There wasn't a lot of fit within the normal variability that you would see in an anomaly here."

To gather on-farm data, the research team enlisted agronomists in Saskatchewan and Alberta through Lyle Cowell of Nutrien Ag Solutions, field staff in Manitoba through John Heard with Manitoba Agriculture, field staff with the Saskatchewan Ministry of Agriculture, and researchers at Saskatchewan Agri ARM sites, another key participant in the project was post-doctoral fellow Gazali Issah.

They point out this army of on-the-ground collaborators enabled the team to collect the on-farm samples in 2020, 2021, and 2022.

To measure uptake - how much the crop takes up nutrients from the soil - plant tissue was collected at a growth stage when it was expected the plant was using the greatest amount of nutrients from the soil. Tissue was dried, crushed and analyzed for nitrogen, phosphorus, potassium and sulphur (macronutrients) as well as copper, boron and zinc (micronutrients). 

For nutrient removal - how much is removed when the harvested grain leaves the field - seed samples were collected at harvest, along with information on crop yield, and analyzed for the same range of nutrients.  

Walley says there are a lot of nutrient removal calculators available, but this one reflects the crop varieties and yield expectations in Western Canada.

"The calculator can help you work through soil test reports and make nutrient adjustments as part of overall fertilizer management,"

The online calculator is now available at prairienutrientcalculator.info 

Funding for the 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.