Wheat School: Top-Dressing Nitrogen to Boost Protein


With changes to the way wheat is marketed and the arrival of higher-yielding varieties, there’s growing interest in boosting wheat protein content with in-season nitrogen applications in Western Canada.

The basic recipe is 10 gallons per acre of 28-0-0 with 10 gallons of water applied with a flat fan nozzle shortly after anthesis or flowering, explains Brunel Sabourin of Manitoba-based Antara Research in this Wheat School episode. (continued…)

Keys for boosting protein with foliar N:
(from Jochum Wiersma, University
of Minnesota

  • Apply up to 10 gpa of 28-0-0 with an
    equal amount of water – the water is
    needed to reduce leafburn;
    more water is advantageous
  • DO NOT apply during the heat of
    the day – early evening application
    will reduce leaf burn considerably
  • DO NOT tankmix this N with any
    fungicides at Feekes 10.51,  but
    rather apply the additional N
    5 to 7 days after anthesis
  • The probability of a response by the
    crop is about 80 percent.
  • Only expect an increase of 0.5 to 1.0
    full point in grain protein with the
    additional 30 lbs N/A.

He cautions if applied in the wrong conditions, foliar nitrogen can do more harm than good.

“If we’re applying it in the heat of the day with 40 kilometre an hour winds and hot temperatures, it can cause a lot of leaf burn and hurt yield that way,” says Sabourin. “So it’s recommended to go as close to dewpoint as you can, later at night, past the heat of the day.”

Whether additional nitrogen can be justified economically depends on the protein premium in the market, but he notes changes in the way grain companies are posting wheat prices after the end of the Canadian Wheat Board’s single desk and the introduction of higher-yielding American wheats with lower protein levels have spurred Western Canadian producers to look at ways to boost protein.

Sabourin is one of several industry collaborators working with John Heard, Manitoba Agriculture’s soil nutrient specialist, on researching the yield and protein responses of these new “higher-yielding” wheat varieties to different nitrogen rates and timings.

“As we move into more common yield goals of 70, 80, 90 bushels with some of these spring wheats, it’s about figuring out how hard we need to fertilize,” he says. “If you use the typical recipe of so many pounds per bushel, with some of these high yields, we’re asking for 200 pounds of nitrogen, which is a significant investment to put in ahead of the crop.”

They’re also looking at ways of measuring if a crop is short on nitrogen during the growing season using tools like nitrogen rich strips and chlorophyll/NDVI sensors.

Additional info on post-anthesis N for boosting protein:

Related articles on RealAg:

Wake up with RealAgriculture

Subscribe to our daily newsletters to keep you up-to-date with our latest coverage every morning.

Wake up with RealAgriculture

Other Episodes

Wheat School (view all)Season 6 (2015) Episode 15

Please register to read and comment.


Register for a RealAgriculture account to manage your Shortcut menu instead of the default.