Splitting nitrogen in a corn crop can increase profitability and benefit the environment, but to be successful on both counts, growers need to keep a close eye on the weather.
This is the conclusion drawn by University of Guelph researchers Tasmia Kabir, Aaron Delaporte, Joshua Nasielski and Alfons Weersink after examining 19 years of weather data from Ontario’s Elora research station to develop nine different weather scenarios. . They also analyzed corn yield and nitrogen loss to measure the benefit of the nitrogen management practices used in each weather scenario.
The study focused on three different nitrogen management practices: traditional broadcast urea before planting at 120 lbs / acre; 60 lbs / acre preplant urea followed by fractional application at V6 of UAN; and 60 lbs / acre of preplant urea followed by a fractional application at V13 of UAN.
In this episode from RealAgriculture’s Corn School, Nasielski explains that the most profitable and environmental strategy for any given year really depends on the weather. Research shows that splitting nitrogen applications and adjusting the second application rate according to weather conditions increased farm profits and reduced nitrogen losses to the environment only during dry years .
Fractional nitrogen applications increased farm profits by 15 to 20 percent in the dry season, and 1 to 16 percent in the wet season, compared to pre-plant application. (Story continues after the video.)
Comparing the timing of application, it was more cost effective to make the second nitrogen application just before the onset of silks (V13) than at the six leaf stage, except during wet and cold seasons.
From an environmental perspective, the researchers found that fractional applications reduced both nitrate leaching and nitrous oxide emissions by up to 24%, and ammonia volatilization losses by up to 55%. % compared to pre-factory distribution. Overall, making the second application at V13 minimized nitrogen loss in all weather conditions.
But management that minimized losses to the environment has not always maximized the profitability of the operation. Fractional nitrogen applications maximized economic and environmental benefits only during dry seasons.
Nasielski notes that in an average season, divided nitrogen actually reduced profits by nine percent, primarily due to custom application costs during the season and a two-bushel / yield penalty. acre when nitrogen is delivered at V13 under average conditions.
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