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ESN Smart Talk® Blog

Management

The 4Ls of Nitrogen Management 

Graphic of nitrogen fertilizer granule with polymer coating

When it comes to nitrogen management, we often hear about the 4Rs, but have you ever heard of the 4Ls? John Heard, former Manitoba Ag soil fertility specialist, recently discussed this idea with Bernard Tobin at RealAgriculture. Heard shared that in addition to the 4Rs, growers should be thinking about the 4Ls: lift-off, leftover, loitering and leakage.  

Here’s how Heard defines each of the 4Ls: 

  • Lift-off: Volatilization of surface or shallow-applied urea or UAN 
  • Leftover: Crop residue and ensuring microbes don’t chew up valuable nitrogen that’s intended for the new crop 
  • Loitering: Potential loss through nitrification if applying nitrogen early in the season before the crop can use it 
  • Leakage: Leaching from coarse/sandy soils or denitrification from saturated soils 

Any form of nitrogen loss is also a loss of your input dollars and potential yield. Heard emphasizes that understanding the 4Ls of nitrogen loss can trigger how to use the 4Rs (rate, place, source, time) in your nitrogen management strategy to effectively manage each form of loss.  

Watch the interview to hear Heard’s in-depth explanation of these elements and strategies to manage each.