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Wet Dutch agricultural field with puddles. Tire tracks of a tractor are visible in the foreground.

eKonomics News Team

This past spring has been one of the wettest on record for many of the Midwestern states. Unfortunately, wet weather drives nitrogen loss (of nitrate specifically). For coarser-textured soils, leaching of nitrate is the primary loss mechanism. For finer-textured soils, denitrification is a significant loss mechanism.

So, what do you do to decide if you should consider additional supplemental nitrogen this summer? For the western part of the Corn Belt (we will just call it west of Interstate 35), the pre-sidedress nitrate test (or late spring soil nitrate test) could be a viable option (different states have different critical levels — like Nebraska and Minnesota). For the eastern Corn Belt, pre-sidedress nitrate test is primarily limited to acres that have received recent manure applications or have a history of forage legume production (like Illinois and Indiana).

There have been ample opportunities for nitrogen loss this spring, and there is plenty of field evidence that young corn is already experiencing nitrogen stress (yellowing of the lower leaves in response to nitrogen deficiency). The reality is additional nitrogen is likely necessary to ensure a good yield, but there are some soil sampling options to determine if more is actually needed.