Higher rainfall considerations: Is supplemental N required?

University of Minnesota Southern Research and Outreach Center soil scientist Jeff Vetsch talks with Linder Farm Network about some considerations when it comes to the higher rainfall amounts and nitrogen.

TRANSCRIPT

Linder Farm Network: It’s time for the AFREC Spotlight, the Agricultural Research and Education Council with Jeff Vetsch, Southern Minnesota Research and Outreach Center soil scientists. Jeff, what are some of the considerations when it comes to the higher rainfall amounts and nitrogen?

Jeff Vetsch: I would say there’s three to four things to consider, when making the decision whether or not you should apply supplemental nitrogen for corn to these areas. The first is think about the growth stage of the crop, you know, how far along are we? And most of the corn in Southern And Southeastern Minnesota this year was because we had really good spring conditions, most of it was planted in mid to late April. Here at SROC, our corn that was planted either in mid or late April is in that V14 to V15 growth stage. Therefore, it’s kind of getting near the end of the time when we would recommend these additional end applications.

If we wait too late, a significant part of the N has been taken up by the plant. Usually it’s around R1, we think about 70% and at that point the soil can probably provide the rest. So we are kind of getting at the tail end of those application timing windows, especially some of these fields now are super wet. So if you’re going to try to use ground rigs, there might be another three or four or five day delay and then trying to get a retailer if you’re going to have custom hire, which obviously with standing corn, that’s likely, that may be another delay. So that’s probably the first thing to think about.

Remember that this corn is pretty far along, so making this application at this time may or may not give a return on investment. The second thing is think about how the corn crop looked prior to and now after the heavy rain. At least prior, most of the corn in Southern And Southeastern Minnesota looks fantastic. There were no symptoms or signs of nitrogen deficiency. So it’s really less likely that additional nitrogen is needed compared to corn that was struggling or showing deficiency symptoms prior to the heavy rain.

And then the other thing to think about is how many times does a field, or if you have a field that had excessive rain, how many times has that field had excessive rain this year?

Linder Farm Network: Jeff Vetsch, Southern Minnesota Research and Outreach Center soil scientist. For more information, mnsoilfertility.com.