I've been getting a lot of questions about needing additional N for corn; growers are torn between putting some UAN in with herbicides vs. spreading urea. I’d caution them against using UAN as a carrier on emerged corn if they are applying herbicides. Yes, there are a few products that allow this, but the labels also say that crop injury can be expected. I’ve done it, and it was fairly hard on the corn. If we have good growing conditions after the application, the corn may heal up and be fine; on the other hand, it is a lot of stress on the young crop. I have seen stand loss from post emerge applications of UAN and herbicides, especially when we get stressful weather after applications. So, if possible, I’d lean toward some sort of NH3 or UAN sidedress or spread urea over the top.
Weeds are getting big in the no-till, so be sure to scout well and hammer them with your burndown or they may haunt us for months.
Related article: Advice for farmers who still need to apply N for this year's corn
Clarke McGrath On-Farm Research and Extension Coordinator - Iowa Soybean Research Center
Clarke McGrath currently serves as the On-Farm Research and Extension Coordinator.
Prior to joining Iowa State University, McGrath spent nearly a decade as a retail agronomist and manager in the GROWMARK system, earni...