Clayton Novak said: I'm pretty sure Ron and Larry are on the right track here. I took Beth Guertal's (Auburn PhD) seminar on advanced N fertilization at the national and my takeaway was that the stabilized N sources have a urease inhibitor which decreases volatilization. However a straight 46-0-0 that you solubilize does not need to be watered in right away either as you are introducing the nitrogen to the plant through leaf tissue- the majority of the N enters the plant within the first 4-6 hours (She did go on to say that watering in the evening following application is fine because the 4-6 hour window was met). Obviously, if you were putting out the 46-0-0 dry you would water that in- but clearly no one here is asking that. I have used both the 47-0-0 Umaxx and a straight 46-0-0 (both solubilized) on fairways, but not at the elevated rates some of you are talking about. When I pressed Beth, her response was that a less expensive soluble N (like the 46-0-0) is a perfectly adequate source, particularly during periods of stress when nutrient uptake is limited by decreased root growth. After taking the seminar I am going to try a fertilizer program using Polyon as the foundation, soluble 46-0-0 at 15#/A every 21 days incorporated in with fungicide sprays(June- August) and follow up with a half pound of Nature Safe in late August. Beth did a great job presenting- I would recommend giving her a call.
Thanks for the info. Clayton. Looking at some of the rates in this thread some are using it as a foliar and then I completely agree that using a stabilized urea is a waste of money over straight urea. If it is absorbed through the leaf, which it should be at those rates, then why the need for stabilization?
But if you look at Paul's rate in the first response in this thread, he is applying close to #1 per thousand of N at times but usually splitting it to half that rate. Either way I am guessing, and hopefully Paul can confirm, that he is watering it in almost immediately. Maybe I'm wrong but that is what I would do at that rate.
My input has been based on granular applications and I was thinking that the seminar Red referred to was discussing the higher, slow release rates such as what Paul is applying. That is why the confusion on my part. In my mind the urease inhibitor should, at least in theory, be beneficial for these types of applications. However, maybe the act of irrigation, whether granular or from spraying, is adequate to move the urea into the canopy enough that straight urea is no longer subject to volitalization.
At any rate, once you guys figure it out let me know. I'm going back to manure applications, which my previous are worth at this time.