View Full Version : Late fall fertilization-Urea

11-06-2010, 02:42 PM
Having a debate with a person and need help; we are friends for years so just trying to figure this out.

We are in MA and I apply UREA (1lb per 1K) after lawn cessation of turf growth and do not water in. My buddy says if should be applied and then watered in (rain; too late for sprinklers here). Says it might burn..I have never seen that...Yea it will volatilization with soil moisture but burn.....in these temps.

Okay guys, what is the right direction since I cannot win!!!:)

11-07-2010, 10:32 AM
I will take a stab at this and then probably get schooled by someone who really knows what they are talking about. I guess that is how we learn!

IMHO (which may be wrong logic) I would not wait until all growth has ceased. You still want the plant to uptake the N and convert it to fuel for next year. Best to still have a couple weeks of slow growth left when making the app of Urea. I would want it to be watered in also just to take full advantage of what you put down, not to prevent burn. One pound of Urea not watered in is not going to burn especially at lower temps. Still have to be careful and spread the correct rate!

That is what I think, can't wait to hear what others say.

11-07-2010, 11:28 AM
In theory, soil temps will still be warm...so the roots will absorb the nitrogen, and store it for next year. Nitrogen is not really an energy source. However photosynthesis works fine at low temps, so food (as starch) accumulates in the roots. The roots get fat and deep. However growth is almost zero below 45 degrees. I admit I am influenced by information from professors at Michigan State University.

Applied evenly, burn should not be a problem. Probably too cold for volitilization also. I applied urea to my own lawn yesterday November 9.

11-07-2010, 11:43 AM
The turf needs to be actively photosynthesizing (not necessarily actively growing) for any N application to be beneficial. Additionally, the nitrogen cycle essentially stops at soil temps around 40 F, so as soil temps approach 40 F, applying a fert that is dependent on the N-cycle (ex. urea), regardless of what the plant is doing, is pointless.

If the above two processes have slowed to the point of essentially being stopped, then you are not only wasting time and money, but you could well be contributing to surface/ground water pollution.

11-10-2010, 05:31 PM
Thanks guys...At least I am correct it will not burn...I have WAY to many links to edu's about the benefits of urea.
With AVG temps about 42 +/- top growth is stopped but roots growing...taking up the 46-0-0.....

For $13.25 for 50 lbs I will take it!!!!