Fall/Winter urea question

[flyin-lowe]

It is getting real close to time for me to put down my last nitrogren application of the year. I have 3 acres to cover this year. One acre is well established, one acre is a couple years old but I overseeded in early September. The last I acre was completely new this spring and I also aerated and overseeded it mid September. I was thinking I had read on hear some time ago that on newer lawns or a fresh overseed you should use 1/2 pound per 1000 square feet instead of 1 pound per 1000 square feet. Should I go light on the areas I overseeded or just go 1 lbs nitrogen per 1000 on all of it? Since it is such a large area I have to watch the weather and apply it before a rain. The map is showing the soil temp currently at 52 degrees but showed the 7 day average as 50 degrees. I am thinking I will put it down the next rain that is forecasted.

[MorpheusPA]

At this point, 1 pound per K for a last app of the year is fine for all areas. While you could, theoretically, go a little light on the September-seeded areas if you wanted, it's not really necessary and the more established grasses in those areas will benefit from the higher level of nitrogen anyway.

I'm also not necessarily a stickler on hitting the timing all that precisely. Top growth is slowing severely, with solar winter starting tomorrow (not astronomical winter, solar winter; entirely different thing; the 12 weeks of least daylight). Air temperatures have dropped, ground temperatures are dropping and not likely to rebound too much for too long.

Now, for many people north or west of me, is close enough. Now is a bit early here, but it would do if it had to.

[flyin-lowe]

There is no rain in the forecast for a week or two right now. The problem is next week temps are supposed to be above average, into the 60's. I am guessing this will be our last little warm stretch and hope by the times more rain gets here the temps will be down a little.
Thanks for the advise.

[bolson32]

Where are you located Flyin? I'm in the twin cities and I'm kind of in the same boat as you. 1.5 acres and doing the rain dance. I mowed a week ago and I don't think there's been much top growth, a tiny bit, but it's gotta be close to done.

I'm just wondering what 5 days in the 60s will do as is forecasted, I assume the nights will stay pretty cold so in don't think it will suddenly start growing again but I'm a novice at this. Looks like rain forecasted for next Tuesday I think I'll do l drop on Monday if I can.

[flyin-lowe]

I am in east central Indiana. The online map shows our soil temps in the upper 40's. I went out this morning with an instant reed thermometer and checked several spots and all showed 47-48 degrees. They are calling for rain this coming Thursday and it is supposed to get cold again this weekend. So assuming the forecast stays the same I will try to get my nitrogen down Wednesday night or Thursday morning depending on when the rain is supposed to start.

[MorpheusPA]

You're entirely safe doing it now if you want; the few days of lag don't matter in the slightest and you won't damage the lawn or lose anything appreciable to the air.

Losses happen in high pH plus higher temperatures. November...not so much.

[bolson32]

Dropped mine yesterday, not gonna rain or snow for a few days but glad Morph confirmed it's fine!

[flyin-lowe]

I have read it is best to put it down right before a rain if you can't water it in. There can be issues if it sits on the ground because it can start to dissolve from the dew but it won't get deep into the soil like it does from a rain. It can also loose some of it's potency the longer it sits without rain. I have ready by varying amounts, some say it needs to be watered in within 24 hours, other say it's not a huge deal. My yard is big enough I have learned to watch the weather and hope for the best.

The place I used to get it from in bulk no longer carries it but another nearby co-op has it for $25.00 per 50 lbs bag. Not sure if that is a great price or not. I used to know the guy that ran the local co-op and he would give me enough to do my old yard. They are generally selling it by the ton so a couple hundred pounds was not a big deal to him. He always said they spilled more than that when they loaded big trucks.
The spot I am doing is approximately 3 acres, I'm going to put down 250 pounds.

[bolson32]

I paid $17.99/50 lb bags this summer, but I hear all high nitrogen sources have skyrocketed so $25 probably isn't bad right now.

[flyin-lowe]

I got almost all of the urea down this evening before it got dark. I always apply at half the rate and run one direction, then load the 2nd half and do the other direction. I am down to 1 fifty pound bag left to put down on the last acre. As of right now there is a 90 % chance of rain starting late tomorrow morning and they are calling for close to 1/2 inch, so that's all I can hope for. After this Ill be able to put things to bed until spring.

[MorpheusPA]

It can also loose some of it's potency the longer it sits without rain. I have ready by varying amounts, some say it needs to be watered in within 24 hours, other say it's not a huge deal.

It's very strongly influenced by pH and temperature. High pH, above 7.0 and particularly above 7.5, increases losses. Higher temperatures, most notably above 75, also increase losses. But at anything less than a week or so, it's not much of an issue; it doesn't surface hydrolize that fast even if it dissolves in dew. Hydrolysis requires a much more complicated set of processes.

If you have a neutral to acid pH and it's cold outside, your losses are going to be minimal to zip. I don't much worry about it with a pH of 6.3 and temperatures of 60 and under unless rain isn't expected in 10 days or more--and even then, it's minimal.

https://www.gov.mb.ca/agriculture/crops ... rogen.html

[flyin-lowe]

You took the words right out of my mouth......LOL

Thanks for the info. I got the last bag of mine down early this morning and it started raining a couple hours later.

[ronfitch]

Where are you located Flyin? I'm in the twin cities and I'm kind of in the same boat as you. 1.5 acres and doing the rain dance. I mowed a week ago and I don't think there's been much top growth, a tiny bit, but it's gotta be close to done.

I'm just wondering what 5 days in the 60s will do as is forecasted, I assume the nights will stay pretty cold so in don't think it will suddenly start growing again but I'm a novice at this. Looks like rain forecasted for next Tuesday I think I'll do l drop on Monday if I can.

Always a dance.

Irrigation system is already blown out. Mowed on last Saturday and still had clippings, so still too soon, IMO. Will mow again this tomorrow to see if there are clippings - regardless, the big maple next door finally dropped its leaves this week, so I need to mulch them, if things dry out enough to mulch mow.

My thermometer shows 4" depth still near 40 degrees and online sites match that for my area (Bolson32, these are near us: https://app.gisdata.mn.gov/mda-soiltemp/).