Fall Nitrogen Regimens

[andy10917]

You're at 5.23% and still pushing OM? I don't want to get off-topic on this thread (it gets a lot of reads annually soon). I'll find your soil test and see why we have you still pushing OM. I'll respond in your Soils thread and ping you to it.

EDIT: I checked - I didn't recommend boosting OM higher, that's Leifcat1's idea. Wow.

[sain6815]

So, looking at going the urea route this year.

Is it difficult to apply such a small amount? 1lb per / k using 46-0-0 weekly.

I've got one of these:

ImageUploadedByYard Help1469274576.469305.jpg

Sent from my iOS device using the Yard Help App

[McLovin]

So, looking at going the urea route this year.

Is it difficult to apply such a small amount? 1lb per / k using 46-0-0 weekly.

I've got one of these:

ImageUploadedByYard Help1469274576.469305.jpg

Sent from my iOS device using the Yard Help App

That is what I use for urea on about 20 ksf. I calibrate the amount it holds per fill and I can really fling the urea around the lawn with it.

[sain6815]

So, looking at going the urea route this year.

Is it difficult to apply such a small amount? 1lb per / k using 46-0-0 weekly.

I've got one of these:

ImageUploadedByYard Help1469274576.469305.jpg

Sent from my iOS device using the Yard Help App

That is what I use for urea on about 20 ksf. I calibrate the amount it holds per fill and I can really fling the urea around the lawn with it.

Cool. That was my thought. Glad someone else has tried with the same little spreader.

And I only have a little over 2k sq ft


Sent from my iOS device using the Yard Help App

[andy10917]

The modifications to the Fall Nitrogen Regimens thread for 2016 have been made. While there are 27 pages of responses, the first post of the thread is what you want to read, if you want to get the basic ideas...

[tlinden]

Thanks!

[bauer time]

Sweet, thanks Andy. Trying the aggressive approach for the first time this year, looking forward to it.

[chrismar]

The modifications to the Fall Nitrogen Regimens thread for 2016 have been made. While there are 27 pages of responses, the first post of the thread is what you want to read, if you want to get the basic ideas...

Is there a changelog of sorts anywhere? It'd be interesting (at least for me) to see how it's evolved over the years.

[ Post made via iPhone ]

[bpgreen]

The modifications to the Fall Nitrogen Regimens thread for 2016 have been made. While there are 27 pages of responses, the first post of the thread is what you want to read, if you want to get the basic ideas...

Is there a changelog of sorts anywhere? It'd be interesting (at least for me) to see how it's evolved over the years.

[ Post made via iPhone ]

archive.org

[osuturfman]

There is a new method out there as well that has been developed at the University of Wisconsin and is now being tested in other cool season locations. The new method calls for one application of no more than 0.5 lb N/M with an N source that's up to 50% slow release.

See below for a post I made last year responding to some basic questions about the new method.

Interesting. This brings up a few more ideas and questions I have, that I think you will be able to answer based on the evidence presented so far...

I will do my best.

-Does a mid Fall pause still seem to be important for Nitrogen with the latest research?

Yes and no, please let me clarify.

Let me preface the answer by saying the "pause", as it's referred to on BL, is really the tipping point for shoot (top) growth diminishing, with the bulk of the energy in the plant shifting to root production from that point forward. Andy has gone out of his way on this site many times to explain when and how this transition occurs. I think where it gets frustrating for all is that this point happens "around" the first frost but, is not always an exact science. As a side note, Andy should be commended for trying to explain this concept over, and over, and over.

Yes, it is important insofar as it is a clear sign that the plant has begun to harden off and prepare itself for winter. With the traditional model this would have been a sign that it's time to hold short and get ready to put out your final app of N in the next 3-5 weeks depending on growth. The new model would view the pause as the definitive sign that all N apps should cease from that point forward. Basically, the research shows that N uptake will be severely reduced each week through that period in say mid-October here in Ohio through the remainder of the growing season.

So in essence no, the pause is not as critical of period to identify with the new model. That's probably a good thing for the average folks because it can be somewhat subjective when you are truly passed that point in the growing season.

See this photo below for the growth curves of roots and shoots in cool season grasses.



Pay particular attention to both shoots and roots right around October. Top growth peaks, slows down while roots keep right on chugging for another 4-6 weeks. That period is the "pause" and what the new model basically tells us is, that whatever N was able to enter the plant prior to that will serve it well through the root growth period. Whatever slow release N is still able to release during that period (depends on your N source) can continue to be taken up albeit at an ever decreasing rate. The good thing here is that most slow release N sources rely on soil temperatures, microbial activity, soil moisture, or some combination of those to release their nutrients. So as soil temps and microbial activity is declining through that same period due to cooler weather and shorter days, less N is being released into the rootzone which is a good thing as the plant is able to take up less and less as the days and weeks of mid-autumn pass by. This is a big reason why the new model is a much more responsible in terms of its environmental impact.

-Let's say your average first frost is mid October as an example. What would a sample N program utilizing the 50% slow release method look like starting in, say, August for timing and amounts? And would you still shut down K apps in mid October?

0.5 lb N/M app of a 50% slow release product around September 15th and I would be done. I would not put any K apps down after your first true frost. Tip frost doesn't count.

-I seem to recall some studies finding no significant difference between traditionally winterized and non-winterized high-input turf conditions, which is at odds with what many of us have observed. Could such a finding have been not because traditional winterizing does nothing, but rather because the experimenters were, without realizing, already "winterizing" due to their frequent light N apps starting in September? And so, further traditional winterizing made little or no difference?

Yes, very well could have been the traditional Labor Day app that really did the job and not the late season app. The way I understand that this came about was a grad student noticed that some of the unfertilized check plots in their late season N plots rated better in the fall and spring than those that received late season N. Next thing you know there's a full blown study. So absolutely it could have been the preceeding apps that were winning the battle that the late season app was unduly credited for. Very good point.

-Finally, how long has this method been in use? Is it brand new? How long has the "traditional" method been in use, for that matter? Is there even a current consensus on the "gold standard" method at this time?

Wisconsin has data going to either 2010 or 2011, so they've been playing around with it for awhile. I have read several books from as far back as the mid-1960's discussing late season N apps, so it's been beaten into the heads of turf managers for several generations. I think that's where it's going to take some reeducation of a great number of people. To take one of the sacred dogmas of turf management and essentially tear it all down and start fresh.

I really believe that in 3-5 years this new model will be the gold standard. There's also a good chance that they'll have the timing better modeled to climatic conditions to take some of the guesswork out of properly timing the app.

Just an alternative that's very simple and highly effective.

[ Post made via Android ]

[Billy]

So, you're advocating that all N applications should be wrapped up by the time that top growth stops and that your final N app should coincide with turf need (growth) in the fall?

I like it. This is a very sound and plant-based approach. Prepare to be flamed here.

[ Post made via iPhone ]

[osuturfman]

So, you're advocating that all N applications should be wrapped up by the time that top growth stops and that your final N app should coincide with turf need (growth) in the fall?

I like it. This is a very sound and plant-based approach. Prepare to be flamed here.

[ Post made via iPhone ]

Ha! I've been there and back several times in my 3+ years here. Roll with the punches and help people along the way.

[ Post made via Android ]

[andy10917]

Is there a changelog of sorts anywhere? It'd be interesting (at least for me) to see how it's evolved over the years.

Nope. I read the questions from the past year and try to address recurring questions and themes.

[js12337]

Any benefits or issues with using SuperU Urea 46-0-0 with the aggressive program?

[ Post made via iPhone ]

[andy10917]

Prepare to be flamed here.

Not happening. I would love for there to be something effective that can make the grass as dense and dark as the current regimen, with much less work. When one app can do this, I'll be sold. I have to admit to skepticism on one app doing the density changes the current regimen brings - why wouldn't one app do that any other time? Until then, the current regimen is what I'll be using - I wanna stall the Honda.

[Michael Wise]

Prepare to be flamed here.

ImageUploadedByYard Help1471311556.524967.jpg

Suck it up, buttercup.

[llO0DQLE]

Hey Billy I'm waiting for your reply to Barley's question regarding CEC on your "How to interpret your soil test" thread.

[ Post made via Android ]

[LoneRanger]

I'm still waiting for my rebate... oops wrong thread. Sorry.

[Billy]

Hey Billy I'm waiting for your reply to Barley's question regarding CEC on your "How to interpret your soil test" thread.

That's a question that's not germane to that thread's topic. Barley can create another thread to discuss that, if he would like. CEC doesn't quite work in the manner that he alluded to, so it would take some background explanation to get to the final answer.

[ Post made via iPhone ]

[micvog]

0.5 lb N/M app of a 50% slow release product around September 15th and I would be done. I would not put any K apps down after your first true frost.

Do you still put down 4-5 #/K of N? What does that schedule look like?

The stumbling block for me that would prevent me from even trying this approach is I don't know how to get sufficient nitrogen without violating one of the following three "rules":

1. 1. First nitrogen app is after Spring flush
   2. Don't push top growth in the summer
   3. Target 1#/K of N per month (not saying I agree with this one - I am at about 1.6# of N per month with Milorganite)

Spring flush ends mid-May for me and first frost is mid-October. If I skip a month during summer, and put down 0.5# in September, that leaves me with 3.5# of N per K for the year, and I know that doesn't give me the lawn I want.