# Is this Fertilizer Burn on my KBG?



## AndyS (Jun 13, 2020)

Based on advice and experience from forum members I decided to apply urea to my new KBG grass (32 DAG) at 0.25lb per 1K with 1 gallon of water as a carrier per 1K.

As a test I deliberately oversprayed my 'test plot' with at lest double if not triple rate (hard to judge exactly) just to see what would happen.

My lawn responded great, with quicker fill-in of barer areas, though no excessive growth. My test plot however grew at about an inch every day or two with the higher rate. About 5 days later that test plot seemed to have tip burn, but since I don't have experience with fert burn I though I'd get confirmation that that's what I'm looking at:


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## badtlc (Aug 22, 2019)

I have a thread on the first page with pics and it looks similar to yours. I'm pretty sure mine was nitrogen burn. I'm pretty sure yours is too.

Also like yours mine was not immediate. It took a few days before the brown started showing up.


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## NateDawg24 (Sep 11, 2019)

I believe it is as well (too much nitrogen). I did a test pot split into four corners with each corner receiving a different treatment. The one with the highest nitrogen looked basically the same as your grass.


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## zackroof (Oct 27, 2019)

Is there any kind of recovery from this, or just grow out?


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## AndyS (Jun 13, 2020)

Excellent - thanks @badtlc and @NateDawg24 - based on this I'm definitely going to stick with 0.25N every week and not be tempted to go higher :thumbup:


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## AndyS (Jun 13, 2020)

zackroof said:


> Is there any kind of recovery from this, or just grow out?


Water I guess? I'll start flushing it and see it it makes a difference...


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## badtlc (Aug 22, 2019)

AndyS said:


> zackroof said:
> 
> 
> > Is there any kind of recovery from this, or just grow out?
> ...


Watering worked for me but be warned you will need to mow every two days until you get the brown gone.


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## AndyS (Jun 13, 2020)

badtlc said:


> AndyS said:
> 
> 
> > zackroof said:
> ...


Much appreciated - hoping to get another dose of 46.0.0 down tomorrow. I guess I better be even with my spraying!


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## ken-n-nancy (Jul 25, 2017)

Are all of the folks that have seen this on their lawns been *spraying* the nitrogen?

If so, how long have you been waiting after spraying before watering in the nitrogen?

I've never sprayed any nitrogen before, just pre-emergents, herbicides, and fungicides.

With granular applications of quick-release urea, I've regularly applied far more N than you're talking about. In specific, I have regularly applied 1#N/ ksqft in a single granular fast-release urea application (46-0-0) for many years with no problems.

In a different thread, I even noted that @Harts mentioned applying a granular application of 1#N/ksqft on his lawn in a single application. He then did that same application 1-week later, and then again 1-week later. Yes, 3#N/ksqft in a span of two weeks. He didn't burn his lawn.

However, I know from his posts that he also regularly applies 0.25#N/ksqft by spraying. However, since he doesn't have the problem you all are encountering, there's something that he's doing right that is avoiding the problem being described in this thread. I suspect he's watering in his applications more quickly after making the application, but that's just a hunch.


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## AndyS (Jun 13, 2020)

ken-n-nancy said:


> Are all of the folks that have seen this on their lawns been *spraying* the nitrogen?
> 
> If so, how long have you been waiting after spraying before watering in the nitrogen?


I've certainly been spraying. 0.25N / 1K foliar app with a couple of hours wait before watering in. That produced no issues.

I deliberately doused my test plot, probably over 0.5 and closer to 0.75. I similarly left that a few hours before watering. Even at that level with a foliar app it looked amazing until about day 5 when the burning came in. My guess is it'll come roaring back, but we'll see.

I love having a test plot. I wish I had 5 of them for different experiments. The only downside of using a plastic container with a couple of drainage holes is that the N probably hangs around the plant longer that it would do in real conditions.


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## g-man (Jun 15, 2017)

@AndyS How much carrier are you using? Are you keeping the lawn irrigated? If so, how much and how often?


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## badtlc (Aug 22, 2019)

ken-n-nancy said:


> Are all of the folks that have seen this on their lawns been *spraying* the nitrogen?


Mine was a fast release granule.


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## AndyS (Jun 13, 2020)

g-man said:


> @AndyS How much carrier are you using? Are you keeping the lawn irrigated? If so, how much and how often?


@g-man 1 gal per 1K sw ft with 0.25 N. Still irrigating every day.

Same mix was used for the test plot, but at a much higher rate (I.e. I doused it).

Interestingly, after only 24 hours and some rain, about half of the tip burn has gone from that test plot already. Here's a side-by-side over 24 hours:


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