# Umax urea sprayable?



## Pezking7p (May 23, 2020)

So I just made the trip to a local turf supply place to pick up some urea. Well they only had something called umaxx urea. They were bragging that it was slow release, And would feed for 6-8 weeks. Turns out this stuff has a urease inhibitor in it, so I balked a bit and we ended up finding some AMS, which I bought.

But my question is, for spoon feeding purposes, was this the right choice or would the umaxx have been fine?


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## Mightyquinn (Jan 31, 2017)

The UMAXX is a Stabilized nitrogen which is different from a slow release. The Urease Inhibitor prevents the soil microbes from breaking down the Nitrogen and allows it to stay in the soil longer making it available to the grass.

THIS probably explains it better than I can.


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## Pezking7p (May 23, 2020)

Mightyquinn said:


> The UMAXX is a Stabilized nitrogen which is different from a slow release. The Urease Inhibitor prevents the soil microbes from breaking down the Nitrogen and allows it to stay in the soil longer making it available to the grass.
> 
> THIS probably explains it better than I can.


Thanks, Quinn. I thought I read that the urea is not absorbable by the plant out of the ground until Urease breaks it down. Foliar applications I think I saw that the plant will absorb urea directly, but yah, I wasn't sure at the time that it was Modified with a urease inhibitor, they just said it's a slow release urea. I was too awkward to be like "let me take 20 minutes and research the minutia of spraying this stuff". They were super busy.

I don't think the AMS will be an issue since my soil isn't super acidic. Just harder to dissolve as I understand it.

Cheers and thanks again.


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## CarolinaCuttin (Sep 6, 2019)

@Pezking7p One word of caution, the disadvantages of the AMS are that you can't spray as much N as a foliar app without burning, and it doesn't get absorbed nearly as well as urea through the foliage. Urea is a true foliar, if applied to the leaf surface, 90% or more can enter the plant within 4 hours.


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## Pezking7p (May 23, 2020)

CarolinaCuttin said:


> @Pezking7p One word of caution, the disadvantages of the AMS are that you can't spray as much N as a foliar app without burning, and it doesn't get absorbed nearly as well as urea through the foliage. Urea is a true foliar, if applied to the leaf surface, 90% or more can enter the plant within 4 hours.


Thanks for the heads up. I actually thought it was the other way around with respect to absorption. I did know AMS was more susceptible to burning.

Am I still good for 4 hours before watering? Still ok for 0.25 lb/M right?


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## CarolinaCuttin (Sep 6, 2019)

@Pezking7p I was told that by a guy who worked in the golf industry and started his own foliar fertilizer company. They did extensive research on what specific forms of nutrients were best suited to being taken up by the leaf, and urea is the best form for nitrogen uptake. AMS is certainly still effective as a foliar, just not as much. I've also noticed that a lot of high quality fertilizer companies use urea almost exclusively for their foliar products. I feel like I have read a paper comparing different nutrients before but I haven't found it yet.

Also, it's not as important which route the nutrient enters for lawns as it is for greens which might have stressed out root systems and aren't able to absorb nutrients efficiently through the roots. Healthy lawns should be pretty effective at taking up N through the soil.

All that to say that urea is probably slightly better but no reason to discourage AMS, you should get great results. 0.25 lbs N/M with AMS is toward the upper end of the spectrum, definitely want to make sure it's watered in after 4 hours. I've left 0.25 lbs N from urea on a bentgrass green for over 24 hours with no issue, but I would be hesitant to do that with straight AMS. For a lawn it's probably fine.


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## g-man (Jun 15, 2017)

AMS salt index is higher. You can cause white tips if you use a low carrier rate. Use 2g/ksqft for foliar.


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## Pezking7p (May 23, 2020)

g-man said:


> AMS salt index is higher. You can cause white tips if you use a low carrier rate. Use 2g/ksqft for foliar.


Dang. I'm starting to regret this decision. So my 15 k sqft needs 30 gallons to spoon feed? Ugh. Think I can get away with a higher rate if I chase it with a hose right away?

Maybe I'll try to spread the AMS....will be tough at 0.25 lbs, though.


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## Greendoc (Mar 24, 2018)

I have applied as much as 2.5 lb AMS or 0.5 lb N as a spray, but that is in front of an irrigation system. As in, I finish an area and it gets watered in behind me. You can try it with the understanding that there be no delay between application and watering in. Might even want to apply a few 1000 sq ft at a time and water in


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## g-man (Jun 15, 2017)

Spreading AMS is very easy and very doable. I would not complicate trying to spray it.

Do 1lb of AMS/ksqft and that will get you 0.21lb if N/ksqft. You can do to 2lb AMS too.


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## Pezking7p (May 23, 2020)

Thanks. I'll spread the AMS for now.


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