# Liquid Nitrogen



## corneliani (Apr 2, 2019)

Nitrogen is the same no matter the carrier, be it water or granular prills, so the question as to what is best isn't necessarily from an a.i. perspective but more of a delivery preference. Each has its own pros/cons. Some things that come to mind:

Liquid Pros: 
- a more thorough distribution of the nitrogen over the applied area
- better control of a.i. amount, especially at lower rates
- enables foliar feeding option for quicker uptake of some of that N
- cheaper/more cost efficient to add concentrate N in your own liquid carrier (assuming you're not buying pre-mixed nitrogen, that is).

Liquid Cons:
- requires lots of carrier (18k sqft would require at least 18 gal of solution, possibly even 36-gal for higher app rates)
- requires a calibration level that can be a bit intimidating, taking walking speed/nozzle type/pump pressure into account. 
- coats the leaf surface and can cause leaf burn (ie desiccation) quicker, esp on hot/sunny days. Need to be conscious about application time of day. For ex, mid-day applications in full sun require lots more carrier than evening apps to minimize tip burn.

Granular Pros: 
- easy to grasp/understand calibration as it's a visual product. 
- easy application process as you can see where you've been & where you're going.
- great for large & open areas as most spreaders throw 6 - 10' swaths (at 3-4mph walking speed). 
- can incorporate encapsulation methods that control the release of N for longer-duration release curves (big big big pro)
- can be applied in higher N amounts as the granules tend to make their way to the soil surface, not causing the leaf burn seen with liquid apps (do not apply on wet turf, obviously).

Granular Cons: 
- more expensive than concentrate when comparing $ per pound of N.
- application ranges can be limiting at the lower ends of the spectrum (physically hard to distribute granules smoothly & evenly at 1/2#N and lower, for ex).
- not as thorough of a distribution method as granules can fall inches apart from each other, leaving some gaps between them (this is not that big a deal with soil apps as the plant roots will eventually find that N, but worth mentioning).
- not as precise of an application method, esp in tight spaces, as granules can overshoot lawn areas. Will need to be blown back onto lawn if spread on concrete. 
- soil/root application only, no foliar feeding option.

This developed into a more detailed post than I intended so I hope it helps. It is not an all-encompassing list but just some things that were coming to mind as I was typing.


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## g-man (Jun 15, 2017)

@Virginiagal I copied the post over here.

What are the safe rates for *liquid foliar* (no immediate irrigation):

Urea - 0.5lb of N in 1 gallons of water. This equates to 1lb of actual urea in 1 gallon of water.
AMS - 0.25lb of N in 2 gallons of water. This equates to just over 1lb of AMS in 2 gallons of water.

Still be careful with the overlaps of your application since the overlap area will get twice as much. In the peak of summer, I prefer to apply in the late evening, let it sit for at least 4hrs and then do a short irrigation cycle. This further limits the risks. Injury is normally some white tips in the leaf blade that will go away in the next mow.

*For liquid nitrogen soil applications (immediate irrigation)*:

- the rate can be up to 1lb of N/ksqft of fast release sources. Use a carrier rate that will ensure even distribution in your yard. After application do at least ~1/4in of water to get the nitrogen into the soil and "clean" the leaf.

*Frequently asked questions:*

I can't find urea but I want to spray it, what can I do?
- You can buy DEF (Diesel Exhaust Fluid) at Walmart or your local gas station. DEF is urea + deionized water and very safe for your lawn. 10oz of DEF ~= 0.1lb of N.

Can I mix XYZ too? 
- you need to do a jar test and check. Also think, do I want both (the nitrogen + XYZ) as a foliar or soil. You should not mix a foliar and soil product into the same tank.

Can I dissolve the bag of fertilizer from big box store and spray it?
- Most likely no. Most of the products have binders and other components that might not be soluble and might not go thru your back sprayer. Look at the label. If it doesnt say soluble, it most likely is not.

Can I use a hose end sprayer for foliar?
- Some do, but it is not ideal. The water pressure, your walking speed, the spray pattern will yield uneven spreading. Further, the water droplet size is very big, so most of the product will roll into the soil.


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## Virginiagal (Apr 24, 2017)

Yes, on its own is good. But I was thinking of it going under Popular Soil Fertility links at the top, so people can find it anytime. And if you edit, add "of water" after 1/4 inch. The rates do matter in soil applications, like in general you don't want to do over 1 lb of nitrogen at a time. Fine to do less. Can do more if it's over 50% slow release. There is no carrier for a soil application. It's good to have the foliar amounts and carrier amounts spelled out as it's often asked about. it's probably in the blitz thread somewhere but that has gotten so long.


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