Fall Nitrogen Regimens

[ken-n-nancy]

Thanks. How soon after urea being spread does it need to be watered in?

It is best for urea to be watered in shortly after application for two reasons: (1) urea pellets resting directly on blades of grass can cause localized "burn" of the blades, particularly if dampened lightly, but not watered in, such as by dew which wets the grass blades and the urea pellets, but isn't sufficient to dissolve the urea pellets into the soil, and (2) urea does start to lose some nitrogen to volatilization to the air, but this effect is not as extreme as sometimes reported as a "scare tactic."

The amount of volatilization per day is highly dependent upon a variety of factors, such as moisture (more moisture is worse), soil pH, and temperature. If you want to read more about this, google can help you find some relevant reading material, such as Management of Urea Fertilizer to Minimize Volatilization and Management to Minimize Nitrogen Fertilizer Volatilization.

In any case, I personally think it is best for the urea to be watered in with 0.5 inches of gentle rain or irrigation within 1-2 days of application to minimize some of it being lost to the air or burning the grass.

[andy10917]

I prefer to see it get watered in before the next dew cycle (meaning overnight). Dew is enough water to cause the breakdown of prills, and not enough to dilute it to acceptable levels.

[PSU4ME]

Thanks guys, I'll plan accordingly

[bigterp]

What does everyone recommend on watering in coated urea? Is it as necessary to water in coated versus regular?

[ken-n-nancy]

What does everyone recommend on watering in coated urea? Is it as necessary to water in coated versus regular?

In general, coated urea is "safe" to leave not watered in -- it won't "burn" the grass from being on the lawn but not watered in.

However, most coated ureas do not actually start to "release" until they become wet. So, if one wants the fertilizer to start to provide benefit, the coated urea should be watered in order to start the process of breakdown. The details of this depend upon the specific type of slow-release urea, what the coatings are, etc.

For more information to better understand various turfgrass fertilizer types, I like an article from the U. of Florida Extension, Selected Fertilizers Used in Turfgrass Fertilization. Penn State also has a good article providing more information on slow release fertilizers of various types, Enhanced Efficiency Nitrogen Fertilizers for Turfgrasses.

So, bottom line -- it's not necessary to water in coated fertilizers to prevent damage to the grass, but the benefit of the fertilizer doesn't start to take place until it is watered in.

[LouisvilleGrubber]

The 2017 Updates of this thread have started -- that means that it's time to get your Fall Urea stocks ready to go!

Do you have your's in stock yet?

I sure this has been answered before, but I can't find it in a search. Is that half used bag sitting in my garage from last Fall still usable?

[andy10917]

Yes, as long as it didn't fuse itself into a single big lump.

[ken-n-nancy]

I sure this has been answered before, but I can't find it in a search. Is that half used bag sitting in my garage from last Fall still usable?

Not only is the one from last fall still usable, but the one that your dad left in his garage back in 1992 is still usable, as long as it has remained spreadable and hasn't fused into a big lump. If it has partially fused, just smash it some through the bag, and it will be fine to spread again!

It doesn't go bad any more than a bag of rock salt for spreading on ice goes bad.

[Billybob]

I just picked up a 50 lb. bag of 46-0-0 at the local agway for $16. That's my best price yet

[Zareth]

So.. mine has fused into a solid lump. Should I just try to hammer it up in the wheel barrow or buy a new bag?

[Marinegrunt]

So.. mine has fused into a solid lump. Should I just try to hammer it up in the wheel barrow or buy a new bag?

That's your call. If it breaks up easy why spend the money on a new bag? I'd throw the whole bag in a wheel barrow, use the top part of a 2lb maul or sledge, and just keep smashing the bag. Leaving it in the bag will keep the fertilizer contained in a small space making it easier to smash. You might have some small clumps to deal with once you're ready to use it though.

If you don't feel like messing with it but a new bag. It usually breaks up pretty easy unless it got really wet.

If it's too hard to smash, and you're really tight, weigh it and dissolve it in water for a liquid fertilizer.

[ken-n-nancy]

So.. mine has fused into a solid lump. Should I just try to hammer it up in the wheel barrow or buy a new bag?

Well, if you don't use the bag you have, then the question is how to dispose of it? In all honesty, the environmentally conscious solution would be for appropriate "land application" -- which would involve spreading it as fertilizer!

I'd try to figure out if there is a way you have to grind / smash it up into spreadable pieces. I'd be inclined to hammer on the bagged product to break it up into spreadable pieces, as if I were turning oreo cookies into cookie crumbs for a pie crust. However, I have no idea how well that will work, especially if your bag got wet, in which case it really could be just about a solid mass.

EDIT: google-fu to the rescue! You just need one of these: urea lump crusher.

[RichS]

How much water is needed to adequately dilute 46-0-0? After putting it down late Sunday, predicted rain didn't show , so I put sprinklers out for about 3 hours last night - probably .3-.35 inches.

[seiyafan]

That should work.

[Billybob]

Did my first app of .5 lbs of nitrogen (1 lb. urea) and timing worked out perfect, it rained all day.

[ken-n-nancy]

How much water is needed to adequately dilute 46-0-0? After putting it down late Sunday, predicted rain didn't show , so I put sprinklers out for about 3 hours last night - probably .3-.35 inches.

Generally, 1/4" is sufficient. However, the only way to be sure is to look down in the grass after watering it in and see if the prill are completely dissolved away. If they're gone, you applied enough water. If they're still there, then either you have gaps in your sprinkler coverage, or you didn't water it enough...

[PSU4ME]

Aimed to do my first app tonight and there is a fine line between my spreader allowing the prick out and doing more than 1lb per 1k. I measured and calibrated the walk but over the course of 23k, I prob put down 26lb but there was some waste on walk ways and driveways

[andy10917]

there is a fine line between my spreader allowing the prick out and doing more than 1lb per 1k.

This is a family channel, sir

[PSU4ME]

there is a fine line between my spreader allowing the prick out and doing more than 1lb per 1k.

This is a family channel, sir

Lol my bad. Prill, prill I meant!!!

[Jsdepasquale]

Got two bags of Urea for $9.50 each at the local farm grain elevator! Woo hoo!