# Maximum pounds of urea per gallon

Discussion in 'Pesticide & Herbicide Application' started by DFW Area Landscaper, Dec 14, 2004.

1. ### DFW Area LandscaperLawnSite Silver Memberfrom DFW, TXMessages: 2,116

I'm thinking of purchasing a 50 gal spray tank, but I wasn't sure what the maximum number of pounds of Urea I could mix in before it becomes saturated. The 50 gal spray tank will be jet agitation only.

Anyone know how many pounds of urea can be mixed with 50 gallons of water using jet agitation?

Thanks,
DFW Area Landscaper

2. ### HamonsLawnSite Senior Memberfrom Overland Park, KSMessages: 706

I think you must be asking the wrong question.

I mean you could dissolve atleast 200# of urea in 50 gallons of water -- but unless you are melting ice, I don't know what you would use it for.

What you want to do is figure out how many gallons per thousand you are going to spray your yards with and then decide how much nitrogen you are hoping to apply.

So if you were spraying 3 gallons per thouand and you wanted to apply 1#N per thousand then you would dissolve 16.5 pounds in your 50 gallon tank. YOU could then apply this to 16.5k of turf

I'm guessing what you are really trying to figure out is --- is 50 gallons big enough for you? Probably not if you are applying fertilizer which needs quite a bit of carrier -- but...if you are applying herbicides then you can get by with 1.5 gallons per thousand and get 33k or so out of one tank.

3. ### DFW Area LandscaperLawnSite Silver Memberfrom DFW, TXMessages: 2,116

Hamons,

Thanks for the reply. I just know that on average, last summer, we would apply about 1/2 a bag of Lesco 28-3-10 to each lawn. Each lawn is an average of about 4,000 sq ft of turf.

30% of the 28-3-10 is slow release. So if my math is right, on average, we were applying about 1.22 pounds of urea per thousand.

My concern with adding more than a 50 pound bag of urea to 50 gallons of water is, at what point do you reach saturation, where in the pellets will no longer dissolve?

If I can easily dissolve 1.5 bags (75 pounds) of urea in a 50 gallon tank of water, agitated only by jets, that would be great.

Later,
DFW Area Landscaper

4. ### HamonsLawnSite Senior Memberfrom Overland Park, KSMessages: 706

Well if you applied "about" 1/2 bag per 4k lawn we'll say that is 6.25#/1000. Since your fertilizer was 28% nitrogen then you applied appled about 1.75# per thousand. Thats VERY rich to be putting down in the summer. Guessing the 30% slow release was SCU if it was from Lesco -- so thats still urea -- with some sulfur covering it.

However, lets say that worked really well for you and you wanted to 1.75#N per thousand again this year. And you wanted to dissolve 75# of urea in your tank. Then you would need to be accurately spraying at .6 gallsons per thousand.

Will that work for you? I would have no idea how I would be able to apply .6 gallons per thousand accurately with a skid sprayer.

BE careful -- Fertilizing this isn't like your pansy problems last year. If you do this wrong you aren't talking about replacing a few flats of pansies -- you'll replacing an entire yard!!!!!

5. ### RicLawnSite Fanaticfrom S W FloridaMessages: 11,969

What you guys with the perma greens and apply at low rates per thousand Sq Feet don't understand is Volatilization. I send TimsTurf and e-mail about this same subject last night and I am not going to retype it here. However the bottom line is. High urea and low water will cause the nitrogen to evaporate before it can get to the turf. Our Air is 78% nitrogen and Guess how Urea is made. It is sucked out of the air and then heated and put under pressure to form prilled Urea. That is why Russia makes so much. They have vase natural gas resources and it takes energy to make Urea.

6. ### DFW Area LandscaperLawnSite Silver Memberfrom DFW, TXMessages: 2,116

I think you guys aren't realizing, or maybe I'm mis-understanding: The green up I see on a bermuda lawn a week or ten days after the application is a result of the uncoated urea pellets in the Lesco 28-3-10. The coated urea pellets need time to break down and cause any green up.

I need to go back and re-read the label, but if memory serves me, I think that bag has 70% uncoated urea and 30% slow release.

If I'm applying 1/2 a bag of Lesco 28-3-10 on a typical 4,000 sq ft lawn to get the green up I desire, thats approx 6.25 pounds of 28-3-10 per K. Of that 6.25 pounds, only 1.75 pounds are nitrogen. But only 70% of that is nitrogen is quick release, which is what is causing the immediate green up. That's only 1.22 pounds of quick release nitrogen per thousand.

In order to get 1.22 pounds of nitrogen on a 1,000 sq ft of lawn, and apply the material at 2 gallons per thousand, I would need mix 1.33 bags of urea into a 50 gallon spray tank.

Am I right on this?

Later,
DFW Area Landscaper

7. ### RicLawnSite Fanaticfrom S W FloridaMessages: 11,969

DWF

Do me and your self a favor. Try 1/4 of a bag of urea 46-0-0 in your 50 gallon tank and spray it at 4 gal per thousand. Then use your 1.33 bags per 50 gallons at 2 gallons per thousand. Do this side by side where you know you have a good sample to study. BTW liquid will not last like SR granules.

Now the rate is 1/2 lb N Vs 1.25 lb N per thousand. However you should get the same initial response and not the nitrate leaching into the ground water. I think you need to realize Ground water contamination is a rather large issue. But at least look at it from an IPM stand point.

IMP=I Pay for Materials

8. ### DFW Area LandscaperLawnSite Silver Memberfrom DFW, TXMessages: 2,116

Ric,

You've got me thinking on this. I might be able to save a ton on material costs using a spray solution. This is definitely gonna be cheaper than paying \$18.xx per bag (50 pound) of 25-2-5 with Pre-M.

Am I missing something or are liquid apps a lot cheaper than granular?

Later,
DFW Area Landscaper

9. ### RicLawnSite Fanaticfrom S W FloridaMessages: 11,969

DWF

Sure they are cheaper if you do the TrueGreen Thing. But what are you trying to do?? Be an agronomist or make money?

Somewhere in between those two factor should be the real answer. Liquids can offer everything that granules can but not at a cost savings. Therefore Use Slow release granules and supplement them with liquids. That is about all I can tell you. I don't know your soil needs so I can't tell you what to use.

10. ### James CormierLawnSite Bronze Memberfrom MaMessages: 1,217

Your missing the cost of the pre m in your liquid mix, thats why it seems so much cheaper.

Plus 18 bucks for that product seems very high