# What Would this Blend Be?



## Tim/South (Dec 12, 2011)

I stopped by the CO-OP to price fertilizer.

I want to blend 5,000 lb. of 34-0-0 with 5,000 lb. of potash and 1,000 lb. of DAP. I became easily confused.

The lady ran the blend through the computer and it came out as 20-4-20.

What am I missing on the numbers? If N is 34% and K is 60%, why would the N & K be equal in number?


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## qcfarms (Dec 14, 2014)

I am guessing that she added nitrogen components of the 34-0-0 and the 18-46-0 (DAP) you get close to equal on the nitrogen and potash. Just running the numbers you get 1700 lbs of nitrogen from the 34-0-0 and 180 lbs of nitrogen from the DAP for a total of 1880 lbs of nitrogen. As far as potash you get 3500 lbs. My ratio would be 17-4-32 but I'm no expert.


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## vhaby (Dec 30, 2009)

qcfarms said:


> I am guessing that she added nitrogen components of the 34-0-0 and the 18-46-0 (DAP) you get close to equal on the nitrogen and potash. Just running the numbers you get 1700 lbs of nitrogen from the 34-0-0 and 180 lbs of nitrogen from the DAP for a total of 1880 lbs of nitrogen. As far as potash you get 3500 lbs. My ratio would be 17-4-32 but I'm no expert.


5000 K2O x .60 = 3,000 lb

3000 divided by 11000 = .2727

Wouldn't potash be 27% ? 17-4-27

Don't understand dealer's 20-4-20, but maybe I'm not thinking correctly either.


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## swmnhay (Jun 13, 2008)

I come up with 17-4-27 also

We use Urea here which is 46% N


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## glasswrongsize (Sep 15, 2015)

The only way I can get it to come out close to 20-4-20 with 11000lbs fertilizer and using those three components (assuming 34-0-0, 18-46-0, and 0-0-60), is to put on 6200 lbs 34-0-0, 3800 lbs of 0-0-60 and 1000 of 18-46-0 (DAP)

Those numbers seem too far off from your requests to be "fat-fingered" into the keyboard.

73, Mark


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## Hugh (Sep 23, 2013)

The answer is: * 17.3 -15.3 - 20*

Dap is diammonium phosphate, which is 18-46-0.

Let's add these three together and divide by 3.

34- 0- 0

18-46- 0

0 - 0 -60

52 - 46 - 60 divide each unit by 3 and we get: 17.3 -15.3 - 20

How do we proof this?

Well a 100 lbs of 34-0-0 has 34 pounds of nutrents

and 100 lbs of 18-46-0 has 64 lbs of nutrents

and 100 of 0-0-60 has 60 lbs.

Mix all of this together and you have 34+64+60 ( 158 pounds of nutrients ) take a 100 pounds of this mix (1/3) and you have 158 divided by 3 = 52.66 add the formula above together (17.3 -15.3 - 20) and you get 52.66, the proof


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## glasswrongsize (Sep 15, 2015)

Hugh said:


> The answer is: * 17.3 -15.3 - 20*
> 
> Dap is diammonium phosphate, which is 18-46-0.
> 
> ...


Unless I misunderstand everything, you missed the ratio of 5000 lb/5000 lb/ 1000 lb. In your above equation, you used 100 lbs for each ingredient. To use 100 lbs of 0-0-60 and 34-0-0, you only get to use 20 lbs of 18-46-0

73, Mark


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## deadmoose (Oct 30, 2011)

Good reasons above to never trust other's numbers. Only 40% are accurate (probably between 15-95% depending on who is doing the math). Five responses (including original), 4 different answers. On a good day this can work in your favor, and a bad day not so much.


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## Hugh (Sep 23, 2013)

Sorry, I misread, though it was 5,000 lbs each material.

Refiguring, you would have 11,000 lbs of material in total. The N would be 5,000 x .34 = 1700 + 180 lb. N in the DAP total N = 1880 lb.

The phosphates would be 46% of 1000 lb or 460 lb

The potassium (K) would be 60% of 5000 lb or 3000 lb.

to get the percentages,

1880 divided by 11000 = .1707 or 17% N

460 divided by 11,000 = .0418 or 4% P

3000 divided by 11,000 = .2727 or 27 % K

So, then: 17-4-27, the same # vhaby came up with.


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## Hugh (Sep 23, 2013)

deadmoose said:


> Good reasons above to never trust other's numbers. Only 40% are accurate (probably between 15-95% depending on who is doing the math). Five responses (including original), 4 different answers. On a good day this can work in your favor, and a bad day not so much.


 You are saying: "Only 40% are accurate (probably between 15-95% depending on who is doing the math.." You are doing math here, so then it follows your statement is only 15% - 95% accurate. Wow.. a real catch 22 or is it catch 37 ?


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## qcfarms (Dec 14, 2014)

deadmoose said:


> Good reasons above to never trust other's numbers. Only 40% are accurate (probably between 15-95% depending on who is doing the math). Five responses (including original), 4 different answers. On a good day this can work in your favor, and a bad day not so much.


Your right......I've got a math degree and couldn't get the potash right. For some reason I kept using 3500 lbs instead of 3000 lbs......not sure how I got .6*5000 to equal 3500....duh.


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## Hugh (Sep 23, 2013)

"Your right......I've got a math degree and couldn't get the potash right. For some reason I kept using 3500 lbs instead of 3000 lbs......not sure how I got .6*5000 to equal 3500....duh."

Today I applied 1/2 pound per acre of boron to my orchard. I figured the numbers at least 5 times, and waited three days before I put it out because mistakes will be made, and boron can be toxic at the wrong levels. Einstein made math mistakes, and he had his first wife check his math on his relativity paper. Don't feel bad, just write it down and recheck over and over.

A math degree doesn't mean you won't brain fart, it just means your fart could be larger that most of ours...


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## hay wilson in TX (Jan 28, 2009)

Interesting thread!

We still pay for what the clerk's figures come to. .

I like Hugh's response.

.


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## mlappin (Jun 25, 2009)

First of all, recognize what you are and don't fight it.

If your a night owl, then do your figuring at night, if your an early bird then do your math at the ass crack of dawn.

Most people try to force themselves to do paperwork, bookwork, etc at the times opposite they do their physical labor.

Personally I'm a night owl, I do my best work in the dark, left completely alone with no distractions, however I also avoid doing bookwork or taxes at night as by time I come in, my physical toils have left me too fuzzy to any ciphering.

All these different answers have come in from simple mistakes in math, it's not really rocket science after all.

BTW, I agree with Vhaby


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## Tim/South (Dec 12, 2011)

I am just happy that I finally have the formula to figure the blend. I have never looked into it before.

Thankful for the free education.


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## r82230 (Mar 1, 2016)

I had a similar problem, with local Helena lady in the office, she came up with a different set of numbers than what I ordered/expected. Turns out both of our numbers for the analysis where right, but she decide to put in different amounts of product. I requested 8,000# of potash and 2,000# of DAP (4 to 1 ratio) and she decide that I wanted a 5 to 1 ratio. She put in10,000# of potash and 2,000# of DAP, which was 'too much' for the spreader, and lower both amounts down, coming up with her numbers.

Finally got her to just enter the pounds I wanted and not to worry about the analysis (which I originally requested).

I was aiming for about 250# K, 50# Ph per acre replacement, for the 5 ton target goal production (top end goal). My actual tonnage is closer to 4 tons per acre and this formula, gives me about 230# K and 46# Ph more than enough for replacement/maintenance, I believe.

I have remember "figures never lie, but liars figure".


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## swmnhay (Jun 13, 2008)

I always order by analysis per acre not pounds of product.It's the way it's done here.

I might order 18-46-120 which is 100 lbs acre of 18-46-0 and 200 lbs off 0-0-60 per acre.300 lbs total product per acre.


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## glasswrongsize (Sep 15, 2015)

swmnhay said:


> I might order 18-46-120 which is 100 lbs acre of 18-46-0 and 200 lbs off 0-0-60 per acre.300 lbs total product per acre.


My calculations put your 100 lbs of 18-46-0 and 200 lbs of 0-0-60 at 6-15.3-40
73, Mark


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## swmnhay (Jun 13, 2008)

glasswrongsize said:


> My calculations put your 100 lbs of 18-46-0 and 200 lbs of 0-0-60 at 6-15.3-40
> 73, Mark


yes it's 300 lbs of 6-15.3-40.
But the actual N-P-K per acre is 18-46-120

I order 18-46-120 per acre. X the acres.Their computer program computes what they need to mix.


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## glasswrongsize (Sep 15, 2015)

swmnhay said:


> yes it's 300 lbs of 6-15.3-40.
> But the actual N-P-K per acre is 18-46-120
> I order 18-46-120 per acre. X the acres.Their computer program computes what they need to mix.


Aaaah....I understand! That makes sense. The lightbulb JUST came on to another way of figuring.

73, Mark


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## Tim/South (Dec 12, 2011)

glasswrongsize said:


> Aaaah....I understand! That makes sense. The lightbulb JUST came on to another way of figuring.
> 
> 73, Mark


Just when I thought I understood and now in the dark again.


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## glasswrongsize (Sep 15, 2015)

Tim/South said:


> Just when I thought I understood and now in the dark again.


My formula was pounds of n,p,and k per 100 lbs; Cy's formula is pounds of n,p, and k per acre.

My "6-15.3-40" is correct for the mix of 100 lbs of 18-46-0 and 200 lbs of 0-0-60 (300 lbs total), there is 6-15-40 in EACH 100 lbs, but he is putting on 300 lbs per acre, so (per acre) he is putting on 18-46-120 of actual per acre.

If you take my figures (per cwt) and multiply by 3 (per cwt as he is putting on 300 lbs per acre of the "100 lb formula".

If you know that you get your soil analysis and decide you need 180 lbs of K per acre, you order 300 lbs of 0-0-60 per acre to achieve it. If you also want 18 lbs of N and 46 lbs of P per acre, you order 100 lbs per acre of DAP (18-46-0). When they mix the 400 lbs of fertilizer and spread it you will be receiving the aforementioned quantities of each nutrient per acre, but the actual "mix" would now be 4.5-11.5-45.

Another way to explain it is Cy's figures are actual nutrients requested per acre; my figures were percent of nutrient in the mix.

I hope that was not MORE confusing?

73, Mark


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