# Triple superphosphate vs MAP



## ceriano (Oct 6, 2021)

What's the application rate for triple superphosphate 0-44-0 or monoammonium phosphate-MAP 10-50-0. Is one preferred to another?


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## Virginiagal (Apr 24, 2017)

To get 1 lb of phosphate, divide 1 by the percentage number, thus 1 divided by .44 equals 2.27. So 2.27 lb of 0-44-0 has 1 lb of phosphate. For 10-50-0, divide 1 by .50 to get 2. So 2 lb will give you 1 lb of phosphate and also 0.2 lb of nitrogen.


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## Virginiagal (Apr 24, 2017)

Either is fine for acidic soil (won't lower pH much). Summer is not a good time to fertilize with anything in central VA. Grass has enough stress as is. Wait until late August or early September or even mid Sept if the weather is still in the 90s day after day.


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## ceriano (Oct 6, 2021)

Virginiagal said:


> Either is fine for acidic soil (won't lower pH much). Summer is not a good time to fertilize with anything in central VA. Grass has enough stress as is. Wait until late August or early September or even mid Sept if the weather is still in the 90s day after day.


Awesome will do. Southern state had a few bags of triple superphosphate, figured to grab them before they are gone.


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## ceriano (Oct 6, 2021)

Virginiagal said:


> Either is fine for acidic soil (won't lower pH much). Summer is not a good time to fertilize with anything in central VA. Grass has enough stress as is. Wait until late August or early September or even mid Sept if the weather is still in the 90s day after day.


How many applications do you recommend in the fall? 2? 
So far I've put down 30lbs of 24-25-4 starter fert this season. If my math is correct that'd be about 0.75lbs of P per 1000. I'm not planning to use starter fert in the fall so "p" application needs to be done separately. My soils is deficient in P and K. I was thinking to do 2-3 apps of MAP and pull another test sample next spring see where I am.


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## Virginiagal (Apr 24, 2017)

What are you planning to use for nitrogen and potassium in the fall fertilizations? VA Tech on another page goes into detail about when to fertilize and how much, don't they? Probably it ends up being, at most, 3-4 lb of nitrogen a year. And they're saying you need half of that amount for phosphorus and potassium. You've done 1.5 lb per 1000 of phosphate already, which is all they are recommending for someone doing 3 lb of nitrogen a year. The fall fertilizations are the most important ones and you should go heavy in the fall, light in the spring (1.4 lb is not light). Keep up the lime applications fall and spring.


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## ceriano (Oct 6, 2021)

Virginiagal said:


> What are you planning to use for nitrogen and potassium in the fall fertilizations? VA Tech on another page goes into detail about when to fertilize and how much, don't they? Probably it ends up being, at most, 3-4 lb of nitrogen a year. And they're saying you need half of that amount for phosphorus and potassium. You've done 1.5 lb per 1000 of phosphate already, which is all they are recommending for someone doing 3 lb of nitrogen a year. The fall fertilizations are the most important ones and you should go heavy in the fall, light in the spring (1.4 lb is not light). Keep up the lime applications fall and spring.


I think I have only done 0.75LBS of phosphorous not 1.5lbs/1000, right? If 2lbs per 1000 is desired then I probably need to do at least one more application in the fall.


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## Virginiagal (Apr 24, 2017)

You're right, 0.75. I misread and thought you'd put down two applications already. You can get one lb each of'n, p, and k with an application of balanced fertilizer. Wouldn't that be simpler? How are you planning to do the potassium?


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## ceriano (Oct 6, 2021)

I did 20lbs of SOP in spring I'm planning to do another 20lbs in the fall. That should take care of potassium. The fertilizer I have is 30-0-8 so that should add some potassium too. I need to add something to raise phosphorus.


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## Virginiagal (Apr 24, 2017)

Sounds good.


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