# Triple superphosphate



## CLT49er (Jun 19, 2020)

Trying to correct P deficiency. Neither Siteone or Ewing had superphosphate and couldnt order it for me. Maybe a state regulation? Soil test suggested 3/lbs per 1k with 2 apps. So only need 24lbs. 50lb online is $70+.

Charlotte NC folks - any local supplier you are aware of?


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## GA250 (Jul 4, 2020)

Not sure about NC, found mine at Seed World 20# bag with shipping runs around $40


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## CLT49er (Jun 19, 2020)

Yeah. I see that too. Thanks. Expectations was different when I saw Ewings website had 50lb for $32. And seedworld is $70 with shipping.


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## g-man (Jun 15, 2017)

For 5k lawn, why not MAP or what is sold as "starter" fertilizer at most stores?


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## CLT49er (Jun 19, 2020)

Just had to look up what MAP was. Thanks! Both stores didnt have anything close to that NPK.

Might try again Penningtons starter. 23-24-7. Seems like the lowest amount of K. My K is excessive. Seems like a good value. (Think it left a lot of filler rock stuff behind. I could be wrong) Then I can switch to Milo or something similar in the heat of summer.


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## Phids (Sep 24, 2020)

CLT49er said:


> Trying to correct P deficiency. Neither Siteone or Ewing had superphosphate and couldnt order it for me. Maybe a state regulation? Soil test suggested 3/lbs per 1k with 2 apps. So only need 24lbs. 50lb online is $70+.
> 
> Charlotte NC folks - any local supplier you are aware of?


How low were your phosphorus levels? The more I have researched plant science, the more I am inclined to be very weary of over applying phosphorus because of its negative impact on beneficial mycorrhizae.


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## CLT49er (Jun 19, 2020)

See below. Last years test was nearly the exact same. I didnt do much to correct other than one app of start fert and one app of milo.


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## Phids (Sep 24, 2020)

It looks like you're not actually that low, so if it were me, I would not be overly concerned with raising P too much because overdoing it can lead to harmful toxicity, and it may not decrease all that quickly. With that said, your Soil pH level looks like it's on the acidic side, and so raising it actually makes P more available. My inclination would be to continue with Milo applications (6-4-0) since that would give you what you need in smaller doses without making your lawn any more toxic with additional Potassium.


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## CLT49er (Jun 19, 2020)

Thanks @Phids.

On the PH, I did a heavy correction last year per soil test recommendation. Only bumped up .5 in this years soil test but learned that it will take a few years to get several inches down. Did another 20lbs this month and also in the fall.


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## Phids (Sep 24, 2020)

My pH level was at 5.7, so I also put down lime (400 lbs. ) over the course of several months last year. When I spoke directly with the Univ. of Georgia extension office about my soil test, I was told it takes 6-12 months for lime to be incorporated into the soil, so it will be interesting to see how much it has changed once I get my next soil test done.


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## CLT49er (Jun 19, 2020)

If you think about it let me know your results. I did 70lbs/1k last May (all at once!). 20lbs in September and again last week.

Do you mean 400lbs over your whole yard or per 1k?


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## Phids (Sep 24, 2020)

It was 400 lbs total for about 5k area. My original plans were to apply 1000 lbs total to bring pH up to the low- to mid-6s, but I never got around to applying the rest. My soil test results from the extension office indicated that 5.7 pH was actually sufficient, but I had heard elsewhere that the sweet spot is above 6.0.


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