Need help interpreting soil test results

By and large follow the recommendations provided. Soil pH will be raised prob to about 6.5 over a period of months with the addition of a slow reacting lime, which is near where St Augustine performs best. Use calcidic or dolomitic lime (calcium carbonate and or calcium/magnesium carbonate, slow acting) should be available at the big box stores. In my opinion do not use fast acting hydrated lime (calcium hydroxide) or burnt lime (calcium oxide) - your pH is not so acidic for St Augustine that it needs rapid acting lime. Use something like this LINK but don’t use this LINK

Phosphorus, follow the the AgCenter recommendation - I’m guessing this likely for the front yard only where P is low. A bag and 1/2 of this. LINK

Nitrogen - use a lawn fertilizer (not weed & feed containing herbicide) with a N-P-K of 33-0-x or 24-2-11 - or something similar to that at a rate of 1 pound of N per 1000 sq ft. For the actual amount to apply per 1000 sq ft divide the % N into 100 so, if using a 33-x-x, 3.3 lbs per 1000 sq ft or for a 24-x-x, 4 lbs of lawn fertilizer per 1000 sq ft. Apply the first application when the grass greens and grows enough for you cut the grass twice, prob around April 1 to April 15. Second application in June, third application in August and you are done for the year.

Do another soil test in Nov/Dec to check how much the pH has been raised by the lime addition and tweak it from there.

Note: lawn fertilizers are going to be very low in phosphorus by design, often 0 or maybe 2 %, Potassium levels vary among lawn fertilizers a good bit that’s why I used an “x” as opposed to a real number. The lawn fertilizer I use is a LESCO 24-2-11.

Where’d you get it done? By LSU? Was wondering how long it took to get results back

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dolomitic lime

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His magnesium is already high, so I wouldn’t bother with this. I assume this is some variety of clay soil? If so make sure your drainage is optimized.

Usually takes about 7-10 business days to get the results back.

I may be missing something or I could be confused, but if his soil sample shows he needs 7.5# of N per 1k sq ft for the front and 13# for the back, why would he only put it at a rate of 1# per thousand in your assessment? Shouldn't this be 2ish # for the front to equal it out over the 3 fertilizations?

FWIW, I could be completely mixed up with this.

Soil samples don't give N results because of how fast it disappears from the lawn. The way I read it LSU didn't say he needed that amount of fert. It looks like that is the numbers that he came up with himself.

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may be missing something or I could be confused, but if his soil sample shows he needs 7.5# of N per 1k sq ft for the front and 13# for the back, why would he only put it at a rate of 1# per thousand in your assessment? Shouldn't this be 2ish # for the front to equal it out over the 3 fertilizations?

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To clarify, the AgCenter N recommendation for this yard is 7.5 lbs N per 2,500 sq ft FY = 3 lbs N per 1000 sq ft total for the years split equally among 3 applications therefore the amount of nitrogen per application is 1 lb N per 1000 sq ft. Ditto the same process for calculation for the backyard.

The standard recommendation for N fertilization of St Augustine is 1 lb N per 1000 sq ft per application, with usually 3 applications per year.

I understand what the primary purpose is. I’m just saying I wouldn’t bother with the dolomitic variety since his magnesium is already acceptable. Just use the calcitic.