# BG South Carolina Soil Test - Centipede



## Spittin_Fire (Jun 8, 2021)

1st time poster, long time reader! I appreciate any and all time individuals take to read and respond. I don't need a perfect lawn, but want a great lawn. I've had a really hard time getting my lawn to fill in completely and be lush.

Background:
House built in 2018 with centipede sod
Samples were taken between 5 to 6 inches with a soil sample probe over multiple locations. I realized after reading the instructions that I should have aimed for 4 inches, but I had already sampled and sent in. I also wanted a good indication of soil structure, so hopefully 5 to 6 inches isn't that detrimental.
Roughly 3000 sq ft yard, with irrigation. Usually water twice a week, mow once or twice a week.
Used another lab the last two years. pH was high. 2020 pH was 6.9, was able to get down 50lbs of Sulfur over 3 different applications in 2020. 2021 pH 6.4. Both were through Spectrum Analytic.
Have put down about 30 lbs. of sulfur this year.
I know soil test should be done at the beginning of the year prior to any applications, but I was curious as to how the lawn was progressing this year. I did put down about .5 inch of compost this spring, 40lbs of Anderson's Humichar, Anderson's Professional PGF 16-0-8 at recommended settings for 3000 sq ft, as well as the 30 lbs. of sulfur mentioned above over two applications so far.


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## Spittin_Fire (Jun 8, 2021)

I did forget to mention that I threw down some Ironite about 3 weeks ago.


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## Virginiagal (Apr 24, 2017)

I'm going to link to Clemson's guide to centipede maintenance:
https://hgic.clemson.edu/factsheet/centipedegrass-maintenance-calendar/

Logan Labs tries to get nutrients into certain ratios and I disagree with that approach. So I am skeptical of their targets and deficits. You have asked another forum for their advice and since they analyze only Logan reports, you might as well just go with their feedback. I would just say to continue to try to lower the pH as centipede likes it under 6.0. And don't use more than 2 lb of nitrogen per 1000 sq ft in a year. You probably need some magnesium but I'm not going to recommend an amount.


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## g-man (Jun 15, 2017)

^ +1

And avoid doing compost or anything with P. Centipede does not like P.


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## Spittin_Fire (Jun 8, 2021)

I am looking for any and all advise. I'm working as hard as I can, and possibly even pushing it a little to bring the soil pH down. I realize it's a slow and biological transformation into sulfuric acid. I realize everyone probably has their favorite lab to send samples to, but honestly, I just love to take as much advise as I can from everyone willing to share. I have a very sandy soil as well, so I'm trying my hardest to also amend the soil, which between compost and peat moss seem to be the only two options. The lawn reacted very well to the compost and was the greenest it has been in two years. I know from reading that centipede does not like Phosphorus, and quite honestly I don't even know if the value is good, bad or indifferent. I'm assuming from everything I scoured on the net that Mg is low and Epsom Salt is my best bet, but I'm not even sure how much to put down.

Thanks in advance for any and all consideration!


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## Virginiagal (Apr 24, 2017)

You may be interested in Ridgerunner's soil test thread. Logan uses Mehlich 3, I believe:
https://thelawnforum.com/viewtopic.php?t=1088
If you want to calculate your magnesium shortage and how to adjust, you can do it using the info in that thread. However, centipede is such a strange grass and normal soil requirements may not apply. Everything I've read is that it thrives on neglect and poor soil. I suggest calling your local extension office and asking them if they have information about what the soil nutrients levels should be for centipede. You could share your soil tests (you have two this year, right?). Maybe you can even communicate with a Clemson turfgrass specialist.


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## Ridgerunner (May 16, 2017)

Every 1#/M of Epsom Salt will theoretically add 2.3 ppm of Mg. Remember that your soil CEC bucket is full: 78.8% Ca, 4.3% Mg, 3.4% K, etc. = 100%. When anything is added to a bucket that is full, something has to spill out. In addition, excessive application can make it harder for turf to access the other nutrients due to sheer volume of proportions. I'd suggest spoon feeding 2-3 lbs/M every couple of months (2 maybe 3 applications total this season) and look for any turf improvement or decline. Retest next season and see where you are.
Your saturated paste test results do indicate possible issues. Biochar and granular HA may be a more effective remedy and allow you to avoid adding P. I don't know what the tolerance threshold of Centipede is for P, but for any other turf, your P levels wouldn't be considered excessive. At 40ish ppm it's just above the middle of the sufficiency range.


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## Spittin_Fire (Jun 8, 2021)

Thanks Ridgerunner...I did put 40lbs of Andersons Humichar down around April. I know this is more than the settings recommended for 3000 sq ft, but all the the reading I garnered over applicating wasn't that big of an issue. I also put down 16-0-8 Anderson's fertilizer with HumicDG at the recommended rates. I then put down a good layer of compost with a compost spreader. I stay away from Phosporus as much as possible due to everything I read saying P is bad for centipede grass.

Are you suggesting adding the recommended epsom salt as well as another application of Humichar?


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## Ridgerunner (May 16, 2017)

> Are you suggesting adding the recommended epsom salt as well as another application of Humichar?


Yes, sir.
Your paste results show very low values for all nutrients except S. A paste test is just a snapshot and is far, far from conclusive, but if it is indicative of a pattern, then adding chelating CEC (biochar or better yet, granulated HA) might help in nutrient retention. Definitely NO guarantees, it will probably show no effect, but it won't hurt anything either.
Do some research as their are other sources for Mg than just Epsoms.


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