# 1st soil test - Looking for some advise



## starkus (Mar 12, 2018)

1st time poster long time lurker.

Need some help with a soil test for a centipede lawn in the midlands of South Carolina.

My lawn is 3,000 sq feet. The soil is red clay. I do 2 to 3 applications of Ringer fertilizer per year (no phosphorous). I try to stay close to 2 lbs of N per 1,000 per year. I cut it about 1 1/2 and mulch the clippings.

*Questions*
1. Centipede prefers a ph of 5.5. Should I do anything to try to lower it? From what I've read lowering is hard and expensive. They didn't recommend doing anything even on the sample that read 6.8.
2. Is the excess calcium in the soil an issue or just a fact of life with red clay?
3. Anything else that sticks out to the more knowledgeable folks?

Front Yard Soil Test


Back Yard Soil Test


Pic of the front yard from last summer


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## viva_oldtrafford (Apr 4, 2018)

Few thing to look at when you're looking to lower the soil pH - Elemental Sulfur (cheapest material - and can take up to 4 months to work) / Iron Sulfate - More $$$ because you need about 7x more IS than ES, but it works within a few weeks / Sphagnum moss peat - again, pricey, but very long lasting - think years after incorporated (it has a pH of 4-4.5) / Ammonium sulfate - acidifying fertilizer (not too pricey).

Base saturation test looks fine. Ca is dominating the exchange cites, but being a divalent cation, that's to be expected (most of the time). It's not something to worry about.


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## J_nick (Jan 28, 2017)

@Ridgerunner


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## Ridgerunner (May 16, 2017)

First, Welcome to TLF.
What lab (university) did the test?
Could you call them and ask which testing they used? (probably Mehlich 3 or Mehlich 1)

I have no experience with centipede (or any warm season turf).
If recollection serves me well:
It does not do well in soils with a pH above 6
It does not do well with more than a couple of pounds of N annually (disease and thatch)
It does not do well with higher levels of soil phosphorous. (Chlorosis)
It does need sufficient potassium especially in the Fall
Even for a turf grass it is very shallow rooting
That sound about right?

Are you interested in staying with the centipede or are you considering other grasses? ( Your pics od look pretty decent with the exception of a few areas)
Not familiar with Ringer/ Is that an Organic? could you link to a guaranteed analysis?
It it's an organic, are you committed to organics or would you be willing to use synthetics, at least for a couple of years?


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## J_nick (Jan 28, 2017)

Ridgerunner said:


> Not familiar with Ringer/ Is that an Organic? could you link to a guaranteed analysis?
> It it's an organic, are you committed to organics or would you be willing to use synthetics, at least for a couple of years?


Ringer Lawn Restore it's an organic 10-0-6


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## Ridgerunner (May 16, 2017)

Thank you. @J_nick


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## Gibby (Apr 3, 2018)

@starkus welcome to TLF and finally another person in the Midlands! Checkout our member map here https://thelawnforum.com/viewtopic.php?f=8&t=2220

I have centipede also and have a very high soil PH, 6 to 8.1 depending on the part of the yard. Over at ATY, I was told it was useless to try to lower the PH.... So I have not considered it, or looked into it, but now I might consider it as I am thinking about switching out my front turf to bermuda or zoysia.

For centipede I follow a hybrid program based on the leaflet from Woodley's which from my understanding they worked with an University to create. 


I apply 2 apps of Pre-Emergent during the year(spring/fall), I was using what they recommended(dimension) but I got some prodiamine to try this year.

I do 1 app of the synthetic fertilizer at the beginning of the year with 15-0-15. Then about every 6 weeks I put down milorganite.

For weeds I use Celsius spiked with MSM. And for sedge, I use sedgehammer.

This year I might drop the synthetic ferts, but haven't decided yet. Going to do another soil test. I found that Carolina Fresh Farms on Clemson Rd does them for free. Here is mine from last year if you want to compare.


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## starkus (Mar 12, 2018)

Thanks @Ridgerunner. Clemson (Go TIGERS!)did the soil samples. I called them and they use Mehlich 1.

At this point I pretty committed to centipede. Honestly, the front yard looks really good in the summer time and justifying the time and expense of killing it is a tough sell. Backyard struggles in spots around trees and high traffic places.

Centipede is the dominate grass in my area. If you move into a production builder type neighborhood here 95% of the time its centipede. If you go to Lowes/Home Depot to get sod that is what they have.

I know this will make some folks here cringe but the bare spots in the lawn are places I had sprayed a round of Sethoxydim to kill some bermuda that had crept into the lawn.

Open to any type of fertilizer. Like many beginners the content that is easily available and understandable seems to push you the organic route.


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## starkus (Mar 12, 2018)

viva_oldtrafford said:


> Few thing to look at when you're looking to lower the soil pH - Elemental Sulfur (cheapest material - and can take up to 4 months to work) / Iron Sulfate - More $$$ because you need about 7x more IS than ES, but it works within a few weeks / Sphagnum moss peat - again, pricey, but very long lasting - think years after incorporated (it has a pH of 4-4.5) / Ammonium sulfate - acidifying fertilizer (not too pricey).
> 
> Base saturation test looks fine. Ca is dominating the exchange cites, but being a divalent cation, that's to be expected (most of the time). It's not something to worry about.


Thanks for the info. I'm gathering the consensus is to do something to lower the ph but don't stress to much over it. Hope that is correct.

Glad to know the high calcium is not a problem.


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## starkus (Mar 12, 2018)

@Gibby Thanks for the info and glad there is another person familiar with the centipede struggle.

That plan is pretty similar to what I had landed on for last year when I wanted to push the lawn:


I have found this the tough thing about centipede is that each place you look tells you to do different stuff. NC State says to do one thing, Clemson says another, garden centers say something else, and youtube lumps in all warm seasons turfs together. I've got a fairly extensive spreadsheet developed at this point.

Pre-emergents have been an adventure. Last year I did Prodiamine on Feb 1., Hi-Yield's Dimension mid May, and Mid September Prodiamine. Still had a pretty big Poa problem this spring. Reading through this thread Lawn Site Official Centipede Thread  got me concerned about the "root pruning" effects of those so I was going to use Gallery and  Simazine to see if I got better results.


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## Gibby (Apr 3, 2018)

starkus said:


> I have found this the tough thing about centipede is that each place you look tells you to do different stuff. NC State says to do one thing, Clemson says another, garden centers say something else, and youtube lumps in all warm seasons turfs together. I've got a fairly extensive spreadsheet developed at this point.


You can share your spreadsheet here...

https://thelawnforum.com/viewtopic.php?f=4&t=2257


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## Ridgerunner (May 16, 2017)

> At this point I pretty committed to centipede. Honestly, the front yard looks really good in the summer time and justifying the time and expense of killing it is a tough sell. Backyard struggles in spots around trees and high traffic places.
> 
> Centipede is the dominate grass in my area. If you move into a production builder type neighborhood here 95% of the time its centipede. If you go to Lowes/Home Depot to get sod that is what they have.


I wasn't being judgmental. The conditions in which Centipede thrives are so different from those of most other grasses, that I wanted to know if you had any future plans that would be contrary to my suggestions.
I did a little reading on Centipede and to my surprise, I was pretty accurate with my initial recollections. So, I'll keep those in mind.

To start, I have a thread in the FAQs section that has the sufficiency ranges for nutrient levels based on the Mehlich 1 test. You may want to compare your test values to those just to get an idea of where your levels are. Please note, those values are not tailored to Centipede and may or may not have any useful relationship for targeting "desired" levels of nutrients. For know, just use it as a resource to get your bearings. It is for ppm values. Dividing your soil test lbs/acre values by 2 will give you your soils values in ppm. BTW, the images of your test are blurry and hard to read. When I click on them I get some kind of error message page.
When every source I came across recommends low soil levels of P and a pH <6, one can be pretty confident that there is reliable validity to those recommendations for Centipede grass.
Your observations reflect this. The lawn with the lower pH and P levels is doing better than the lawn in the soil with the higher pH and P.
Consequently, I would suggest you be so guided in making adjustments to your soil.
First, as pH is so important to the performance and health of Centipede, I suggest you consider lowering it.
Attempting to adjust soil with a pH greater than 7.2 is pretty much a "fool's errand", like trying to desalinate the ocean. A field study was done in the early 2000's to test the effect of sulfur applied to a heavy loam soil with a pH of 8. The equivalent of 225lbs/M (they applied 10,000 lbs per acre) of sulfur was incorporated into the soil. Soil pH the following year was 7.4. In years 3,4 and 5 it was 7.6 and for the next 5 years it held steady at 7.8. That's a lot of sulfur for a permanent pH reduction of only 0.2 pH, a pH drop that would have no significant improvement in plant health or crop production.
However, reducing pH in soils with a pH of 7 or lower is realistically doable and attainable. Based on a loam soil, it is consistently roughly calculated that 2#/M of elemental sulfur will lower pH by 0.1. 90% ES is relatively cheap in 50# bagsNo more than 5#/M should be applied at any one time and no more than 10#/M should be applied in a calendar year. Synthetic fertilizers have a greater acidifying affect than organic fertilizers. 2.8 lbs/M of ammonium sulfate (21-0-0) has the same effect as 1# of sulfur. A lot of variables come into play: CEC,, soil texture, climate and watering practices, but IMO, you could apply 4#/M of elemental sulfur ASAP, use ammonium sulfate as your fertilizer and apply another 4#/M of elemental sulfur at the end of Summer. Theoretically, that would lower the pH 6 soil to around 5.5 and the pH 6.8 soil to about 6.3, only a test next year will tell.
I would suggest that you avoid any additions of P this year. As Milorganite contains significant amounts of P, I would suggest you not use it.
If you decide to use ammonium sulfate as your fertilizer, and can't find fertilizer containing it that also contains a significant portion of potassium (K), you will want to source potassium sulfate (SOP) and apply 3# of K/M. That would be 6# of the SOP product broken up into three or more evenly spaced application through the growing season for the front lawn and 2# of K/M in the back yard. That would be 4# of SOP product and could be applied at 2# of SOP/M at the same time as your N feedings. Dividing up the SOP so that it is more heavy in the Fall would be advantageous for Centipede.
Any chlorosis issues can be resolved with spray applications of Iron sulfate (2 oz/4 gallon of water).
I would suggest that you invest in 5 gallon buckets with lids to store the ES and SOP to keep them dry as 50# will last you a couple of years on a 3000 sq ft lawn.
Hope that helps. Sorry for getting so specific with my suggestions. As always, it's your lawn and decision.


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## starkus (Mar 12, 2018)

@Ridgerunner that is a knowledge bomb! Appreciate you taking the time to write that up.

Dumb question.... is 4#/M = 4 lbs per 1000 sq feet?

Found ammonium sulfate for $19 a bag for 50lb bag at Ewing. The guy I talked to wasn't sure if they sold elemental sulfur. So ES might take some work to find. Anyone have any ideas on where to purchase that?


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## Ridgerunner (May 16, 2017)

> is 4#/M = 4 lbs per 1000 sq feet?


Yes.
If you use Ammonium Sulfate (21-0-0), you will need to supplement it with a Potassium source, Preferably: (potassium sulfate, sulfate of potash) SOP at the rates I suggested above. I would avoid MOP, muriate of potash or potassium chloride due to the high salt index.

EDIT: FWIW: https://www.ewingirrigation.com/best-0-0-50-sop-greens-grade


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## Ridgerunner (May 16, 2017)

If you get greens grade, be aware of the small prill size, you'll need to make spreader adjustments to get the right amount down.


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## jayhawk (Apr 18, 2017)

https://www.mbferts.com/SQM-Ultrasol-POTASH-SOP-0-0-52-Soluble-Potassium-Sulfate-520.htm
Fyi
Looks to be a good source


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