# Midwest Labs Warm Season Lawn Test Advice



## daviddsims (Apr 15, 2018)

After seeing @Ridgerunner talk about Midwest Labs soil testing I thought I would give them a try. I use them at work for other testing so it was a pretty easy choice. I chose the S3C package with recommendations. I currently have centipede in the back yard but am converting it over to bermuda soon. @g-man or anyone else care to take a look and give advice?


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## daviddsims (Apr 15, 2018)

Does their recommendations per 1k mean that's the total that should be applied across the season? Also why the gypsum recommendation?


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## Ridgerunner (May 16, 2017)

What's your soil like? Very Sandy (larger soil particles)? Although it's been my experience that Midwest is very reliable, I notice that on the report they have classified 1.3% OM as VL (very low), but on the bar graph they classify it as optimal to very high. I'd call or e-mail) them Monday for clarification and ask if whatever created that glitch would skew any of the other reported values on the report. Just to make sure. I'm not sure whether their reports and recs are done by an agronomist or a computer algorithm.


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## daviddsims (Apr 15, 2018)

Good catch @Ridgerunner on the OM. My soil is very sandy and doesn't hold nutrients very well. I'll give them a call on Monday and see what they say.


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## Ridgerunner (May 16, 2017)

daviddsims said:


> Does their recommendations per 1k mean that's the total that should be applied across the season? Also why the gypsum recommendation?


Sorry, didn't see you had posted a follow up. Yes, the recs are for a whole season and are reported as lbs/acre, so divide by 43.5 to get pounds/thousand. Then divide that up between the number of applications you wish to apply (no more than 1lb/M of any one nutrient in a 30 day period.)
Regarding the gypsum recommendation: Gypsum is usually recommended to 1. raise soil Ca levels (particularly when it is desired not to affect current pH.), 2. to remove Na from the soil (pretty effective) or 3. to remove Mg and raise the Ca:Mg ratio with the goal of improving soil tilthe (effectiveness is debatable). It's somewhat hard to decipher the philosophy of each lab and the individual agronomist they employ when judging the recommendations they give. It's often based on either SLAN, BCSR, MLSN or their own data bases created for local soils, general soil classes, climate and specific crops. It can also be combination of all the aforementioned. In this case, my best guess is that they wish to increase Ca levels (SLAN sufficiency values for Ca is >500 ppm) while not raising pH. Lower pH will make micro-nutrients more available and studies have found pH levels close to 6 have lower incidence of disease in Southern climates. One might politely disagree or not.


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## g-man (Jun 15, 2017)

@Ridgerunner their recommendations are strange to me. The second sheet says gypsum or elemental sulfur. The or makes me think that they are trying to address the low sulfur. Using gypsum to raise sulfur is something I've not considered in the past. I think these recommendations are just from a computer algorithm.

David, let's get back to the issue at hand. Soil pH is 6.0. This is fine for growing Bermuda. Your cec is low and like you mentioned, the soil will not hold to nutrients very much. Twice a month applications at half the monthly rate would be beneficial.

P and K can be improved. You should use SOP to address the low sulfur along with the P.


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## daviddsims (Apr 15, 2018)

I'm having heck finding SOP anywhere near me. I've called every store around me and had no luck. I'll definitely do the half rates when I get it. Thanks for the advice everyone.


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## Ridgerunner (May 16, 2017)

@g-man I hadn't bothered looking at the recommendations. If a report includes a bar chart, I like to scan it to get a quick overview and see what areas the lab has identified as very deficient or excessive. when looking at the raw data of the soil test (page 1), I didn't get past pH and CEC when I saw the discrepancy for OM and posted to verify that this was a sand soil and request David contact Midwest to clarify. 
I have seen gypsum recommended to address S quit a few times. I should have included that in my reasons why gypsum applications are usually recommended. @daviddsims i.e. I should have written: 1. raise soil Ca or S (sulfate) levels (particularly when it is desired not to affect current pH.). 
Gypsum is about 29% Ca and 23% S. 200 lbs/acre would increase Ca by 29 ppm and S by 23 ppm. 10 lbs of S/acre would increase S levels by 5 ppm. Recommended S values sufficiency ranges vary. Carrow recommends 15-40 ppm, Midwest recommends 13-19. @g-man so yeh, the recommendations are a little strange, but they wouldn't create issues. Consistency would be nice though. It's the reason I don't like to default to lab recommendations even when I often do for expediency.


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## daviddsims (Apr 15, 2018)

I spoke with one of the agronomist at Midwest and he said the OM was an error on the computer program. @g-man and @Ridgerunner he also said the gypsum was to flush some of the sodium out of the soil since it was at 31 ppm. Anyways, good customer service responding right away this morning.


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## Ridgerunner (May 16, 2017)

Thanks for following up. :thumbup:


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