# g-man 2021 Soil Test



## g-man (Jun 15, 2017)

Around March the weather was nice after a bit of rain, so it was perfect to collect soil samples. I walked thru the yard and collected around 20 different samples, mixed them and got them ready for shipping. That same day or that week I also spread some XGRN into the lawn to aid in fungus recovery.

A few days later I noticed the soil sample was being tested in the Waypoint system. But looking at the values, there was something wrong. The pH was at around 6, P and K was super low. Overall the answer was very simple. It was not my soil.

I contacted Waypoint asking what was going on. Since they have my previous soil test, it was clear that somehow they screwed up. They immediately offer to retest for free and they sent me a UPS shipping label to send the sample.

I was troubled by the issue, so I did discuss further with them. Part of my day job is failure mode analysis and investigations, so I quickly started a fish bone in my head. While all of their testing process will yield accurate results, it all depends on proper sample management/tracking.

The most likely spot for an issue is at their incoming process. Multiple boxes, samples within the boxes must get to their facilities. Someone need to open, go thru the paper work, enter it into their internal system, grab the samples, pulverize and assign an internal tracking number. I could imagine that this is not a trivial task. Ideally you would process one at a time (open box, enter info, collect sample, etc), clear it all out before you move to the next sample. But this way will take a lot of time vs trying to do multiple samples at once or multiple employees handling the samples (one opens, one in the PC, one labeling, etc).

I could see the error happening. The worst part is that there is no way to detect the failure mode unless like me, you know your soil and know what to expect. This issue can happen in any lab (soil, blood work, covid test). I also know that I'm not the only one that had the same problem. After the conversations, they offered for me to tour their facilities and see their process. They do want to make it better. I declined since it will be a 2 day trip.

So I waited a month to let the XGRN clear up a bit. Not ideal, but ok. My sampling was not as robust as the first one since I was a bit annoyed of sampling again.









The phosphorous keeps increasing. I plan to continue adding more. It doesnt move thru the soil profile as fast.

Potassium still needs improvement. Looking at 2020, I only did 2.8lb/ksqft, so I need to focus more on this one.

The rest looks fine and the lawn looks good, so I do nothing.

2020 soil test


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## ksturfguy (Sep 25, 2018)

Nice catch @g-man . Now you have me worried lol I'm using waypoint for the first time. They got my sample yesterday so hopefully I get the right results haha. Never used a legit lab before so really know way to know. Just have to trust them. Never thought of that scenario happening though.


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## g-man (Jun 15, 2017)

The chance of this error happening is very very low. I think the risk is acceptable. Your other option ($$) is to go sample again and send it to a different lab with similar test methods.


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## ROJ_3030 (Sep 28, 2019)

Glad you were able to get the ol' switch-a-roo sorted out with Waypoint. I have imagine that's extremely rare like you mentioned. Quite interesting to compare your soil test to mine. Looks like you used an SW1 or SW3 test? This helps me to draw some conclusions and shape my current plan.

Couple questions for you: If 2.8lb / sqft of Potassium wasn't enough for 2020, how much do you plan to apply this year? Also, how much Phosphorous did you apply in 2020 and how much do you plan to apply this year?


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## g-man (Jun 15, 2017)

g-man said:


> 03Nov2020
> 
> ~2lb/ksqft of MAP (11-52-0) (10lb actual). This was the last fertilizer application of the year. The totals for the year are:
> 
> ...


I plan to apply 1lb K02/ksqft monthly. Phosphorous, maybe 2-3lb/ksqft.


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## ROJ_3030 (Sep 28, 2019)

Awesome, that makes sense. I appreciate the response. This is all aligning well with my current plan.


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## ROJ_3030 (Sep 28, 2019)

Hey @g-man, I also meant to ask if you're planning to do anything to drop pH? Elemental sulfur or citric acid?


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## g-man (Jun 15, 2017)

Changing the pH in 6in of this heavy soil would be impossible. Just the irrigation water pushes the pH up with our hardwater. I did threw down 5lb/Ksqft of elemental sulfur to help with fungus in that top 1/2in layer of soil and because it is cheap for my 6k lawn.


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## ROJ_3030 (Sep 28, 2019)

With that being said, you give all of us high pH people hope. Your turf is second to none.


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## jha4aamu (Oct 16, 2017)

g-man said:


> g-man said:
> 
> 
> > 03Nov2020
> ...


I am curious as to why you would want to add more P when the soil tests showed it at "VERY HIGH"? I got my soil sample results back from Waypoint about a month ago and my P was "Optimum" at 40ppm. I even asked about potentially applying some SOP since I just purchased some and they recommended not to.

I admittedly am not well versed on interpreting soil test results


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## g-man (Jun 15, 2017)

@jha4aamu two reasons:


> So I waited a month to let the XGRN clear up a bit. Not ideal, but ok. My sampling was not as robust as the first one since I was a bit annoyed of sampling again.


1) The XGRN could skew the results to be higher than real.

2) in M3 the value was 58ppm, which is actually fine. 100ppm would be high, but since the soil pH is high, I like to error towards the high side and target 75ppm in M3.


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## Ridgerunner (May 16, 2017)

> a fish bone in my head


 I really like that phrase. haven't heard it used in a few years.
Interesting that the Olsen P went up significantly while the M3P stayed steady. Two tests don't make a pattern, but still interesting. I can't remember how long you're been using Olsen, but have you seen a pattern? Wonder if that could be due to the slight change in pH or maybe something else you did?


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## g-man (Jun 15, 2017)

@Ridgerunner this type of fishbone (Ishikawa)









Year- ph - Olsen - M3
2021 - 7.9 - 24 - 58
2020 - 8.1 - 16 - 60
2019 Front - 7.7 - 20 - 45
2019 Back - 7.9 - 10 - 14
2018 - 8.1 - XX - 5 - only tested M3

The only difference in the last year is that I'm using more XGRN 8-1-8. It is a composted stuff from chicken manure, AMS, SOP. I still use MAP for P too. I copy all my data into a statistical software (JMP) and tried to build control charts, but it is just not enough data yet. I really should be testing front and back separately.


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## doverosx (Aug 7, 2019)

We use fishbone analysis for the inspect & adapt ceremonies with SAFe. I'm on my work computer right now so the image is blocked but I'm stoked to see your results!

Looks great. I suspect you'll be aiming for higher K rates to pump up the levels; possibly higher than N.


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