# Pete1313's Waypoint Analytical Soil Test



## Pete1313 (May 3, 2017)

I changed up my soil test procedure this year by sampling the whole soil core from 0-4" opposed to just the 3-4" depth in previous years. I also changed labs and went with Waypoint Analytical. Although it is not an "apples-to-apples" comparison since the labs are different, I wanted use this thread to share the results and how the numbers might change around when sampling the whole amount from 0-4"(even after calculating lbs/acre to ppm). Also to show the different results format from Waypoint, which I am liking.

Here are some of my results and amendments that I did over the last couple years.

2016 Physical analysis. Sample depth 3-4"









2016 Soil Test. Sample depth 3-4"
Amendments In 2016:
5.9 lbs/M of N
3.2 lbs/M of P2O5
3.5 lbs/M of K2O
.035 lbs/M of B









2017 Soil Test. Sample depth 3-4"
Amendments In 2017:
5.7 lbs/M of N
2.4 lbs/M of P2O5
2.5 lbs/M of K2O
57 lbs/M Gypsum (21% Ca, 17% S)
.02 lbs/M of B









2018 Soil Test from Waypoint Analytical. Sample depth 0-4". Soil physical properties are also included in the report (extra charge).

















I like how Waypoint gives some general recommendations that are included in the price. The S3M test which is what I got costs $16.50 from the Iowa lab and includes those recommendations. The soil physical test is $25. I also had them do 2 different recommendations(no charge for multiple recommendations) as I wanted to see their difference between a bluegrass lawn and a bluegrass athletic field.

Some of the notables I see are when I sampled at the 3-4" depth the physical properties were 30% clay, 49.2% silt, 20.8% sand. This year with a 0-4" sampling, it changed to 16.8% clay, 48.4% silt, and 34.7% sand. I interpret that to mean their is less clay in the top inches of soil and more sand. Other things I noticed are the OM went up, Ca is up as well as the Ca/Mg ratio (but I applied gypsum), P is down, and K is up.

@Ridgerunner, I know we talked earlier and am very interested to hear your thoughts on soil sample depths and how they changed around the numbers in my case and also what you think about the Waypoint Analytical Soil Test format. Also what do you make about the different recommendations for a bluegrass lawn compared to a athletic field(addition of .5 lb/M of P2O5 and .33 lb/M of S)? Also based on the Ca/Mg ratio, and that the Ca is in the medium range(per the test) what do you think about adding some gypsum to the amendment list this year?


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## stotea (Jul 31, 2017)

Thanks for sharing, Pete. What's the argument for sampling at 3-4" vs 0-4"? Is it just that more root mass is located within the 3-4" range (if that's actually true)?


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## Ridgerunner (May 16, 2017)

> your thoughts on soil sample depths and how they changed around the numbers in my case and also what you think about the Waypoint Analytical Soil Test format.


I do like Wayside's format. It's easy to read with the nutrient values in a list format. The method of extraction, M3/ Mehlich lll is stated next to each nutrient and the visual chart is convenient for a quick scan and evaluation/identification of any nutrient deficiencies or excesses. I prefer testing the 0-4" zone as it accounts for any fertilizer that was applied but hasn't had time to work down. That helps prevent over-application and it isn't as if there isn't plenty of root there. 
A change in numbers is expected. Beyond the difference that will occur between two labs using the same extraction process, the lion's share of change will be due to fertilizer additions, plant uptake and soil dynamics from year to year. The increase in reported OM isn't surprising. I like to tell people who ask me "What is the easiest way to increase my OM% ?" "Only have the top one inch of your soil tested next time."  
Did you account for LL's method for reporting values so you are comparing apples to apples? Anything reported ppm is fine, but anything they report as lbs/acre will need adjusted. Just in case:
For a 4" depth, LL is only reporting 2/3 of the value in an acre slice furrow (the easiest method, _per me_, for doing calculations.)
The 2016 LL test reports Ca, Mg, K, Na and P in pounds.
To cover 4" to 6":
Ca= 1890 X3/2 = 2835
Mg= 818 X3/2 = 1227
K= 185 X3/2 = 278
Na= 36 X3/2 = 54
LL reports P as P2O5, so it needs an additional calculation to convert P2O5 to elemental P
P2O5= 150 X3/2 = 225 /2.3 = 98 lbs of elemental P
Now that we have them all converted to lbs per acre furrow slice, we convert lbs to ppm simply by dividing by 2:
Ca= 2835 /2 = 1418 ppm
Mg= 1227 /2 = 614 ppm
K= 278 /2 = 139 ppm
Na= 54 /2 = 27 ppm
P= 98/ 2 = 49 ppm



> Also what do you make about the different recommendations for a bluegrass lawn compared to a athletic field(addition of .5 lb/M of P2O5 and .33 lb/M of S)?


My best guess as IMO there is plenty of P in the soil: To promote growth and and repair to counter the extra wear and tear. P is important nutrient for root growth (and rhizomes) and also promotes/stimulates root growth. Adding a little in Spring and Fall will provide a "shot" to the KBG. Notice also that they recommend additional N to promote additional growth. S is more important for plant growth and in greater volume than is often credited. (Check the Sufficiency values for S under M3 in my thread. 15-40ppm.)



> Also based on the Ca/Mg ratio, and that the Ca is in the medium range(per the test) what do you think about adding some gypsum to the amendment list this year?


That's not a major concern, although at Ca:Mg ratios lower than 3:1, Ca may start (start) to become less available. That's a judgement call. Adding more calcium will help change the ratio, but doing it will knock off some potassium from cation sites and may bind with P reducing P availability to some extent. Not that any of that is a major concern, just a consideration. I'd probably still do it, but I'm not the decider in chief here.
Let me know if there is anything else you'd like me to take a stab at or clarify.
Thanks for sharing this. :thumbup:


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## Pete1313 (May 3, 2017)

Thanks for your response @Ridgerunner! I did make the calculations to convert lbs/acre to ppm to compare. I did it alittle different but the results were the same. I took lbs/acre at a 4" depth (2/3 acre slice furrow) and multiplied by .75 to get the ppm equivalent. I did make a rookie mistake and didn't catch that LL reports P2O5. So the P in 2016=49ppm, 2017=47ppm, and 71ppm on the 2018 test. Thanks for pointing that out. It is nice to learn the conversions to compare the tests even though the sampling method and labs were both different.

Thanks for taking a stab at why they made different recommendations for a lawn vs. athletic field. Regarding the S recommendation, would adding sulfate based fertilizers or adding gypsum slowly bring that number higher?

I think I want to add some more gypsum this year as well. If I were to add 30 lbs/M of gypsum (21% Ca, 17% S) should that in theory add 207.9ppm of Ca to next year's test result. I'll try the math your way.
30lbs/M of gypsum
× 44(to convert to acres)
× .21(% of Ca in gypsum)
× 3/2(to convert to acre slice furrow)
÷ 2(to get ppm)
= 207.9 ppm
Can you estimate an increase by calculating this way? Or is that not correct? By adding Ca, that will knock off some K, and bind some P, will it also knock off some Mg? Also if I add some gypsum should I be adding alittle more P and K to the recommendations to make up for the losses?

Lastly(for now ), the Ca and Mg numbers are both really high when comparing to the recommendations from the M3 section of your soil test thread, I have read and believe based on my soil that high Mg makes the soil tighter, harder or appear chemically compacted. Thoughts? Are there any issues of a high Ca soil and should I not be chasing the Ca/Mg ratio?


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## Pete1313 (May 3, 2017)

stotea said:


> Thanks for sharing, Pete. What's the argument for sampling at 3-4" vs 0-4"? Is it just that more root mass is located within the 3-4" range (if that's actually true)?


I'm not sure the argument for sampling at the 3-4" range. I did it because I was told it was the preferred way at the time, but now that i question it, I believe that 0-4" is going to be a more accurate approach for me. I believe it to be what Ridgerunner said. It accounts for any fertilizer that was applied that has not worked it's way down. Otherwise you could keep applying a nutrient and if it is stuck in the first few inches of soil, the soil test will still come back as saying deficient when that may not be the case.


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## Ridgerunner (May 16, 2017)

NP Pete.
I'm not quite following your .75 conversion factor (I can be very slow on the uptake), but there are many ways to skin a cat, whatever works for you.


> I think I want to add some more gypsum this year as well. If I were to add 30 lbs/M of gypsum (21% Ca, 17% S) should that in theory add 207.9ppm of Ca to next year's test result. I'll try the math your way.
> 30lbs/M of gypsum
> × 44(to convert to acres)
> × .21(% of Ca in gypsum)
> ...


Using 44 (to convert to acres) is fine, I use 43.5, but this just isn't that an exact of a science.
"× 3/2(to convert to acre slice furrow)" This step is not needed (I employed it only to convert LL reported values at 4" to acre furrow slice).
Correct formula:
30lbs/M of gypsum
× 44(to convert to acres)
× .21(% of Ca in gypsum)
÷ 2(to get ppm)
= 139 ppm

When it comes to Ca and Mg soil levels, you are pretty much stuck with what you have and just work around it. Although additions work out pretty effectively, other than scrambling all of the other Base Cations. Trying to reduce the soil content of either one is less viable. 
Although I mentioned that Ca begins to be less available when Ca:Mg ratios fall below 3:1, there are many studies that have shown that the effect is not a dramatic impediment to crop performance. When I said that I probably would add Gypsum, it was based on my reading that your Ca: Mg ratio was 2.78:1. I misread (I need to use the magnifier to read your reports and I didn't when I was answering that question). Your ratio is actually 2.15:1. The hardest part of soil adjustment (or with any hobby that we tend to be obsessive about) is restraint. Think: "Serenity Prayer."
From that perspective (and keeping it simple and ignoring the other soil interactions that may/would occur):
Your current meq for Mg is 4.3, Call it a 4
To reach a Ca:Mg ratio of 3:1, you need to raise Ca meq to 12.
Current Ca meq level is 9.2
12 - 9.2 = 2.8 meq (shortage, or amount need to get to a 3:1 ratio)
each whole unit of meq is equal to 400lbs of Ca/acre.
400 X 2.8 = 1120lbs of elemental Ca.
Calculating 21% Ca content gypsum needed:
1120 /.21 = 5333 lbs/acre
That's 5333 /43.5 = 123 lbs of gypsum/M.
Just to get to a ratio that most likely wont produce any significant performance changes.

On the Mg effect and tighter soils: No research comes readily to mind, but I'd guess you wouldn't see any significant change in soil structure until you reached a 5 or 7:1 ratio. To me, that's not realistic.
In addition, we surface apply our amendments. So we are flooding the top layers of soil with whatever nutrient we are adding until that nutrient works its way down and diffuses throughout the soil. This creates large ratio imbalances in the top layer. A (albeit "temporary"- Definition of "temporary" depending on the rate of movement of any particular nutrient) rob Peter to pay Paul situation.
On adding P or K (or anything) in an effort to counteract reactions due to gypsum additions: I'm not a fan, as the dynamics are just too unpredictable for calculation. Your current levels are plenty above minimum, I don't see any likely performance improvement to an addition and a higher likelihood of creating other imbalances. Let's avoid the discussion of BCSR and keep it simple. 
If your nutrient values are above minimums, your good. On the other end of the spectrum, you want to avoid excessive values, but only concern yourself with the ones you have control over (i'e, the ones we regularly fertilize with N, P, S, and K.) If your values are at or approaching excessive, cut back on that or eliminate any additions until that value falls.
I would suggest you turn your attention to determining maintenance fertilizer values. 
Hope that helps.
You've got a real handle on these calculations and adjustments. :thumbup:


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## g-man (Jun 15, 2017)

One thing I noticed odd in the report was that they used m3 for phosphorus given the pH being 7.4.

I think that some of us try to maintain an above average lawn and we use above normal nitrogen. This increase in grow, means that the lawn consumes above average phosphorus and pottasium. Adding P and K to replace becomes important


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## Ridgerunner (May 16, 2017)

g-man said:


> One thing I noticed odd in the report was that they used m3 for phosphorus given the pH being 7.4.
> 
> I think that some of us try to maintain an above average lawn and we use above normal nitrogen. This increase in grow, means that the lawn consumes above average phosphorus and pottasium. Adding P and K to replace becomes important


Good point! @g-man 
I meant to mention that. 7.4 pH is at the top of the scale for M3 accuracy. A number of agronomists/soil scientists (I'm always tempted to shorten that to SS, but doesn't seem appropriate) recommend pH 7.2 as the cut off for accurate results. It's something for those with high pH soil using Wayside to watch (e.g. any unexplained big swings from test to test)
Another thing is that Wayside reports ENR. Just kind of a fun value to know.


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## Pete1313 (May 3, 2017)

Thanks for the detailed response. I will admit that I am not knowledgeable when it comes to soil test results, but enjoy doing some calculations and love to learn. I appreciate the discussion!


Ridgerunner said:


> NP Pete.
> I'm not quite following your .75 conversion factor (I can be very slow on the uptake), but there are many ways to skin a cat, whatever works for you.


I soil tested at 4" which is 2/3 acre slice furrow. An acre slice furrow is 2 million lbs so a 2/3 acre slice furrow is 1.333 million lbs. If you take 1.333 million lbs ×(.75) = 1 million lbs or 1/2 acre slice furrow.



Ridgerunner said:


> > I think I want to add some more gypsum this year as well. If I were to add 30 lbs/M of gypsum (21% Ca, 17% S) should that in theory add 207.9ppm of Ca to next year's test result. I'll try the math your way.
> > 30lbs/M of gypsum
> > × 44(to convert to acres)
> > × .21(% of Ca in gypsum)
> ...


I think this makes sense to me. When I calculated that it would add 207.9ppm I assumed that I am only interested in the 4" of soil I tested. So My calculation would be higher since the applied amount of Ca was only calculated on 2/3 acre slice furrow. In your calculation it is amount of Ca applied to a full 1 acre slice furrow and then ÷ 2 for ppm. So although I am only interested in the 0-4" depth it is assumed that the Ca is not just going to be in the 0-4" range. In short, are all calculated nutrient additions based on a 1 acre slice furrow even though im only sampling to 4"?



Ridgerunner said:


> When it comes to Ca and Mg soil levels, you are pretty much stuck with what you have and just work around it. Although additions work out pretty effectively, other than scrambling all of the other Base Cations. Trying to reduce the soil content of either one is less viable.
> Although I mentioned that Ca begins to be less available when Ca:Mg ratios fall below 3:1, there are many studies that have shown that the effect is not a dramatic impediment to crop performance. When I said that I probably would add Gypsum, it was based on my reading that your Ca: Mg ratio was 2.78:1. I misread (I need to use the magnifier to read your reports and I didn't when I was answering that question). Your ratio is actually 2.15:1. The hardest part of soil adjustment (or with any hobby that we tend to be obsessive about) is restraint. Think: "Serenity Prayer."
> From that perspective (and keeping it simple and ignoring the other soil interactions that may/would occur):
> Your current meq for Mg is 4.3, Call it a 4
> ...


Thanks for the thorough explanation and putting it into perspective! 123 lbs of gypsum is alot to get to a 3:1 ratio. Multiply that by 40k sq ft that I maintain, and a cost/benefit really comes into play.


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## Pete1313 (May 3, 2017)

Ridgerunner said:


> g-man said:
> 
> 
> > One thing I noticed odd in the report was that they used m3 for phosphorus given the pH being 7.4.
> ...


This year the N inputs will be higher then normal since it is the first year after a renovation. Im probably looking to apply around 6 lbs/M of N +/-. How does that relate to P and K recommendations?

I'll admit I had to Google ENR (Estimated Nitrogen Release). What does a number of 140 mean?


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## Ridgerunner (May 16, 2017)

> I soil tested at 4" which is 2/3 acre slice furrow. An acre slice furrow is 2 million lbs so a 2/3 acre slice furrow is 1.333 million lbs. If you take 1.333 million lbs ×(.75) = 1 million lbs or 1/2 acre slice furrow.





> I think this makes sense to me. When I calculated that it would add 207.9ppm I assumed that I am only interested in the 4" of soil I tested. So My calculation would be higher since the applied amount of Ca was only calculated on 2/3 acre slice furrow. In your calculation it is amount of Ca applied to a full 1 acre slice furrow and then ÷ 2 for ppm. So although I am only interested in the 0-4" depth it is assumed that the Ca is not just going to be in the 0-4" range. In short, are all calculated nutrient additions based on a 1 acre slice furrow even though im only sampling to 4"?


Got it. Thanks. I couldn't see the forest for the trees. I do all calculations at the acre slice furrow, as it helps me avoid mistakes, then adjust total pounds of amendment to whatever is the desired depth (4", etc.). That's gotten so ingrained that I'm oblivious I guess.
With that in mind, the total 123lbs of gypsum/M would be 82lbs/M for the 4" depth. Rational regarding the value of adjustment still remains the same.



> This year the N inputs will be higher then normal since it is the first year after a renovation. Im probably looking to apply around 6 lbs/M of N +/-. How does that relate to P and K recommendations?


I must get an addition to my thread done and in place that explains my perspective of the application of MLSN method/philosophy in respect to our home lawns. 
In regards to the relationship between N applications and corresponding turf grass demand, the most recent philosophy/theory (supported by experiences being reported, loosely qualifying as: "field testing.") is that for every 1#/M of N applied, the turf needs about .2 # of P (this amount is pretty constant between turf species) and about .5# of K (this amount varies between turf grasses with .5# of K being on the low end of the spectrum). The goal is to find the amount of NPK to apply for your specific turf, soil texture and climate so that soil test values stay constant. If subsequent soil test indicates the level of a particular nutrient (P or K) is raising, then lower the next year's input of that nutrient. If the soil test show a drop, increase the amount of that nutrient. Adjust year to year until the values/levels stabilize. A good first year starting point is that 1-.2-.5 fertilizer ratio application.
While we're on nutrients, M3 P extraction for >7.2/7.4 soils could result in under-reporting of P. i.e., it is possible/probable that your true P levels are slightly higher than the reported values.



> I'll admit I had to Google ENR (Estimated Nitrogen Release). What does a number of 140 mean?


It's an estimate of the amount of N that your soil's OM would be expected to release through decay during the growing season. It's pounds of N per acre, so 140 /43.5 = 3.2lbs of N/M. It is only an estimate and actual release will vary based on amount of fresh vs stable OM, the micro-organism population, climate and even the type of mater that is the source of OM (e.g. straw would actually draw N as it decomposed). It's a poor man's "Soil Health Test" (See Google for terms: Haney, Solvita and Soil Health Index.)
Thanks for your patience with me.


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## g-man (Jun 15, 2017)

Pete, I'm still learning all of this. So far I've discovered a couple of way to determine how much the lawn uses of each of the elemental nutrients from the MLSN model. For example, it will use half the lb of N applied, of * elemental * K. So you will use around 3lb/M of K (elemental) for the 6lb of N/M. For P it uses 0.2 of P per 1ln of N. (elemental)

This cheat sheet explains how to calculate the usage. I'm trying to use GP for my yard. http://files.asianturfgrass.com/mlsn_cheat_sheet.pdf

Examples around using MLSN and lawn usage here: http://www.turfhacker.com/2018/03/mlsn-math-step-by-step.html

Edit: I was typing while RidgeRunner posted. I'm glad to hear our values match (0.2P and 0.5K). While I'm not fully embracing MLSN, I like the adjustment/thinking of what the lawn uses plus what it has.


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## Ridgerunner (May 16, 2017)

> I like the adjustment/thinking of what the lawn uses plus what it has.


 :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: 
I think it makes much more sense than trying to apply the traditional approach for analysis and application that arose from agriculture. It's just much more intuitive and understandable for use with home lawn turf.
It's just more comon sensical. (is that a word?)
EDIT: and I've recently been finding articles where we aren't alone in that conclusion. :nod:


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## Pete1313 (May 3, 2017)

Ridgerunner said:


> Thanks for your patience with me.


 I should be saying that to you! 

Awesome info Ridgerunner and g-man! Regarding my K, it looks like it is right in the sweet spot at 178ppm so their 1 lb/M of K2O recommendation is most likely accounting for the crop using some of the K when applying 3 lbs/M of N. And since I am going to apply more N this year since it is a first year lawn, I will most likely need to up the amount of K2O and then monitor whether the amount on next year's test goes up or down and adjust to estimate the usage rate of my lawn over time? Same goes for P. I don't remove my clippings. Is the 1.0N, 0.2P, 0.5K based on removing clippings or mulching them back in?


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## Ridgerunner (May 16, 2017)

> Awesome info Ridgerunner and g-man! Regarding my K, it looks like it is right in the sweet spot at 178ppm so their 1 lb/M of K2O recommendation is most likely accounting for the crop using some of the K when applying 3 lbs/M of N. And since I am going to apply more N this year since it is a first year lawn, I will most likely need to up the amount of K2O and then monitor whether the amount on next year's test goes up or down and adjust to estimate the usage rate of my lawn over time?


 :nod: :thumbup: 


> I don't remove my clippings. Is the 1.0N, 0.2P, 0.5K based on removing clippings or mulching them back in?


It's a generic recommendation. A suggested starting point. For cool season grasses, I've seen recommendations for loam soils where clippings are left of 1-0.125-0.5. and 1-0.25-0.75 when clippings are removed, for sands, potassium rates increase to as high as 1.
@g-man may have additional or more specific information.


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## g-man (Jun 15, 2017)

The 0.2P and 0.5K are for removed clippings. I could not find for recycled clippings. I think the approach of using next year results to keep tweaking is the best.


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