# soil test and questions



## Dad2021 (Apr 2, 2021)

Hey , first time posting. What do you think of my soil test results? Last year I went with Yardmastery or soil savvy but based on what I've been reading here I went with Midwest labs. I knew my pH was high so I wanted the AA extraction and Olsen bicarb. I've also read that some parts of the test are typical of lawns in my area (clay soil) irrigated with city water. I took my samples on March 26th, which is somewhat early for me but the ground was well thawed. They were at 3-4" depth. I didn't let the plugs dry out though, forgot that part. This is my third year with this lawn. Thanks in advance!
1.	I usually apply one organic fert app before summer, that's the main source of P. Do I skip it this year? I love how my lawn looks after that one milo app every year. 
2.	Will put down AS granular in the fall. Will .7N/M every three weeks be ok or is that a bit much for fast release? 
3.	I was alarmed at the iron level. I haven't applied much except for the 1-3% content that's in my granular fert. I can't do foliar anything until I get a bit more time on my hands. Do I avoid iron altogether?
4.	Have you seen calcium levels this high? 
5.	I have a fert with 8.5% chlorine on the label, is chlorine harmful? 
6.	Any other thoughts?

Thanks so much guys, I've really enjoyed/appreciate all I've learned here.


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## Deadlawn (Sep 8, 2020)

Yes, I would definitely skip fertilizers this year! The only thing I might do is add some elemental sulfur to try and get your pH down a bit. That being said, there are plenty of people here on these forums who grow nice lawns with pH in the 7.5 to 8.0 range.

Keep in mind that even if your iron is high as in your case, plants are unable to take up iron when the pH is as high as yours. Yellowing is a symptom of iron chlorosis although yellowing can be due to other things as well. If your grass turns yellow, maybe give it an iron foliar feed. If the lawn looks good as in "ain't broken", don't fix it!


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## g-man (Jun 15, 2017)

I'm going to phone a friend on this one. The weak bray is low and i think the strong one too, but why is the Olsen towards the high side?

Now to the rest. You can do 0.25lb N/ksqft weekly in the fall. Your iron is not that high, but with your pH, it is not available to the turf. Milo is giving you a good response because the iron is plant available. A lot of the areas in the Midwest have a lot of limestone and thats part of the reason the calcium and pH are high. Don't worry about it. Chlorine is not something the plant needs, but some ferts have it (MOP).


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## g-man (Jun 15, 2017)

@Ridgerunner ^


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## Deadlawn (Sep 8, 2020)

g-man said:


> Milo is giving you a good response because the iron is plant available.


I'm confused. How can the iron be plant available when his soil pH is so high?


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## g-man (Jun 15, 2017)

Biosolids form a form of chelation to the iron. This prevents the iron from turning into an oxide in high pH.


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## Deadlawn (Sep 8, 2020)

g-man said:


> Biosolids form a form of chelation to the iron. This prevents the iron from turning into an oxide in high pH.


Interesting. I wonder if that would work for chlorosis in acid loving plants while trying to get the pH down.


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## Ridgerunner (May 16, 2017)

Midwest is a very good reliable lab and for a soil with a pH >7, ammonium acetate and Olsen will provide the most useful data for determining plant available levels of nutrients. You chose well.
As I stated, Olsen is the most reliable indicator of P availability in higher pH soils. The sufficiency range is 12-28. At 27 ppm, your soil P content is sufficient for the next growing season without further P addition. 
P1 and P2 aren't reliable indicators of P availability in higher pH soils, they are part of Midwest's AA test package. you paid for them, so they are included. Although not dispositive, the difference in P1 and P2 values can give a general indication of the proportion of P readily available or labile vs the proportion that is likely tied up (in a higher pH soil, probably tied up as calcium phosphate) and unavailable. In higher pH soils, we already knew much of the P would be tied up. Still it's somewhat informative to see a numeric indicator.
You've got good nutrient levels across the board. Nice.
I'd suggest you get into a maintenance fertilization program and monitor with soil testing for a couple of years and make adjustments if needed. Follow @g-man 's advice on fertilization. Milo is a good source in high pH for maintaining P (and maybe some of your iron, but g-man might recommend folliar as more efficient for color) but limit your Milo apps (and K applications) based on a 4-1-2 ratio. Remember for every 6 parts of N in Milo, you are applying 4 units of P. That's a lot. Good luck.


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## Deadlawn (Sep 8, 2020)

Ridgerunner said:


> Midwest is a very good reliable lab and for a soil with a pH >7, ammonium acetate and Olsen will provide the most useful data for determining plant available levels of nutrients. You chose well.
> As I stated, Olsen is the most reliable indicator of P availability in higher pH soils. The sufficiency range is 12-28. At 27 ppm, your soil P content is sufficient for the next growing season without further P addition.
> P1 and P2 aren't reliable indicators of P availability in higher pH soils, they are part of Midwest's AA test package. you paid for them, so they are included. Although not dispositive, the difference in P1 and P2 values can give a general indication of the proportion of P readily available or labile vs the proportion that is likely tied up (in a higher pH soil, probably tied up as calcium phosphate) and unavailable. In higher pH soils, we already knew much of the P would be tied up. Still it's somewhat informative to see a numeric indicator.
> You've got good nutrient levels across the board. Nice.
> I'd suggest you get into a maintenance fertilization program and monitor with soil testing for a couple of years and make adjustments if needed. Follow @g-man 's advice on fertilization. Milo is a good source in high pH for maintaining P (and maybe some of your iron, but g-man might recommend folliar as more efficient for color) but limit your Milo apps (and K applications) based on a 4-1-2 ratio. Remember for every 6 parts of N in Milo, you are applying 4 units of P. That's a lot. Good luck.


Higher pH is relative. The OP's pH is 7.6. For P to be unavailable, the pH would have to be higher than that. As shown in this chart, most P is still available to plants at 7.6pH:


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