[pvmntsaw]

Hello everyone and happy 4th!

New to the forum as of today and looking for some bearings.

A little back story...last fall I began honest attempts at renovating my lawn. It had been fairly thin/weed prone, etc. I aerated, top dressed and over seeded. On advice of others, I began using Milorganite fertilizer as was told this would be good for the soil over time and fairly goof proof. So I applied the Sept and Nov recommended applications. Had a fairly good germination rate with the over seed and things started to fill in quite a bit. All seemed well.

Fast forward to this year. I did not see an extreme "green up" in spring. I applied the recommended May application of Milo and then decided to take a soil test mid June to get a snapshot of what was going on. My soil test numbers, aside from pH, which was in range, were evidently EXTREMELY elevated. Almost toxic in my front lawn according to the lab. I did not get a test for micros, only the big guns. And they were as follows:

pH-6.5
Phosphorus-266
Potassium-920
Organic Matter-9.2

We have lived in this location for only about 8 years. I'm sure the lawn has been an established one for at least 80+years, so anyone's guess on what's been done before me, etc. I may have been using "slightly" over bag rate on the Milo, but nothing outrageous.

Now with the summer, lawn is doing fairly poor and I'm unsure if I'm dealing with just regular drought stress (I'm not irrigating), a possible fungus issue due to elevated OM levels? Or just that everything is so darn tied up in the soil that the grass isn't sure what I'm asking it to do.

I'm just at a frustrating point and not sure which step to take next. I'm holding off on any more Milo, which I'm assuming would be a correct step. I've had a suggestion of focusing on humic acids and micros in order to help unlock some of the p and k?

Any advice at all would be appreciated.

 

[g-man]

Welcome to TLF.

Could you post an image? Was the test done to Mehlich 3?

 

[pvmntsaw]

Thanks for the welcome g-man!

I will definitely attempt to get a few images and post them.

As far as the testing method you've referenced, I do not find it indicated anywhere on my report nor on the labs website.

I chose because seemed one of the easier to navigate labs recommended by my local county extension.

 

[g-man]

I've never seen a 920 (ppm?) value for K. There are a couple of possibilities that explain this. 1) it is actually high, 2) sampling error, 3) lab solvent error, 4) tester error, 5) reporting error.

Let's try to some of these out. Could you also post an image of the test results and explain for sampling technique?

 

[pvmntsaw]

Sure.

First off, here are a few images as requested.

 

[pvmntsaw]

And, image of results. Taken from word doc, so apologies if it looks skewed.

 

[g-man]

From the images, it looks like it could take some nitrogen, but wait until the weather improves or go very low (0.20lb N/ksqft).

In regards to the testing. I'm skeptical about them. Why? The Optimal Range for K is 350-450. I dont know of a test that has that range. Maybe this is in lb/acre. I would give the lab a call and try to get more info around their test methods, unit of measurement, so we are not guessing. Our soil guru might have some insights @Ridgerunner.

Or, take soil samples from 0 to 4in depth from multiple spots (+10) in the yard ( Sampling techniques) and send to a different lab. Many of us had success with these labs:

- Waypoint Analytical in TN Packages S3M ($16.50) or SW1 ($26.50) if your suspect high pH (do you have hardwater?)
- Midwest Labs Tests Packages S1A and S3
- A&L Great Lakes Packages Complete under Home & garden ($30)
- There are many other options, but look for one that participates in the NATP program

One I dont personally like since they dont report their test methods or any rational for the optimal range, SoilSavvy. Others like it, but I wont be of much help with that report.

 

[Ridgerunner]

Not a "guru," not even a "wizard," but I'll try to give some input.
The copy and paste did mess with the format and jumbled things a bit, but it appears the values are reported as #/acre. So ppm values are half of the stated #/A values.
Still, the ppm values are very high. The good news is that I know of no research that has determined any level for P or K at which they are toxic to plants. (Not that one should go looking to find those levels) However, although P & K may not be toxic in themselves at high levels, both can affect the relationship (availability or demand) other nutrients have with the plant, which can be detrimental to turf health and vigor. For instance, among other issues, P can tie up iron, making it less available and K can reduce plant uptake of Mg, both of which can adversely affect photosynthesis. A more detailed test (like one of the ones suggested by @g-man ) can help determine a source of a turf issue. Without a more comprehensive test, until then, it would be ill advised, based on those reported levels to apply anything other than N/with proper irrigation. No P or K. No Ca or Mg or any micro nutrients. With OM levels at 8+%, the addition of humic acid is very unlikely to make any difference and it will not "unlock" nutrients that your test reveals are already abundantly available. Hopefully g-man is willing to help you create a plan based on the results from a new test.
IMO, your issue looks to be primarily drought stress.

 

[pvmntsaw]

Looks as though a new test is in my future then. :thumbup:

Everything that you have both said makes perfect sense to me and proof that second opinions are a must.

I appreciate all of the input, will look into all companies recommended, and report back once the second test has commenced.

In the meantime, I will see how it goes with some irrigating, and leave the humic and n in the garage for now.

 

[pvmntsaw]

Just an update as I got kind of busy in the days following the holiday.

New samples have been taken and will be shipped off to Waypoint Analytical, IL tomorrow. I went with the S3M as instructed, even though they suggested the standard lawn and garden test for my purposes over the phone. I knew, from reading up on some of your posts, that this would not provide me the in depth I am looking for. I also went ahead and threw in a sol salts test, just out of curiosity, as this continued decline/severe drought stress has me thoroughly perplexed. I also added a texture, seeing as how they offer it, just for my future reference.

Hopefully a fairly quick turn around, as I have read, and will report back and post results when available to me.

 

[g-man]

Did you check prices? The IL one has a higher price than the TN one for the same tests. USPS charges the same for the shipping, so I send it to TN.

 

[pvmntsaw]

No. They do huh? I didn't think to check I guess, as I'm basically "right up the block" so to speak from this one in Champaign.

It's all boxed up and ready to go, so I'm not going to stress about it this time, but if I chose to use the TN lab next year, would info carry over? Or would new account have to be set up etc?

Thank you though. I now know better for next time.

 

[g-man]

Pete1313 called. It is $40 vs $16.50.

https://thelawnforum.com/viewtopic.php?f=24&t=1896&hilit=Waypoint&start=20#p38010

 

[pvmntsaw]

Wow. That is a significant difference.

Good ol Illinois! Jeesh.

My soil will definitely be traveling South in the future.

 

[pvmntsaw]

Thank you so much guys! This is SO comprehensive as opposed to the first one!!!
And communication and response time were miles apart. Thank you, thank you, for putting me on the right track with your recommendation. Interpret away! :lol: Ps. Since I'm new, please let me know if there's a better way to post an attachment like this, or if images are fine. Thanks.

 

[Ridgerunner]

@pvmntsaw
A couple of questions.
How confident are you in your soil samples? Did you take 8 per every 3000 sq feet of lawn or so? Were you consistent in depth? Did the samples include the whole soil profile from 0 to 4" down?
To your knowledge, at anytime since you've owned the home has anyone applied Sul Po Mag, or K-Mag? Other sources of potassium and or magnesium?
How well does your soil drain? Does water stand on the surface after a rain?
How difficult is it to dig into? Ever tried the screwdriver test?

 

[pvmntsaw]

I am 100% confident in my samples this time around. I used a proper sampling probe. Made sure to sample consistently to 4". And yes, everything sans thatch and turf layer. My entire lawn front and back in it's entirety is approx 3000 sq ft, and even then I overdid it with core amounts, just to be assured.

Since we have owned the home, I have only applied Milorganite fertilizer. I too was pretty floored to see the magnesium results. Not sure where all of that would be coming from.

I would say that drainage is alright in most areas but yes, I have occasionally noticed during periods of irrigation that water will stand for a bit. As far as compaction and the screwdriver test, I feel that it has been on par. Not extremely hard to dig, no. I have applied one application of humic acid, before our interchanges, in hopes of loosening the soil even further for another overseed in fall, but stopped all applications of anything until I can get back on track.

Leads me to another question, even though I can see various other things need to be addressed. They suggest some liming in the front yard...how advisable is that with a dolomitic lime if the magnesium is already so high? If advised to do so this fall, wouldn't then a calcium sulfate be a more prudent choice given the circumstances? Just thinking.

 

[Ridgerunner]

All nutrient levels are at or above sufficiency levels. That's unusual, especially for a soil that hasn't been worked. In addition I see none (with the exception of the below caveat) that would be considered excessive as to be detrimental to turf.
I would suggest you consider employing a maintenance fertilizer program, as a starting point, have you read the "condensed/simplified" program in my thread? The body of the tutorial thread may help you with better understanding some of the other factors reported in a soil test.
In my view there are two goals in employing the results from a soil test.
The major goal and the most important foal, is to insure that the soil provides sufficient nutrients for the turf. Primarily, I limit my suggestions to this goal.
A much more minor goal IMO, is the ratios between nutrients. This is because: 1. there is divergent recommendations from soil scientists/agronomists on what these ratios. if any, should be, and 2. the near impossibility of accurately matching these ratios within the soil, and 3. the range between high and low are commonly so great, that adjustment is almost never called for. ThereforI avoid playing with this ratios like the plaque
That being said, your soil has two areas of approaching nutrient ratio imbalances that I think you should be aware of.
First is Ca:Mg. There are a few agronomists that have determined that there is no ratio needed. That plants will perform well at any ratio. However, a majority of specialist suggest that there is a minimum and maximum ratio beyond which turf issues may occur. Those ratios unfortunately, of course, vary, consequently I've adopted to use what I think are reasonable minimum and maximum ratios based on those that have been commonly suggested. That minimum Ca:Mg recommended ratio is 3:1, below which Ca deficiencies can occur (plus there is the soil structure issue, which you fortunately aren't experiencing) Yours: 2.64:1 and 2.28:1.
Second is Mg:K ratios. Although suggested ratio ranges vary here too, there is more consensus that staying within the max and min ratios is an important factor, consequently, again, I've adopted to use what I think are reasonable minimum and maximum ratios based on those that have been commonly suggested. That maximum Mg:K ratio is 10:1 above which K deficiencies are expected to occur. Yours: 10.8:1 and 9.3:1.
I'm not forewarning that your ratios will detrimentally affect your turf/soil nor am I recommending that you make adjustment, that is your decision. This is nothing more than an FYI for your consideration.

 

[pvmntsaw]

Completely understood on the FYI considerations and much appreciated.

I have been reading up slightly on the same topics, so I can at least somewhat relate to what you are conveying concerning these ratios.

Nice to hear that there is no immediate threat from a soil perspective. Now if I can get my cultural practices into line...

I am off to seek out your thread that you have mentioned. Have an excellent evening and once again thank you.