# Soil Test Results: Act now or wait?



## Chief Brody (Aug 6, 2020)

Hi all,

This is my first ever soil test and I opted for the Yard Mastery offering.

While I am pleased with it for the most part, obviously I need to make some amendments.

My questions are:

1. My P levels are high and I'm not sure why. Is that something that lowers over time? (I've only ever applied Milo & N-Ext bio stim pack)

2. This test came from my Zoysia front yard. I'm in the transition zone just west of Baltimore, so since the grass is on it's way to dormancy, should I even attempt putting anything down right now, or should I wait until spring?

Thanks!


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## ken-n-nancy (Jul 25, 2017)

Chief Brody said:


> 1. My P levels are high and I'm not sure why. Is that something that lowers over time?


For some levels (calcium, for example) to be "too high" can be a bit of a problem. However, phosphorus levels being "too high" isn't a problem for the lawn unless the levels are insanely high.

The high level of phosphorus from your soil test just means that there is no need for you to apply phosphorus with future fertilizer applications. There is no need for you to try to do anything to reduce the phosphorus level in your soil.

Runoff of phosphorus-containing fertilizer on a lawn that is graded such that runoff occurs, particularly from poorly timed fertilizer applications (such as on frozen ground or immediately before runoff-producing heavy rainfall) is very bad for the environment. As a result, any applications of phosphorus-containing fertilizers are highly discouraged if one's soil already has sufficient phosphorus for the lawn. Indeed, such applications are actually against the law in many states. However, unless the phosphorus level is insanely high, excess phosphorus doesn't have an adverse impact upon the lawn itself.



Chief Brody said:


> (I've only ever applied Milo & N-Ext bio stim pack)


Milorganite contains significant phosphorus compared to the amount of nitrogen. Regular use of milorganite will tend to raise phosphorus levels over time. However, the phosphorus in milorganite is not highly water soluble and is not anywhere near as prone to leaching off as the phosphorus typically used in synthetic fertilizers. Milorganite advertises their product as having "non-leaching phosphorus."


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## Ridgerunner (May 16, 2017)

> For some levels (calcium, for example) to be "too high" can be a bit of a problem.


Could you expand on this? I've seen this mentioned a couple of times in posts by people and I'm unfamiliar with this Ca concept.
Thanks.


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## ken-n-nancy (Jul 25, 2017)

Ridgerunner said:


> ken-n-nancy said:
> 
> 
> > For some levels (calcium, for example) to be "too high" can be a bit of a problem.
> ...


Sorry if the comment was misleading -- I didn't intend for it to be; my intent was to reassure the original poster, @Chief Brody, that a "too high" phosphorus level on a soil test isn't typically a problem that causes issues with the lawn itself, and that one shouldn't need to actively do things to lower their phosphorus level due to a "too high" level for phosphorus on a soil test.

In other words, if one has a "too high" level of phosphorus on a soil test, it almost surely won't cause problems for the lawn to apply a phosphorus-containing fertilizer, such as the Milorganite mentioned by the OP (unless the phosphorus level is truly insane -- like from a phosphorus mine.)

However, rather than have the OP think that one can always just apply more of a nutrient, even if the soil test says "too high," I wanted to mention that isn't the case for all nutrients. Calcium was the first one that came to mind as one that is often "too high" for people and that can cause trouble if people with a "too high" level just keep applying more to their lawn, thinking, if "moderate" is good, then "too high" must be better and "way too high" must be better yet.

For calcium, it's not that "too high" calcium is a problem in itself, but if the calcium level is "too high" (say as in a soil test from somebody living in Dallas / Forth Worth) and tests at, say, 93% base saturation, then they necessarily will have a very high pH (well over 8), which will lead to nutrient availability problems for various other nutrients. In particular, for that person to go ahead an apply lime to their lawn (thinking that "more is better") they will make their problem worse.

I'm sorry if my quick reply oversimplified to the level of being misleading.

PS: I realize, @Ridgerunner, that most of the above explanation isn't needed for you, and that I probably could have answered your question in a few words that you would have understood right away, but I wanted the fuller explanation for others that may be reading, too!


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## ken-n-nancy (Jul 25, 2017)

Chief Brody said:


> 2. This test came from my Zoysia front yard. I'm in the transition zone just west of Baltimore, so since the grass is on it's way to dormancy, should I even attempt putting anything down right now, or should I wait until spring?


@Chief Brody, I hadn't really meant to ignore this second question you asked -- it's just that I've never had any warm season lawn, such as Zoysia, so I really don't know the pro/con of soil applications for Zoysia. Hopefully somebody with some warm season lawn experience can chime in to answer that question, too!


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## Virginiagal (Apr 24, 2017)

@ken-n-nancy There is a reason to avoid high phosphorus levels: the mycorrhiza. Here are two articles (hoping to pique your interest in these marvelous fungi):
http://pubs.cahnrs.wsu.edu/publications/pubs/fs269e/
https://s3.wp.wsu.edu/uploads/sites/403/2015/03/mycorrhizae.pdf

For people with high phosphorus, we can't lower phosphorus levels but we can at least avoid putting more on. That would include Milorganite.

That said, I don't have confidence in Yard Mastery tests. Here are threads on problems with this sort of test:
https://thelawnforum.com/viewtopic.php?t=16135
https://thelawnforum.com/viewtopic.php?t=8530


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## Virginiagal (Apr 24, 2017)

No one answered your question about WHEN to fertilize. Here is a guide on zoysia from Clemson (South Carolina):
https://hgic.clemson.edu/factsheet/zoysiagrass-maintenance-calendar/
Maryland's guide wasn't as detailed:
https://extension.umd.edu/hgic/topics/planting-and-maintaining-zoysia-lawn


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## Chief Brody (Aug 6, 2020)

Thanks everyone for the input and thanks @Virginiagal for the link!


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