# Soil Test and Fertilizer Plan Woes



## Madmun (8 mo ago)

Hi there!

I'm new to the forum and new to homeownership, so apologies in advance for the long post and my ignorance!

My issue is, I'm having a really hard time interpreting my soil test results and translating them into a plan. I've watched videos, read dozens of articles and posts, messed around with calculators, but it's just not clicking with me. I really don't want to mess up my lawn any more than it was when I inherited it. Any guidance you could provide would be much appreciated.

Location: North Carolina, 7b (near border of 8a)
Grass type: Bermuda (and weeds)
Lawn zones: FYARD - 1600 sq ft, SYARD - 1000 sq ft, BYARD - 2200 sq ft
Steps taken so far: 

Applied Prodiamine earlier in spring
 Applied grub killer/preventer earlier in spring
Purchased Celsius and Certainty for weeds (not applied)
Purchased MSM for bahiagrass invading a portion of lawn (not applied)
Picked up a sprinkler, but having trouble because of oddly shaped lawn and deck
Completed soil test - results at bottom of post 

Lime: For zones FYARD and BYARD they are recommending lime. I understand there are two different types of lime, one with magnesium and calcium, and one without. But my soil test doesn't seem to include these values, so I was going to purchase this and apply as the test directed.

Now for where I'm losing it:

FYARD - I understand the soil test shows I am low in P and slightly in K. and that they recommend 20 lbs/1000 sq ft of 5-10-10 or an equivalent from the Group A in the table at the bottom. 

Firstly, is this per month?? Or for the whole season?
Also, why would I apply less Nitrogen than the 1 lb/1000 sq ft/month that I'm seeing everywhere? I.e. why wouldn't I go with 10-10-10? (I read that I shouldn't apply more than 1 lb/1000 of any single nutrient, so I know I can't just put down more 5-10-10)
Do I apply the higher P fertilizer all season? Or just once and then switch to something with only N?
I currently have this in my shopping cart since I haven't been able to find 5-10-10

BYARD - In this zone I am high in P, so I understand that I should be applying N only.

I haven't been able to find N only fertilizer around me except for this
Should I spring for that? Or is something like this fine since it's close to an equivalent from the table Group D?

SYARD - Here I am low in P.

Again, why would I go with 5-10-5 when the equivalent options from Group B provide more N? Namely, 18-24-10
Either way, the only products I've found that are close to this group are labeled as "starter" fertilizers
I also read a post mentioning triple superphosphate for P only. Would it be better to purchase something like this and apply alongside an N-only fert?
I've tried playing around with the Purdue calculator and comparing to the recommended amounts and the table of equivalents from the soil test, but that only confused me more. None of the "@ 20 lbs" recommendations from the list seem to match up with what I get calculating myself or with a calculator..

As you can probably tell, I'm at my wits end here. I recognize that I'm probably stressing myself out unnecessarily, and that I'm likely missing simple answers. I'm not used to doing this much research and still coming away confused.

I really appreciate any time or effort spent responding to this mess. Please let me know if there's any other info I can provide.

Cheers!


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## Virginiagal (Apr 24, 2017)

North Carolina tests are sort of hard to understand. I found a publication which says the rates given for phosphorus and potassium are for the year. 
https://www.ncagr.gov/agronomi/pdffiles/stnote4.pdf
They're saying for the front yard you need 20 lb (per 1000 sq ft) of 5-10-10. That would give you 1 lb of nitrogen and 2 lb each of phosphorus and potassium. So for the year, you need 2 lb of phosphorus and 2 lb of potassium there per 1000 sq ft.

For the side yard, they recommend 20 lb of 5-10-5. That gives you 1 lb of nitrogen, 2 lb of phosphorus, 1 lb of potassium. For the backyard, just nitrogen.

You don't have to find those particular grades of fertilizer. You can get the NPK in a variety of ways and I don't recommend going over 1 lb of a nutrient in a single application, which is what NC is advising with its 20 lb of this and that. I suggest using 10-10-10 at 10 lb per 1000 sq ft for TWO applications for the front yard. TWO applications of starter fertilizer, targeting the rate to l lb of phosphorus, will take care of the side yard. The other applications for those yards can be just nitrogen.

As for the "just nitrogen" either of those you found would be fine. It's going to be harder to spread the 46-0-0 evenly as you have to make two pounds of stuff cover 1000 sq ft. Use the lowest setting and hopefully make at least two passes in perpendicular directions. A lot of fertilizers have a lot of nitrogen and no phosphorus and just a bit of potassium. Having that bit of potassium isn't going to hurt a thing. For that matter, if you're rather not mess with three different kinds of fertilizer, you can use the balanced fertilizer instead of starter for the side yard. The extra potassium won't hurt.

The soil test says for Bermuda to fertilize May, July, September. The NC publication I found says May, June, July, August, which sounds more like what Bermuda needs for nitrogen.

As for lime, they did not test for calcium and magnesium levels. You might as well use dolomitic lime.


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## Virginiagal (Apr 24, 2017)

Correction: if you use starter fertilizer, target the rate to the nitrogen. It will put you over 1 lb for phosphorus per application and over the 2 lb for the year but that's ok. Your Bermuda will need the full lb of nitrogen for that month. Your side yard is so small, I would be inclined to just use the balanced fertilizer there for those two applications.


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## Madmun (8 mo ago)

@Virginiagal, thank you so much for clarifying. I was pulling my hair out trying to reconcile what the soil test recommended against everything I was reading and calculating. Your post makes perfect sense. Thanks again.


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## Virginiagal (Apr 24, 2017)

They certainly don't make it easy. It wouldn't be reasonable to be putting down 6 lb of phosphorus per year, for example, with three applications of 5-10-10 at 20 lb per 1000 sq ft. But they don't say on the soil test that the phosphorus and potassium recommendation is for only one application. I looked around to be sure it was for just the one application. It would be better if they just came out and said you need 2 lb of phosphorus per 1000 sq ft for the year. And then let you figure out how to get it.


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## Mightyquinn (Jan 31, 2017)

Welcome to TLF!!!

I think @Virginiagal pretty much covered everything in regards to your soil test and like she said, don't get too caught up in the numbers as long as you are in the ball park you will be fine. The NC State soil test isn't that great and I use to use it but was never really happy with the results, I know they use to offer free testing back in the day during a certain time frame but not sure if that's still a thing or not and that can be enticing. If you are still into taking care of the lawn next year look into Waypoint or maybe another accredited lab, there is a thread about it around here.

If you lawn is thin and not very thick, I would shoot for 1 lb of Nitrogen a month until September but break that up into 2-3 applications if you can. Everything else will come with in time, just be patient.

I'm assuming you have weeds since you bought some Celsius and Certainty so if you would like some help with them just let us know and we will be more than happy to help, just let us know what kind of spraying equipment you have so that we know what we are working with.


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