# Help Interpreting Soil Test



## LAlawnnut (Feb 11, 2019)

Hey guys,

Below are my soil tests for my roughly 8k sq ft yard I'm working on. I found a feed store with pelletized lime so I am going to put that down at their recommended rate to help the PH. I am looking for help with the rest. It seems I need a ton of N and I'm not sure what the most cost effective way to get that much N down is, and if I should go ahead and do it all now. I also need recommendations for the P and K portion, as I'm having trouble figuring out what products to use to raise those. Is there anything else I need besides those above?


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## pennstater2005 (Jul 17, 2017)

@LAlawnnut I moved this into the Soil Fertility subforum for more eyes on it. And welcome to TLF!!!


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## iowa jim (Jan 22, 2018)

These recommendations are for the whole year and not to be applied all at one time. Im not a soil expert but there should be somebody coming along to help you out.


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## LAlawnnut (Feb 11, 2019)

Morning bump. Anyone got any recommendations to fix the soil


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## g-man (Jun 15, 2017)

St. Augustine has very different requirements than Bermuda. Which one you think you have or want to dominate?

The pH is low for Bermuda, but i think it is fine for st. Augustine. If you want Bermuda, then you need to add lime.

Phosphorus is very low at 4ppm. But again, st. likes a low phosphorus.

K is a also low.

In your first table the list some of the products they recommends. For phosphorus, TSP (triple super phosphate). For potassium, they recommend MOP(0-0-60), but I would advice trying to find SOP (0-0-50).

For nitrogen, I recommend following the Bermuda Bible for Bermuda. Urea is the cheapest source of nitrogen. For st. Augustine, it doesn't t like too much nitrogen, 1-2lb of N/ksqft for the entire year.


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## jdc_lawnguy (Oct 30, 2018)

@LAlawnnut Welcome to TLF.

I am not an soil nutrient expert, but I am going through the same thing so let me share some knowledge I have recently gained.

Your recommendations above are to be spread across the year.

The recommendations are a little confusing in my opinion looking at them as a newbie with fresh eyes. But let's break them down. I have picked 1 product per nutrient to use as an example.

Nitrogen = N
9.9 #'s of Urea
Urea is 46% Nitrogeen 
9.9 x 0.46 = 4.5 #'s of Nitrogren per 1000 sq/ft
1000 sq/ft is commonly referred to as M
So we have 4.5#'s/M

Phosphorous = P
Triple Super Phosphate is 46% P
6.16 x 0.46 = 2.83 #/M

Potassium = K
Muriate of Potasium is 62% K
4.74 x 0.62 = 2.93#/M

So what your results tell you is you want to put down

NPK at a round rounded ratio somewhere in the area of 4/3/3. You might not find the perfect balance but you will find something close. But what is important is you put down something that contains Each element and the N should be the highest number.

Looking at some common fertilizers I see siteone sells a 12/8/8 which is close to the ratio you are looking for. Note unless you are going liquid and custom blending you may not find exactly what you are looking for.

But let's take this a few more steps.

You need to put down ~4.5#N/M. If you divide that over say 6 apps you are going to want to target ~.75 #N/M per app

Since the fert is 12% N you divide your target N by N to get the number of pounds you need /M to get .75N

0.75/.12=6.3lbs/M of fert

With a yard that is 8/M you would put down 1 50 lb (6.3 x 8 = 50.6) bag per application.

This would give you ~0.75N, 0.5P, 0.5K per feeding

Over the course of 6 applications you would put down the following 
4.5N
3K
3P

Now, I used 6 feeding because I knew it would make the math easier and use a 50# bag per feeding but you can tweak it as need. Just don't add it all at once. 😀


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## LAlawnnut (Feb 11, 2019)

g-man said:


> St. Augustine has very different requirements than Bermuda. Which you think you have or want to dominate?
> 
> The pH is low for Bermuda, but i think it is fine for st. Augustine. If you want Bermuda, then you need to add lime.
> 
> ...


Thank you for the help. I think I have more Bermuda so I will probably just let that take over. I may be wrong and it was hard to tell last year given the poor soil and amount of weeds. Hopefully this year I will get it under control. I should be throwing out lime this weekend


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## LAlawnnut (Feb 11, 2019)

jdc_lawnguy said:


> @LAlawnnut Welcome to TLF.
> 
> I am not an soil nutrient expert, but I am going through the same thing so let me share some knowledge I have recently gained.
> 
> ...


Thanks man I appreciate all the knowledge. I was calculating that I needed 21 pounds of nitrogen so I calculated base on the bag and was thinking I needed a few hundred dollars in fertilizer. You made me feel much better lol


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## SCGrassMan (Dec 17, 2017)

Lots of lime. Your pH is super low.


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## LAlawnnut (Feb 11, 2019)

SCGrassMan said:


> Lots of lime. Your pH is super low.


They recommended 4.59 per 100 sq ft so roughly 46/M. Is it okay to put it all down now at once?


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## SCGrassMan (Dec 17, 2017)

I don't think so. I'd go like 10-20lbs.


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## LAlawnnut (Feb 11, 2019)

SCGrassMan said:


> I don't think so. I'd go like 10-20lbs.


So put down maybe half now and half in the fall?


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## g-man (Jun 15, 2017)

50lb/M of ag lime are safe in a single application and every 6 months.


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## LAlawnnut (Feb 11, 2019)

g-man said:


> 50lb/M of ag lime are safe in a single application and every 6 months.


Based on your experience if I put down 50lb/M right now how long would it take to change the PH, and when should I get another soil test to see where I'm sitting?


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## g-man (Jun 15, 2017)

It takes a long time. This is a marathon, not a 100 meter race. Apply the lime per the test recommendations and test next year around this timeframe.


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## Ridgerunner (May 16, 2017)

Normally, I wouldn't suggested adjusting Mg levels. Seeing as you need lime, you might consider using some dolomitic lime to bring Mg up a touch. I'd suggest no more than 10 lbs of dolomitic per thousand square feet. That could raise Mg levels by 26 ppm if Mg contnet is 12%. Use calcitic lime for the other 36 lbs/M for a total of 46 lbs.M of lime.


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## LAlawnnut (Feb 11, 2019)

Ridgerunner said:


> Normally, I wouldn't suggested adjusting Mg levels. Seeing as you need lime, you might consider using some dolomitic lime to bring Mg up a touch. I'd suggest no more than 10 lbs of dolomitic per thousand square feet. That could raise Mg levels by 26 ppm if Mg contnet is 12%. Use calcitic lime for the other 36 lbs/M for a total of 46 lbs.M of lime.


How do I tell if it's dolomitic?


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## LAlawnnut (Feb 11, 2019)

g-man said:


> It takes a long time. This is a marathon, not a 100 meter race. Apply the lime per the test recommendations and test next year around this timeframe.


I knew it took a while but I was wondering what a normal time frame is


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## Ridgerunner (May 16, 2017)

LAlawnnut said:


> Ridgerunner said:
> 
> 
> > Normally, I wouldn't suggested adjusting Mg levels. Seeing as you need lime, you might consider using some dolomitic lime to bring Mg up a touch. I'd suggest no more than 10 lbs of dolomitic per thousand square feet. That could raise Mg levels by 26 ppm if Mg contnet is 12%. Use calcitic lime for the other 36 lbs/M for a total of 46 lbs.M of lime.
> ...


The bag analysis label will say that it contains both calcium and magnesium. You want a lime that contains at least 10-12% Magnesium. The finer grind/mesh the better. Shop around and post what you find, if you like.
Here's an example https://www.lowes.com/pd/Sunniland-50-lb-Lime/1000115093
Remember, only put down 10#/M of dolomite and the rest pure calcitic lime.


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## LAlawnnut (Feb 11, 2019)

Ridgerunner said:


> LAlawnnut said:
> 
> 
> > Ridgerunner said:
> ...


Would I spread that by hand since it's pulverized?


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## Ridgerunner (May 16, 2017)

Sorry. I didn't see that. I thought it was pellets. That's should be applied via drop spreader. There are dolomitic limes that are pelleted. Shop around and your"ll find it.


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## ghutch (Nov 8, 2018)

LAlawnnut said:


> g-man said:
> 
> 
> > 50lb/M of ag lime are safe in a single application and every 6 months.
> ...


I put down 40lbs/K² about 9 months ago when my pH was 5.5. Just had another test and it's now 5.7. Going to put 25 down now and another 25 late in the summer...


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