# First soil test: questions



## Stin987 (Mar 27, 2019)

Hello everyone,

I have been educating myself and trying to understand what to throw down on my lawn, when to throw it down, and why I use each chemical and the impact of each. The best place to start is with a soil sample from my local extension Clemson University, and thelawnforum. Below I have attached my front and back yard soil results. My front yard is about 1000 sq ft and the back yard is about 4000 sq ft. I need help and suggestions for the comments section from Clemson and I have a few questions.

Question 1: Comment 425 (back yard) states to broadcast 3 lbs triple superphosphate. Does this mean a 3 pound bag or at a rate of 3lb/1000 sq ft? I assume they mean 3lb/1000 sq ft and during the course of a year. Any product recommendations or tips appreciated?

Question 2: Lime application: When can I put the lime down? How do I calculate the rate of 69lbs/1000 sq ft? I understand how to calculate the rates in regards to the N-P-K ratios of fertilizer, but i'm not sure about lime.

We just moved in last year and this is my first summer here, this is also my first post so hopefully I put it in the correct place.

Attached should be my front and back yard soil sample results and pictures on my front and back yard. Note the yard is a mess in some places after removing 3 trees. It's still a work in progress.

For any additional questions just ask.

Thanks


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## Virginiagal (Apr 24, 2017)

Question 1: They say 3 lb of 0-46-0 per 1000 square ft in early spring. That's a one time application giving you about 1.4 lb/k of phosphorus. The 6 lb of 15-0-15 will supply 0.9 lb/k of nitrogen and 0.9 lb/k of potassium. They make a recommendation for another product in July that is nitrogen with a bit of phosphorus and potassium which will give you about 1 lb/k of nitrogen. You can use more nitrogen during your growing season if you like. Those two applications will give you about 2 lb/k of nitrogen. Leaving the clippings on the lawn helps fertilize. If you don't find the particular formulations they recommend, you can use other products. For the spring application you are looking for something(s) to deliver about 1.4 lb/k of phosphorus and about 1 lb/k of nitrogen and potassium. In general you should limit applications to 1 lb/k of whatever nutrient (like nitrogen) you're applying.

Question 2: They recommend 69 lb/k of dolomitic limestone. You have 4000 square ft so you need 276 lb. I'd split it into two applications, doing one this fall and one in the spring.


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## Stin987 (Mar 27, 2019)

Thank you for the response. 
I just put down: Sta Green 14 lb bag of fertilizer 29-0-5. I put 3/4 of the bag down in the front yard and the rest in the back yard. I don't wanna burn my grass so I decided to put the 2nd bag down next month. I really should water my grass more so it's not so dry.

How are you calculating the lime rates? I tried using google but cannot find my answer.


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## Virginiagal (Apr 24, 2017)

I'm not calculating lime rates. Clemson has done that and come up with the recommendation for 69/k of dolomitic lime for the backyard only. No lime for the front yard.

According to my calculations, your 14 lb bag of 29-0-5 has 4.06 lb of nitrogen (14 x .29) and you say you put 3/4 of that on 1000 square ft (front yard) so you just put down about 3 lb/k of nitrogen in the front yard. The remaining 1 lb went down over 4000 sq ft, so the back yard got 0.25 lb/k of nitrogen. This does not seem right. Is that really what you did?


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## adgattoni (Oct 3, 2017)

Stin987 said:


> How are you calculating the lime rates? I tried using google but cannot find my answer.


Took me a while to find it too. The lime recommendation is on the far right on the orange line under recommendations.


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## g-man (Jun 15, 2017)

@Stin987 Bermuda can handle nitrogen, but 3lb/ksqft is a lot. You will need to water heavily to avoid burn.


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## Stin987 (Mar 27, 2019)

So thinking back a bit harder I might not have used but about 60% of the back in the front yard and 40% in the backyard. I watered after putting the fertilizer down, then watered heavenly the next day and it also ended up raining that night too.

My grass is not burn and has basically been watered 3 different times. I learn best by mistakes. I will post a new picture in about 2 weeks to see how things are looking.


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## Virginiagal (Apr 24, 2017)

If you had put that bag evenly over 5000 square ft (front and back yard), you would have put down 0.8 lb/k of nitrogen over the yards, a reasonable applicable. In general don't go over 1 lb/k of a nutrient at a time. Determine how many pounds of a product will give you the desired rate (most often 1 lb/k) and measure out the pounds needed for the given area. I weigh myself on bathroom scales holding an empty bucket, then add product until I get the needed weight. That is what I spread out over the whole area. I put the spreader on a fairly low setting that still allows the product to come out and make several passes over the yard, first going back and forth one way, then going back and forth perpendicular to the first way. I aim for 2-3 passes. Let's say you have 25-0-0 and want to put down 1 lb/k of nitrogen. You want 5 lb of nitrogen (1 lb for each 1000 sq ft). 5 divided by 0.25 is 20. You need 20 lb of product. Bags come in various sizes. You can weigh the product to get what you need for an application.

Don't forget that Clemson is recommending phosphorus. Early spring is their recommended time but you can apply it now since you missed spring. I would keep it at .7 lb/k and do two applications a month apart to get the 1.4 lb/k they recommended. The backyard could use some potassium.


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## Stin987 (Mar 27, 2019)

Clemson says phosphorus and then you ended with potassium. Was that a typo? If not, why do you say I need potassium.

Fyi: a skid steer destroyed my grass during the removal of two large tress and excessive surface roots.


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## Virginiagal (Apr 24, 2017)

Clemson's recommendation for the backyard is 3 lb of 0-46-0 and 6 lb of 15-0-15 per 1000 sq ft in the spring. That would give you .9 lb of nitrogen, 1.38 lb of phosphorus, and .9 lb of potassium for each 1000 sq ft. For the July application they recommend 6 lb/k of 16-4-8. That would give you .96 lb of nitrogen, .24 lb of phosphorus, and .48 lb of potassium for each 1000 sq ft. Rounding, they recommend 2 lb of nitrogen, 1.6 lb of phosphorus, and 2 lb of potassium for each 1000 sq ft for the two applications combined. That is a recommendation for the year. The first number in a fertilizer number is the percentage of nitrogen, the second is the percentage of phosphorus, the third is the percentage of potassium.

The front yard had high potassium and their recommendations cover nitrogen and phosphorus but not potassium,.

Since you have underfertilized the back and the back needs all three nutrients, you could go with a balanced fertilizer like 15-15-15 or 20-20-20 when you next fertilize the back.


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## Stin987 (Mar 27, 2019)

Virginiagal this the exact answer I was looking for. That makes things so much easier. I can get a small bag of 0-46-0 for the front and balanced fert for the back as you suggested. I will be sure to do the lime before now and fall too.


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