# Soil Test year over year



## Easyluck (Feb 5, 2019)

I thought some members here would enjoy reviewing these results.

I mowed 45 times last season, bagged the clippings and threw them into the compost pile. I was hoping to see phosphorus reduction. But it actually increased so maybe my soil sampling wasn't as similar as last year.

Front lawn fertilizer application included 4.5 lbs of N - 0 lbs of P - 0 lbs of K. The nitrogen consisted of Urea (4 lbs) and Ammonium sulfate (0.5 lbs)

Back lawn 4-0-0.13. Urea 0.5 and ammonium sulfate 3.5 lbs

I'm also in the process of finishing my basement and needed to dig a trench to add plumbing for a bathroom. House was built in 1951, so soil under basement slab is 70 years old. I thought it would be cool to test that soil as a comparison, listed as "control" in the picture.


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## Grizzly Adam (May 5, 2017)

Besides using urea as your nitrogen source, any thought as to why your pH would decrease? What is the tolerance of the testing?


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## Easyluck (Feb 5, 2019)

I was thinking the ammonium sulfate caused the decrease.


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## Grizzly Adam (May 5, 2017)

Easyluck said:


> I was thinking the ammonium sulfate caused the decrease.


Yeah, that too. But you didn't actually address the acidity with elemental sulfur or anything?


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## Easyluck (Feb 5, 2019)

No I did not do any ph adjustments.


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## Lawn Whisperer (Feb 15, 2021)

Easyluck said:


> I mowed 45 times last season, bagged the clippings and threw them into the compost pile. I was hoping to see phosphorus reduction. But it actually increased so maybe my soil sampling wasn't as similar as last year.


Did you apply any other soil amendments like compost or organics?

Lowering P in soil will take while since it is the least used out of the NPK. P availability is also complicated, since it can be locked up due to pH, clay, and/or OM.


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## Easyluck (Feb 5, 2019)

No soil amendments applied.

I did try tournament ready pellets this year. 4 applications 4 weeks apart starting in June


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## Lawn Whisperer (Feb 15, 2021)

I just read this from Ridgerunner's  Soil Test Interpretation Thread.



Ridgerunner said:


> A soil test reports the amount of each nutrient already present in the soil that is/will be AVAILABLE for the growing season (it is not a measurement of the total amount of a nutrient in the soil, again, I repeat, it is the quantity of nutrient available) to the turf for the growing season…


It's possible that your soil has more P than reported and the soil pH change made more of the P available.


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## Easyluck (Feb 5, 2019)

Makes sense. Will continue bagging clippings to see what it will do over the long term.


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## Lawn Whisperer (Feb 15, 2021)

Have you tested the water source (irrigation)? That might be the source of the high P.


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## Easyluck (Feb 5, 2019)

I have not and I dont have irrigation but I do water. The 70 year old basement soil is high in P as well.

My house sits on 9-12 inches of soil before hitting limestone bedrock. See picture

It's a walkout basement so the front yard has a lot more soil before bedrock, however the backyard has about 9-12 inches of soil.


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## Ridgerunner (May 16, 2017)

Interesting. It would appear per the results of your "control" that the soil parent material is high in P content. Wouldn't expect any turf issues due to nutrients. Nothing here to be concerned about. Move along.  
I wouldn't bother bagging. You aren't going to put a dent in those values.


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