I did a soil test of my backyard and am unsure how to proceed with the results. My calcium at ~546ppm is way over. No idea how to lower that or if I should even worry about it. Sulphur is high at ~15ppm. I had wanted to lower my pH slightly but with the high sulphur I'm not sure that's possible.

I was planning to start a twice-a-year topdressing with compost and sand to help level all my dips.

This is a Zoysia/Bermuda mix yard in what I think is clay soil. I'm told my neighborhood was basically built on top of limestone and they had to haul in all the topsoil, of which I don't have much, and another reason why I'm topdressing.

With their fertilizer recommendations and my topdressing, is the high Ca and S something I can do about and/or should even worry about?

Soil Test Results

  • Is this telling you the levels in the soil, or the levels available to plants in the soil? Commented Jun 2, 2017 at 2:43
  • 1
    Looks like levels available to the plants. It's a UNIBEST Soil Savvy test.
    – Ifrit
    Commented Jun 2, 2017 at 3:11
  • And you just want a lawn on it (not vegetables, flowers, trees, and so forth)? Commented Jun 2, 2017 at 8:50
  • It's a lawn with some flowering and non-flowering trees. No vegetables. No fruit bearing trees.
    – Ifrit
    Commented Jun 3, 2017 at 0:17

2 Answers 2


I think your idea of top dressing the lawn with compost is a good one. Do that. Adding organic material to soil is almost always a good thing. Is grass growing alright there already? Just keep adding compost and overseeding until it fills in. I wouldn't worry about the excess calcium and sulfur. Soil tests are generally catered towards farmers and optimizing food production. For a lawn, it's not that big of a deal. In fact my soil has tested out with very high calcium because it is primarily clay, but that has never seemed to affect anything negatively. I would however try to raise those NPK values by adding an organic fertilizer twice a year when you add that compost. Good luck.


I find them very strange.

High sulfur is (as far I know) not problematic.

High calcium is common in chalky soils (so also in clay soils). You will find some method to reduce it (which is the same to reduce pH), in past questions in this site.

But I recommend just to adapt, and choose species that like calcium. There are many, also because it is a common soil. On a small part of your garden, if you want some acid plant, you can change the pH of soil, but I really don't recommend to do it on a large surface.

I'm much more worried about low values of P,K, Fe and B, which are essential for growth.

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