Hello!

I am a CMG Apprentice reaching out from the help desk. I have looked into your question and while there is not significant research comparing the benefits of composting the coffee grounds or adding them directly to the soil, there are general benefits to composting materials before adding them to soil such as increased decomposition rates.

You may find this previous question informative as well (linked below). Coffee grounds alone have a fertilizer value of 2.0 N - 0.3 P - 0.2 K, whereas adding the grounds to compost may ultimately produce a more valuable fertilizer for your garden.

"Are coffee grounds worthwhile in a Colorado garden? #447142"
https://ask2.extension.org/kb/faq.php?id=447142

Thank you,
Emma