Biomes o' plenty adds different types of soil, such as sandy, loamy, and silty. Mulch works fine on regular dirt farmland, but can't be placed on modded farmlands. Alongside this, there are also no dirt clumps for modded soils.

Forge ver. : 14.23.5.2860
Minecraft ver. : 1.12.2
Pyrotech ver. : 1.5.20
Athenaeum ver. : 1.19.2
Dropt ver. : 1.18.0
Biomes o' Plenty ver. : 7.0.1

It's possible that a compat layer could be introduced for handling mulch on blocks other than vanilla farmland.

Any kind of alternate drops for third-party blocks won't be added to Pyrotech though. I suggest using ContentTweaker and Dropt to add your own clumps.

I second this and would very much like to see compatibility with modded dirt in the same vein as logs for campfires.