The term "infernal soil" is not a recognized scientific or geological term. It's likely a fictional or metaphorical term.

Here's why:

* "Infernal" relates to hell, the underworld, or something extremely unpleasant.

* "Soil" is a natural material composed of minerals, organic matter, and living organisms.

Possible Interpretations:

* Fictional context: The term might be used in a fantasy novel or game to describe a cursed or contaminated soil with harmful properties.

* Metaphorical context: It could be used to describe a very barren or unfertile soil, perhaps due to pollution or extreme conditions.

Without further context, it's difficult to determine a precise meaning. If you can provide more information about where you encountered this term, I might be able to give you a more accurate answer.