Mud

From DwarfFortressWiki

Indoor mud is created by filling a stone floor tile with water, then letting the water evaporate. Outdoor mud is created by covering any soil tile with water. Creating mud is essential to providing irrigation for subterranean crops, as well as any crops indoors. The most common sources for mud are the results of irrigation, farming, and draining water sources.

Outdoor mud will completely dry over the winter if it lies undisturbed for the entire time.^Verify If it doesn't, build floor constructions over it and unconstruct them.

In adventurer mode mud objects which you can pick up from muddy tiles are edible.^{v0.27.176.38c}