- Yields: Same as base terrain; may get additional Food, Production, Science and Culture with Volcanic eruptions.
- Additional features:
Volcanic Soil is a very interesting addition to the game. It practically alters the quality of any nearby non-mountainous terrain so that it can accept both Farms and Mines. This doesn't seem like much until you realize the huge versatility it gives to tiles. Granted, Farms may be constructed on every flat tile (and later in the game also on Hills), but being able to build Mines on flat land will help improve a city's Production potential. Besides, if the Volcanic Soil happens to hit a "barren" sort of terrain such as Desert or Tundra, which normally cannot be improved, this terrain instantly turns into "normal" terrain with the added qualities of the special volcanic yields!
Because of the benefits of Volcanic Soil (and dangers caused by possible Eruptions), you should cherish your tiles next to Volcanoes and refrain from placing districts and wonders there. As the game progresses, these tiles will gradually become so rich in yields as to eclipse potentially any other tile type, and you can always "flip" them to provide more Food or Production if you need it at the moment.
Volcanic ejecta is rich in minerals, and thus over time creates a rich soil with excellent drainage, ideal for cultivating certain kinds of crops. For example, grapes grown for wine flourish in volcanic soil, as attested by the Romans planting vineyards on the slopes of Mt. Vesuvius. Coffee, too, does particularly well when grown in volcanic soil. Eruptions refresh the supply of volcanic soil on a volcano, although this usually has negative effects on agriculture during the eruption.