40d:Soil

Soil is the name for the various kinds of ground that can be planted on without irrigation using water. In DF, the category of "Soil" includes all types of sand, clay, ooze and any "non-stone" layer equally, even if you or I generally don't associate that substance with "growing plants".

Topsoil	Tile
Clay	▓
Clay Loam	▒
Loam	░
Loamy Sand*	▒
Peat	≈
Sandy Clay*	▒
Sandy Clay Loam*	░
Sandy Loam*	░
Silt	▓
Silty Clay	▓
Silty Clay Loam	░
Silt Loam	▒
Ocean Floor	Tile
Pelagic Clay	░
Siliceous Ooze	▒
Calcareous Ooze	▒
Sand	Tile
Sand (no color)	░
Black Sand	▓
Red Sand	░
White Sand	▓
Yellow Sand	▓

* - Any soil listed in the upper part of the table does not count as sand for glassmaking, even if its name includes the word "sand."

When starting a new fortress, types and quantities of available soils are listed at the bottom right of the fortress location selection screen. In contrast to rock types, soil type names appear in brown, and are usually closest to the top of the list, and thus, closest to the surface of the ground.

Note, however, that you may only plant cave flora if the tile is marked "Subterranean." To check this, go to the tile in k mode.

Digging into soil does not generate any byproduct materials, unlike digging in rock, and also is a much faster process which makes it much easier to create storerooms and other large areas of empty space, and to train miners.

Soil cannot be smoothed, so it can be difficult to make high value rooms, or pierce aquifers. Also, since soil cannot be smoothed, soil cannot be used to make fortifications.

The only minerals that can be found native to soil are gold, cassiterite, and platinum. However, in unusual cases, it's always possible that a vein from a nearby stone layer could extend into the edge of a soil layer.