|This article is about the current version of DF.|
Mud is a contaminant produced when an area is covered with water, and colors tiles brown. Mud also occurs naturally in deep caverns. Muddied stone can be used for farming, grazing, plant gathering, and growing subterranean trees. "A pile of mud" in water sources can result in "water laced with mud" which can lead to problems if your dwarves use it.
Note: Upon reclaiming a fortress, every single bit of mud will disappear, including even mud in caverns.
 Farming and spontaneous growth on mud
The plants that can be farmed on mud are the same as those that would grow on soil in the same place. Biome-appropriate grass (useful for grazing) and plants (and, if underground, trees) will also spontaneously grow on muddy stone just like any other soil tile. Above-ground plants can't grow or be farmed on underground tiles, and visa versa, though tiles can be made permanently "above-ground" by exposing them to light. And perhaps unfortunately, muddying stone won't allow farming of different above-ground crops from other biomes. Note that underground plants won't spontaneously grow until a cavern has been breached, though farming from seeds is still possible. Note also that saplings need more than 1 z-level to mature into adult, wood-bearing trees. (see tree farming for more.)
Constructed floors behave differently. Plants won't spontaneously grow on them, but farms will grow fine. Muddied smoothed floors might behave differently from muddied rough floors also, but more information is needed.Verify
 Muddying areas
See irrigation for some methods. One common way of creating mud is to flood a good sized area from a lake, thus making mud. Another way is to use a pit/pond from the activity zone menu and have a dwarf throw water over a channeled area into a dug-out area below.
Initial water contact with a clean surface will leave "a dusting of mud", not "a pile of mud". This is sufficient for farming and grazing but not enough to cause any water-contamination problems in reservoirs.
Dumping water on an already muddy area may result in more mud accumulating there, up to "a pile of mud".Verify
 Removing mud
Mud can be removed by constructing something over the mud, then deconstructing it, or by smoothing/engraving stone. Mud on soil is removed easily by constructing a dirt road.
Dwarves will not clean mud as a cleaning labor, though they will at least sometimes clean blood and possibly other contaminants from muddied surfaces. (needs more info)
Magma will remove mud if it evaporates on a tile.
 Muddy water
Using "water laced with mud" can cause health and happiness problems, see the water page for more details. Drinking muddy water is better than dying of thirst, though.
Dug-out reservoirs should be able to store water without contaminating it with mud, since initial flooding with water leaves only "a dusting of mud". However, under some circumstances the reservoir can end up with piles of mud on its floor anyway, especially if slowly filled using buckets. (more information needed.)
Natural cavern pools have floors covered with "a pile of mud", so make sub-optimal water sources unless they're deep enough that water can be drawn from a tile that doesn't contain "a pile of mud".
|"Mud" in other Languages
[MATERIAL:MUD] - reconstructed from data extracted from memory [STATE_COLOR:ALL:BROWN] [STATE_NAME_ADJ:ALL_SOLID:mud] [STATE_NAME_ADJ:SOLID_POWDER:dirt] [STATE_NAME_ADJ:SOLID_PRESSED:pressed dirt] [BASIC_COLOR:6:0] [BUILD_COLOR:6:0:0] [TILE_COLOR:7:7:1] [SPEC_HEAT:800] [SOLID_DENSITY:1200]