Farm (Civ4)

The Farm is a tile improvement in Civilization IV. It increases the food output of tiles and unlocks the Corn, Wheat, and Rice resources.
== Farm bonus yields ==
In addition to their +0 to +2 yield, Farms also provide a bonus yield when built upon:
* Corn: +2 
* Rice: +1 
* Wheat: +2 
== Building site restrictions ==
There are several restrictions which limit where Farms may be built. To build a Farm, the tile must:
* be improvable (i.e., not contain an Oasis, mountain Peak, or city)
* be within cultural boundaries
* be Flatland
* be adjacent to fresh water and/or an irrigated Farm or city, unless Biology has been discovered, and unless the tile contains Corn, Wheat, or Rice (e.g., an unirrigated Rice may be improved by a Farm to provide the Rice's +1 Farm Bonus Yield, but the farm itself will not provide any additional yield until irrigation is brought to it)
* have direct access to fresh water if it is Desert, Tundra, or Ice (i.e., even with Civil Service or Biology, Farms on these tiles must be directly adjacent to fresh water)
* have an unimproved tile yield of at least 1 (This requirement typically prevents any Ice Farms or non-Floodplain Desert Farms. Technically, though, riverside Ice Farms or non-Floodplain riverside Desert Farms are allowed if the tile has 1 from a food resource like Deer. This does not occur in practice, as standard worldbuilding scripts disallow food resources on such tiles.)
== Spreading irrigation ==
Once Civil Service has been discovered, one can build chains of Farms (and flatland cities) to allow Farms to be built on tiles distant from fresh water sources.
== Strategy ==
If you have yet to discover Calendar, it may be worthwhile to build a Farm on top of an irrigated Banana or Sugar resource, even though they are properly unlocked with a Plantation. These resources provide +1 tile bonus yield at all times, and an irrigated Farm provides another +1 . For example, a riverside Grassland Banana/Sugar with a Farm provides a total yield of: +4 , +1 . While not providing the full yield or access to the resource, this method nonetheless may be instrumental in growing an early city. The Farm can then be replaced with a Plantation once Calendar is discovered.
Long chains of Civil Service Farms are vulnerable to sabotage by Spies. If you find such a situation in an enemy's territory, sabotaging a crucial Farm near the source of fresh water can disable the whole chain of Farms, potentially leading to Starvation in several cities.
== See also ==
* Farm in other games