Farms

Food Yield
Food yield is affected by two main factors: terrain and centralization.

Farms in snow, desert, or mountain terrain will have a -25% decreased yield.

Farms, like homes, are affected by centralization, so make sure farms are near the capitol or near a colony.

Upgrade Costs
Looking at the trends above, it is more economically efficient to build new farms than it is to upgrade existing farms.
 * Farm I +(€ 1.6k, 40 food, €10 upkeep)
 * Farm II +(€ 2k, 40 food, €10 upkeep)
 * Farm III +(€ 2k, 40 food, €10 upkeep)
 * Farm IV +(€ 4k, 40 food, €10 upkeep)
 * Farm V +(€ 6k, 40 food, €10 upkeep)

After reaching Farm V, with the correct research, farms can upgrade into hydrofarms, which require electricity to function.