A couple of farms in SimCity 3000.
Agriculture is an industry type in most SimCity games. It is generally used at the beginning of the game, alongside dirty industry.
Agricultural zones are the least profitable out of the three main industrial zones, as farms take a lot of space in order to develop.
SimCity 3000[]
Farms appear if the player zones a large enough low density industrial area (at least 8x8 tiles). Agriculture will not develop if pollution is too high. They also won't develop in dense industrial zones.
A no-cost ordinance called "Farmer's Market" can be enacted, which promotes agriculture and increases the number of farms.
SimCity 4[]
Agriculture is the low-density industrial zone in SimCity 4. The player can zone bigger lots than other zones, and agriculture helps develop food for the city. Agricultural buildings also generate enormous amounts of water pollution, thus, it is highly recommended to place water pumps as far away from agricultural zones as possible, as water pumps will become polluted from the water pollution.
The reward building, Farmer's Market, is also unlocked after having a certain amount of agriculture buildings in the city.