All I know is I'm making 20k+ per turn with 4 full fleets and 6 full stacks (at least) of Samurai at ~1675 and it's increasing by ridiculous amounts every turn (More than 20 regions by then obviously). That's with all level 1 markets, and +4 food in every province, and as many provinces at fort level as possible.

The wealth produced by the farm itself is insignificant next to the power of the food surplus.

Spoiler Alert, click show to read: 
*psssch-kaah*