Need following cost to upgrade to level 20: 1193195 1534105 1193195 340915 1 57/days 419:29:59
This means you will need a city that has 20 warehouses, and 5 grannaries in order to achieve level 20 farmlands. There are only 25 building spots inside your cities so keep this in mind when making plans for your main city and outpost.
