Fields are special buildings in several ways.
- Fields have a variable size which you decide when placing them
- Fields can only function on fertile soil
- Fields produce resources depending on what crop you plant
The image gives you a general idea of what it looks. But pay some attention to the info panel of a crop field, also visible in the image.
Clearly, like any production building, a field requires an assigned farmer. That farmer will work the field pretty much the entire year round. When exactly you can expect a field to yield its resources depends on the crop that is actually planted. Some take a whole year to grow before they can be harvested, while other crops may get harvested twice a year. For all this time, you will be paying the field's upkeep cost.
What about that soil fertility mentioned above?
If you turn on the soil fertility grid, you'll be able to clearly see where the soil is good for crops. As usual: red is bad, green is good. Planting on the green, means the field will be more efficient, or speaking in quantities, you'll get more.
And that bit about the size?
When placing, stretch the field as much as you like, up to its 12x12 cells maximum.
That only leaves what a field produces...
It's simple. As visible on the image, you can change what crop is planted using the dropdown control. What is available to choose, however depends on what crops you have researched. And several crops are special. You cannot research them or acquire in way other than purchasing from a visiting trader. Don't worry, you won't be able to miss the trader when he arrives. It is handled like an event.