[Feature] Level of farms

Now, our farms will be able to be upgraded. In fact, it is only the plant quality that will be improved.
Depending on current latitude, your will upgrade your farm with your agronomist.
For now, the maximum level is 7.
Each resource has its ideal latitude. More we go away from this latitude less we will able to improve our resources.
As this plot isn't in the ideal latitude for the wheat, the level maximum for this farm is 5 instead of 7.

If you knew in reality, the ideal latitude to sow (tobacco, sugar, cotton, coffee, ...), we would be really interested for all those information.

I like this. For the future, I would make agronomist a normal type of population. Any citizen should be able to take on the job, like pioneer, but expert agronomist should twice as fast for half the gold (just double the time and gold it takes for others to do it).

That's an interesting idea but it would require a big amount of work to make it work that way, M07 would need to rewrite some of his code but it would greatly simplify the concept.

Profession could be available under certain conditions so you don't obtain so easily your first agronomist. And the actual agronomist unit could be the expert agronomist with your characteristics.
Also we could recycle most of the actual code, because references to agronomist could be replaced with the expert agronomist: king giving an (expert) agronomist, buying an (expert) agronomist in Europe, ...

You probably want to use the term "agriculturalist"

I disagree with the last post here. "Agronomist" is definitely the right term in English. How do I know? My dad is one =)

I noticed that when you first make a farm it's not possible to grow any food there, even though an empty tile (i.e. no farm) can grow three food. This means if I have a farmer growing food on a tile, and I build a farm there, there will be two turns while the agronomist works before we can grow anything at all.

Would it be possible to make an "empty" farm with no plants on it continue to produce the base level of food?

For us, units can find food on a tile without farm thanks to nature. Indeed, we can find fruits, animals, ... But once we improve the tile with a farm, nature is "destroyed" by our pioneers. That's why, we don't allow units to produce foods on farm without any plants.