how do u fertile the soil

upgrade your medicine to level three.

You dont upgrade med that would take ages you upgrade farming to level 2 then drop one villager on the narrow stream where there are a few rocks crossing allready.they willl build a dam(if there is nothing else to do, i would suggest making all your adults do it otherwise you will run out of food) it will take a long time. mine took two or three days!

I did that upgrade thingy with the farming and I del Ed my adept farmer and she didn't do anything It said additional research may be require zoo ya:/