go for fertility last ..

I have level 2 farming, building, science and I am now waiting to get back up there again, but is it more important to get the level 3 harvesting, or building? and do I need to go for spirtuality at all?

I would think Level 3 Farming is more important since you want to keep them alive... as it gets harder to rely only on crops if the population gets larger... fishing gives more food esp. Master Farmer get crabs (real one... :P)sometimes