Nature
* Increased chance of getting 3 seed items every time you harvest crops.
* Decreased chance of getting iron when you smelt iron.
Industry
* Decreased chance of getting 2 seed items every time you harvest crops.
* Increased chance of getting iron when you smelt iron.
If I want to do plants AND smelting (who doesn't?) I'll just max out one belief on my main and make an alt for the other, so wouldn't it be easier for players to just make the chance of success for harvesting/smelting increase the more you harvest/smelt? It would make more sense too, basing the bonus on actual work rather than the amount of time logged in.