Make it so farming purity increases each time crops are planted instead of the current + or - system.
In my opinion, Salem farming is much better in that crops only increase or stay the same.
The increases can be only fractions of 1% of your farming skill so it will still take forever but at least you know there is progress being made each harvest.
Current system of having to wait an hour to re-roll for purity doesn't make sense.
In addition having 1 quality value instead of 3 would make the purity/quality easier to understand, i would recommend we go to a single quality value system.