kitty629 wrote:I seem to be missing something as my fields are several months old and still fairly low purity. Is it just turning them over faster that increases it?
Cotton is a good example...
As another posted already- planting inferior seeds on a field gains you nothing.
The trick is to only use improved seeds on fields. Don't have a seed bag in your inventory as you create seeds (thresh cotton/cereals/etc) as this will generalize it all. You want the very best result and build on that.
Pumpkins are kinda BS... as you could at one point get pumpkins from pots which are much easier to raise in purity. (If was how newbs discovered pumpkins to start with!)
As there are many selling study pumpkins the market just now... April 2016... you can get high purity seeds from spitting these... which will in turn improve your fields...
Then even if you plant inferior cabbage/etc seeds... you'll still get somewhat better than you likely had before.
Dross alone won't help you unless, again, you separate out the improved seeds from the rest of the mix.