raptamaiko wrote:ok so its best to continuously plant the same crop in one field? like after 3 or 4 cabbage harvests in the same field, theyll be better?
Yes, it's best to plant the same thing on a field over and over. No, the cabbage won't get better. It works like crop rotation. When you plant cabbages, they fill up the Red bar. Cotton uses the Red bar to produce Indian Cotton when it is over 50 influence. At 50, you only get a little indian cotton and mostly yellow cotton. When the bar is 100% full, you get all indian cotton. Grain uses the Red bar to make Barley in the same way. So, you plan cabbage until the bar is full and you can then get indian cotton or barley out of that field for a harvest or two before going back to cabbage. All the crops are like that. Here's a helpful picture; note the text colors match the bars:

Tier 3 stuff requires you to fill two bars, which can be done by filling one bar, and then planting the second crop you need and fertilizing with massive amounts of hay in order to increase your influence all the way in one harvest.
Corn isn't in the picture I shared, but its needs are listed in the wiki. Once you figure out the others, it'll be easy to understand how that works as well.