So if you place your farms right, they can all get back to 100% efficiency and work properly, without turning the ground bad. A good thing with Multi-Culture is that if you put a bunch of farms together in a single spot, and they're all on Multi-Culture, they increase other farms efficiencies by 10% each.
Multi-Culture on the other hand, never lowers ground quality, at the expense of having -40% efficiency, making the farm much worse on the short hand, but it lasts indefinitely. Mono-Culture is a way of growing plants, don't know much about it but long story short, it allows you to work at 100% efficiency, BUT, and this is a big butt, the ground will slowly turn bad overtime, to the point where it's useless to even plant crops there. So, starting with plantations - They have a work mode called Mono-Culture.
Okay so, there are multiple workmodes for various buildings, but the big ones to focus on right away are on Ranches and Plantations, the ones you're having issues with.
