I like to joke that I'm not necessarily into the organic lifestyle but my cattle are. I think monoculture causes the most issues. Pasture that will serve you well will have a variety of forage for your livestock. Clover is good for the soil, but it causes bloat in cattle if they eat it in abundance. So, knowing what's safe for my cattle and growing a variety of the good stuff for the soil, is what has given me the greatest ROI.
Allowing the land to go through a rest period helps improve it too, but it's one of the toughest things to do. It feels like a waste almost, because instinctively, I want to put all the land to good use, but not allowing for a rest period would be counterproductive in the end.