Crop rotation is not really seasonal

Once you research crop rotation, and irrigated farms, you can have a few farms on the go all rotating through their crops (or doing nothing)
But the seasonal slots seem to start from when the farm was built, so often your farms can overlap.
There should be a single season in the game, and the farm slot is based on that so all farms can synchronize their rotation

Different crops have different growth time. So it is not that simple.