If you have not experienced any disease issues in your growing situation, then rotating the crops in containers or grow boxes is unnecessary. If you have, then it is best to discard the old soil, clean the pots thoroughly and start over with fresh soil next spring.

How to refresh the soil depends on what sort of soil mix you are using. If an inexpensive peat based brand of potting soil (like Miracle Gro), then simple refreshing by replacing 50% with 'new' soil is unlikely to produce very good results. This kind of soil breaks down quickly during a single growing season with watering requirements and becomes compacted and loses aeration. Just adding a quantity of new soil to this collapsed mix will not change this and the "refreshed" soil will not even hold up for a full growing season. That is why a more durable, bark-based mix like the 5-1-1 is preferred by most container gardeners. It doesn't break down or collapse nearly as rapidly and you can get several growing seasons out of it before needing to discard and start over.

Crop rotation is practiced by commercial gardeners who work on such a large scale that regular amendation and complete fertilization of their beds simply isn't practicable. So from a nutrient standpoint, crop rotation doesn't make a lot of sense for home gardens. If you have disease problems in your containers, you could rotate, sterilize the soil, or replace it.

Soilless mix has a lot of organics in it, and as those organics slowly break down, the carbon departs as CO2. So you end up with less mix at the end of the season than you started out with. In fact, that's what happens with compost in in-ground beds. I'd just top your containers off with new soilless mix, and stir to mix and aerate. That's correct that a bark-based mix will depart more slowly. It's also true that after many seasons, the fraction of organics in the mix will drop precipitously, and you'll just have to replace the stuff entirely.

Thanks! There is one container with a disease problem, will get rid of that and use the tips here for the rest (I have bark-based).