Change soil every year?

[TomatoDon]

We've had a very late and wet spring and to work around some of this I now have more than 200 tomatoes planted in 25 gallon cattle feed containers. They are much tougher than black nursery containers, plus they don't have holes punched in the bottom that let's all the water drain out. We drilled holes aboutt 4 inches up to serve as small reservoirs.

Two hundred containers x 25 gallons each is theoretically 5,000 gallons of "soil." I just a mix of rich topsoil and cotton gin trash, which is great organic matter that is like compost that we have in abundance here.

I'm aware of the reasons to not plant tomatoes in the same spot each year, but I also know that Earth-tainers and container growing is very popular, and i doubt that all people can afford to replenish their containers with fresh compost or soil mix every year.

Is there an effective way to treat the soil mix at the end of the year that renders it safe and harmless for re-use the next year? What is the best way to deal with the problem of not growing in the same dirt or soil-mix every year?

Thanks in advance!
Don