Can I Re-Use 'Ring Culture' Reservoir?

[Dign'Dig]

Can anyone advise if the peat 'water reservoir' I used this year with my greenhouse ring culture tomatoes can be re-used next year, and later years too, without changing or sterilisation...
and I guess a similar question - when using a seedbed to get my brassicas to transplant stage is it OK to sow cabbages etc again in the same bed in following years?

[bramble]

I suppose you could but i personally prefer to change the soil. I like to think its fresh soil giving the plants the best chance and avoiding the chance of desease in the soil.