It will have had the nutrients taken out of it, so I think you'd be better using it as a soil conditioner, or else just add it to your compost bin if the potatoes were healthy.

I would definitely advise against using the compost you have grown potatoes in to grow more. Not only as Spritzhenry has said will it have used all its nourishment but, more importantly, if there was any disease in the potatoes it will be in the compost and infect the next lot. Use as a soil conditioner around your flower beds not your veggie beds. If there is any question that your potatoes might have had blight then personally I would not use at all.

That's the trouble with this site, MG - I wanted to add emphasis to the word 'if' in my answer, because what you said was in my mind too.

I kno what you mean SpritzH. we just get on and do the best we can. C