Is that the reason there are sheds local that are full of imported spuds then We irrigate when we can, but not always possible. In the past we have had adjacent fields 1 irrigated 1 not. Might of been luck but you had a job to tell the samples apart.
As for cost, that field was getting 4 passes(2 with each challenger) before i planted then they still have to be power ridged. I'm not a huge fan of our system, but then i don't think de-stonning/clodding is the way to go either. Not on this land anyway. In the past have seen the outcome of it in cornwall with fields like bogs or sometimes on the road after a rain. Not always the machines fault i know.