We recently walked over a professionally planted and machine harvested potato paddock and I was amazed at the left over amount of spuds sitting on the ground where the machine (esp at the ends of the rows) completely missed them when turning..
I was thinking as no one was coming back to get them, instead of them wasting away to be ploughed back into the ground, if anyone did charity work or knew of someone supplying cooked meals to the needy, that perhaps the market garden business would be happy for volunteers to walk about after the machines have left and pick up the remaining spuds.
There was a huge amount, and I thought this would be good and beneficial to both sides, the charity for being supplied the vegetable for a basic food supply, and the market gardening company as corporate responsibility work that would not cost them a dime.
Back in the UK we lived in a spud growing region, they were grown fo McCains and they had a minimum size they would accept, so once the machines had been over the land we went a picked up several carrier bags full in a short space of time.
Unless they are out and out stingey, or spuds have been sprayed with some chemical, all I can see is a win/win situation!
But if you leave the spuds lying out in the open they'll go green and be useful for nothing.... not even stock food. Old spuds are GREAT pig food, by the way.