Rock ‘combine’: Self-propelled picker handles 10 yards a minute

SEBEKA, Minn. — On a field in northeast Otter Tail County, Minn., littered with field stones ranging from pebbles to volleyballs, the RP 1000 moves onward and then upward. A curious, self-propelled contraption moves ahead at about 3 mph, unearthing rocks in a 20-foot width. Irregular rocks disappear into a cylindrical sieve that takes them to a conveyor and then onto a heavy-duty, high-lift box.

By: Mikkel Pates, Agweek