The invention relates to a root crop harvester in the form of a potato harvester (1), comprising a lifting device (2), from which a crop material (E) and also a mixture (G) comprising clods, weeds and similar admixtures (B) can be displaced in the region of screen belts (3) which are arranged downstream thereof. According to the invention, the mixture (G) lying on one of the feed belts (4) reaches a sorting zone, where the crop material (E) is sorted by means of a separating device (6) that is arranged above the feed belt (4) and is acting on the mixture (G) transversely to the direction of feed of the feed belt, in such a manner that two scraper belts (8, 9), which are circulating in the same direction in a scraping direction (7, 7'), capture the crop material (E) by means of respective scraper elements (10, 10'; 11, 11'), and feed said crop material in two adjacently arranged scraping planes (12, 13) to a sorting belt (14) that is arranged downstream thereof. Admixtures (B) that remain on the feed belt (4)