From Onion Equipment
The Top Air Onion Digger Series of harvesters has become a popular solution to undercutting onions in the southern United States. As this area is subject to frequent rains during the harvest season, the onions are best undercut and placed on top of a firm bed. Top Air diggers accomplish this by first undercutting with a blade. Then, conveying the onions up a belted chain bed to remove soil from the roots, which allows for better curing. Then, firming the soil with a roller, which allows rain water to run off the bed. The onions are then laid back on to a firm bed. This method allows the soil free roots and tops to dry in these difficult climatic conditions.