A digger-shaker-inverter is for harvesting root plants is provided. The digger-shaker-inverter includes a frame and a row unit. The row unit includes a first belt driving assembly and a second belt driving assembly. The first belt driving assembly includes a first carrying belt that grips a first side of a vine and a fixed bracket that supports the first carrying belt. The second belt drive assembly include a second carrying belt that grips a second side of the vine, and an adjustable bracket that supports the second carrying belt and adjust to control a distance between the first carrying belt and the second carrying belt.