When the clamp is full, the earth scraped from the field to make the base is then used to cover the root crops to a depth of several inches.
Straw or old hay may be used to protect the upper surface from rain erosion.
A well-made clamp will keep the vegetables cool and dry for many[vague] months.
Most clamps are relatively long and narrow, allowing the crops to be progressively removed from one end without disturbing the remaining vegetables.
The use of a clamp allows a farmer to feed vegetables into market over many months.