Start to plough current furrow over for vegetable (6)
I believe the answer is:
turnip
'vegetable' is the definition.
(turnip is a kind of vegetable)
'start to plough current furrow over' is the wordplay.
'start to' suggests taking the first letters.
'current' becomes 'in' (I've seen this in other clues**).
'furrow' becomes 'rut' ('rut' can be a synonym of 'furrow').
'over' says the letters should be written in reverse.
The initial letter of 'plough' is 'p'.
'p'+'in'+'rut'='pinrut'
'pinrut' in reverse letter order is 'TURNIP'.
'for' is the link.
(Other definitions for turnip that I've seen before include "Root vegetable of the mustard family" , "Rip nut up for a vegetable" , "veggie" , "food item" , "Fleshy edible white or yellow root" .)