Tax, not very good for arable land (3)
I believe the answer is:
ley
'arable land' is the definition.
(ley can mean a piece of land for farming)
'tax not very' is the wordplay.
'tax' becomes 'levy' (I've seen this before).
'not' indicates named letters should be taken away.
'very' becomes 'v' (abbreviation).
'levy' with 'v' taken out is 'LEY'.
'good for' is the link.
(Other definitions for ley that I've seen before include "Supposed line connecting ancient sites" , "Arable land under grass" , "Field; straight track" , "Supposed ancient straight track" .)