A grand country welcoming current fad for farming (12)
I believe the answer is:
agricultural
'farming' is the definition.
('agricultural' can be a synonym of 'farming')
'a grand country welcoming current fad' is the wordplay.
'grand' becomes 'g' ('G' can be a synonym of 'grand').
'country' becomes 'rural' ('rural' can be similar in meaning to 'country'**).
'welcoming' means one lot of letters goes inside another (in sense of 'inviting in').
'current' becomes 'i' (symbol for electric current).
'fad' becomes 'cult' ('cult' can be a synonym of 'fad').
'i'+'cult'='icult'
'rural' placed around 'icult' is 'ricultural'.
'a'+'g'+'ricultural'='AGRICULTURAL'
'for' is the link.
(Other definitions for agricultural that I've seen before include "Lulu Craig art (anag.)" , "Rural; farmed" , "Relating to farming" , "Related to farming" .)