Farming partner given your backing (9)
I believe the answer is:
husbandry
'farming' is the definition.
('husbandry' can be a synonym of 'farming')
'partner given your backing' is the wordplay.
'partner' becomes 'husband' (husband is a kind of partner**).
'given' means one lot of letters go next to another.
'your' becomes 'yr'.
'backing' says the letters should be written backwards.
'yr' written backwards gives 'ry'.
'husband'+'ry'='HUSBANDRY'
(Other definitions for husbandry that I've seen before include "land management" , "farm management" , "Farm business" , "The business of farming" , "The care of crops and animals" .)