Horse the French used for such farming? (6)
I believe the answer is:
arable
'used for such farming?' is the definition.
(arable land can be farmed)
'horse the french' is the wordplay.
'horse' becomes 'arab' (Arab is an example).
'the french' becomes 'le' ('the' in French).
'arab'+'le'='ARABLE'
(Other definitions for arable that I've seen before include "Such land is fit for tillage" , "Suitable to grow crops" , "(Of land) capable of producing crops" , "Fit for crop growing" , "Suitable for farming" .)