Land cultivation (7)
I believe the answer is:
tillage
'land cultivation' is the definition.
'tillage' can be an answer for 'cultivation' (tillage is a kind of cultivation). I also know that 'land' relates to this answer.
This is the entire clue.
(Other definitions for tillage that I've seen before include "Farming" , "Cultivation of the land" , "Cultivation of fields" , "Farmers work at it" , "Farmers undertake it" .)