A woman cultivated soil (4)
I believe the answer is:
lois
'a woman' is the definition.
'cultivated soil' is the wordplay.
'cultivated' indicates an anagram.
'soil' is an anagram of 'LOIS'.
(Other definitions for lois that I've seen before include "Woman" , "- Lane (Superman's girl)" , "- Lane, girlfriend of Superman" , "- Lane, Daily Planet reporter" , "-- Lane, 'Superman' character" .)