Disadvantages end in rolling grassland (9)
I believe the answer is:
drawbacks
'disadvantages' is the definition.
(I know this)
'end in rolling grassland' is the wordplay.
'end' becomes 'back' (back can mean the end of something).
'in' indicates putting letters inside.
'rolling grassland' becomes 'draws' (I can't justify this - if you can you should believe this answer much more).
'back' put within 'draws' is 'DRAWBACKS'.
Can you help me to learn more?
(Other definitions for drawbacks that I've seen before include "Snags" , "difficulties" , "Disadvantages, hindrances" .)