The most common and most likely answer to this crossword clue is the 9 letter word OVERGRAZE
I've seen this crossword clue in Independent
O
V
E
R
G
R
A
Z
E
Buddy explains!
The straight part
We know that "Misuse field" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case misuse field = overgraze.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does OVERGRAZE mean?
OVERGRAZE verb- To graze land excessively, to the detriment of the land and its vegetation
- To allow animals to graze excessively