Form of soil farmers use (4)
I believe the answer is:
silo
'farmers use' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'form of soil' is the wordplay.
'form of' is an anagram indicator (the letters need to be in another 'form').
'soil' anagrammed gives 'SILO'.
Can you help me to learn more?
(Other definitions for silo that I've seen before include "Tower used for storing fodder" , "Cylindrical storage tower" , "Grain storage area" , "Missile pit" , "Large container for oils" .)