Soil surrounding grain farmed initially with contempt (10)

'with contempt' is the definition.

'soil surrounding grain farmed initially' is the wordplay.
'soil' becomes 'sully' (both can mean to mar or stain).
'surrounding' indicates putting letters inside.
'grain' becomes 'corn' (corn is a kind of grain).
'initially' says to take the initial letters.
The first letter of 'farmed' is 'f'.
'corn'+'f'='cornf'
'sully' enclosing 'cornf' is 'SCORNFULLY'.