Modern husbandmen replacing area with old grasses (9)

I believe the answer is:

informers

'grasses' is the definition.

'modern husbandmen' is the wordplay.
'modern' becomes 'in' (I've seen this in other clues).
'husbandmen' becomes 'formers' (I can't explain this - if you can you should believe this answer much more).
'in'+'formers'='INFORMERS'

'replacing area with old' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.

I've seen this clue in The Independent.

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