Nothing in their cup, sadly, rich in nutrients (9)

I believe the answer is:

eutrophic

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'nothing in their cup sadly rich in nutrients' is the definition.
I can't judge whether this defines the answer.

'nothing in their cup sadly' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'in' indicates putting letters inside.
'sadly' is an anagram indicator.
'their'+'cup'='theircup'
'theircup' is an anagram of 'eutrphic'.
'o' put inside 'eutrphic' is 'EUTROPHIC'.

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I've seen this clue in The Guardian.

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