New seed, new demands (5)
I believe the answer is:
needs
'demands' is the definition.
(I know this)
'new seed new' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'new' indicates anagramming the letters.
'seed' anagrammed gives 'eeds'.
'n'+'eeds'='NEEDS'
(Other definitions for needs that I've seen before include "necessity once" , "What we require" , "Calls for" , "Essentials" , "Misses" .)