A set not up to mantra in US city for rural economy (8)
I believe the answer is:
agronomy
'rural economy' is the definition.
(I've seen this before)
'a set not up to mantra in us city' is the wordplay.
I cannot quite see how this works, but
'a' is within the answer.
'not' could be 'no' (I've seen this in other clues) and 'no' is present in the answer.
This explanation may well be incorrect...
'for' is the link.
Can you help me to learn more?
(Other definitions for agronomy that I've seen before include "Rural economy" , "Science of soil and crops" , "Study of crops and soil management" , "Science of soil management and crop production" .)