Picked up every other piece of granite at the bottom of the field (6)
I believe the answer is:
learnt
'picked' is the definition.
(I've seen this before)
'piece of granite at the bottom of the field' is the wordplay.
'piece' becomes 'r' (abbreviation for Rook).
'of granite' becomes 'nt' (I can't explain this - if you can you should believe this answer much more).
'at the bottom of' says to put letters next to each other.
'the field' becomes 'lea' (lea can mean a meadow or field of grass).
'r'+'nt'='rnt'
'rnt' after 'lea' is 'LEARNT'.
'up every other' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for learnt that I've seen before include "Aquired knowledge or skill" , "Acquired by instruction" , "Memorised" , "Picked up" , "Committed to memory" .)