It makes junk depot fight for length (9)
I believe the answer is:
'it makes junk depot' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'fight for length' is the wordplay.
'fight' becomes 'scrap' (a scrap is a minor fight).
'for' is a charade indicator (letters next to each other).
'length' becomes 'yard' (I have seen 'A length ' mean 'yard' so perhaps 'length' could also mean 'yard').
Can you help me to learn more?
(Other definitions for scrapyard that I've seen before include "Place for metal waste", "Steptoes' place", "Dump", "recycling centre", "Metal recycling site".)