Cultivate ebony as cash crop (3,4)

I believe the answer is:

soy bean

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'cultivate ebony as cash crop' is the definition.
I know nothing about this answer so I can't tell whether this works.

'cultivate ebony as cash crop' is the wordplay.
'cultivate' indicates anagramming the letters (I've seen 'cultivating' mean this).
'cash' becomes 'L' (The pound sterling symbol is an elaborate L).
'crop' means to remove the last letter.
'ebony'+'as'+'l'='ebonyasl'
'ebonyasl' with its final letter taken off is 'ebonyas'.
'ebonyas' with letters rearranged gives 'SOY BEAN'.

Can you help me to learn more?

(Another definition for soy bean that I've seen is " Source of oil".)

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