One leaves old king some fertile land (7)
I believe the answer is:
orchard
'some fertile land' is the definition.
(where fruit trees are grown)
'one leaves old king' is the wordplay.
I cannot quite understand how this works, but
'one' could be 'o' (I've seen this in other clues) and 'o' is present in the answer.
'leaves' could be 'char' (I've seen this in other clues) and 'char' is present in the answer.
'king' could be 'r' (abbreviation for rex, king in Latin) and 'r' is located in the answer.
A single letter 'd' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for orchard that I've seen before include "Garden of fruit trees" , "Area set aside to grow fruit" , "Plot for fruit trees" , "Fruit-growing area" , "Enclosure containing fruit trees" .)