It takes a brave sort to tuck into mixed dips in the form of earth (8)
I believe the answer is:
spheroid
'form of earth' is the definition.
'spheroid' can be an answer for 'form' (spheroid is a kind of form). I am not sure about the 'of earth' bit.
'it takes a brave sort to tuck into mixed dips' is the wordplay.
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'takes' is an insertion indicator (take can mean to capture or invade).
'a brave sort' becomes 'hro' (I am not sure about this - if you are sure you should believe this answer much more).
'to tuck into' indicates putting letters inside.
'mixed' indicates anagramming the letters.
'e' inserted within 'hro' is 'hero'.
'dips' is an anagram of 'spid'.
'hero' inserted inside 'spid' is 'SPHEROID'.
'in the' is the link.
Can you help me to learn more?
(Other definitions for spheroid that I've seen before include "Kind of globe, not perfectly round" , "Almost-perfect-ball shape" , "Round shape" , "Almost the shape of a ball" , "Solid" .)