ΔE 18.1, loose: different enough that you should pick on purpose. Earth is noticeably darker, more muted than Desert Brown.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Earth is noticeably darker, more muted than Desert Brown.
The same difference applies the other way round: Desert Brown is noticeably lighter, more saturated.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Desert Brown on the colour wheel See Earth on the colour wheel
All matches: Desert Brown equivalents · Earth equivalents