dertu -der-de'u- gismu

x₁ is a quantity of/contains/is made of dirt/soil/earth/ground from source x₂ of composition x₃.

Also: x₁ is earthen; x₃: composition including x₃, which need not be exhaustive of composition. See also kliti, terdi, loldi.

In notes:

kliti: x₁ is a quantity of/contains/is made of clay [moist, clammy dirt] of composition including x₂.
loldi: x₁ is a floor/bottom/ground of x₂.
terdi: x₁ is the Earth/the home planet of race x₂; (adjective:) x₁ is terrestrial/earthbound.
derba'o: b₁ initially grows b₂ beyond the soil; b₁ sprouts b₂ from the ground.
derpesxu: d₁=p₁ is a quantity of mud of composition d₃=p₂, made from dirt from source d₂
rokspi: s₁=r₁ is a pebble/piece of stone of type/composition r₂=s₂ from location r₃.
victerlu'i: v₂=l₃ is trash/rubbish/garbage/refuse removed from v₃=l₂ by v₁=l₁ (agent)
zandi: x₁ is dirty/contaminated with debris/contaminant x₂ by standard x₃
lumbrinki: x₁ is an earthworm of species x₂.
trufeli: x₁ is a truffle (genus Tuber) of species x₂