You searched for: “geobionts
geobiont (s) (noun), geobionts (pl)
In biology, an organism spending its whole life in the soil or in the ground: Earthworms, grubs, centipedes, millipedes, snails, slugs, and insect larvae are just a few forms of life that are considered to be geobionts and exist in soil.

Geobionts permanently inhabit the soil and affect its structure.