Topsoil
From Tardis Wiki, the free Doctor Who reference
Topsoil was a particularly fertile kind of soil, which was especially useful for gardening.
The Gardeners brought soil from their home world to Tellus IV. (PROSE: The Secret in Vault 13)
Once, the crew of a colony ship carrying topsoil awoke from cryo-sleep to find that their topsoil had grown into fields and meadows. (PROSE: A Good Life)
