‘Carthago delenda est!” cried Cato the Elder, “Carthage must be destroyed!”
And so the Romans did, reportedly by leveling the city, selling its surviving citizens into slavery, and then sowing the land with salt.
The Spanish adopted a similar practice. When a landowner was convicted of treason, salt was poured upon their lands, spelling death not only for the resident plants, but also humans, and any animals, birds and insects that depended on those lands for their habitat.