What is a pronoun for earth?

The pronoun for "earth" is "it", the third person singular present pronoun for the neuter gender. With poetic license, the planet Earth is sometimes referred to as "Mother Earth", and it that instance the personal pronoun would be "she" for the singular feminine gender. The relative pronouns "who", "which", and "that" could also have earth as an antecedent, the first one only in the poetic sense of "Mother Earth".