If you are referring to a musical composition, literary work or art idealizing rural life, it is pastoral.
Pastorial is a misspelling.
Pastoral is correct.
Pastoral refers to the duty of a pastor in taking care of souls and also their rural life and scene.
"Ministers of the Lord have been delegated to the pastoral lifestyle in their service of God."
Pastorial is the incorrect spelling for the word, pastoral. It is unacceptable in official writings and texts.