The story might involve a community that uses wheat to create a unique gravestone as a tribute to someone who had a significant relationship with agriculture or nature. It could also explore cultural or religious meanings attached to such an unconventional gravestone.
Perhaps it's a story of love and loss, where the wheat gravestone serves as a reminder of a person's connection to the land and the harvest. Or it could be a fantasy story with magical elements tied to the creation and significance of the gravestone.