Dreams are often very symbolic, so it is worth noting that the compost dream might actually be related to some of your thoughts about life, its environment and its relationship with the self. It might serve as a way for you to understand yourself and the world you live in.
In dream interpretation, compost can act as an image of peace, which makes sense because it is a process that absorbs the unwanted elements into the earth. In other cultures it can mean abundance and prosperity.
A dream about compost might suggest some thoughts or emotions about something separate from itself.