What is the mixed soil material for blueberry plants?
The ingredients are easy to get and not expensive
Certified GKH Gardening Expert
The important part of the mix is two things. Ammonium Sulfate, rather than Ammonium Nitrate- Blueberries are very sensitive to nitrates, and using any fertilizers with nitrates will result in discolored plants, and eventual death.
The pH must be a little on the acidic side as well- Blueberries don't really like neutral to alkaline soil.
The good news is that Ammonium Sulfate will lower the pH of your mix. You, sort of, kill two birds with one stone.
Here is an article that will help you to care for blueberry plants: https://www.gardeningknowhow.com/edible/fruits/blueberries/growing-blueberry.htm