what is chemicals are in the soil around volcanoes that makes it so fertile. website link acceptable (:?
It really depends on what species your are growing. Some mushrooms grow well on wood (woodchips, sawdust, etc.). Some need soil with high organic matter, while others need high organic matter or fecal matter. Google the mushroom name with substrate or growing medium.
go to SHROOMERY ,COM they have every answer to any mushroom question you could have
its 2/3 cup vermiculite, 1/3 cup water, 1/3 cup brown rice to one jar. use a 250mil on, mason jar. and there you go. oh and a pressure cooker. You know, you could just buy a mycobag and save yourself the time and the anger of contamination.