Dirt consists of much more than mere minerals. That's why the most important parts of the plants we grow may be the underground root systems we rarely see. .
The addition of microbes and fungi does more than provide nutrients for the plants, explains David Perkins, a San Francisco-based farm and garden consultant. It actually modifies the structure of the soil itself.
For serious gardeners and growers, Perkins adds, understanding soil biology offers myriad benefits.