"The soil is the environment of many plant activities. Plants are anchored in it, water and nutrients are absorbed from it, vast stores of food are accumulated in underground plant parts, and it is in the soil where much vegetative propagation occurs. Of the two environments in which plants grow, the soil is much the more complex. This is true whether air and soil are each considered from the physical, chemical, or biological viewpoint. The soil not only affects the development and activities of roots directly, but also, by modifying the functioning of roots, it affects the growth and yield of aboveground parts. Next to the living organisms which it supports, soil is perhaps the most complex, the most interesting, and the most wonderful thing in nature. [Editor: My Emphasis] It is not mere dirt."