As an inert substance -- the substrate, or dirt, or ground
is formed from the constituent bedrock of a place depending on
its distant geological or the recent climatic events.
As a living substance, soil is created by bacteria, fungi
and plants in the process of growth and decay. This organic part
of the soil is actually living and composed of carbon being degraded
by other organisms. The greater the organic matter the richer
the soil actually is.
Topsoil is a thin veneer of life.
Together substrate and living soil comprise the life giving
foundation of all ecological systems that sustains life, commerce, population, and public health on earth.
Ecosystem services | the value in nature is mostly from soil formation | Leopold's ideas on soil