Soil is easy to ignore. We might notice it when
gardening or playing outdoors. But even when we
forget about it, soil is always there, everywhere.
Most of what we see are mineral particles that
we recognize as sand, silt or clay. There's also
plenty of water and air. But soil also is alive. It
contains countless fungi and microbes. They
help recycle the dead by breaking down the
remains of plants, animals and other organisms.
Scientists study these things every day. These
specialized researchers get their hands dirty to
learn more about the very important ways that
soils help us. They think soil is so important that
they named 2015 the International Year of Soils.
Soil, they note, is not only essential for life but
also plays a role in everything from flood control
to climate change.
More than dirt
If you were to divide a soil sample into 20 parts,
9 parts would be made up of the stuff we think
of as dirt: clay, silt and sand. These are
inorganic particles, which means they come from
non-living sources. A full half, or 10 parts, would
be equally divided between air and water. The
last part would be organic , made from dead and
decaying organisms. The soil also would contain
countless numbers of minuscule microbes,
mostly fungi and bacteria.
Treat your soil with care so that it
 can serve you well when needed.
Source: Google and personal knowledge