Pedologists, or soil scientists, define soil as the naturally occurring unattached mineral or organic material
at the earth's surface that is capable of supporting plant growth. Soil is a
complex biological system that has developed in Alberta since the last
glaciations 10,000 years ago.
Soil formation is a continuous, but slow, process. The productive portion of the soil is the topsoil, a relatively thin layer of
well-structured soil containing essential nutrients, microbes and organic matter
needed to support vigorous plant life. It can take more than 100 years for one centimetre
of topsoil to form. This thin cover is the foundation of
all terrestrial life. Soils also help to determine how
the land is used. Fertile soils can be used to cultivate
crops, as part of the agricultural industry. In fact,
agricultural activity is one of the most dominant uses
of land in Alberta.
The composition of soil can vary widely, but it is usually
a mixture of mineral particles (sand, silt and clay), organic remains in various
stages of decomposition, water, air and a wide variety of living organisms. The
community of organisms that live below the surface is vital to the condition of
soil. Organisms like beetles, worms, mites, fungi, algae, and
bacteria, break down and mix the organic matter in the soil. They also help
aerate the soil as they move through it. These organisms are important nutrient
recyclers, decomposing organic matter and returning its nutrients to the soil.