Dre Joann Whalen - Organic carbon in the living soil

Organic carbon is a large, dynamic pool in soils of the world. It is a source of energy and carbon substrates for an incredible diversity of living organisms, from microscopic prokaryotes and fungi to the soil macrofauna, which are visible to the naked eye. The traditional view of organic carbon as a stable or passive substance in soil is challenged by an emerging paradigm of organic carbon as both substrate and product of biological activity in the living soil.

The objective of this presentation is to review what we have learned about soil organic carbon in the past decade and explain how this influences the accumulation or depletion of organic carbon, based on study of agricultural soils in Quebec. We will discuss how the soil organic carbon balance is influenced by agricultural disturbances, such as tillage, as well as cropping systems that include crop rotations and short-rotation forestry. Finally, we will consider how land application of organic residues, such as municipal wastes and biochar, will impact the organic carbon balance in Quebec.