Residue Management: Back to the Roots.

Addressing the issues of climate change and sustainable biomass feedstocks have soil as a common theme. Managing crop residues is directly related to soil management. Understanding how soil and crop residue management interact provides insight on how to assure agricultural soil can serve as a carbon dioxide sink and not a source. The concept of minimum source carbon provided the basic science for preliminary estimates of how much crop residue (e.g., corn stover or wheat straw) needs to be returned to the land and conversely what may be available for harvest. Above-ground crop residue contributes to controlling erosion and maintaining soil organic carbon. More carbon from roots is humified into soil organic carbon than above-ground residue. Decades of research by Dr. Allmaras contributed to the on-going research to simultaneously sequester carbon and build sustainable bioenergy systems. Examples of how his research reaches into the future to solve present problems will be presented.