Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 7/12/2007
Publication Date: N/A
Citation: Interpretive Summary: TConcern over global climate change frequently ends up considering everybody else’s contribution, but only reluctantly evaluating the local situation. Agricultural emissions of greenhouse gases are one of many factors affecting climate change. A workshop held in Gorizia, Italy on June 15-16, 2006 entitled “Soils and Water Management: A Challenge to Climate Change” was sponsored by the Organization for Economic and Cooperation Development and focused on the contributions of agricultural production systems. One of societies concerns deals with removing and disposing of waste materials. Burial in soil is a common approach for everything from municipal wastes to crop residues. However, when these materials are incorporated in soil they decompose and emit greenhouse gases and sometimes unpleasant odors. During the process of soil incorporation and tillage, soil microbial activity is enhanced and some of the carbon that was previously sequestered as soil organic matter is released. All in all, waste and crop residue management is very complex and deserves special consideration as society strives to develop biofuel technologies.
Technical Abstract: This paper is the summary chapter of materials presented at an OECD (Organization for Economic and Cooperation Development) workshop entitled “Soils and Waste Management: a Challenge to Climate Change“ held in Gorizia, Italy, 15-16 June, 2006. Presentations at the workshop will be published in a special issue of Waste Management. Concerns over global climate change have many entities within the agricultural community as well as outside interests questioning the contributions that agriculture is making to the problem and the role it might play in remediation. There is little doubt that agricultural wastes and manure can potentially contribute to greenhouse gas emissions either through respiration or anaerobic decomposition. It is also a known fact that natural soil processes contribute to climate change by emitting carbon dioxide, methane, and nitrous oxide. The extent to which the emission process can be offset or even reversed is related to tillage and residue management practices. The ultimate question comes down to identifying the environmental processes and management practices that will ultimately sequester carbon or at least delay its return to the atmosphere. Situations and enterprises that involve composting were shown to be preferable for environmental and societal reasons compared to soil incorporation of food processing wastes and crop residues. Agricultural management practices, especially tillage, that stimulate soil respiration are known to increase carbon dioxide emissions. Crop residues represent a form of carbon storage that can be used to produce biofuels, but a convincing argument can be made that the most sustainable use of animal manures and residues from grain crops involves returning these materials to the soil and thereby improving chemical, physical, and biological properties that support plant life and the biological capture of solar energy.