Submitted to: Agrociencia Magazine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/14/2011
Publication Date: 12/1/2011
Citation: Karlen, D.L. 2011. Potential soil quality impact of harvesting crop residues for biofuels. Agrociencia Magazine. 15(2):120-127. Interpretive Summary: People around the globe are asking how we can be sure harvesting crop residues or other plant materials as feedstock for bioenergy production is sustainable. This presentation introduces the concept of soil quality assessment using the Soil Management Assessement Framework (SMAF). Preliminary results from a multi-location study are presented and show that soil organic carbon is an important indicator to monitor. This information will be useful to conservationists and scientists around the world and to entrepeneurs striving to develop sustainable feedstock production strategies.
Technical Abstract: Humankind is in the midst of one of the greatest technological, environmental and social transitions since the industrial revolution, as we strive to replace fossil energy with renewable biomass resources. This presentation will (1) briefly review increased public interest in harvesting crop residues as feedstock for bioenergy, (2) discuss the role for soil scientists to address those interests, and (3) examine how soil quality assessment can be used to help quantify soil biological, chemical and physical response to this new demand. Rising global energy demand, dependence on unstable imports, volatility in price, and increasing public concern regarding fossil fuel combustion effects on global climate change are among the factors leading to an increased interest in development and use of renewable biomass sources for energy production. This is not the first time agriculture has been called upon to supply biomass for bioenergy, so our knowledge base is not devoid, but many soil and crop management changes have been made since the 1970s. It is now recognized that although controlling soil erosion by wind and water is no less important than in the past, it is not the only factor that needs to be considered when evaluating the sustainability of land management practices including harvest of crop residues as bioenergy feedstock. The concept of soil quality assessment is reviewed and the Soil Management Assessment Framework (SMAF) is used to illustrate how such assessments can be used for assessing impacts of harvesting crop residue as feedstock for bioenergy production. Preliminary results of the SMAF assessment show that soil organic carbon (SOC) is one of the lower scoring indicators and therefore needs to be monitored closely. Innovative soil and crop management strategies, including a landscape vision are offered as ideas for achieving sustainable food, feed, fiber, and energy production.