Stephen Del Grosso is a Soil Scientist for the USDA Agricultural Research Service (ARS) in Fort Collins, CO. He is also affiliated with the Natural Resource Ecology Laboratory (NREL) at Colorado State University. He is responsible for estimating nitrous oxide emissions and nitrate leaching from agricultural soils for the annual EPA Greenhouse Gas Inventory and is the co-editor and co-author of the most recent USDA Agriculture and Forestry Greenhouse Gas Inventory. Dr. Del Grosso uses models to compare different mitigation strategies intended to reduce greenhouse gas emissions from cropped and grazed soils and to evaluate the net environmental impacts of different biofuel cropping systems. In addition to running models, he oversees a field experiment that investigates how crop rotations, fertilizer additions, and tillage practices interact to control greenhouse gas emissions and crop yields.