The need to meet food demand while protecting environmental quality and natural resources for future generations is a scientific challenge that has been grossly underestimated, and this theme provides a unifying framework for my research. Agricultural systems must ultimately contribute to solving the most pressing environmental problems facing humankind because agriculture is practiced on 33% of the earth's surface. Hence, the ultimate goal of my research and educational programs is to ensure that increases in food production do not compromise the quality of soil and water resources or threaten the ecological integrity of natural ecosystems. Current projects focus on understanding process controls on carbon sequestration in agricultural soils, energy efficiency of major rainfed and irrigated cropping systems in the north-central USA, the potential for ecological intensification of maize-based cropping systems, and use of crop simulation models to improve crop and soil management decisions. As a member of interdisciplinary research teams, our goal is to seek fundamental knowledge about the dynamic, interactive effects of climate and crop/soil management practices on short- and long-term performance of agroecosystems-with a focus on carbon sequestration, greenhouse gas emissions, nitrogen and energy efficiency, and crop productivity.