Economic, political, biological, and environmental forces are all seemingly pushing for more corn planted following corn. This is true not just in Iowa, but across the Midwest. The promise of more ethanol plants and the associated increase in demand for grain as well as potentially stover are obvious factors influencing the discussion relative to increasing corn acres and the need for more corn following corn in our cropping systems. In addition to these economic factors is the concern about the intrusion of Asian soybean rust into the Corn Belt that could potentially reduce soybean yields and increase production costs. All of the talk over the last few years of a 'soybean yield plateau' has added to this discussion and interest in more corn. But now, with the excellent soybean yields in most of Iowa for 2005 and escalating fuel and fertilizer prices following hurricane Katrina, some of the enthusiasm for corn following corn is dampened. Before discussing the newest research data on corn following corn, let's discuss some of the known pitfalls and potentials of this cropping system. Pitfalls of Corn following Corn: It is well documented that second-year corn yields are often reduced relative to first-year corn yields. Yield reductions over the years often have ranged from 5 to 15% for corn following corn compared to first year corn (Benson, 1985; Nafziger et al., 2005; Pedersen and Lauer, 2003). Input costs for N often increase because of increased N demand and added costs for pest management, especially insect control, are likely higher. Stand establishment is more variable with corn following corn in many cases. Promises of Corn following Corn: On the positive side, soybean yields may go up; soybeans often respond positively to crop rotation too. More corn grain (and in the future, possibly stover) will be available for ethanol, and with proper management, more residue will remain on the surface and more carbon returned to the soil. Corn following corn is truly a multifaceted issue!