There is insufficient experimental data to accurately assess the effects of long-term tillage and rotation systems on greenhouse gas fluxes in the Midwest Corn Belt. This research was initiated to determine short- and seasonal fluxes of CO2 and CH4 in soils that have been uniformly managed using MP, CP and NT tillage practices in CC and RC for the last 3 decades. Short-term CO2 emission measured for 168 h after fall primary tillage was higher for CP than for MP at all time of measurement. On a seasonal basis, CO2 emission during the growing season was significantly affected by rotation (CC averaged 16% higher than RC), but not by tillage systems. However, among tillage systems CO2 emission was numerically in the order: NT