Many farmers are expanding the corn-soybean rotation to include more corn after corn (i.e. second-year corn). The adoption of conservation tillage practices in a corn-soybean rotation is commonplace. Farmers on poorly-drained soils in the northern Corn Belt now find themselves wondering if conservation tillage will produce economically optimum yields or should they return to conventional tillage systems when corn follows corn. The objectives of the this multi-year study were to measure the effects of various tillage practices for second-year corn and the residual effects of tillage for corn following soybean on second-year corn grain yield and economic return. The study was conducted on a tile drained Nicollet-Webster clay loam soil complex (Aquic Hapludolls and Typic Endoquolls, respectively). Tillage treatments were arranged in a split-plot design with tillage for corn following soybean [deep zone tillage (DZT), strip tillage (ST), and chisel plow (CP)] as the main plots and tillage for second-year corn (moldboard plow, CP, DZT, ST, and disk] as the sub plots. Moldboard plow tillage for second-year corn increased yields from 0.7 to 1.2 Mg ha^-1 and economic return $12 ha^-1 compared with CP, DZT, ST, and disk.