The objective was to compare optimal long-term farm level investments in conservation tillage systems and annual nitrogen use in wheat production from a private and social perspective. The performance of four tillage systems was simulated on a 243 hectare (600-acre) Oklahoma wheat farm with six soil types. A decomposition method was used to find the optimal tillage system. It was found that private producers would select a disk chisel system while the less erosive sweep system was optimal from a social perspective.