Presenter: Rwit Chakravorty

Location: 368A Heady Hall

Title: Coordination and Efficiency of Tile Drainage Investments in the US Corn Belt

Abstract: Subsurface tile drainage has played a crucial role in U.S. agriculture since the late 1800s, and it remains a subject of considerable interest and debate in the context of sustainable intensification of agriculture. This paper examines the impact of tile drainage on county average corn and soybean yields and yield resilience using 2017 U.S. Census of Agriculture data. Employing a control function approach with land slope as an instrumental variable to address endogeneity, we find a significant, positive effect of tile drainage on yield, especially in high precipitation areas. Additionally, tile drainage reduces long-term yield variability, enhancing yield resilience. Using the point estimates from the econometric analysis, we find that the marginal value of investment in additional tile drainage exceeds approximations of annualized costs in large parts of our study area. Potential agricultural surplus gains from tiling are found to be higher in areas with flatter topography, which require higher coordination among neighboring farmers. Climate change simulation results show up to 12% higher soybean yields and up to 10% higher corn yields for tiling-adapted counties than those that remain at 2017 levels of tiling.