ARS | Publication request: An analysis of the role of tile-drained farmland under alternative nitrogen abatement policies

Submitted to: Journal of Agricultural and Resource Economics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2006
Publication Date: December 1, 2006
Citation: Petrolia, D.R., Gowda, P. 2006. An analysis of the role of tile-drained farmland under alternative nitrogen abatement policies. Journal of Agricultural and Resource Economics. 31(3):580-594.

Interpretive Summary: Agricultural nitrogen loading to rivers and streams has been cited as one of the primary sources of nitrates that lead to hypoxic zones, with the most notable being in the Gulf of Mexico, stretching across coastal Louisiana and Texas. Such hypoxic areas have become known as ¿dead zones¿ because fish vacate them for more oxygen-rich waters, and slower-moving bottom-dwellers, such as crabs and snails, are suffocated. Unfortunately, the economic studies completely fail to account for subsurface (tile) drainage, which is used extensively on farms throughout the Mississippi River Basin. Given that there are roughly 75 million artificially-drained acres (surface and subsurface) throughout the Mississippi River Basin and that about 90 percent of all corn and soybeans are produced there, it is clear that research must make drained farmland an explicit part of any nitrogen-reduction analysis. In this study, we compared the results of abating nitrogen under a land-efficient policy that retires drained land with those of a cost-efficient policy that keeps drained acres in production and retires non-drained land. Results indicated that tile drainage dominated the abatement process in both policy options.

Technical Abstract: Agricultural nitrogen is a major contributor to Gulf of Mexico hypoxia, and research has shown that agricultural drainage is a major reason why. This work compared the results of abating nitrogen under a land-efficient policy with those of a cost-efficient policy, paying particular attention to the role of drained land. Following the latter resulted in lower abatement costs and less land retirement in some cases. Overall, an acre-efficient policy achieved abatement through retirement of drained land, whereas a cost-efficient policy kept drained acres in production under nitrogen management, with retirement of non-drained land. Under both cases, tile drainage dominated the abatement process.