Water Resources Research Act Program

Details for Project ID 2009ND177B

Effects of Iron Bacteria on Subsurface Tile Drains: Influence on Nutrient Transport

Institute: North Dakota
Year Established: 2009 Start Date: 2009-03-01 End Date: 2010-02-28
Total Federal Funds: $4,000 Total Non-Federal Funds: $8,000

Principal Investigators: Scott Korom

Abstract: The reclamation of land by drainage has altered the American landscape since the earliest of settlements. Today, it is estimated that greater than 110 million acres of agricultural land in the United States is artificially drained. The use of subsurface drainage continues to grow in the Midwest and has allowed for reclamation of previously unproductive land for agricultural purposes. The use of subsurface drainage is a double-edged sword; it is estimated that the principal contributor of nitrogen inputs in the Gulf of Mexico and the North Atlantic Ocean are agricultural in origin. Subsurface drainage bypasses the reduced zones where denitrification is most likely to occur, contributing to higher nitrate yields as it is discharged directly to surface water. Remediation of nitrate contaminants is effectively completed through the process of denitrification, typically through natural attenuation. This naturally occurring process reduces nitrate (NO3-) to harmless nitrogen gas. The objectives are to determine denitrification rates in the aquifer sediments, denitrification rates in the gravel envelop surrounding the tile drains, and quantities of P and NH4+-N uptake and denitrification taking place in the drains. The aim of this study is to develop a procedure for subsurface drainage cleaning that optimizes hydraulic efficiency and reduces nutrient transport.