Fig. 1.

Daily stream flow and nitrate concentrations in the Embarras River at Camargo, IL, and the Upper Salt Fork River at St. Joseph, IL. Flow-weighted annual nitrate concentrations are indicated with red dots.

 


Fig. 2.

Annual nitrate N yields and stream flow in the Embarras River at Camargo, IL, and the Upper Salt Fork River at St. Joseph, IL.

 


Fig. 3.

South tile (ST) and North tile (NT) nitrate concentrations and tile flow during 2012. Vertical dashed lines show period of drainage water management on NT.

 


Fig. 4.

Tile nitrate concentrations and flow of the inlet to the bioreactor, along with outlet concentrations during 2012.

 


Fig. 5.

Continuous corn (C–C) and corn–soybean (C–S) tile nitrate concentrations during 2011 through 2012. For the C–S, corn was grown in 2010 and 2012, and soybean was grown in 2011.

 


Fig. 6.

Nitrate yields from tile drains in two fields during 2011 through 2013. Tile B had a cover crop planted in the fall of 2012. The 2011 water year was a partial year, with data from 1 April through 30 Sept. 2011.