Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2007
Publication Date: 11/5/2007
Citation: Smith, D.R., Armstrong, S. 2007. Nutrient Transport in Tile-Fed Drainage Ditches. American Society of Agronomy Annual Meeting Abstracts. November 4-8, 2007, New Orleans, LA. 2007 CDROM.
Technical Abstract: Drainage ditches receive water and associated contaminants from agricultural fields via surface runoff or sub-surface tile drains. Little consideration has been given to the processes affecting nutrient transport once in surface water. The objective of this research was to evaluate the nutrient fate and transport at three sites along a drainage ditch in Northeastern Indiana. Three sites were selected for this study along a tile-fed drainage ditch. The contributing areas of these sites were: 1) 299 ha; 2) 2230 ha; and 3) 4420 ha. Ammonium (NH4-N) and phosphorus were injected into the ditch at these three sites to increase the concentration by approximately 0.4 mg/L NH4-N, and 0.2 mg/L P. For each injection, water samples were collected every five minutes for 2 hours at five locations downstream from the injection point. Sediments were collected for physical and chemical characterization. Changes in nutrient concentrations downstream from the injector were used to calculate nutrient uptake length (Snet), nutrient uptake velocities (Vf), and nutrient mass nutrient uptake rates (U). The Snet increased with increasing drainage area, whereas Vf and U decreased with increasing drainage area. The values of these parameters were correlated to the particle size distribution of the ditch sediments, and the velocity and discharge of water at the three sites. Data from this research will shed insight into the processes that govern nutrient fate and transport in tile-fed drainage ditches.