and analyzed in the laboratory at Purdue University.
Two field-scale studies are evaluating movement of agricultural chemicals through soil into subsurface drainage water. The SEPAC site in Jennings County began in 1983 and the Water Quality Field Station (WQFS) in Tippecanoe County began in 1993. The WQFS uses 5 ft deep clay wall barriers to isolate each plot from surrounding plots, ensuring that water and chemicals measured in each drain accurately represent the particular treatment on that plot. Objectives at the WQFS include evaluating both short- and long-term rotations, fertilizer practices, manure applications, and pesticide treatments, and comparing all of the treatments to a background control treatment of reestablished native prairie grass (bluestem). At SEPAC the impact of four drain spacings, all receiving the same crop and soil management practices, is evaluated.