Effect of Drainage System Layout on Yield, Yield Uniformity, and Water Quality
R. A. Cooke*
Case Corp.; ILLINOIS C-FAR

The overall goal of this research is to improve the characterization of subsurface drainage processes in tile-drained watersheds and to quantify the effect of several depth and spacing combinations on yield, yield uniformity, and water quality. In the long run, the results can be used to select subsurface drainage management practices that optimize yield, water quality, or both.

Effectiveness of Controlled Drainage on Poorly Drained Soils in Illinois
R. A. Cooke,* S. E. Walker, M. C. Hirschi
Illinois C-FAR

This research project is designed to test the hypothesis that controlled drainage systems on poorly drained soils in Illinois will reduce the concentration of nitrate in tile effluent without having an adverse effect on crop yield. It involves the continuous monitoring, over a two-year period, of tile effluent from two pairs of fields. Each pair will consist of a controlled drainage system and a conventional drainage system with similar soils, crops, size, and climate.

Evaluation of Water Quality from Alternative Cropping Systems Using a Multiple-Paired Design
R. A. Cooke,* G. F. McIsaac
Illinois Department of Agriculture

The main objective of this project is to quantify the concentration of soil and agricultural chemicals in subsurface drain effluent from sustainable (organic) and more conventional cropping practices used on farms in Illinois. Sustainable systems are paired with conventional systems with similar soils, crops, drainage system size, and climate, and both are monitored. The pairing of organic with conventional fields on similar soils effectively eliminates climatological and soil differences, major sources of external variability. The use of multiple pairs serves to provide the replicates necessary to broaden the range of applicability of the research findings.