|The Morrow Plots|| Field
Professor and Extension Specialist
Department of Agricultural Engineering
Figure 1. Color infrared
|“Out of sight, out of mind” is how most of us feel about field drainage tile lines, if we even know they exist. Yet they comprise a vast drainage infrastructure that has significant impact on production agriculture. Beginning sometime shortly after the Civil War and continuing through today, drainage tile systems speed the de-watering of wet, yet productive, soils and release that water back to surface channels. Because tiles are below ground and out of sight, we tend to overlook them and their importance. Some of the most productive soils on Earth would be nonproductive without them.||
Figure 2. Tile map of SW 160
acres of section shown in Figure 1.
Tile drainage systems are difficult to monitor and locate. Direct location of the tiles involves “probing” with specially designed tile probes, or excavation. Locating tile lines over large areas using tile probes is very time-consuming and exhausting. Excavation is expensive and disruptive to soil structure.
Color Infrared (CIR) film aerial photography, flown from small, manned aircraft, is the current technology used to locate field drainage tiles in central Illinois. Tile maps (Figure 1) are derived from aerial photos and are available to Champaign County farmers at a reasonable per-acre cost through the Champaign County Soil and Water Conservation District (CCSWCD). Other districts are utilizing this technology as well.
While these maps are proving to be very valuable to farmers, the knowledge of tile system location and size is also extremely important to water quality research and environmental assessment. Current hydrology and water-quality computer simulation models, such as those used by the United States Environmental Protection Agency and other agencies, do not accurately represent the effect of tile drainage on stream and reservoir water quality. Projects funded by the Illinois Council on Food and Agricultural Research (C-FAR) are creating new simulation models and model components that use the detailed tile maps available for selected east-central Illinois watersheds. The developed procedures can then be added to the models used for Total Maximum Daily Load determinations, for example.
|Department of Crop Sciences
College of Agricultural, Consumer and Environmental Sciences
University of Illinois Extension
© 2001 University of Illinois
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