Division of Extension
This study was conducted from 2004-2007 and may no longer reflect current conditions as weather, management practices, and available data have evolved. This research remains valid, but should be considered alongside more recent findings. Farms near Lake Michigan in Manitowoc County, Wisconsin were facing a tough question: how much are agricultural fields contributing to water […]
If you farm on steep slopes in Wisconsin, you’ve likely watched good soil wash away after a hard rain. That runoff carries more than dirt — it carries phosphorus and nitrogen that your crops need and that nearby streams don’t. A conservation tool called a grade stabilization structure (GSS) may be one of the most cost-effective ways to slow that loss down.
From 2003 to 2010, Discovery Farms and the U.S. Geological Survey monitored surface runoff from three field watersheds to measure how this system affects soil, phosphorus, and nitrogen loss.
From 2003 to 2008, researchers monitored both surface runoff and tile drainage at multiple field sites to understand how this large-scale farming system affects water quality on the fine-textured red clay soils common to northeastern Wisconsin.
From 2005 to 2009, Discovery Farms and the U.S. Geological Survey monitored surface runoff and tile drainage on two fields at Koepke Farms to measure how this system affects soil, phosphorus, and nitrogen loss.
Because nitrate is negatively charged, it does not bind with negatively charged soil and readily moves with water. Typically nitrate losses are more prevalent in subsurface water like tile drainage, while high phosphorus and sediment losses are associated with surface waters. Although we do have highly accurate ways to measure tile drainage water quality, such as 24/7 automated flow samplers, this approach is typically not economically or logistically feasible for individuals looking to monitor tile drainage on their own farm.
The use of tile drainage is becoming more popular in Wisconsin. Installing a tile drain system can be a great tool to dry soil out faster, improving the timeliness of field operations throughout the cropping season. However, how do tile systems influence water movement off of the field, and what are the water quality implications?
