Drainage and The Environment

Agricultural drainage is the use of surface ditches, subsurface permeable pipes, or both to remove standing or excess water from poorly drained lands. Many soils in the Upper Midwest, the U.S. and the world have poor internal drainage. Farmers are willing to make significant investments in agricultural drainage systems for two major reasons: 1.) Crop emergence, development and yields. 2. Improves conditions for timely tillage, planting and harvesting. Impacts to the environment from subsurface drainage include: decreased surface runoff and increased infiltration that carry soluble constituents. The primary concerns for impaired surface waters within Upper Midwest are turbidity and low DO. Of a concern for the Gulf of Mexico is nitrogen. Practices of shallow placement of tile, and controlled drainage techniques, with improved nutrient management, show great promise to reduce flows and load of soluble constituents.