Submitted to: International Agricultural Engineering Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/31/2005
Publication Date: 12/30/2005
Citation: Fausey, N.R. 2005. Drainage management for humid regions. International Agricultural Engineering Journal. 14(4):209-214. Interpretive Summary: Drainage of agricultural lands is important to remove excess water from the surface of the soil or from within the soil profile for economic production of crops. The water removed by drains contains sediment and crop nutrients which pollute streams and lakes. We studied ways to reduce the amount of water and pollutants leaving the soil through the drains. We found that managing the drainage outlet during the nongrowing period significantly reduced the amounts of water and nutrients carried to streams by subsurface drains compared to unmanaged drainage outlets. This is important to farmers, conservationists, environmentalists, and state and federal agencies responsible for assuring water quality in streams.
Technical Abstract: Surface and subsurface drainage are essential agricultural management practices for farmers in humid regions with slowly permeable soils in order to achieve economically viable production levels. Historically, agricultural drainage systems have been installed and allowed to function by relying on gravity or pumping to convey all the water that reached the pipes and ditches away from the area needing the drainage improvement. Drainage effluent is now known to increase the quantity of offsite flows and to contain soluble nutrients, agrichemicals, and salts that can negatively impact the receiving stream or water body. Environmental and ecological impacts may result from these pollutants such as increased flooding, lake eutrophication, development of hypoxic zones, loss of habitat, reproductive failures in wildlife species, and contamination of drinking water supplies. A replicated field plot experiment was conducted to examine the hydrology, water quality, and crop yield impacts of controlled drainage, uncontrolled drainage, and subirrigation drainage on Hoytville silty clay soil in Ohio. Controlled drainage resulted in less water and nitrate released offsite and a lower concentration of nitrate in the vadose zone water than with uncontrolled drainage.