Several key innovations are coming on line to dramatically improve both agricultural productivity and water quality by management of water flowing through tile lines. The first of these is Drainage Water Management where water is held in the field during the dry periods of the growing season and during fallow periods to improve productivity, and water quality. The second is Sub-Irrigation, which uses the same subsurface tile lines used for drainage to irrigate crops. These two systems can dramatically improve farm economic viability and cost-effectively reduce nutrient loss to waterways.
DWM refers to controlling the flow of water discharged from tile lines to improve environmental performance and agricultural production. Without controls, tile lines drain water and associated materials from fields around the clock year round. However, drainage typically is only needed during
part of the year, and closing off drainage during most of the year will significantly reduce nutrient loss and improve yields.
Read more here……Innovations in Water