Details about conservation drainage
Subsurface tile drainage is a water management practice increasingly utilized in agricultural fields in Minnesota to improve field access for planting and harvesting and to increase crop production. At the field scale, tile drainage typically reduces surface runoff by increasing subsurface runoff, and increases total annual runoff volume by reducing water availability for evaporation, primarily during the spring and fall when crops are not growing. Conventional tile drainage can increase the loss of soluble crop nutrients from fields, such as nitrate nitrogen and soluble phosphorus, as well as increase the transport of herbicides, pesticides and pathogens. Increased runoff volume can, in turn, increase the risk of downstream flooding and sediment transport. The purpose of this document is provide information to financial and technical assistance providers and farm operators about conservation practices that reduce the impact of tile drainage on the environment while maintaining or enhancing productivity.