Adoption of Subsurface Tile Drainage Under Fargo Clay Soils.

Installing subsurface tile drainage under poorly drained high clay soils is a common practice to remove excess water. This long-term on-farm project has been evaluating the feasibility of adopting conservation tillage practices under tile drained condition and optimizing tile depth and spacing under Fargo clay soils. Tile was installed in June 2013. During 2015 growing season, corn-soybean rotation had higher yield than continuous corn for both tile drained and surface drained soils. Under tiled drainage, chisel-plough had higher yield than NT; but under surface-drained condition, NT had higher yield than chisel for both rotation. For tile-spacing and-depth experiment, surface drained had the highest yield, whereas the lowest yield was observed under tile with 50 ft spacing and 4-ft depth. From both experiments, it was evident that high rainfall intensity might increase the nitrate leaching loss and resulted into yield loss under tile drained condition.