Soybean Cultivar Response to Subsurface Drainage and Subirrigation in Northeast Missouri.

Management of soybean [Glycine max (L.) Merr] on claypan soils with drainage (DO) or drainage plus subirrigation (DSI) may depend on correct cultivar selection. Field research in 2007 and 2008 evaluated effect of cultivar (Kruger 382, Morsoy 3636, Asgrow 3602, Pioneer 93M96 and NKS37-N4) and DO or DSI at 6.1- and 12.2-m drain tile spacings on soybean response. Kruger 382 yield increased 470 kg/ha with DSI on a 6.1-m spacing compared to DO, but yields were similar between DO and DSI systems for other cultivars. Using DSI and DO, Kruger 382, Morsoy 3636, and Asgrow 3602 increased yields 15 to 46% compared to the non-drained control. However, Pioneer 93M96 or NKS37-N4 yields were not affected by DO or DSI. Oil concentration of Morsoy 3636 and Asgrow 3602 decreased up to 0.3 percentage points with DO at a 6.1 m spacing, but drainage had no effect on oil concentration of Kruger 382, Pioneer 93M96, or NKS37-N4. It was important to match high yielding cultivars with appropriate drainage water management systems.