Subsurface drainage and subirrigation for increased corn production in riverbottom soils

Subsurface (tile) drained agricultural landscapes within the U.S. Midwest are challenged with addressing both deficit and excess water conditions while minimizing negative impacts on water quality. Drainage water recycling (DWR) provides an opportunity to improve water quality along with potential increased crop yield resiliency. This research evaluated the effect of drainage water recycling (DWR) using drainage plus subirrigation and free drainage (FD) on grain yield production and crop nutrient removal compared to nondrained (ND) soil under a continuous corn (Zea mays L.) cropping system in upstate Missouri. A 26 and 20% increase in corn grain yield with DWR (9.3 Mg ha(-1)) and FD (8.6 Mg ha(-1)) was observed over the 6-yr study compared to ND (6.9 Mg ha(-1)). A significant (P = .04) year x treatment interaction showed the substantial effect of variable precipitation on yields within a growing season and over the study period. No significant effect of treatment was found on grain nutrient concentration or grain quality (oil, protein, or starch concentrations). Plant biomass (P = .85), nutrient concentrations, and plant nutrient uptake (P > .05) were similar among drainage water management treatments; however, grain nutrient (total nitrogen [TN], total carbon [TC], P, and K) removal with DWR and FD was greater than ND. As farmers experience more extreme weather conditions, such as drought and more intense rainfall events, improved drainage and DWR can increase corn grain yield resiliency.