Waterlogged corn responded to post‐flooding N in Ohio

Precipitation patterns in the U.S. Midwest have become more erratic, increasing the occurrence of flooding and soil waterlogging. Current nitrogen (N) management recommendations for corn ( Zea mays L.) do not fully consider the effects of excess water or the use of split N applications when determining optimal N rates. This research aimed to examine the interaction between waterlogging and N applications on corn N uptake and grain yield, and to determine whether N sufficiency values for plant and soil nutrient status under normal conditions remain applicable after waterlogging. Waterlogging was induced during early vegetative stages (V4–V6) prior to sidedressing. The treatments included no waterlogging, 3 days of waterlogging, and repeated waterlogging (3+3 days) as the whole plot factor. The combination of a preplant (0 or 100 lb N ac −1 ) and sidedress (0, 60, 120, or 180 lb N ac −1 ) N application was the subplot factor and was randomized within each whole plot. Waterlogging reduced corn grain yield by up to 25% compared with the non‐waterlogged control; however, yield responses to N application were similar regardless of waterlogging duration. Application of 100 lb N preplant + 120 or 180 lb N ac −1 sidedress produced the greatest yield. Ear leaf N concentration at flowering (R1) exceeding 2.75% corresponded to the greatest grain yield at harvest. These results indicate that corn was responsive to N applications after being waterlogged. The ear leaf N sufficiency value of 2.75%–3.0% used in non‐waterlogged conditions also corresponded to the greatest yielding treatments in the waterlogged corn. This suggests a similar sufficiency value (2.75%) is applicable after waterlogging to gauge corn's uptake of post‐waterlogging N applications. Further multilocation research should be conducted to expand our understanding of corn resilience and corn N response under waterlogging conditions.