Ratoon Rice Response to Nitrogen Fertilizer

Field research was conducted for 2 years to determine the N fertilizer application rate producing maximum ratoon rice grain yields. The long‐grain rice cultivars Cheniere, CL161, Cocodrie, and Cypress were grown using a delayed‐flood, drill‐seeded production system. Immediately following harvest of the main crop, N fertilizer at rates of 30, 60, 90, or 120 lb/acre was applied as urea. No ratoon rice lodging was observed in any site‐year at any N fertilizer application rate. Ratoon days to 50% heading was delayed 1 day when the N fertilizer application rate was increased from 60 to 90 or 120 lb/acre. Ratoon rough rice yield increased significantly from 2390 to 2710 lb/acre as the N fertilizer application rate increased from 30 to 90 lb/acre, but increasing the N fertilizer application rate from 90 to 120 lb/acre did not improve ratoon rough rice yields. No ratoon rice lodging was observed in any site‐year at any N fertilizer application rate. In this study, the N fertilizer application rate producing maximum ratoon rice yields in the Gulf Coast area of the United States was 90 lb/acre.