PREDICTING PRECISION NITROGEN SIDE-DRESS APPLICATIONS FOR MAIZE WITH A SIMULATION MODEL

Three fertilization strategies × three irrigation strategies were compared in replicated plot study designed to evaluate management strategies with the potential to improve water use efficiency (WUE) and nitrogen use efficiency (NUE) in the southeastern Coastal Plain of the USA. Scheduling irrigation using the SmartIrrigation Corn App and automated soil moisture sensor networks, and applying side-dress nitrogen using fertigation resulted in higher WUE and NUE. One fertigation treatment used the STICS crop growth model (INRA, France) to schedule side-dress applications. The model simulations matched field observations well for biomass, nitrogen in biomass and yield but did less well for soil water and nitrogen content. Fertigation scheduling with the model resulted in high yield but not in higher NUE than other fertigation scheduling approaches. Using models like STICS to predict the timing of N applications in maize has potential but additional research is needed to develop robust methodologies.