The soil testing or leaf analyses are expensive and time-consuming. In addition, tissue testing is a destructive method, which limits its use as a diagnostic tool for nutrient use efficiency of cereal plants. The rapid tissue tests for cereal plants are not widely used because critical levels can vary greatly from site to site and can change rapidly over time. Matching crop N demand with flexible, split applications may have economic and environmental advantages above supplying fixed rates at fixed growth stages. In the absence of accurate and rapid N testing methods, many growers currently...