Relationships between chlorophyll meter readings and leaf chlorophyll concentration, N status, and crop yield: A review 1

Prediction of crop nitrogen (N) requirements is necessary for efficient fertilizer N utilization and protection of groundwater against contamination. Soil tests for available N have been successful in predicting crop N needs in arid regions, but have met with less success in humid regions. Tissue tests have shown promise for crop N requirement prediction, but time required for sampling and laboratory analyses may disallow timely producer...