Factors such a rice variety, preflood N fertilizer rate, and weather conditions influence soil N availability to rice. The use of instruments such as chlorophyll meters have shown potential for predicting when midseason N is needed. Chlorophyll Meters Chlorophyll is a green pigment present in plants that captures the sunlight that is used in photosynthesis. Nitrogen is a key element found in chlorophyll molecules. The meter approximates the amount of chlorophyll present by measuring the amount of light that is transmitted through a leaf.
Chlorophyll meters can provide instantaneous, on-site information in a nondestructive manner.
Fields can be monitored easily throughout the year. The chlorophyll meter is user friendly and can compute the average value of several samples. How to use Chlorophyll Meters Calibration of a chlorophyll meter is necessary each time the meter is used. Before inserting plant tissue, calibrate by pressing on the finger rest to close the head. After the meter beeps, a display is shown indicating the meter is ready for the first sample.