Background:
Too little nitrogen application reduces rice grain yield and too much N application to soil imbalances the nutrients, pollutes the water sources and food and increases the susceptibility of rice crop to insect pests and diseases. Synchronizing N fertilizer application to plant needs, will optimize the grain yield, nutrient use efficiency and reduce pollution. The chlorophyll meter by its capacity to measure the leaf greenness and N status indirectly will help in proper timing of N application at various growth stages of the rice crop:
Technology Details:
Leaf colour chart is a tool to measure the greenness of the rice crop. The Leaf colour chart had been tested initially by the DRR during 1997-98 in a collaborative Project – CREMNET funded by IRRI. The earlier chart was prepared with 7 shades of different gradient of the green colour. The same was tested in AICRIP centers as well as in farmers’ fields. Later the chart was modified to 5 gradient green shades which represent the N content of the plants in situ.