Nitrogen Management Through Leaf Colour Chart (LCC)

• Time of application is decided by LCC score.
• Take observations from 14 days after transplanting (DAT) in transplanted rice or 21 days after sowing (DAS) in direct seeded rice.
• Repeat the observations at weekly intervals up to heading.
• Observe the leaf colour in the fully opened third leaf from the top as index leaf.
• Match the leaf color with the colours in the chart during morning hours (8-10 am).
• Take observation in 10 places.
• LCC critical value is 3.0 in low N response cultivars like White Ponni and 4.0 in other cultivars and hybrids.
• In the case of sodic soils, LCC critical value is 4.0 for varieties and 5.0 for hybrids.
• When 6/10 observations show less than the critical colour value, N can be applied as per the following recommendation : Application of 25 kg N ha^-1 at 7 DAT followed by N @ 40 kg ha-1 each time for kuruvai/ short duration rice / 30 kg ha^-1 each time for medium & long duration rice as and when the leaf colour value falls below the critical value monitored from 14 DAT.
• For aged seedlings : Basal application of 35 kg N per ha is recommended to avoid yield loss when seedlings aged 35 - 45 days are used for transplanting
  and the LCC based N management can be followed from 14 DAT.