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.
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.
