N management through LCC
- Time of application is decided by LCC score
- Take observations from 14 DAT in transplanted rice or 21 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 cultures like White Ponni and 4.0 in other cultivars and 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 (1 bag urea) at 7 DAT followedby 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 of 4 for varieties and hybrids and critical value of 3 for white ponni, 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.
**Recommendation of P&K fertilizer rates based on SSNM approach for rice growing tracts of Tamil Nadu (other than Cauvery Delta)
| Sl. No. |
Location |
Calibrated SSNM fertilizer dose (kg/ha)* |
| P2O5 |
K2O |
| 1 |
Cauvery delta |
| (i) Old delta |
35 |
50 |
| (ii) New delta |
35 |
80 |
| 2 |
Coimbatore District |
| (i) General |
30 |
40 |
| (ii) Annamalai block |
30 |
80 |
| 3 |
Killikulam |
30 |
50 |
| 4 |
Trichy |
35 |
50 |
| 5 |
Ambasamudram |
40 |
50 |
| 6 |
Bhavanisagar |
20 |
25 |
| 7 |
Paiyur |
25 |
45 |
| 8 |
Yethapur |
30 |
45 |
| 9 |
Aruppukottai |
20 |
30 |
| 10 |
Cuddalore |
30 |
50 |
** The above SSNM based fertilizer P and K arrived based on yield response are recommended for specific soil series prevailing in different rice growing areas for adoption by farmers |
