| Treatments | RI | RII | RIII | Mean |
| T1 = Control (no urea) | 12.5 | 13.3 | 13.3 | 13.1 |
| T2 = Recommended urea soil applied (130 kg・ha−1) | 20.7 | 19.8 | 19.7 | 20.1 |
| T3 = 1% urea at 35 days after sowing | 20.1 | 23.3 | 23.8 | 22.4 |
| T4 = 1% urea at 60 days after sowing | 21.2 | 22.1 | 22.3 | 21.8 |
| T5 = 1% urea at 85 days after sowing | 20.9 | 21.7 | 21.7 | 21.4 |