| Treatments | RI | RII | RIII | Mean |
| T1 = Control (no urea) | 754 | 830 | 965 | 849.6 |
| T2 = Recommended urea soil applied (130 kg・ha−1) | 1911.8 | 1827.9 | 1817.3 | 1852.3 |
| T3 = 1% urea at 35 days after sowing | 1850.1 | 2147.2 | 2192.3 | 2063.2 |
| T4 = 1% urea at 60 days after sowing | 1953.7 | 2032.9 | 2054.3 | 2013.6 |
| T5 = 1% urea at 85 days after sowing | 1931.0 | 1998.9 | 1998.9 | 1976.3 |