The significantly highest plant height (198.06 cm) was measured for treatment 120 kg N/ha and the lowest plant height (162.6 cm) was measured for treatment 0 kg N/ha at 95 days after sowing. Likewise, significantly shortest period to tasseling (74.3 days) and silking (78.0 days) under the application of 120 kg N/ha but at par with treatment 90 kg N/ha (75.1 days) and (78.7days) respectively and longest period to tasseling (79.7 days) and silking (85.4 days) under the application of 0kg N/ha but at par with treatment 30 kg N/ha (78.7) and (84.6 days) respectively was obtained. Likewise, the highest grain yield (3.7 t/ha) was obtained for treatment 120 kg N /ha which was significantly higher than all other treatments but at par with treatment 90 kg N/ha (3.5 t/ha) and the lowest grain yield (1.5 t/ha) was obtained for treatment 0 kg N/ha which was significantly lower than all other treatments but at par with treatment 30 kg N/ha (1.8t/ha). Overall study shows that almost all parameters of spring maize increase significantly with the increasing dose of nitrogen up to 90kg/ha. But no significant difference was observed on yield and yield attributes while increasing the nitrogen dose from 90 to 120 kg/ha. Thus, for the optimum and sustainable production of spring maize, 90 kg N/ha can be used as a recommended dose in Madichaur, Rolpa.
Keywords: Spring maize, Doses, Nitrogen, Growth, Yield.