Effect of different doses of nitrogen on growth and yield of maize (Zea mays) in Bhadrapur, Jhapa

The aim of the study was to find out the appropriate dose of nitrogen (N) that gives higher productivity and recommend it, as the farmers in Bhadrapur municipality are not aware of the nitrogen dosage due to which they either over-dose or under-dose the maize. A field trial was conducted in a farmer’s field to evaluate the effect of different doses of nitrogen on the growth and yield of maize in Bhadrapur, Jhapa, Nepal. Randomized Complete Block Design (RCBD) was used with 7 different treatments which were replicated thrice. The following treatments were used: T1 (Control), T2 (NPK 60:60:60 kg ha-1), T3 (NPK 90:60:60 kg ha-1), T4 (NPK 120:60:60 kg ha-1), T5 (NPK 150:60:60 kg ha-1), T6 (NPK 180:60:60 kg ha-1) and T7 (NPK 210:60:60 kg ha-1). T6 had the tallest (214.45 cm) and the girthiest (2.65 cm) plants which also had a greater number of leaves (13.35) at 60 DAS as compared to others. Similarly, T7 had the longest (22.24 cm) and girthiest (4.98 cm) cobs. T3 had the highest number of lines per cob (16.99). In the case of number of grains per line, T7 had the highest number of grains (37.59). Similarly, in context of thousand kernel weight, grain yield and biological yield, T6 (328.57 gm), T7 (12.22 mt ha-1), and T6 (40.17 mt ha-1) were superior, respectively. T3 had the highest HI (0.32). The Benefit Cost Ratio was seen the highest in T7 with a ratio of 1.5. NPK 180:60:60 kg ha-1 can be recommended for foliage production and NPK 210:60:60 kg ha-1 can be recommended for grain production as the Benefit Cost Ratio in these fertilizer combinations is comparatively superior.