Impact of Nitrogen on Growth, Yield and Seed Quality of BRRI dhan28

Abstract

Nitrogen is not only a major nutrient but is often the most limiting nutrient element for rice production. However, the improper use of nitrogen fertilizer deteriorates growth, reduces yield, and declines seed quality of rice. The present study was conducted to determine the optimum nitrogen dose and examine the effects of different doses of nitrogen on the growth, yield, and seed quality of BRRI dhan28. The experiment was laid out in a Randomized Complete Block Design (RCBD) with six nitrogen treatments: T₀ = 0 kg N ha⁻¹, T₁ = 35 kg N ha⁻¹, T₂ = 70 kg N ha⁻¹, T₃ = 105 kg N ha⁻¹, T₄ = 140 kg N ha⁻¹, and T₅ = 170 kg N ha⁻¹. Data on rice growth characters, yield-contributing characters, and seed quality parameters were collected and analyzed statistically. Results showed that the total number of tillers per m² increased significantly with increasing levels of nitrogen, as did total dry matter production. At harvest, the tallest plant (89.28 cm), maximum tillers hill⁻¹ (23.50), and highest total dry matter hill⁻¹ (76.59 g) were obtained from the higher dose of nitrogen, T₅ (170 kg N ha⁻¹). Growth parameters increased with increasing rates of nitrogen, whereas yield-contributing parameters were found to be superior at moderate nitrogen levels, particularly under the treatment T₃ (105 kg N ha⁻¹). The highest grain yield (3.92 t ha⁻¹), biological yield (7.29 t ha⁻¹), and harvest index (53.76%) were obtained from the application of 105 kg N ha⁻¹. Nitrogen application significantly influenced seed quality in terms of speed of germination, vigor, viability, and seed color. Therefore, a nitrogen dose of 105 kg N ha⁻¹ was recommended for BRRI dhan28.