Growth, Yield and Nitrogen Use Efficiency of New Rice Variety under Variable Nitrogen Rates

Abstract

Globally, the current important concern is to minimize nitrogen use in crop culture under climate change condition. The experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh during the rainy season of 2014 to assess growth, yield and nitrogen use efficiency of a new rice variety. The new rice variety (BUdhan 1) was treated with six levels of nitrogenous fertilizer in a randomized complete block design replicated three times. The nitrogen levels 0, 20, 40, 60, 80 and 100 kg N ha -1 constituted the treatment variables. Results revealed that growth of the new rice variety favored at higher levels of applied nitrogen although it flattened at 80 and 100 kg N -1 . Preanthesis assimilates reserves contributed to sustaining the yield of the variety which indicated that current photosynthesis was insufficient to support the present yield level. The assimilate remobilization varied from 109.21 to 232.93 g&middotm -2 between the nitrogen levels where the maximum amount of remobilization was observed at 60 kg N -1 . The highest grain yield (5.36 t&middot -1 ) was found when the variety was fertilized with 60 kg N -1 . Application of 60 kg N -1 also showed the highest nitrogen use efficiency (344.50 kg grain/kg N applied) of the variety. We concluded that application of the intermediate level of nitrogen was economical and environment-friendly for the cultivation of new rice variety.