Nitrogen Use Efficiency of Boro Rice Varieties (Oryza sativa L.) Using Different Sources of Nitrogen Fertilizer

Abstract

Nitrogen Use Efficiency (NUE) integrates nitrogen (N) in different crop parts and depends upon the sources from which it derives. Higher NUE is essential for high yield potential and minimizing N loss after addition in soil. For this, a pot experiment was set up to evaluate the NUE of three boro rice varieties which are BRRI dhan61, BRRI dhan68, and BRRI dhan28 considering two sources of commercial urea fertilizer. These sources were termed as T₁ (Urea, Kingdom of Saudi Arabia origin) and T₂ (Urea, Qatar origin) while the control treatment was designated as T₀.  All the pots were arranged in a completely randomized design with four replications. Various NUE parameters such as partial factor productivity (PFP), crop recovery efficiency (CRE), agronomic efficiency (AE) and physiological efficiency (PE), agronomic as well as yield contributing characteristics of rice were studied. Results indicated that T₁ showed the highest PFP, CRE, and AE in BRRI dhan68 which were 34.43 kg kg^-1, 0.70 kg kg^-1, and 26.32 kg kg^-1, respectively, whereas the highest PE (81.58 kg kg^-1) was observed in BRRI dhan28 with T₂. All the rice varieties showed the highest nitrogen uptake by grain when treated with T₁. Maximum grain yield (30.99 g pot^-1) was found in BRRI dhan68 in T₁ treated soil, which increased by 13.65% and 33.11% from BRRI dhan61 and BRRI dhan28, respectively. Agronomic as well as yield contributing characteristics such as height, tiller per plant, panicle per plant, straw yield, etc. were also highest in T₁-treated soil irrespective of the rice plant studied. Considering the results of this experiment, it can be concluded that T₁ treatment has a relative advantage compared to T₂ used as nitrogen fertilizer sources because it enhanced N use efficiencies and may lead to reduced N losses in rice production.

South Asian J. Agric., Vol. 10, No.1-2, 2024: 62-71