Urea Deep Placement in Rice as an Option for Increasing Nitrogen Use Efficiency

Prilled urea applicator is a nitrogen saving technology. Aiming to find out the efficiency of BRRI prilled urea applicator, a field experiment was conducted during boro season of 2013-2014 at the Bangladesh Rice Research Institute (BRRI) experimental farm, Gazipur and at farmer’s field of Dhirasshram village under Gazipur Sadar Upazilla, Gazipur, Bangladesh. Four treatments viz. 1) hand broadcasting of prilled urea as per BRRI recommendation (T₁), 2) prilled urea application by applicator (70% of the BRRI recommended dose) (T₂), 3) hand broadcasting of prilled urea (70% of the BRRI recommended dose) (T₃) and 4) N-control (T₄) were evaluated in the study. The T₂ treatment gave the highest grain yield of 6.96 t·ha^-1 and 7.20 t·ha^-1 at BRRI farm and Dhirasshram village, respectively, followed by those of T₁ treatment. The highest agronomic use efficiency was obtained from T₂ treatment in both the locations. Similar scenario for apparent recovery efficiency, utilization efficiency and partial factor productivity was also observed in T₂ treatment. Moreover, about thirty percent prilled urea was saved due to deep placement of urea by applicator in boro season.