Enhancing Yield and Nitrogen Utilization of Boro Rice with Urea Super Granules

A field experiment was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during boro season to assess the comparative performance of prilled urea (PU) and urea super granule (USG) on the growth, yield, and nitrogen uptake of BRRI dhan29. The experiment was laid out in a randomized complete block design with three replications. The treatment combinations were T1: Control, T2: PU at 7 days after transplanting (DAT)+27 DAT+47 DAT, T3: PU at 10 DAT+30 DAT+50 DAT, T4: PU at 15 DAT+35 DAT+55 DAT, T5: USG at transplanting, T6: USG at 7 DAT, T7: USG at 10 DAT and T8: USG at 10 DAT+30 DAT where PU and USG were applied @ 216 kg N ha-1. PU was applied as surface broadcasting whereas USG was placed at 6-8 cm depth by hand between four hills at every alternate row. The results revealed that all the treatments showed better performances than control (T1). Results found that yield components, yield, and nitrogen uptake of BRRI dhan29 responded significantly to deep placement of USG than PU. Treatment T6 (USG at 7 DAT) produced the highest grain and straw yields of 6.56 t ha-1 and 6.95 t ha-1 respectively. Treatment T6 (USG at 7 DAT) also showed the highest grain yield increase (57.16%) and straw yield increase (52.37%) over control. The highest grain, straw, and total N uptake of 87.28, 32.71 and 120 kg ha-1 respectively were obtained in the treatment T6 (USG at 7 DAT). The overall results clearly indicate that deep placement of USG at 7 DAT in rice field increases rice yield and efficient uptake of the applied N. So, treatment T6 (USG at 7 DAT) could be recommended as best treatment for reducing N losses, conserving environment and improving sustainable production of rice.