Effect of Different Doses of Urea on the Yield of Boro Rice Varieties in Haor Areas of Bangladesh

The experiment was carried out at Sunamganj district during November 2016 to May 2017 to observed the effect of urea fertilizer on the yield of boro rice varieties in haor areas of Bangladesh. Two factors experiment viz. Varieties BRRI dhan29 and BRRI dhan58; and six urea fertilizer levels including: 340 (F1), 320 (F2), 300 (F3), 280 (F4), 260 (F5), and 165 kg ha-1 (F6) [Farmer’s practice (FP)] were used. In case of F1-F5, the MoP-TSP-CaS04-ZnS04 as 127-112-75-11 kg ha-1 were used while Farmers’ practice (FP) was done with only 82 kg ha-1 TSP. The experiment was laid out in two factors randomized complete block design (RCBD) with three farmers’ replications. Data were collected on growth, yield and yield contributing characters of boro rice. Plant height varied at harvest stage in relation to variety and fertilizer. The tillers production hill-1 varied at harvest in case of variety and urea application. Higher plant height was found in BRRI dhan58 (93.9 cm) in comparison to BRRI dhan29 (90.3 cm). Plant height was also influenced due to urea fertilizers application. The higher tillers hill-1 (15.9), effective tillers hill-1 (12.3) and longer panicle length (21.1 cm) were produced by BRRI dhan58 at harvest compared to BRRI dhan29. The longest panicle (21.4 cm) was produced in the treatment F3 (300 kg urea ha-1). Higher number of sterile spikelets panicle-1 (58.5) and 1000-grain weight (23.2 g) was produced by BRRI dhan58. Higher number of grains panicle-1 (137.5) was produced by BRRI dhan29. The highest grain yield (6.7 t ha-1) and straw yield (7.91 t ha-1) were obtained in the treatment F3 (300 kg urea ha-1). The experimental soil analyses showed that the nutrient contents in post-harvest soils were higher compared to initial soil due to balanced fertilizer application. It is concluded that 300 kg urea ha-1 promoted highest grain yield.