Effect of Urea Super Granule Deep Placement on Rice Cultivation In The Tidal Coastal Area of Khulna Region

Abstract

A field experiment was conducted during the period from July to December, 2011 at Prof. Purnendu Gain Field Laboratory of Agrotechnology Discipline, Khulna University, Khulna to observe the effect of urea super granule deep placement on rice cultivation in the coastal area of Khulna region. There were seven treatments of different forms and doses of urea viz. without nitrogen (WN), recommended N as prilled urea (PU - 216 kg ha⁻¹), recommended N as urea super granules (USG - 216 kg ha⁻¹), 75% recommended N as USG (USG-162 kg ha⁻¹), 50% recommended N as USG (USG-108 kg ha⁻¹), 125% recommended N as PU (PU-270 kg ha⁻¹) and 125% recommended N as USG (USG-270 kg ha⁻¹). The experiment was laid out in a randomized complete block design (RCBD) with three replications. Urea super granules (USG) were placed manually at the depth of 8-10 cm in the middle of four hills in alternate rows at 8 days after transplanting and prilled urea (PU) (216 kg ha⁻¹ and 270 kg ha⁻¹) was applied in three equal splits. The other fertilizers such as P, K, S and Zn were applied at recommended doses. The results revealed that different forms and doses of nitrogen significantly affected plant height (cm), number of effective tillers hill⁻¹, number of filled grains panicle⁻¹, 1000 grain weight (g) and grain yield (t ha⁻¹). Urea super granules (USG) @ 216 kg ha⁻¹ produced the highest plant height (134.4 cm) at harvest, longest panicle (22.19 cm), highest number of filled grains panicle⁻¹ (100.8), highest 1000 grain weight (31.98 g) and as a result the highest grain yield (5.79 t ha⁻¹), but statistically identical grain yield (5.6 t ha⁻¹) was obtained when USG was applied only @ 108 kg ha⁻¹ (50% recommended N) and 162 kg ha⁻¹ (75% recommended N). The lowest grain yield and yield contributing characters were found from control treatment. The result showed that 50% reduction of N can be possible by using USG without significant yield loss