Effects of level, time, and splitting of urea on the yield of irrigated direct seeded rice

Abstract

To determine effects of level and time of application of urea on grain yields, components of grain yield, and nitrogen use efficiency by irrigated direct seeded rice (Oryza sativa L. var. IR 298-12-1-1-1), three field experiments were conducted at the Gezira Agricultural Research Station during the period 1976–78. The treatments included the factorial combination of three levels of nitrogen as urea (0,75 and 150 kg N/ha) two or three splits, and three times of topdressing of urea (early season application, 10 days after rice emergence, DRE; maximum tillering stage, 40 DRE; and panicle initiation stage, 75 DRE).