Indian Journal of Agronomy

A field experiment was conducted during the rainy (kharif) season of 2014 at Varanasi, Uttar Pradesh, to study the effect of nitrogen levels and zinc application on yield and zinc content of direct-seeded (Oryza sativa L.) rice (DSR). Among the different nitrogen levels, the application of 150 kg N/ha recorded the highest yield attributes, viz. effective tillers at harvesting (77 running/m), panicle length (24.75 cm), grains/panicle (205), test weight (22.47 g) and panicle weight (2.4 g), which resulted in the highest grain (4.34 t/ha) and biological yield (10.08 t/ha). Among different zinc schedules; the application of 0.3% ZnSO₄.H₂O spray at anthesis recorded the highest yield attributes, viz. effective tillers at harvesting (72 running/m), panicle length (24.11 cm), grains/panicle (202), test weight (21.48 g) and panicle weight (2.73 g), resulting in highest grain (4.36 t/ha) and biological yield (10.27 t/ha). Harvest index was also influenced by nitrogen levels but not by zinc scheduling, although it was found nonsignificant. However, the highest net returns ( 41.27 × 10³/ha) and benefit: cost ratio (1.04) were recorded with the application of 150 kg N/ha, while in case of zinc scheduling the maximum net returns ( 43.27 × 10³/ha) and benefit: cost ratio (1.10) were reported with the application of 0.3% ZnSO₄.H₂O spray at anthesis. Combine application of 150 kg N/ha and 0.3% ZnSO₄.H₂O spray at anthesis was found optimum for grain yield (5.58 t/ha) of direct-seeded rice.