Effect of nitrogen levels and split doses on the productivity of aerobic rice.

摘要

A field experiment was conducted in Coimbatore, Tamil Nadu, India, during kharif 2006 to optimize the level and split doses of nitrogen (N) for aerobic rice cultivation. The treatments consisted of five N levels (100, 125, 150, 175 and 200 kg/ha) in the main plots and three split doses of N (1/4+1/4+1/4+1/4, 1/6+1/3+1/3+1/6 and 1/5+1/5+2/5+1/5) in the subplots. N was applied at 15 days after sowing (DAS), tillering, panicle initiation and flowering stages. The application of 175 kg N/ha recorded significantly higher growth attributes, yield attributes and grain yield (4876 kg/ha) over 100 and 125 kg N/ha. However, this was comparable with 150 kg N/ha (4789 kg/ha). Among the split doses, N application as 1/6 at 15 DAS+1/3 at tillering+1/3 at panicle initiation+1/6 at flowering stage produced higher growth, yield attributes and grain yield (4594 kg/ha) over other split doses. Thus, application of 150 kg N/ha with a split dose of 1/6 at 15 DAS+1/3 at tillering+1/3 at panicle initiation+1/6 at flowering stages was found to be the optimum N management for higher productivity of aerobic rice.