Effect of irrigation scheduling and nitrogen application on productivity and profitability of direct seeded rice (Oryza sativa)

A field experiment was conducted during the rainy (kharif), season of 2015, to study the effect of irrigation scheduling and split application of nitrogen on productivity and profitability of direct-seeded rice (DSR) (Oryza sativa L.). The experiment was laid out in split-plot design with 12 treatment combinations including 4 irrigation schedules, viz, 0 kPa; 10 kPa, 20 kPa and 10 kPa during entire stage except 40 kPa at tillering to flowering stages in main plot and 3 N (120 kg/ha) application methods, viz. control (N₀), half recommended dose of nitrogen (RDN) as basal + one-fourth RDN at week 2 + one-fourth RDN at week 5, and one-fourth RDN as basal + one-fourth RDN at week 2 + one-fourth RDN at week + one-fourth RDN at week 9 after sowing in subplot were taken with 3 replications. Irrigation scheduling at 0 kPa resulted in the highest yield attributes, grain and straw yields and net returns of DSR, which was remained at par with 10 kPa. Four times split application of N as one-fourth RDN as basal + one-fourth RDN at 2 week + one-fourth RDN at week 5 + one-fourth RDN at week 9 recorded significantly high grain and straw yields and net returns over half RDN as basal + one-fourth RDN at week 2 + one-fourth RDN at week 5 and control. Thus, irrigation threshold of 10 kPa with 4 times split application of RDN can be applied to DSR to get higher yield and net returns.