Effect of irrigation and nitrogen management on yield and economics of SRI-grown hybrid rice (Oryza sativa)

Abstract

A field experiment was conducted during rainy season (2014-15) at Banaras Hindu University, Varanasi to standardize water saving and economical nitrogen management options for hybrid rice (Oryza sativa L.) under SRI.The experiment was laid-out in a three-times replicated split-plot design involving three irrigation scheduling, viz. irrigation at 2 days after disappearance of ponded water (DADPW), 5 DADPW and 8 DADPW assigned to main-plotsand five nitrogen management options, viz. 100% recommended dose of nitrogen (RDN, 150 kg N/ha), 100% RDN+ Sesbania aculeata, 75% RDN + Sesbania aculeata, 100% RDN + BGA (12 kg/ha) and 75% RDN + BGA (12 kg/ha) were allotted in sub-plots. Results reveal that scheduling of irrigation at 2 DADPW was recorded significantly higher dry matter accumulation (DMA), leaf area index (LAI), yield attributes and finally enhanced grain yield andnet returns by 16.2, 20.3% and 11.7 and 12.6% during 2014 and 2015, respectively over 8 DADPW but statistically at par with scheduling of irrigation at 5 DADPW. Among nitrogen management options, application of 100% RDN(150 kg N/ha) + BGA (12 kg/ha) recorded higher DMA, LAI, yield attributes and finally enhanced grain yield andnet returns by 14.4, 22.8% and 12.6 and 18.5%, respectively over application of 100% RDN alone. Hence, irrigation at 2 DADPW and combined application of 100% RDN + BGA (12 kg/ha) can be recommended for obtaining higher yield and profit from hybrid rice under SRI.