Response of rice (Oryza sativa) hybrids to integrated nitrogen management under different methods of cultivation

Abstract

A field experiment was conducted during the rainy (kharif) seasons of 2012 and 2013 at Varanasi, Uttar Pradesh, to study the effect of integrated nitrogen management on performance of rice (Oryza sativa L.) hybrids under different methods of cultivation on sandy clay-loam soil. The experiment was laid out in a split-plot design with 2 crop-establishment methods and 2 hybrids assigned to main plots, and 6 integrated nitrogen-management treatments were allocated in subplots and replicated thrice. Transplanting of rice under system of rice intensifica- tion (SRI) and rice cv. Arize 6444 recorded significantly higher growth attributes, viz. plant height, tillers/hill, leaf- area index, and dry-matter accumulation/hill, with almost all yield-attributing characters and yield, except plant height and panicle length which were significantly higher PHB 71 than Arize 6444. The SRI planting increased the grain and straw yield by 14.76% and 13.11% over normal transplanting. Similarly, SRI planting and Arize 6444 cultivar also gave significantly maximum benefit in respect to gross returns, net returns ( 66,138 and 61,535/ha) and benefit: cost ratio (1.86 and 1.66) over normal transplanting and PHB 71. Among all the inte- grated nitrogen-management treatments, application of 50% recommended dose of nitrogen (RDN) + 50% N through FYM + Azospirillum recorded significantly higher growth attributes, yield attributes, grain yield (6.94 t/ha), straw yield (9.16 t/ha), harvest index, net monetary returns ( 68,064/ha), but application of 125% RDN was found economically feasible in respect to benefit: cost ratio (1.88) owing to lower cost of cultivation.