Effect of crop-establishment methods and integrated nitrogen management on productivity of hybrid rice (Oryza sativa)-wheat (Triticum aestivum) cropping system

A field experiment was conducted during the 2 rainy (kharif) and winter (rabi) seasons (2012–14) on sandyclay-loam soil at Varanasi, to study the effect of crop-establishment methods and integrated nitrogen management on productivity of hybrid rice (Oryza sativa L.)-wheat (Triticum aestivum L. emend. Fiori & Paol.) cropping system. The experiment was laid out in a split-plot design, comprising crop-establishment methods (normal transplanting and system of rice intensification) and 2 hybrids (‘PHB 71’ and ‘Arize 6444’) in combination as main plot and 6 integrated nitrogen-management practices [100% recommended dose of fertilizer (RDF), 125% recommended dose of nitrogen (RDN), 50% RDN + 50% N through farmyard manure (FYM), 50% RDN + 50% N through FYM + Azospirillum, 100% N through FYM and No fertilizer)] as subplot treatments, replicated thrice. System of rice intensification (SRI) improved the growth attributes, viz. plant height, number of tillers, dry-matter accumulation, and increased the grain yield by 14.7% over normal transplanting (5.69 t/ha) and recorded significantly higher net monetary returns and output: input ratio over normal transplanting. Rice hybrid, ‘Arize 6444’ showed significantly higher growth attributes, grain yield, economic return/day and net return with output: input ratio. Integrated N management with 50% RDN + 50% N through FYM + Azospirillum resulted in high growth, yield, crop productivity, return/day and net returns. However output: input ratio were recorded higher with 125% RDN followed by 100% RDN. Residual effect of preceding experimental variables particularly normal transplanting, hybrid ‘PHB 71’ and application of 50% RDN + 50% N through FYM + Azospirillum recorded the highest number of effective tillers, grains/ear 1, 000-seed weight and grain and straw yield of succeeding wheat.