Production potential of wheat (Triticum aestivum) crop as influenced by residual organics, direct and residual fertility levels under rice (Oryza sativa)-wheat cropping system

A field experiment was conducted during the winter seasons of 1995-96 and 1 996-97 at Pusa, Bihar, to study the effect of residual organics, residual f ertility and fertility levels on the yield of wheat (Triticum aestivum L. e mend. Fiori & Paol.) crop under rice (Oryza sativa L.)-wheat cropping syste m. Fertilizers applied to rice crop did not show any significant effect on the succeeding wheat crop. Among the organic manures applied to rice crop, biogas-slurry and rice straw incorporation resulted in significant residual effect. Biogas-slurry recorded significantly higher grain yield of wheat ( 39.90 and 40.04 q/ha) than rice-straw incorporation (36.94 and 39.00 q/ha), green-manure (32.57 and 33.83 q/ha) and no organic manure (31.20 and 32.24 q/ha) during 1995-96 and 1996-97 respectively. Significantly higher grain yield was obtained with the application of recommended fertilizer level (12 0, 60 and 40 kg N, P, and K/ha) to wheat in both the years.