Effect of residual and applied phosphorus on yield and quality of fodder sorghum (Sorghum bicolor L. Moench) in wheat (Triticum aestivum L.) based cropping system and relative economics of the system

The present investigation was carried out to study the effect of phosphorus application timings and its sources in wheat-sorghum cropping system during rabi 2004 and kharif 2005, The soil was loamy in texture, neutral in reaction with low available N, P and OC and medium in available K. The treatments comprising of two factors viz. four P application timings to preceding wheat crop and second factor comprising four sources of P applied to the succeeding sorghum fodder crop in split plot design. Study indicated that wheat crop performed better with application of P than its delayed application through improvement in P up-take. However, in subsequent sorghum fodder crop, delayed application of P in preceding wheat crop proved instrumental in production of higher fodder yield. Among sources FYM as a source of P in sorghum, caused phenomenal increase in growth parameters. Delayed application of P in wheat and application of P in sorghum through different sources favoured crude protein content. However, effect on crude fiber content of the fodder sorghum was non-significant. Delayed application of P in wheat followed by recommended P through FYM in sorghum proved beneficial with a benefit cost ratio ranging from 2.07 to 2.08.